Method for improving the germination rate of flemingia macrophylla seeds by cryopreservation

Abstract

The application discloses a kind of super-low temperature preservation methods of Fagara macrophylla seeds, comprising the following steps: 1) in dark condition, using silica gel desiccant to dry Fagara macrophylla seeds to its moisture content is 5.5-9.5%;2) using loading liquid to soak dried seed, take out, using vitrification reagent to soak, soak, take out seed, add pre-cooled vitrification protective reagent, transfer into liquid nitrogen and carry out super-low temperature preservation.The application establishes the technical procedure of super-low temperature preservation of Fagara macrophylla germplasm resources, fills the blank in the field of super-low temperature preservation technology of Fagara macrophylla seeds, and can prolong the preservation time of seeds through super-low temperature preservation technology, to ensure that seeds maintain strong viability.

Description

Technical Field

[0001] This invention belongs to the field of seed technology. More specifically, this invention relates to a method for cryopreservation of *Millettia speciosa* seeds and for improving germination rate. Background Technology

[0002] *Flemingia macrophylla* Prain, a legume, is also known as Da Zhu Wei, Qian Jin Li, Qian Jin Hong, Hong Yao Tou, and Bai Ma Shi, and is commonly used in traditional Zhuang and Yao medicine. The roots of *Flemingia macrophylla* are rich in flavonoids, polysaccharides, alkaloids, and other physiologically active substances, and are used medicinally. They are bland, sweet, and neutral in nature, and have the effects of dispelling wind and dampness, removing blood stasis, relieving pain, and strengthening muscles and bones. They can be used to treat gynecological diseases, rheumatic pain, abdominal distension, qi deficiency and foot swelling, impotence, and lumbar muscle strain. Currently, *Flemingia macrophylla* is a popular traditional Chinese medicine in the market, and is a major ingredient in prepared Chinese medicines such as Fuke Qianjin Pian, Jinji Jiaonang, and Zhuangyao Jianshen Wan. This shows that *Flemingia macrophylla* and its preparations have a wide range of clinical applications, especially in the treatment of gynecological diseases, where they are remarkably effective. In folk medicine, the roots of *Flemingia macrophylla* are also used in medicinal diets.

[0003] Due to the increasing market demand for *Millettia speciosa*, extensive harvesting has led to a decline in wild resources. Furthermore, the harsh natural environment, small seed size, hard outer shell, and difficulty in absorbing water and swelling result in low natural reproduction rates and germination rates of only around 10%. Seed deterioration or aging during storage also reduces germination rates. Artificial seedling cultivation is time-consuming and resources are extremely limited. Currently, wild *Millettia speciosa* resources are facing depletion, and artificial cultivation suffers from low yields, slow growth, and high market prices, making promotion difficult and unable to meet market demand in the short term. Therefore, providing a suitable method for preserving *Millettia speciosa* seeds to improve germination rates is of great significance for the cultivation and germplasm resource preservation of *Millettia speciosa* seeds. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0005] One objective of this invention is to provide a method for cryopreserving seeds of *Millettia dielsiana*, which ensures that the seeds retain strong viability after preservation and thus achieves a high germination rate.

[0006] To achieve these objectives and other advantages of the present invention, a method for cryopreservation of seeds of *Millettia speciosa* is provided, comprising the following steps:

[0007] 1) Dry the seeds of *Mallotus macrocarpa* to a moisture content of 5.5-9.5% using silica gel desiccant under dark conditions;

[0008] 2) Soak the dried seeds in the loading solution, take them out, soak them in the vitrification reagent, after soaking, take out the seeds, add pre-cooled vitrification protective reagent, and transfer them into liquid nitrogen for ultra-low temperature preservation.

[0009] Preferably, the loading solution is MS medium containing 1-3 mol / L glycine and 0.1-0.5 mol / L sucrose.

[0010] Preferably, the vitrification reagent comprises 20-40% glycine, 10-30% ethylene glycol, 10-30% dimethyl sulfoxide, and 0.1-0.5 mol / L sucrose.

[0011] Preferably, the soaking time for the seeds in the loading solution is 20-30 minutes.

[0012] Preferably, the seeds are soaked in vitrification reagent for 20-40 minutes.

[0013] Preferably, the drying of *Millettia dielsiana* seeds using silica gel desiccant is carried out in a drying device, said drying device comprising:

[0014] The outer barrel has an open top structure, and a barrel lid is provided on the top of the outer barrel, with a vent hole on the barrel lid;

[0015] An inner barrel is disposed within an outer barrel. The inner barrel contains a first cylinder, a second cylinder, and a third cylinder. The first cylinder and the inner barrel wall together define a first desiccant cavity. The first cylinder and the second cylinder together define a seed cavity. The second cylinder and the third cylinder together define a second desiccant cavity. The inner barrel wall, as well as the cylinder walls of the first, second, and third cylinders, are each provided with a first vent hole. Seeds to be dried are placed in the seed cavity. The first and second desiccant cavities are filled with silica gel desiccant. A sealing element is provided at the top of the third cylinder.

[0016] A weighing device includes a weight sensing device and an annular support plate. The weight sensing device is disposed at the bottom of the seed receiving cavity, and the annular support plate is slidably disposed in the seed receiving cavity and disposed above the weight sensing device.

[0017] The display control panel is located on the wall of the outer barrel and is electrically connected to the weight sensing device. The display control panel is used to display the weight of the seeds in the seed holding chamber.

[0018] Preferably, the lower part of the outer barrel is provided with a first partition plate and a second partition plate, which define a third desiccant receiving cavity at the lower part of the outer barrel. The first partition plate and the second partition plate are provided with a plurality of second vent holes. The third desiccant receiving cavity is filled with silica gel desiccant. The first partition plate is located below the inner barrel to support the inner barrel. The bottom of the outer barrel is provided with an air inlet, and a fan is provided at the air inlet. The fan is electrically connected to the display control panel.

[0019] Preferably, the bottom of the inner tub is provided with an annular support edge.

[0020] Preferably, the method for drying *Millettia speciosa* seeds using the aforementioned drying device includes the following steps:

[0021] A) Fill the first desiccant chamber and the second desiccant chamber with silica gel desiccant, and place fresh large-leaved dwarf pine seeds in the seed chamber;

[0022] B) The weight sensor senses and obtains the mass of the seeds in the seed container, displays the mass m1 of the fresh seeds on the control panel, records the stored mass m1 and inputs the average moisture content h1 of the seeds;

[0023] C) Every 5-10 minutes, the display control panel starts the fan to run for 1-5 minutes. After the fan finishes running, the weight sensor detects the seed mass in the seed container and transmits the real-time detection result m2 to the display control panel. The display control panel calculates the real-time moisture content of the seeds and displays it on the display screen of the display control panel in real time.

[0024] The method for calculating seed moisture content is as follows:

[0025] Seeds were randomly selected from the seed bag and weighed. The seeds were then placed in a 105℃ oven and dried for 10 hours before being weighed again. After weighing, the average moisture content of the batch of seeds was calculated using the formula: Average moisture content of seeds h1 (%) = (fresh weight - dry weight) / fresh weight × 100%.

[0026] The initial mass m1 of the seeds is obtained by randomly picking seeds from the seed bag and placing them into the seed container cavity. The real-time mass of the seeds is m2. The formula for calculating the seed moisture content h2 after the seeds are dehydrated in the seed container cavity is: real-time seed moisture content h2 (%) = (m1*h1-m1+m2) / m2*100%.

[0027] D) If the real-time moisture content of the seeds is lower than the preset value, the control panel will send a drying end signal through the alarm device.

[0028] A method for improving the germination rate of *Millettia dielsiana* seeds preserved at ultra-low temperatures includes the following steps:

[0029] a) Remove the seeds of *Flemingia macrophylla* that have been preserved using the above method from liquid nitrogen, thaw them at room temperature, rinse them with running water, air dry them, and then perform a peeling process using a peeling device.

[0030] b) After the seeds of *Millettia dielsiana* have been ground, place them neatly into a culture dish lined with moist filter paper, and then place it in a constant temperature and light incubator for cultivation until the seeds germinate.

[0031] The present invention has at least the following beneficial effects:

[0032] First, this invention establishes a technical procedure for the cryopreservation of *Millettia dielsiana* germplasm resources, filling a gap in the field of cryopreservation technology for *Millettia dielsiana* seeds. Through cryopreservation technology, the storage time of seeds can be extended, ensuring that the seeds maintain strong viability.

[0033] Secondly, this invention has explored different ultra-low temperature preservation methods, vitrification agent components and ratios, thawing times, and seed skin-grinding treatments suitable for *Millettia speciosa* seeds. These conditions work synergistically to improve seed germination rate and maintain the stability of *Millettia speciosa* seed genetic resources.

[0034] Third, the vitrification cryopreservation method for *Millettia divaricata* of this invention is simple, stable, and reliable, and can effectively and safely preserve *Millettia divaricata* seeds for a long period of time. It is a practical new method for the preservation of *Millettia divaricata* germplasm resources.

[0035] Fourth, the drying device of the present invention can monitor the moisture content of seeds in real time during the drying process, which provides convenience for obtaining large-leafed dwarf thorn seeds with any moisture content.

[0036] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the drying apparatus of the present invention;

[0038] Figure 2 This is a schematic diagram of the abrasive structure of the present invention.

[0039] 1. Outer barrel; 2. Barrel lid; 3. Inner barrel; 4. First cylinder; 5. Second cylinder; 6. Third cylinder; 7. First desiccant container; 8. Seed container; 9. Second desiccant container; 10. Sealing component; 11. Weight sensor; 12. Annular support plate; 13. First partition plate; 14. Second partition plate; 15. Third desiccant container; 16. Air inlet; 17. Fan; 18. Annular support edge; 19. Box body; 20. First feed inlet; 21. First screen; 22. First discharge outlet; 23. First collection plate; 24. First discharge port; 25. First grinding cylinder; 26. Second feed inlet; 27. First collection port; 28. First collection box; 29. ​​First filter screen; 30. First bran collection trough; 31. First exhaust port; 32. First grinding cylinder 33. First spiral conveyor pipe; 34. Second screen; 35. Third feed inlet; 36. First baffle; 37. Second discharge outlet; 38. Second collecting plate; 39. Second discharge outlet; 40. Second grinding cylinder; 41. Fourth feed inlet; 42. Second collection outlet; 43. Second grinding roller; 44. Second spiral conveyor pipe; 45. Second filter screen; 46. Second bran collection trough; 47. Second vent hole; 48. Second collection box; 49. Third collecting plate; 50. Third discharge outlet; 51. Sixth feed inlet; 52. Second baffle; 53. Third grinding cylinder; 54. Third collection outlet; 55. Third grinding roller; 56. Third spiral conveyor pipe; 57. Third filter screen; 58. Third bran collection trough; 59. Third vent hole; 60. Third collection box; 61. Drive motor. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0041] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0042] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods, and the reagents and materials mentioned are commercially available. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to fixed connection or setting, detachable connection or setting, or integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0043] This invention provides a method for cryopreservation of seeds of *Millettia dielsiana*, comprising the following steps:

[0044] 1) Dry the seeds of *Mallotus macrocarpa* to a moisture content of 5.5-9.5% using silica gel desiccant under dark conditions;

[0045] 2) Soak the dried seeds in the loading solution, take them out, soak them in the vitrification reagent, after soaking, take out the seeds, add pre-cooled vitrification protective reagent, and transfer them into liquid nitrogen for ultra-low temperature preservation.

[0046] In another technical solution, the loading solution is MS medium containing 1-3 mol / L glycine and 0.1-0.5 mol / L sucrose.

[0047] In another technical solution, the vitrifying agent comprises 20-40% glycine, 10-30% ethylene glycol, 10-30% dimethyl sulfoxide, and 0.1-0.5 mol / L sucrose.

[0048] In another technical solution, the soaking time for seeds in the loading solution is 20-30 minutes.

[0049] In another technical solution, the seeds are soaked in a vitrifying agent for 20-40 minutes.

[0050] In another technical solution, the seeds of *Millettia dielsiana* are dried using silica gel desiccant in a drying device, such as... Figure 1 As shown, the drying apparatus includes:

[0051] The outer barrel 1 has an open top structure, and the top of the outer barrel 1 is provided with a barrel cover 2, which has a vent hole (not shown in the figure);

[0052] The inner barrel 3 is disposed inside the outer barrel 1. The inner barrel 3 is provided with a first cylinder 4, a second cylinder 5, and a third cylinder 6. The first cylinder 4 and the barrel wall of the inner barrel 3 together define a first desiccant receiving cavity 7. The first cylinder 4 and the second cylinder 5 together define a seed receiving cavity 8. The second cylinder 5 and the third cylinder 6 together define a second desiccant receiving cavity 9. The barrel wall of the inner barrel 3 and the barrel walls of the first cylinder 4, the second cylinder 5, and the third cylinder 6 are all provided with a first vent hole (not shown in the figure). The seed receiving cavity 8 contains seeds to be dried. The first desiccant receiving cavity 7 and the second desiccant receiving cavity 9 are filled with silica gel desiccant. The top of the third cylinder 6 is provided with a sealing member 10.

[0053] The weighing device includes a weight sensing device 11 and an annular support plate 12. The weight sensing device 11 is disposed at the bottom of the seed receiving cavity 8, and the annular support plate 12 is slidably disposed in the seed receiving cavity 8 and disposed above the weight sensing device 11.

[0054] A display control panel (not shown) is installed on the wall of the outer barrel 1. The display control panel is electrically connected to the weight sensing device 11 and is used to display the weight of the seeds in the seed holding chamber 8.

[0055] In another technical solution, the lower part of the outer barrel 1 is provided with a first partition plate 13 and a second partition plate 14, which define a third desiccant receiving cavity 15 at the lower part of the outer barrel 1. The first partition plate 13 and the second partition plate 14 are provided with a plurality of second vent holes (not shown in the figure). The third desiccant receiving cavity 15 is filled with silica gel desiccant. The first partition plate 13 is located below the inner barrel 3 to support the inner barrel 3. The bottom of the outer barrel 1 is provided with an air inlet 16, and a fan 17 is provided at the air inlet 16. The fan 17 is electrically connected to the display control panel.

[0056] In another technical solution, the bottom of the inner tub is provided with an annular support along the 18th inch.

[0057] In another technical solution, the annular support plate 12 is provided with several third vent holes (not shown in the figure).

[0058] In another technical solution, the method for drying the seeds of *Millettia speciosa* using the aforementioned drying device includes the following steps:

[0059] A) Fill the first desiccant chamber 7 and the second desiccant chamber 9 with silica gel desiccant, and place the fresh large-leaved dwarf pine seeds in the seed chamber 8;

[0060] B) The weight sensing device 11 senses and obtains the mass of the seeds in the seed holding cavity 8, displays the mass m1 of the fresh seeds on the control panel, records the stored mass m1 and inputs the average moisture content h1 of the seeds;

[0061] C) Every 5-10 minutes, the display control panel starts the fan 17 to work for 1-5 minutes. After the fan 17 finishes working, the weight sensor 11 detects the seed mass in the seed container 8 and transmits the real-time detection result m2 to the display control panel. The display control panel calculates the real-time moisture content of the seeds and displays it on the display screen of the display control panel in real time.

[0062] The method for calculating seed moisture content is as follows:

[0063] Seeds were randomly selected from the seed bag and weighed. The seeds were then placed in a 105℃ oven and dried for 10 hours before being weighed again. After weighing, the average moisture content of the batch of seeds was calculated using the formula: Average moisture content of seeds h1 (%) = (fresh weight - dry weight) / fresh weight × 100%.

[0064] The initial mass m1 of the seeds is obtained by randomly picking seeds from the seed bag and placing them into the seed holding cavity 8. The real-time mass of the seeds is m2. The formula for calculating the seed moisture content h2 after the seeds are dehydrated in the seed holding cavity 8 is: real-time seed moisture content h2 (%) = (m1*h1-m1+m2) / m2*100%.

[0065] D) If the seed moisture content is lower than the preset value, the control panel will send a drying end signal through the alarm device.

[0066] The drying device of the present invention allows for real-time monitoring of the seed moisture content, providing convenience for obtaining seeds with any moisture content. Furthermore, the drying device of the present invention can replenish air in a timely manner during the drying process, which helps to maintain the seed viability.

[0067] This invention also provides a method for improving the germination rate of *Millettia dielsiana* seeds preserved at ultra-low temperatures, comprising the following steps:

[0068] a) Remove the seeds of *Flemingia macrophylla* that have been preserved using the above method from liquid nitrogen, thaw them at room temperature, rinse them with running water, air dry them, and then perform a peeling process using a peeling device.

[0069] b) After the seeds of *Millettia dielsiana* have been ground, place them neatly into a culture dish lined with moist filter paper, and then place it in a constant temperature and light incubator for cultivation until the seeds germinate.

[0070] In another technical solution, the seeds are treated with a peeling device, such as... Figure 2 As shown, the skin resurfacing device includes:

[0071] The box body 19 has a first feed inlet 20 on its top, and the cross-section of the box body 19 is rectangular;

[0072] The first screening and grinding structure includes a first screening structure and a first grinding structure, both of which are disposed within the housing 19.

[0073] The first screening structure includes:

[0074] The first screen 21 is inclined downward, and the upper end of the first screen 21 is opposite to the position of the first feed inlet 20. The right side of the box body 19 is provided with the first discharge outlet 22, and the lower end of the first screen 21 is opposite to the position of the first discharge outlet 22 so that seeds that fail to pass through the first screen 21 are discharged from the first discharge outlet 22.

[0075] The first collecting plate 23 is located below the first screen 21. The first collecting plate 23 has a funnel-shaped structure to collect seeds passing through the first screen 21. The first discharge port 24 of the first collecting plate 23 is located on the right side of the box 19.

[0076] The first skin-refining device includes:

[0077] The first grinding cylinder 25 is located below the first collecting plate 23. A second feed inlet 26 is provided on the right side of the first grinding cylinder 25. The second feed inlet 26 is positioned opposite to the first discharge port 24 so that the seeds can enter the first grinding cylinder 25 through the second feed inlet 26. A first slag discharge hole (not shown in the figure) is provided at the bottom of the first grinding cylinder 25. A first collection port 27 is provided on the left side of the first grinding cylinder 25.

[0078] The first grinding roller 32 is rotatably disposed in the first grinding cylinder 25;

[0079] The first spiral conveying tube 33 is rotatably disposed in the first grinding cylinder 25 and coaxially disposed with the first grinding roller 32. The first spiral conveying tube 33 is positioned opposite to the second feed inlet 26 to convey seeds toward the first grinding roller 32.

[0080] The first filter screen 29 is disposed below the first grinding cylinder 25;

[0081] The first bran collection trough 30 is located below the first filter screen 29. The first vent hole 31 is provided on the trough wall of the first bran collection trough 30. The first vent hole 31 is connected to the negative pressure generating device through a pipe.

[0082] The first collection box 28 is located on the left side of the box body 19 and is opposite to the first collection port 27 to collect seeds that have been ground and peeled by the first grinding cylinder 25.

[0083] The second screening and grinding structure includes a second screening structure and a second grinding structure, both of which are disposed within the housing 19.

[0084] The second screening structure includes:

[0085] The second screen 34 is located below the first bran trough 30. The second screen 34 is inclined downward. The upper end of the second screen 34 is located on the right side of the box body 19. The right side of the box body 19 is provided with a third feed inlet 35. The side of the box body 19 is provided with a first baffle 36. The first baffle 36 and the side wall of the box body 19 together define a first channel to guide the seeds discharged from the first discharge outlet 22 into the second screen 34 through the third feed inlet 35. The left side of the box body 19 is provided with a second discharge outlet 37. The lower end of the second screen 34 is opposite to the position of the second discharge outlet 37 so that the seeds that fail to pass through the second screen 34 are discharged from the second discharge outlet 37.

[0086] The second collecting plate 38 is located below the second screen 34. The second collecting plate 38 has a funnel-shaped structure, and the second discharge port 39 of the second collecting plate 38 is located on the left side of the box body 19.

[0087] The second skin resurfacing device includes:

[0088] The second grinding cylinder 40 is located below the second collecting plate 38. A fourth feed inlet 41 is provided on the right side of the second grinding cylinder 40. The fourth feed inlet 41 is positioned opposite to the second discharge port 39 so that the seeds can enter the second grinding cylinder 40 through the fourth feed inlet 41. A second slag discharge hole (not shown in the figure) is provided at the bottom of the second grinding cylinder 40. A second collection port 42 is provided on the right side of the second grinding cylinder 40.

[0089] The second grinding roller 43 is rotatably disposed in the second grinding cylinder 40;

[0090] The second spiral conveying tube 44 is rotatably disposed in the second grinding cylinder 40 and coaxially disposed with the second grinding roller 43. The second spiral conveying tube 44 is positioned opposite to the fourth feed port 41 to convey the seeds toward the second grinding roller 43.

[0091] The second filter screen 45 is located below the second grinding cylinder 40;

[0092] The second bran collection trough 46 is located below the second filter screen 45. The second bran collection trough 46 has a second vent hole 47 on its wall. The second vent hole 47 is connected to the negative pressure generating device through a pipe.

[0093] The second collection box 48 is located on the right side of the box body 19 and is opposite to the position of the second collection port 42 to collect the seeds that have been ground and peeled by the second grinding cylinder 40.

[0094] The third skin-grinding device is located inside the housing 19;

[0095] The third skin-refining device includes:

[0096] The third collecting plate 49 is located below the second collecting chaff trough 46. The third collecting plate 49 has a funnel-shaped structure. The third discharge port 50 of the third collecting plate 49 is located on the right side of the box body 19. The left side of the box body 19 is provided with a fifth inlet. The side of the box body 19 is provided with a second baffle 52. The second baffle 52 and the side wall of the box body 19 together define a second channel to guide the seeds discharged from the second discharge port 37 into the third collecting plate 49 through the fifth inlet.

[0097] The third grinding cylinder 53 is located below the third collecting plate 49. The right side of the third grinding cylinder 53 is provided with a sixth feed port 51, which is opposite to the third discharge port 50 so that the seeds can enter the third grinding cylinder 53 through the sixth feed port 51. The bottom of the third grinding cylinder 53 is provided with a third slag discharge hole (not shown in the figure), and the left side of the third grinding cylinder 53 is provided with a third collection port 54.

[0098] The third grinding roller 55 is rotatably disposed in the third grinding cylinder 53;

[0099] The third spiral conveying tube 56 is rotatably disposed in the third grinding cylinder 53 and coaxially disposed with the third grinding roller 55. The third spiral conveying tube 56 is positioned opposite to the sixth feed port 51 to convey the seeds toward the third grinding roller 55.

[0100] The third filter screen 57 is located below the third grinding cylinder 53;

[0101] The third bran collection trough 58 is located below the third filter screen 57. The third bran collection trough 58 has a third vent hole 59 on its wall, which is connected to a negative pressure generating device through a pipe.

[0102] The third collection box 60 is located on the left side of the box body 19 and is opposite to the third collection port 54 to collect the seeds that have been ground and peeled by the third grinding cylinder 53.

[0103] A drive motor 61 is located at the bottom of the housing 19 and is used to drive the first grinding roller 32, the second grinding roller 43, and the third grinding roller 55 to rotate.

[0104] In this system, the mesh size of the first screen 21 is smaller than that of the second screen 34; the gap between the first grinding roller 32 and the first grinding cylinder 25 is L1; the gap between the second grinding roller 43 and the second grinding cylinder 40 is L2; ​​and the gap between the third grinding roller 55 and the third grinding cylinder 53 is L3. <L2<L3。

[0105] In this technical solution, the sieving action of a sieve is used to classify seeds according to their particle size. Seeds of different sizes enter different grinding devices to achieve a better grinding effect on the seeds. This avoids the problem when using existing grinding devices, where larger seeds are over-grinded due to their different particle sizes, which damages the seeds and affects their germination, while smaller seeds are not fully ground, affecting their germination and uniformity.

[0106] The technical principle of this technical solution is as follows:

[0107] Seeds enter the housing 19 through the first feed inlet 20. Under the action of the first screen 21, seeds with smaller particle sizes are screened and collected through the first collecting plate 23. They then enter the first grinding cylinder 25 through the second feed inlet 26. The seeds are conveyed towards the first grinding roller 32 under the action of the first spiral conveyor pipe 33. The seeds are peeled under the rotation of the first grinding roller 32. The bran residue enters the first bran collection trough 30 through the first filter screen 29 under the action of negative pressure. The peeled seeds enter the first collection box 28 through the first collection port 27.

[0108] Seeds that fail to pass through the first screen 21 enter the second screen 34 through the first channel. Under the action of the second screen 34, seeds with smaller particle sizes are screened and collected through the second collection plate 38. They then enter the second grinding cylinder 40 through the fourth feed port 41. The seeds are conveyed towards the second grinding roller 43 under the action of the second spiral conveyor pipe 44. The seeds are peeled under the rotation of the second grinding roller 43. The bran residue enters the second bran collection trough 46 through the second filter screen 45 under the action of negative pressure. The peeled seeds enter the second collection box 48 through the second collection port 42.

[0109] Seeds that fail to pass through the second screen 34 enter the second collection plate 38 through the second channel and then enter the third grinding cylinder 53 through the sixth feed port 51. The seeds are conveyed towards the third grinding roller 55 under the action of the third spiral conveyor pipe 56. The seeds are dehulled under the rotation of the third grinding roller 55. The bran residue enters the third bran collection trough 58 through the third filter screen 57 under the action of negative pressure. The dehulled seeds enter the third collection box 60 through the third collection port 54.

[0110] This invention enables simultaneous sieving and grinding of seeds, improving grinding efficiency and uniformity, solving the problems of over-grinding or under-grinding, and increasing seed germination rate.

[0111] <Example 1>

[0112] A method for cryopreservation of seeds from *Millettia speciosa* includes the following steps:

[0113] 1) Dry the seeds of *Mallotus macrocarpa* to a moisture content of 5.5-9.5% using silica gel desiccant under dark conditions;

[0114] 2) Soak the dried seeds in the loading solution, take them out, soak them in the vitrification reagent, after soaking, take out the seeds, add pre-cooled vitrification protective reagent, and transfer them into liquid nitrogen for ultra-low temperature preservation.

[0115] Furthermore, the loading solution is MS medium containing 1-3 mol / L glycine and 0.1-0.5 mol / L sucrose.

[0116] Furthermore, the vitrification reagent comprises 20-40% glycine, 10-30% ethylene glycol, 10-30% dimethyl sulfoxide, and 0.1-0.5 mol / L sucrose.

[0117] Furthermore, the soaking time for the seeds in the loading solution is 20-30 minutes.

[0118] Furthermore, the seeds are soaked in vitrification reagent for 20-40 minutes.

[0119] <Example 2>

[0120] A method for cryopreservation of seeds of *Millettia speciosa*

[0121] The preservation method is the same as in <Example 1>, except that the seeds of *Mallotus macrocarpa* are dried using silica gel desiccant in a drying device, which includes:

[0122] The outer bucket 1 has an open top structure, and the top of the outer bucket 1 is provided with a bucket lid 2, which is provided with a vent hole;

[0123] The inner barrel 3 is disposed inside the outer barrel 1. The inner barrel 3 is provided with a first cylinder 4, a second cylinder 5, and a third cylinder 6. The first cylinder 4 and the barrel wall of the inner barrel 3 together define a first desiccant receiving cavity 7. The first cylinder 4 and the second cylinder 5 together define a seed receiving cavity 8. The second cylinder 5 and the third cylinder 6 together define a second desiccant receiving cavity 9. The barrel wall of the inner barrel 3 and the barrel walls of the first cylinder 4, the second cylinder 5, and the third cylinder 6 are all provided with first ventilation holes. Seeds to be dried are placed in the seed receiving cavity 8. The first desiccant receiving cavity 7 and the second desiccant receiving cavity 9 are filled with silica gel desiccant. A sealing member 10 is provided on the top of the third cylinder 6.

[0124] The weighing device includes a weight sensing device 11 and an annular support plate 12. The weight sensing device 11 is disposed at the bottom of the seed receiving cavity 8, and the annular support plate 12 is slidably disposed in the seed receiving cavity 8 and disposed above the weight sensing device 11.

[0125] The display control panel is located on the wall of the outer barrel 1. The display control panel is electrically connected to the weight sensing device 11 and is used to display the weight of the seeds in the seed holding chamber 8.

[0126] Furthermore, the lower part of the outer barrel 1 is provided with a first partition plate 13 and a second partition plate 14, which define a third desiccant receiving cavity 15 at the lower part of the outer barrel 1. The first partition plate 13 and the second partition plate 14 are provided with a plurality of second vent holes. The third desiccant is filled with silica gel desiccant. The first partition plate 13 is located below the inner barrel 3 to support the inner barrel 3. The bottom of the outer barrel 1 is provided with an air inlet 16, and a fan 17 is provided at the air inlet 16. The fan 17 is electrically connected to the display control panel.

[0127] Furthermore, the bottom of the inner tub is provided with an annular support along the 18th inch.

[0128] Furthermore, the annular support plate 12 is provided with several third vent holes (not shown in the figure).

[0129] The method for drying seeds of *Millettia speciosa* using the aforementioned drying device includes the following steps:

[0130] A) Fill the first desiccant chamber 7 and the second desiccant chamber 9 with silica gel desiccant, and place the fresh large-leaved dwarf pine seeds in the seed chamber 8;

[0131] B) The weight sensing device 11 senses and obtains the mass of the seeds in the seed holding cavity 8, displays the mass m1 of the fresh seeds on the control panel, and records the stored mass m1 and the input average seed moisture content h1.

[0132] C) Every 5-10 minutes, the display control panel starts the fan 17 to work for 1-5 minutes. After the fan 17 finishes working, the weight sensor 11 detects the seed mass in the seed container 8 and transmits the real-time detection result m2 to the display control panel. The display control panel calculates the real-time moisture content of the seeds and displays it on the display screen of the display control panel in real time.

[0133] The method for calculating seed moisture content is as follows:

[0134] Seeds were randomly selected from the seed bag and weighed. The seeds were then placed in a 105℃ oven and dried for 10 hours before being weighed again. After weighing, the average moisture content of the batch of seeds was calculated using the formula: Average moisture content of seeds h1 (%) = (fresh weight - dry weight) / fresh weight × 100%.

[0135] The initial mass m1 of the seeds is obtained by randomly picking seeds from the seed bag and placing them into the seed holding cavity 8. The real-time mass of the seeds is m2. The formula for calculating the seed moisture content h2 after the seeds are dehydrated in the seed holding cavity 8 is: real-time seed moisture content h2 (%) = (m1*h1-m1+m2) / m2*100%.

[0136] D) If the real-time moisture content of the seeds is lower than the preset value, the control panel will send a drying end signal through the alarm device.

[0137] <Example 3>

[0138] A method for improving the germination rate of *Millettia dielsiana* seeds preserved at ultra-low temperatures includes the following steps:

[0139] a) Remove the seeds of *Flemingia macrophylla* preserved by the preservation method in <Example 2> from liquid nitrogen, thaw them at room temperature, rinse them with running water, air dry them, and then perform a peeling process using a peeling device.

[0140] b) After the seeds of *Millettia dielsiana* have been ground, place them neatly into a culture dish lined with moist filter paper, and then place it in a constant temperature and light incubator for cultivation until the seeds germinate.

[0141] <Example 4>

[0142] A method to improve the germination rate of *Millettia dielsiana* seeds stored at ultra-low temperatures.

[0143] The method is the same as in <Example 3>, except that the seeds are treated with a peeling device, which includes:

[0144] The box body 19 has a first feed inlet 20 on its top, and the cross-section of the box body 19 is rectangular;

[0145] The first screening and grinding structure includes a first screening structure and a first grinding structure, both of which are disposed within the housing 19.

[0146] The first screening structure includes:

[0147] The first screen 21 is inclined downward, and the upper end of the first screen 21 is opposite to the position of the first feed inlet 20. The right side of the box body 19 is provided with the first discharge outlet 22, and the lower end of the first screen 21 is opposite to the position of the first discharge outlet 22 so that seeds that fail to pass through the first screen 21 are discharged from the first discharge outlet 22.

[0148] The first collecting plate 23 is located below the first screen 21. The first collecting plate 23 has a funnel-shaped structure to collect seeds passing through the first screen 21. The first discharge port 24 of the first collecting plate 23 is located on the right side of the box 19.

[0149] The first skin-refining device includes:

[0150] The first grinding cylinder 25 is located below the first collecting plate 23. A second feed inlet 26 is provided on the right side of the first grinding cylinder 25. The second feed inlet 26 is positioned opposite to the first discharge port 24 so that the seeds can enter the first grinding cylinder 25 through the second feed inlet 26. A first slag discharge hole is provided at the bottom of the first grinding cylinder 25. A first collection port 27 is provided on the left side of the first grinding cylinder 25.

[0151] The first grinding roller 32 is rotatably disposed in the first grinding cylinder 25;

[0152] The first spiral conveying tube 33 is rotatably disposed in the first grinding cylinder 25 and coaxially disposed with the first grinding roller 32. The first spiral conveying tube 33 is positioned opposite to the second feed inlet 26 to convey seeds toward the first grinding roller 32.

[0153] The first filter screen 29 is disposed below the first grinding cylinder 25;

[0154] The first bran collection trough 30 is located below the first filter screen 29. The first vent hole 31 is provided on the trough wall of the first bran collection trough 30. The first vent hole 31 is connected to the negative pressure generating device through a pipe.

[0155] The first collection box 28 is located on the left side of the box body 19 and is opposite to the first collection port 27 to collect seeds that have been ground and peeled by the first grinding cylinder 25.

[0156] The second screening and grinding structure includes a second screening structure and a second grinding structure, both of which are disposed within the housing 19.

[0157] The second screening structure includes:

[0158] The second screen 34 is located below the first bran trough 30. The second screen 34 is inclined downward. The upper end of the second screen 34 is located on the right side of the box body 19. The right side of the box body 19 is provided with a third feed inlet 35. The side of the box body 19 is provided with a first baffle 36. The first baffle 36 and the side wall of the box body 19 together define a first channel to guide the seeds discharged from the first discharge outlet 22 into the second screen 34 through the third feed inlet 35. The left side of the box body 19 is provided with a second discharge outlet 37. The lower end of the second screen 34 is opposite to the position of the second discharge outlet 37 so that the seeds that fail to pass through the second screen 34 are discharged from the second discharge outlet 37.

[0159] The second collecting plate 38 is located below the second screen 34. The second collecting plate 38 has a funnel-shaped structure, and the second discharge port 39 of the second collecting plate 38 is located on the left side of the box body 19.

[0160] The second skin resurfacing device includes:

[0161] The second grinding cylinder 40 is located below the second collecting plate 38. A fourth feed inlet 41 is provided on the right side of the second grinding cylinder 40. The fourth feed inlet 41 is positioned opposite to the second discharge port 39 so that the seeds can enter the second grinding cylinder 40 through the fourth feed inlet 41. A second slag discharge hole is provided at the bottom of the second grinding cylinder 40. A second collection port 42 is provided on the right side of the second grinding cylinder 40.

[0162] The second grinding roller 43 is rotatably disposed in the second grinding cylinder 40;

[0163] The second spiral conveying tube 44 is rotatably disposed in the second grinding cylinder 40 and coaxially disposed with the second grinding roller 43. The second spiral conveying tube 44 is positioned opposite to the fourth feed port 41 to convey the seeds toward the second grinding roller 43.

[0164] The second filter screen 45 is located below the second grinding cylinder 40;

[0165] The second bran collection trough 46 is located below the second filter screen 45. The second bran collection trough 46 has a second vent hole 47 on its wall. The second vent hole 47 is connected to the negative pressure generating device through a pipe.

[0166] The second collection box 48 is located on the right side of the box body 19 and is opposite to the position of the second collection port 42 to collect the seeds that have been ground and peeled by the second grinding cylinder 40.

[0167] The third skin-grinding device is located inside the housing 19;

[0168] The third skin-refining device includes:

[0169] The third collecting plate 49 is located below the second collecting chaff trough 46. The third collecting plate 49 has a funnel-shaped structure. The third discharge port 50 of the third collecting plate 49 is located on the right side of the box body 19. The fifth discharge port is located on the left side wall of the box body 19 above the third collecting plate 49. The fifth inlet is located on the right side of the box body 19. The second baffle 52 is located on the side of the box body 19. The second baffle 52 and the side wall of the box body 19 together define a second channel to guide the seeds discharged from the second discharge port 37 into the third collecting plate 49 through the fifth inlet.

[0170] The third grinding cylinder 53 is located below the third collecting plate 49. The right side of the third grinding cylinder 53 is provided with a sixth feed port 51, which is opposite to the third discharge port 50 so that the seeds can enter the third grinding cylinder 53 through the sixth feed port 51. The bottom of the third grinding cylinder 53 is provided with a third slag discharge hole, and the left side of the third grinding cylinder 53 is provided with a third collection port 54.

[0171] The third grinding roller 55 is rotatably disposed in the third grinding cylinder 53;

[0172] The third spiral conveying tube 56 is rotatably disposed in the third grinding cylinder 53 and coaxially disposed with the third grinding roller 55. The third spiral conveying tube 56 is positioned opposite to the sixth feed port 51 to convey the seeds toward the third grinding roller 55.

[0173] The third filter screen 57 is located below the third grinding cylinder 53;

[0174] The third bran collection trough 58 is located below the third filter screen 57. The third bran collection trough 58 has a third vent hole 59 on its wall, which is connected to a negative pressure generating device through a pipe.

[0175] The third collection box 60 is located on the left side of the box body 19 and is opposite to the third collection port 54 to collect the seeds that have been ground and peeled by the third grinding cylinder 53.

[0176] A drive motor 61 is located at the bottom of the housing 19 and is used to drive the first grinding roller 32, the second grinding roller 43, and the third grinding roller 55 to rotate.

[0177] In this system, the mesh size of the first screen 21 is smaller than that of the second screen 34; the gap between the first grinding roller 32 and the first grinding cylinder 25 is L1; the gap between the second grinding roller 43 and the second grinding cylinder 40 is L2; ​​and the gap between the third grinding roller 55 and the third grinding cylinder 53 is L3. <L 2<L3。

[0178] <Effectiveness Test>

[0179] Experiment 1: Effects of different cryopreservation methods on the germination of seeds of *Millettia dielsiana*

[0180] (1) Select seeds from high-quality large-leaf shrub germplasm resources, and choose those that are undamaged, plump, uniform in texture, and free from disease and insect eggs for later use.

[0181] (2) The seeds from (1) were buried in silica gel desiccant and placed in a dark environment at 25℃. Before ultra-low temperature storage, they were rapidly dehydrated for 0h, 3h, 24h, and 72h respectively to obtain seeds of *Millettia dielsiana* with different moisture contents of 9.2%, 7.1%, 6.3%, and 4.8%. Seeds were randomly selected from the seed bag and weighed. The seeds were then dried in a 105℃ oven for 10h and weighed again to obtain the dry weight of the seeds. The average moisture content of the seeds in the bag was calculated using the formula: Average moisture content of seeds (%) = (fresh weight - dry weight) / fresh weight × 100%. Seeds were randomly selected from the seed bag and weighed. The weight of the seeds after dehydration with silica gel desiccant was also weighed, and the average moisture content of the seeds was used to calculate the moisture content of the seeds after dehydration with silica gel desiccant.

[0182] (3) Take the dried seeds of *Morchella esculenta* obtained in (2) and use the unfrozen seeds as the control group. The following different ultra-low temperature preservation methods were used: direct ultra-low temperature preservation method (the seeds of *Morchella esculenta* were directly put into liquid nitrogen and preserved at -196℃), cold storage + ultra-low temperature two-step preservation method (the seeds of *Morchella esculenta* were refrigerated in the freezer (-20℃) for 2 hours and then immediately put into liquid nitrogen for preservation at -196℃), vitrification freezing method for ultra-low temperature preservation (the seeds of *Morchella esculenta* were soaked in the loading solution at 25℃ for 25 minutes, taken out and placed in the cryoprotectant, the test seeds were soaked at 4℃ for 30 minutes, and then the cryoprotectant was replaced with fresh cryoprotectant after pre-cooling at 4℃. The seeds of *Morchella esculenta* were immediately put into liquid nitrogen at -196℃ for preservation).

[0183] (4) Take the seeds of *Millettia dielsiana* that have been frozen and stored in (3) and thaw them naturally at room temperature of 25°C. Rinse them with running water and air dry them for 45 minutes. Then, use a peeling device (whitening machine) in the prior art to peel them for 90 seconds. Place the seeds of *Millettia dielsiana* into a culture dish lined with moist filter paper and place it in a light incubator to be cultured at a constant temperature of 25°C. Observe the germination rate of the seeds.

[0184] Loading solution preparation: 2 mol / L glycerol (146 ml) + 0.4 mol / L sucrose (136.8 g) + MS.

[0185] PVS2 cryoprotectant formulation: 30% glycerol + 15% ethylene glycol + 15% dimethyl sulfoxide + 0.4 mol / L sucrose (136.8 g).

[0186] Table 1. Effects of different cryopreservation methods on the germination of *Millettia dielsiana* seeds.

[0187]

[0188] The results in Table 1 show that different cryopreservation methods promoted the germination of *Millettia dielsiana* seeds, and cryopreservation itself promoted germination. Table 1 also shows that the vitrification freezing group had the highest germination rate when the seed moisture content was 6.3%, indicating that the use of vitrification protectants can reduce the damage to seeds caused by freezing and promote seed germination.

[0189] <Experiment 2> Effects of different vitrification reagents on the germination of seeds of *Millettia speciosa*

[0190] (1) Select seeds from high-quality large-leaf shrub germplasm resources, and choose those that are undamaged, plump, uniform in texture, and free from disease and insect eggs for later use.

[0191] (2) Take the dried seeds from (1) and bury them in silica gel desiccant. Place them in a dark environment at 25℃ and rapidly dehydrate them for 0h, 3h, and 24h before ultra-low temperature storage to obtain seeds of *Millettia dielsiana* with different moisture contents of 9.5%, 6.7%, and 5.5%. Randomly grab seeds from the seed bag and weigh them. Then, put the seeds in a 105℃ oven and dry them for 10h, and weigh them again to obtain the dry weight of the seeds. Calculate the average moisture content of the seeds in the bag using the formula: Average moisture content of seeds (%) = (fresh weight - dry weight) / fresh weight × 100%. Randomly grab seeds from the seed bag and weigh them. Weigh the seeds after dehydration with silica gel desiccant and calculate the moisture content of the seeds after dehydration with silica gel desiccant using the average moisture content of the seeds.

[0192] (3) Take the dried seeds of *Millettia dielsiana* obtained in (2) and use the seeds without vitrification reagent as the control group. First, soak the seeds in the loading solution at 25°C for 25 minutes. Then, take out the soaked seeds and soak them in PVS1, PVS2, PVS3, PVS4, and PVS5 vitrification protectants at 4°C for 30 minutes. Pour out the protectants and replace them with fresh protectants pre-cooled at 4°C. Immediately put them into liquid nitrogen for storage at -196°C.

[0193] (4) Take the seeds of *Millettia dielsiana* that have been frozen and stored in (3) and thaw them naturally at room temperature of 25°C. Rinse them with running water and air dry them for 45 minutes. Then, use a peeling device (whitening machine) in the prior art to peel them for 90 seconds. Place the seeds of *Millettia dielsiana* into a culture dish lined with moist filter paper and place it in a light incubator to be cultured at a constant temperature of 25°C. Observe the germination rate of the seeds.

[0194] Loading solution preparation: 2 mol / L glycerol (146 ml) + 0.4 mol / L sucrose (136.8 g) + MS.

[0195] Glass transition protectant preparation:

[0196] PVS1: 12% glycerol + 13% ethylene glycol + 13% polyethylene glycol + 15% dimethyl sulfoxide;

[0197] PVS2: 30% glycerol + 15% ethylene glycol + 15% dimethyl sulfoxide + 0.4 mol / L sucrose (136.8 g);

[0198] PVS3: 50% glycerol + 50% sucrose;

[0199] PVS4: 30% glycerol + 10% dimethyl sulfoxide + 25% polyethylene glycol;

[0200] PVS5: 15% glycerol + 15% mannitol + 13% dimethyl sulfoxide + 15% ethylene glycol.

[0201] Table 2 Effects of different vitrification reagents on the germination of *Flemingia macrophylla* seeds.

[0202]

[0203] As shown in Table 2, when the moisture content of *Flemingia macrophylla* seeds was in the range of 5.5% to 9.5%, the germination rate of the seeds treated with PVS2 protective solution and then stored at ultra-low temperature was higher than that of the control group. This indicates that PVS2 protective solution has a promoting effect on the germination rate of *Flemingia macrophylla* seeds.

[0204] <Experiment 3> Effects of different treatment times with PVS2 protective solution on the germination of seeds of *Millettia speciosa*

[0205] (1) Select seeds from high-quality large-leaf shrub germplasm resources, and choose those that are undamaged, plump, uniform in texture, and free from disease and insect eggs for later use.

[0206] (2) Take the dried seeds from (1) and bury them in silica gel desiccant. Place them in a dark environment at 25°C and dehydrate them rapidly before ultra-low temperature storage to obtain large-leaf dwarf thorn seeds with a moisture content of 9.5%.

[0207] (3) Take the dried seeds of *Millettia dielsiana* obtained in (2) and put them into a cryotube. Soak the seeds in the loading solution prepared before the experiment at 25°C for 25 min. Take the seeds out and soak them in the prepared vitrifying agent PVS2 at low temperature (4°C) for 0 min, 15 min, 30 min, 45 min and 60 min respectively. Finally, pour out the protectant and replace it with fresh PVS2 protectant pre-cooled at 4°C. Immediately put it into liquid nitrogen at -196°C for storage.

[0208] (4) Take the seeds of *Millettia dielsiana* that have been frozen and stored in (3) and thaw them naturally at room temperature of 25°C. Rinse them with running water, dry them for 45 minutes, and then grind them with a whitening machine for 90 seconds. Place the seeds of *Millettia dielsiana* into a culture dish lined with moist filter paper and place it in a light incubator at a constant temperature of 25°C. Observe the germination rate of the seeds.

[0209] Loading solution preparation: 2 mol / L glycerol (146 ml) + 0.4 mol / L sucrose (136.8 g) + MS.

[0210] PVS2 glass transition protectant formulation: 30% glycerol + 15% ethylene glycol + 15% dimethyl sulfoxide + 0.4 mol / L sucrose (136.8 g).

[0211] Table 3. Effects of different treatment times with PVS2 protective solution on the germination of *Millettia dielsiana* seeds.

[0212]

[0213] As shown in Table 3, when the moisture content of *Millettia divaricata* seeds was 9.5%, the germination rate of seeds treated with PVS2 protective solution for 15 min, 30 min, 45 min, and 60 min was higher than that of the control group. The highest germination rate was 77% after 45 min of treatment, indicating that the appropriate treatment time for PVS2 protective solution was 45 min.

[0214] Experiment 4: Effects of different recovery temperatures on the germination rate of *Millettia speciosa* seeds.

[0215] (1) Select seeds from high-quality large-leaf shrub germplasm resources, and choose those that are undamaged, plump, uniform in texture, and free from disease and insect eggs for later use.

[0216] (2) Take the dried seeds from (1) and bury them in silica gel desiccant. Place them in a dark environment at 25°C and dehydrate them rapidly before ultra-low temperature storage to obtain seeds of *Millettia dielsiana* with a moisture content of 9.5%. (3) Take the dried *Millettia dielsiana* seeds obtained in (2) and place them in a cryotube. First, soak the seeds in the loading solution prepared before the experiment at 25°C for 25 minutes. Take out the seeds and soak them in the prepared vitrification protectant PVS2 at low temperature (4°C) for 30 minutes. Finally, pour out the protectant and replace it with fresh PVS2 protectant pre-cooled at 4°C. Immediately put them into liquid nitrogen at -196°C for storage.

[0217] (4) Take the cryopreserved seeds of *Millettia dielsiana* from (3) and place them in a water bath at 25°C for 2-3 minutes to thaw. Then, rinse them with running water, dry them for 45 minutes, and then grind them with a whitening machine for 90 seconds. Place the seeds of *Millettia dielsiana* into a culture dish lined with moist filter paper and place it in a light incubator at a constant temperature of 25°C. Observe the germination rate of the seeds.

[0218] Loading solution preparation: 2 mol / L glycerol (146 ml) + 0.4 mol / L sucrose (136.8 g) + MS.

[0219] PVS2 glass transition protectant formulation: 30% glycerol + 15% ethylene glycol + 15% dimethyl sulfoxide + 0.4 mol / L sucrose (136.8 g).

[0220] Table 4. Effects of different recovery temperatures on the germination rate of *Millettia dielsiana* seeds.

[0221]

[0222] As shown in Table 4, the germination rate of *Flemingia macrophylla* seeds decreased with increasing revival temperature. At a normal temperature of 25℃, the germination rate reached as high as 69.25%, indicating the best germination effect.

[0223] <Experiment 5> Effects of the bark-scraping device on the germination rate and uniformity of seeds of *Millettia dielsiana*

[0224] (1) Select seeds from high-quality large-leaf shrub germplasm resources, and choose those that are undamaged, plump, uniform in texture, and free from disease and insect eggs for later use.

[0225] (2) Take the dried seeds from (1) and bury them in silica gel desiccant. Place them in a dark environment at 25°C and dehydrate them before ultra-low temperature storage to obtain large-leaf dwarf thorn seeds with a moisture content of 9.5%.

[0226] (3) Take the dried seeds of *Millettia dielsiana* obtained in (2) and put them into a cryotube. Soak the seeds in the loading solution prepared before the experiment at 25°C for 25 minutes. Take the seeds out and soak them in the prepared vitrifying agent PVS2 at low temperature (4°C) for 30 minutes. Finally, pour out the protectant and replace it with fresh PVS2 protectant pre-cooled at 4°C. Immediately put the seeds into liquid nitrogen at -196°C for storage.

[0227] (4) Take the cryopreserved seeds of *Millettia dielsiana* from (3) and place them in a water bath at 25°C for thawing treatment, 35°C, 45°C, and 55°C for rapid thawing treatment for 2-3 minutes. Rinse with running water, dry the seeds for 45 minutes, and then grind them with a whitening machine in the prior art for 90 seconds. The seeds obtained by grinding with the grinding device of the present invention (the seeds collected in the first collection box 28, the second collection box 48, and the third collection box 60 are mixed) are placed in a culture dish lined with moist filter paper and then placed in a light incubator for constant temperature culture at 25°C. The germination rate and uniformity of the seeds are observed.

[0228] Loading solution preparation: 2 mol / L glycerol (146 ml) + 0.4 mol / L sucrose (136.8 g) + MS.

[0229] PVS2 glass transition protectant formulation: 30% glycerol + 15% ethylene glycol + 15% dimethyl sulfoxide + 0.4 mol / L sucrose (136.8 g).

[0230] Table 5. Effects of the bark-grinding device on the germination rate and uniformity of *Millettia dielsiana* seeds.

[0231]

[0232] As shown in Table 5, the grinding device of the present invention can improve the germination rate and uniformity of seeds of *Millettia dielsiana*. This may be because the grinding device of the present invention can effectively grind seeds of different sizes, making the seeds have a more similar water absorption rate. Furthermore, it avoids the situation where larger seeds are over-grinded while smaller seeds are not effectively ground when seeds of different sizes are ground together, thereby improving the germination rate and uniformity of the seeds.

[0233] <Experiment 6> Effect of drying device on the germination rate of seeds of *Millettia speciosa*

[0234] (1) Select seeds from high-quality large-leaf shrub germplasm resources, and choose those that are undamaged, plump, uniform in texture, and free from disease and insect eggs for later use.

[0235] (2) Take the dried seeds from (1) and bury them in silica gel desiccant and dry them using the drying device of the present invention. Place them at 25°C in a dark environment and dehydrate them before ultra-low temperature storage to obtain large-leaf dwarf thorn seeds with a moisture content of 9.5%.

[0236] (3) Take the dried seeds of *Millettia dielsiana* obtained in (2) and put them into a cryotube. Soak the seeds in the loading solution prepared before the experiment at 25°C for 25 minutes. Take the seeds out and soak them in the prepared vitrifying agent PVS2 at low temperature (4°C) for 30 minutes. Finally, pour out the protectant and replace it with fresh PVS2 protectant pre-cooled at 4°C. Immediately put the seeds into liquid nitrogen at -196°C for storage.

[0237] (4) Take the cryopreserved seeds of *Millettia dielsiana* from (3) and place them in a water bath at 25°C for thawing treatment, and at 35°C, 45°C, and 55°C for rapid thawing treatment for 2-3 minutes. Rinse with running water, and after drying the seeds for 45 minutes, use the peeling device of the present invention to peel the seeds (the seeds collected in the first collection box 28, the second collection box 48, and the third collection box 60 are mixed). Place the *Millettia dielsiana* seeds into a culture dish lined with moist filter paper, and place it in a light incubator for constant temperature culture at 25°C. Observe the germination rate and uniformity of the seeds.

[0238] Loading solution preparation: 2 mol / L glycerol (146 ml) + 0.4 mol / L sucrose (136.8 g) + MS.

[0239] PVS2 glass transition protectant formulation: 30% glycerol + 15% ethylene glycol + 15% dimethyl sulfoxide + 0.4 mol / L sucrose (136.8 g).

[0240] Table 6. Effects of drying device on the germination rate of *Millettia dielsiana* seeds.

[0241]

[0242] As can be seen from the results in Table 6, the drying device of the present invention can not only monitor the moisture content of seeds in real time, but also help to improve the germination rate of seeds.

[0243] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for cryopreservation of seeds of *Millettia dielsiana*, characterized in that, Includes the following steps: 1) Dry the seeds of *Mallotus macrocarpa* using silica gel desiccant under dark conditions until their moisture content is 5.5-9.5%; 2) Soak the dried seeds in the loading solution, take them out, soak them in the vitrification reagent, after soaking, take out the seeds, add pre-cooled vitrification protective reagent, and transfer them into liquid nitrogen for ultra-low temperature preservation; The loading solution was MS medium containing 2 mol / L glycerol and 0.4 mol / L sucrose; The vitrification reagent comprises 30% glycerol, 15% ethylene glycol, 15% dimethyl sulfoxide, and 0.4 mol / L sucrose; the seeds of *Millettia speciosa* are dried using silica gel desiccant in a drying device, which includes: The outer barrel has an open top structure, and a barrel lid is provided on the top of the outer barrel, with a vent hole on the barrel lid; An inner barrel is disposed within an outer barrel. The inner barrel contains a first cylinder, a second cylinder, and a third cylinder. The first cylinder and the inner barrel wall together define a first desiccant cavity. The first cylinder and the second cylinder together define a seed cavity. The second cylinder and the third cylinder together define a second desiccant cavity. The inner barrel wall, as well as the cylinder walls of the first, second, and third cylinders, are each provided with a first vent hole. Seeds to be dried are placed in the seed cavity. The first and second desiccant cavities are filled with silica gel desiccant. A sealing element is provided at the top of the third cylinder. A weighing device includes a weight sensing device and an annular support plate. The weight sensing device is disposed at the bottom of the seed receiving cavity, and the annular support plate is slidably disposed in the seed receiving cavity and disposed above the weight sensing device. The display control panel is located on the wall of the outer barrel and is electrically connected to the weight sensing device. The display control panel is used to display the weight of the seeds in the seed holding cavity. The soaking time for seeds in the loading solution is 20-30 minutes; The seeds should be soaked in vitrification reagent for 20-40 minutes. The lower part of the outer barrel is provided with a first partition plate and a second partition plate, which define a third desiccant receiving cavity at the lower part of the outer barrel. The first partition plate and the second partition plate are provided with a plurality of second vent holes. The third desiccant receiving cavity is filled with silica gel desiccant. The first partition plate is located below the inner barrel to support the inner barrel. The bottom of the outer barrel is provided with an air inlet, and a fan is provided at the air inlet. The fan is electrically connected to the display control panel.

2. The method for cryopreservation of *Millettia dielsiana* seeds according to claim 1, characterized in that, The bottom of the inner tub is provided with a ring-shaped support edge.

3. The method for cryopreservation of *Millettia dielsiana* seeds according to claim 1, characterized in that, The method for drying seeds of *Millettia speciosa* using the aforementioned drying device includes the following steps: A) Fill the first desiccant chamber and the second desiccant chamber with silica gel desiccant, and place fresh large-leaved dwarf pine seeds in the seed chamber; B) The weight sensor senses and obtains the mass of the seeds in the seed container, displays the mass m1 of the fresh seeds on the control panel, and records the stored mass m1 and the input average seed moisture content h1. C) Every 5-10 minutes, the display control panel starts the fan to run for 1-5 minutes. After the fan finishes running, the weight sensor detects the seed mass in the seed container and transmits the real-time detection result m2 to the display control panel. The display control panel calculates the real-time moisture content of the seeds and displays it on the display screen of the display control panel in real time. The method for calculating seed moisture content is as follows: Seeds were randomly selected from the seed bags and weighed. The seeds were then dried in a 105 ℃ oven for 10 h and weighed again. After weighing, the average seed moisture content in the seed bags was calculated using the formula: Average seed moisture content h1 (%) = (fresh weight - dry weight) / fresh weight × 100%; Seeds are randomly selected from the seed bag and placed into the seed container to obtain the initial mass m1 of the seeds. The real-time mass of the seeds is m2. The seed moisture content h2 after dehydration in the seed container is calculated by the following formula: real-time seed moisture content h2 (%) = (m1*h1-m1+m2) / m2*100%; D) If the real-time moisture content of the seeds is lower than the preset value, the control panel will send a drying end signal through the alarm device.

4. A method for improving the germination rate of *Millettia dielsiana* seeds preserved using the cryopreservation method according to any one of claims 1-3, characterized in that... Includes the following steps: a) Remove the seeds of *Fragranceia zedoaria* preserved by any one of the preservation methods of claims 1-3 from liquid nitrogen, thaw them at room temperature, rinse them with running water, air dry them, and then perform a peeling treatment using a peeling device. b) After the seeds of *Millettia dielsiana* have been ground, place them neatly into a culture dish lined with moist filter paper, and then place it in a constant temperature and light incubator for cultivation until the seeds germinate.

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