Method and device for changing potato shape through intraspecific grafting

Abstract

The invention discloses a method and a device for changing potato shapes through intraspecific grafting. The method comprises the following steps: (1) cultivating potato seedlings; (2) mutual stock-scion grafting; (3) treating grafted plants to obtain grafted seedlings 1; (4) screening germplasm with oblong potatoes: S1, cultivating the grafted seedlings 1 under the conditions that the temperature is 20-24 DEG C, illumination is performed for 14-16 hours, and then darkness is performed for 8-10 hours, retaining the grown potatoes during the period, and harvesting oblong potato blocks at proper time to obtain tubers 1; s2, using the tuber 1 to replace the Guinong potato 1 to obtain a grafted seedling 2 according to the steps (1)-(3), and managing according to the method S1 to obtain a tuber 2; s3, repeating the step S2 on the tubers 2 for 2-4 times, and harvesting oblong tubers; s4, the oblong tubers are cultivated according to the step (1) and then subjected to low-temperature treatment, low-temperature-resistant plants are selected for potting, harvesting is conducted in good time, and the needed new potato germplasm is obtained. According to the method, the oblong and cold-resistant new potato germplasm can be bred, the variety breeding time is shortened, and the cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of seed breeding, and particularly relates to a method and a device for changing the shape of potatoes through intraspecific grafting. Background Art

[0002] The "Guinongshu No. 1" potato was bred by the Guangxi Academy of Agricultural Sciences Institute of Economic Crops through sexual hybridization. It was approved by the Guangxi Crop Variety Approval Committee in 2013 and became the first potato variety independently bred in Guangxi. The "Guinongshu No. 1" potato is oval in shape, with light yellow skin and flesh. It has a potato aroma when cooked, high yield, strong cold resistance and resistance to late blight. It has great development potential in winter potato crop areas where frost damage and late blight frequently occur. However, the oblong potatoes on the market are more acceptable in the market because they are easy to peel, save labor, and have a low potato loss rate. Therefore, it is of great significance to change the shape of the "Guinongshu No. 1" potato to obtain a new potato germplasm with an oblong shape, unchanged cold resistance and yield.

[0003] Grafting is the process of joining the cuts of two plants together to heal them into a new combined plant. Grafting technology in agriculture is mainly used to increase yield and stress resistance. Many studies have shown that there is material exchange in the plant body after grafting. Plant hormones, small molecule metabolites, inorganic salts, sugars, proteins, DNA and RNA can be transferred between the rootstock and the scion. Therefore, grafting can change the gene expression of the plant. "Feureta" potato is a potato variety introduced from the Netherlands. Its tuber is oblong, but it is not cold-resistant or resistant to late blight, so the production efficiency is unstable. Since "Guinong Potato No. 1" and "Feureta" are both varieties with large planting areas in Guangxi, the applicant tried to graft "Guinong Potato No. 1" and "Feureta" to obtain a new potato germplasm with an oblong shape and high cold resistance, stabilize potato production in winter crop areas, and meet market demand.

[0004] On the other hand, the existing potato aeroponic device generally places a 2-3 cm thick foam board on the top of the aeroponic box, and a planting hole is opened in the board to plant the plants. After the potato is grafted, the grafting part is generally fixed by a fixing clamp, and then the fixing clamp is set on the planting hole, so that the grafting part is above the foam board and does not fall into the box body and is contaminated by the nutrient solution and rots. However, in the early stage of grafting, the grafting part has not healed yet and has wounds, which is very easy to be contaminated by the nutrient solution directly sprayed from the bottom of the box through the planting hole and become sick and rotten, reducing the survival rate of the grafted seedlings. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for changing potato shape by intraspecific grafting, so as to solve the problem that there is no technology for changing potato shape by grafting method, shorten breeding time and reduce breeding cost. The specific technical scheme is as follows:

[0006] A method for changing potato shape by intraspecific grafting comprises the following steps:

[0007] (1) Cultivation of potato seedlings:

[0008] The germinated virus-free "Guinongshu No. 1" and "Feureta" seed potatoes were planted in pots covered with seedling substrates, and grown to 4-5 compound leaves under natural light conditions. Then, they were cut from the connection of the seed potatoes, 2-3 compound leaves were retained, and soaked in rooting liquid for 25-35 minutes. They were transplanted into a self-made aeroponic device. Before they took root, only rooting liquid with rooting powder was sprayed. When the roots were 1-2 cm long, nutrient solution was sprayed, and conventional aeroponic management was carried out to cultivate the plants.

[0009] (2) Mutual rootstock-scion grafting: using "Guinongshu No. 1" as the rootstock and "Feiwu Ruita" as the scion, or using "Feiwu Ruita" as the rootstock and "Guinongshu No. 1" as the scion;

[0010] The grafting operation includes: the method is a cleft grafting method, that is, the stock stem is cut at the thick part under shading conditions, and a 1-2 cm opening is split from the middle, then the lower end of the scion with similar thickness is cut off, 1-2 functional leaves are retained, the scion stem segment is cut into a gentle slope, the two sides are kept symmetrical and the length is equal to the stock opening, and then the scion is inserted into the stock so that the stock cut surface is closely fitted with the scion cut surface, and fixed with a grafting clamp;

[0011] (3) Treatment of grafted plants: The grafted "Guinongshu No. 1" / "Feiwu Ruita" (scion / stock) grafted seedlings or "Feiwu Ruita" / "Guinongshu No. 1" grafted seedlings are further cultivated in the aeroponic device, and the ambient temperature of the aeroponic device is controlled at 20-24° C. and the relative humidity is 60-70% to prevent the grafted seedlings from dehydration and death. In the first week, they are covered with a sunshade net with a shading rate of 70-80%, and then exposed to natural light. The seedlings are cultivated for 3-4 weeks, during which all the long runners are cut off to obtain grafted seedlings 1;

[0012] (4) Screening of germplasm with oblong potato shape and cold resistance:

[0013] S1, cultivating the grafted seedling 1 at a temperature of 20-24° C., with a light period of 14-16 hours and a dark period of 8-10 hours, during which the runners and grown tubers are retained, and tubers are harvested in due time, and tubers with an oblong shape are selected to obtain tubers 1;

[0014] S2, using the tuber 1 instead of "Guinongshu No. 1" to cultivate and graft according to the method of steps (1) to (3) above, to obtain grafted seedlings 2, and then managing according to the method of S1, selecting tubers with oblong shapes, to obtain tubers 2;

[0015] S3, repeating step S2 2-4 times with the tuber 2 to harvest oblong tubers, and obtaining new potato germplasm with an oblong tuber shape;

[0016] S4, subjecting the new potato germplasm with an oblong potato shape to low temperature treatment, selecting low temperature resistant plants for potting, and harvesting them in due time to obtain a new potato germplasm with an oblong potato shape and cold resistance.

[0017] Further, in step (1), the aeroponic device comprises: a first aeroponic box, a second aeroponic box, a first spray system, a second spray system, a planting plate and an annular rubber gasket;

[0018] The first aerosol box is arranged above the second aerosol box, and the first aerosol box and the second aerosol box are connected through the planting plate; the top of the first aerosol box is set as an opening; the first spray system is arranged in the first aerosol box, and the second spray system is arranged in the second aerosol box; planting holes are arranged at intervals on the planting plate, and the annular rubber gasket is arranged above the planting plate and corresponds to the position of the planting holes up and down; the annular rubber gasket includes a stacked first gasket and a second gasket, the first gasket is arranged above the second gasket, the inner diameter of the first gasket is smaller than the inner diameter of the second gasket, and the inner circles of the first gasket and the second gasket are provided with easy-tear openings.

[0019] Furthermore, the annular rubber gasket also includes a third gasket, which is stacked between the first gasket and the second gasket. The inner diameter of the third gasket is larger than the inner diameter of the first gasket and smaller than the inner diameter of the second gasket. The inner circle of the third gasket is also provided with an easy-tear notch.

[0020] Furthermore, the nozzle of the second spray system extends 10-20 cm downward from the junction of the bottom of the planting plate and the second mist culture box at an angle of 30-45 degrees for spraying.

[0021] Furthermore, in step (2), the grafting time is selected within one week before or after New Year's Day.

[0022] Furthermore, in S4 of step (4), the low temperature treatment is: cultivating the oblong potato germplasm according to step (1), cultivating the plants under conventional aeroponic management for 3 weeks, cooling the aeroponic device to 16-20°C for 3-5 days, then cooling to 10-15°C for 5-7 days, and finally cooling to 3-6°C for 5-10 days; during the whole process, the air humidity is maintained at 70-80%, the light intensity is 10000-20000Lux, and the light is illuminated for 16 hours and the dark culture is carried out for 8 hours every day.

[0023] Furthermore, in S4 of step (4), the low-temperature-resistant plants are plants whose leaves do not become lighter or yellower, and whose edges and tips do not turn brown.

[0024] Furthermore, the mist cultivation device can be placed in a temperature-controllable air-conditioned room for temperature and humidity control, and / or, a temperature control device, a light control device and a humidity sensor are provided in the first mist cultivation box, the temperature control device includes a temperature probe, a heating tube and a temperature controller, the temperature probe and the heating tube are electrically connected to the temperature controller respectively, and the temperature in the first mist cultivation box is controlled by the temperature controller; the light control device includes an LED lamp and a time controller, the LED lamp is connected to the time controller, and the lighting time in the first mist cultivation box is controlled by the time controller; the humidity sensor is connected to the first spray system to control the air humidity in the first mist cultivation box.

[0025] Compared with the existing technology, the present invention has the following beneficial effects:

[0026] 1. The present invention grafts "Guinongshu No. 1" potato seedlings and "Feureta" potato seedlings that have grown to 4-5 compound leaves, and after grafting, uses a homemade aeroponic device for aeroponic management, and screens cold-resistant germplasms with oblong potatoes, thereby breeding new cold-resistant potato germplasms with oblong potatoes, thereby meeting the production demand for varieties with oblong potatoes and cold resistance.

[0027] 2. The mist cultivation device of the present invention can reduce the contact between the grafting wound and the water vapor coming out of the box body by providing an annular rubber gasket on the planting plate, reduce the phenomenon of disease and rot, and improve the survival rate of the grafted seedlings; the nutrient solution nozzle extends downward about 15 cm from the joint of the bottom of the planting plate and the box body at an angle of 30-45 degrees. On the one hand, it prevents the nozzle from directly spraying into the planting hole on the planting plate from below and causing contamination of the grafting port. On the other hand, it can spray at a close distance and spray more evenly on the roots, so that the roots can absorb nutrients more efficiently, promote faster healing of the grafting port and plant growth.

[0028] 3. When screening a new cold-resistant germplasm with an oblong potato shape, the present invention first performs multiple generations of grafting to screen out a potato germplasm with an oblong potato shape. Due to the grafting transmission effect, the oblong potato germplasm has the cold-resistant gene transmitted by "Guinongshu No. 1", but the expression amount is low. Then, through low-temperature treatment, the cold-resistant gene in the oblong potato germplasm is fully expressed, and then a new potato germplasm with an oblong potato shape and stable traits and cold resistance is bred, which is more conducive to production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0030] Figure 1 It is a schematic diagram of the external structure of the aeroponic device of the present invention.

[0031] Figure 2 Schematic diagram of the internal structure of the aeroponic device of the present invention.

[0032] Figure 3 It is a schematic structural diagram of the annular rubber gasket of the present invention.

[0033] Figure 4 It is a schematic diagram of the disassembled structure of the annular rubber gasket of the present invention.

[0034] Figure 5 The figure is a comparison chart of the cold resistance of the germplasm bred in Example 2 and Comparative Example 1.

[0035] Figure 6 The shape of the tubers of the germplasm bred in Example 2 when harvested after potting is oblong.

[0036] Figure 7 The shape of the tubers produced by the germplasm bred in Example 2 in the aeroponic device is oblong.

[0037] Among them, the main reference numerals are described as follows:

[0038] 1. First mist culture box; 2. Second mist culture box; 3. Planting plate; 31. Planting hole; 4. Annular rubber gasket; 41. First gasket; 42. Second gasket; 43. Third gasket; 44. Tear-off; 5. Temperature control device; 51. Temperature probe; 52. Heating tube; 53. Temperature controller; 6. Light control device; 61. LED lamp; 62. Time controller; 7. First spray system; 8. Second spray system; 81. Nozzle; 9. Shade curtain; 10. Collection door; 11. Humidity sensor. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "top", "bottom", "top surface", "bottom surface", "inside", "outside", "inner side", "outer side" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0041] In the description of the present invention, the meaning of "several" is one or more, the meaning of "more" is more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there are terms "first", "second" and "third" in the description, they are only used for the purpose of description and distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is a description of an embodiment of the present invention based on its overall structure.

[0043] Example 1

[0044] Combination Figure 1-2 , an aeroponic device, comprising: a first aeroponic box, a second aeroponic box, a first spray system, a second spray system, a planting plate, and an annular rubber gasket; the first aeroponic box is arranged above the second aeroponic box, and the first aeroponic box and the second aeroponic box are connected through the planting plate;

[0045] The first aerosol cultivation box is provided with a first spray system, a temperature control device, a light control device and a humidity sensor; the first spray system is used to control the air humidity in the first aerosol cultivation box; the temperature control device is used to control the temperature in the first aerosol cultivation box; the light control device is used to control the light in the first aerosol cultivation box; the humidity sensor is used to sense the humidity in the first aerosol cultivation box; the top of the first aerosol cultivation box is set as an opening, and when it is necessary to spray sodium chloride solution or phytophthora suspension, it can be operated from the opening;

[0046] The second aeroponic box is provided with a second spray system, which is provided at four corners and is used to regularly spray water or nutrient solution to the roots and tubers of the plants in the second aeroponic box; the second aeroponic box is also provided with a shading curtain, a collection door and other structures;

[0047] The planting plate is provided with planting holes at intervals, and the planting plate is used for planting crops. The stems and leaves of the crops grow in a first aeroponic box above the planting plate, and the roots and tubers of the crops grow in a second aeroponic box below the planting plate.

[0048] The annular rubber gasket is arranged above the planting plate and corresponds to the position of the planting hole in the upper and lower parts; the annular rubber gasket is used to block the water vapor from the second aerosol box and fix the crops on the planting plate.

[0049] Specific, combined Figure 3-4 , the annular rubber gasket includes a stacked first gasket, a second gasket and a third gasket, the first gasket is arranged above the second gasket, the inner diameter of the first gasket is smaller than the inner diameter of the second gasket, and the inner circles of the first gasket and the second gasket are provided with an easy-tear notch. The third gasket is stacked between the first gasket and the second gasket, the inner diameter of the third gasket is larger than the inner diameter of the first gasket and smaller than the inner diameter of the second gasket, and the inner circle of the third gasket is also provided with an easy-tear notch. The annular rubber gasket is made of rubber and has a certain elasticity, which can adapt to the growth of crops. The setting of the easy-tear notch allows the gasket to be taken off according to the growth of the crop stems. Preferably, the easy-tear notches of the first gasket, the second gasket and the third gasket are staggered.

[0050] Combination Figure 2 The nozzle of the second spray system extends downward 10-20 cm from the junction of the bottom of the planting board and the second mist culture box at an angle of 30-45 degrees to spray. On the one hand, it prevents the nozzle from spraying directly from below into the planting hole on the planting board and causing contamination of the grafting point. On the other hand, it can spray at a close distance and spray more evenly on the roots, allowing the roots to absorb nutrients more efficiently, promoting faster healing of the grafting point and plant growth.

[0051] Furthermore, the temperature control device includes a temperature probe, a heating tube and a temperature controller. The temperature probe and the heating tube are electrically connected to the temperature controller respectively, and the temperature in the first mist culture box is controlled by the temperature controller.

[0052] Furthermore, the light control device includes an LED lamp and a time controller, which are electrically connected to control the lighting time in the first mist culture box through the time controller. The LED lamps are arranged around the top to make the plants receive more uniform light.

[0053] Furthermore, the humidity sensor is connected to the first spray system to control the air humidity in the first aerosol culture box.

[0054] In addition, in another embodiment, the first mist culture box is also replaced by a support frame. When it is set as a support frame, the temperature, light and humidity of the stems and leaves of the plants are all uniformly controlled by the equipment in the air-conditioned room.

[0055] The mist culture device of the present invention is used to cultivate grafted potato seedlings. By providing an annular rubber gasket on the planting plate, the water vapor from the second mist culture box can be blocked and the grafting wound can be raised, so as to reduce the contact between the grafting wound and the water vapor coming out of the box body, reduce the phenomenon of disease and rot, and improve the survival rate of the grafted seedlings. The nutrient solution nozzle extends downward by about 15 cm from the joint of the bottom of the planting plate and the box body at an angle of 30-45 degrees. On the one hand, it is prevented from spraying directly from below into the planting hole on the planting plate to cause contamination of the grafting port. On the other hand, it can spray at a close distance and spray more evenly on the roots, so that the roots can absorb nutrients more efficiently, promote faster healing of the grafting port and plant growth.

[0056] Example 2

[0057] Material cultivation and grafting were carried out in a potato aeroponic room of the Economic Crops Research Institute of the Guangxi Academy of Agricultural Sciences, with natural light, a temperature of 20°C, and a relative humidity of 60%. The potato aeroponic room was equipped with a plurality of aeroponic devices described in Example 1. Both "Guinongshu No. 1" and "Feureta" potatoes can be purchased from the Guangxi Academy of Agricultural Sciences or general markets.

[0058] A method for changing potato shape by intraspecific grafting comprises the following steps:

[0059] (1) Cultivation of potato seedlings:

[0060] The germinated virus-free "Guinongshu No. 1" and "Feureta" seed potatoes were planted in pots covered with seedling substrates, and grown to 4-5 compound leaves under natural light conditions. Then, they were cut from the connection of the seed potatoes, 2-3 compound leaves were retained, and they were soaked in rooting liquid for 25 minutes. They were transplanted into a homemade aeroponic device. Before they took root, only rooting liquid with rooting powder was sprayed. When the roots were 1-2 cm long, nutrient solution was sprayed, and conventional aeroponic management was carried out to cultivate the plants.

[0061] (2) Mutual rootstock-scion grafting: Use "Guinongshu No. 1" as the rootstock and "Feiureita" as the scion; the grafting time should be within one week before New Year's Day;

[0062] The grafting operation includes: the method is a cleft grafting method, that is, the stock stem is cut at the thick part under shading conditions, and a 1-2 cm opening is split from the middle, then the lower end of the scion with similar thickness is cut off, 1-2 functional leaves are retained, the scion stem segment is cut into a gentle slope, the two sides are kept symmetrical and the length is equal to the stock opening, and then the scion is inserted into the stock so that the stock cut surface is closely fitted with the scion cut surface, and fixed with a grafting clamp;

[0063] (3) Treatment of grafted plants: The grafted "Feureta" / "Guinongshu No. 1" (scion / stock) seedlings were further cultivated in the aeroponic device, and the ambient temperature of the aeroponic device was controlled at 20°C and the relative humidity was 60% to prevent the grafted seedlings from dehydration and death. In the first week, they were covered with a sunshade net with a shading rate of 70%, and then exposed to natural light. The seedlings were cultivated for another 4 weeks, during which all the long runners were cut off to obtain grafted seedling 1;

[0064] (4) Screening of germplasm with oblong potato shape and cold resistance:

[0065] S1, the grafted seedling 1 is further cultivated under the conditions of a temperature of 20° C., a light intensity of 10000 Lux for 14 h, and a dark temperature of 10 h, during which the runners and grown tubers are retained, and tubers are harvested in due time, and tubers with an oblong shape are selected to obtain tubers 1;

[0066] S2, using the tuber 1 instead of "Guinongshu No. 1" to cultivate and graft according to the method of steps (1) to (3) above, to obtain grafted seedlings 2, and then managing according to the method of S1, selecting tubers with oblong shapes, to obtain tubers 2;

[0067] S3, repeating step S2 twice with the tuber 2 to harvest oblong tubers, and obtaining oblong potato germplasm;

[0068] S4, subjecting the potato germplasm with an oblong tuber shape to low temperature treatment, selecting low temperature resistant plants for potting, and harvesting them in time to obtain potato germplasm with an oblong tuber shape and cold resistance; cultivating the low temperature resistant plants in an aeroponic device, and producing oblong tubers, such as Figure 7 As shown;

[0069] The low temperature treatment comprises: cultivating the oblong potato germplasm according to step (1), cultivating the plants under conventional aeroponic management for 3 weeks, cooling the aeroponic device to 16° C. for 3 days, then cooling to 10° C. for 5 days, and finally cooling to 5° C. for 5 days; during the whole process, the air humidity is maintained at 70%, the light intensity is 10000 Lux, and the light is illuminated for 16 hours and the dark is cultivated for 8 hours every day;

[0070] The low temperature resistant plants are plants whose leaves do not become lighter or yellower, and whose edges and tips do not appear brown.

[0071] Example 3

[0072] Material cultivation and grafting were carried out in a potato aeroponic room of the Economic Crops Research Institute of the Guangxi Academy of Agricultural Sciences, with natural light, a temperature of 24°C, and a relative humidity of 70%. The potato aeroponic room was equipped with a plurality of aeroponic devices described in Example 1. Both "Guinongshu No. 1" and "Feureta" potatoes can be purchased from the Guangxi Academy of Agricultural Sciences or general markets.

[0073] A method for changing potato shape by intraspecific grafting comprises the following steps:

[0074] (1) Cultivation of potato seedlings:

[0075] The germinated virus-free "Guinongshu No. 1" and "Feureta" seed potatoes were planted in pots covered with seedling substrates, and grown to 4-5 compound leaves under natural light conditions. Then, they were cut from the connection of the seed potatoes, 2-3 compound leaves were retained, and soaked in rooting liquid for 35 minutes. They were transplanted into a self-made aeroponic device. Before they took root, only rooting liquid with rooting powder was sprayed. When the roots were 1-2 cm long, nutrient solution was sprayed, and conventional aeroponic management was carried out to cultivate the plants.

[0076] (2) Mutual rootstock-scion grafting: use "Feureta" as the rootstock and "Guinongshu No. 1" as the scion; the grafting time should be within one week after New Year's Day;

[0077] The grafting operation includes: the method is a cleft grafting method, that is, the stock stem is cut at the thick part under shading conditions, and a 1-2 cm opening is split from the middle, then the lower end of the scion with similar thickness is cut off, 1-2 functional leaves are retained, the scion stem segment is cut into a gentle slope, the two sides are kept symmetrical and the length is equal to the stock opening, and then the scion is inserted into the stock so that the stock cut surface is closely fitted with the scion cut surface, and fixed with a grafting clamp;

[0078] (3) Treatment of grafted plants: The grafted "Guinongshu No. 1" / "Feiureita" (scion / stock) seedlings were further cultivated in the aeroponic device, and the ambient temperature of the aeroponic device was controlled at 24°C and the relative humidity was 70% to prevent the grafted seedlings from dehydration and death. In the first week, they were covered with a sunshade net with a shading rate of 80%, and then exposed to natural light. The seedlings were cultivated for another 3 weeks, during which all the long runners were cut off to obtain grafted seedling 1;

[0079] (4) Screening of germplasm with oblong potato shape and cold resistance:

[0080] S1, the grafted seedling 1 is further cultivated at a temperature of 24° C., with a light intensity of 10000 Lux for 16 hours and a dark condition for 8 hours, during which the runners and grown tubers are retained, and tubers are harvested in due time, and tubers with an oblong shape are selected to obtain tubers 1;

[0081] S2, using the tuber 1 instead of "Guinongshu No. 1" to cultivate and graft according to the method of steps (1) to (3) above, to obtain grafted seedlings 2, and then managing according to the method of S1, selecting tubers with oblong shapes, to obtain tubers 2;

[0082] S3, repeating step S2 for 4 times with the tuber 2 to harvest oblong tubers, and obtaining oblong potato germplasm;

[0083] S4, subjecting the potato germplasm with an oblong shape to low temperature treatment, selecting low temperature resistant plants for potting, and harvesting them in due time to obtain potato germplasm with an oblong shape and cold resistance;

[0084] The low temperature treatment comprises: cultivating the oblong potato germplasm according to step (1), cultivating the plants under conventional aeroponic management for 3 weeks, cooling the aeroponic device to 20° C. for 5 days, then cooling to 15° C. for 7 days, and finally cooling to 5° C. for 10 days; during the whole process, the air humidity is maintained at 80%, the light intensity is 20,000 Lux, and the light is illuminated for 16 hours and the dark culture is carried out for 8 hours every day;

[0085] The low temperature resistant plants are plants whose leaves do not become lighter or yellower, and whose edges and tips do not appear brown.

[0086] The tubers harvested from the germplasm of this example were long oval in shape. After the seedlings grown from the germplasm were placed in a -2°C environment for 24 hours, the leaves and plants grew normally and had strong cold resistance.

[0087] Comparative Example 1

[0088] The method of comparative example 1 is similar to that of example 2, except that: there is no low temperature treatment step in step (4), that is, there is no S4, and the potatoes of S3 with an oblong shape are used as germplasm.

[0089] After planting the germplasm obtained in Example 2 and Comparative Example 1, the seedlings grown from the germplasm in Example 2 and Comparative Example 1 were placed in a -2°C environment for 24 hours to identify their cold resistance. The results are as follows: Figure 5 As shown, Figure 5 In the figure, the left side is the plant of Example 2, and the right side is the plant of Comparative Example 1. The leaves and plants of Example 2 grow normally, have strong cold resistance, and the potato shape is long oval when harvested (see Figure 6 ); while the seedlings grown from the comparative example 1 germplasm had 2 to 3 leaves that wilted and curled, indicating that the method of the present invention can select cold-resistant potato materials with an oblong shape.

[0090] Comparative Example 2: The method of Comparative Example 2 is similar to that of Example 2, except that a conventional potato aeroponic device is used to manage the grafted seedlings. That is, the potato aeroponic device is not provided with an annular rubber gasket, and the nozzle of the second spray system extends upward from the bottom of the second aeroponic box. As a result, the grafted survival rate is only 68%. The grafted seedlings cultured by the potato aeroponic device of Example 1 have a survival rate of more than 95%.

[0091] In summary, the present invention grafts "Guinongshu No. 1" potato seedlings and "Feureta" potato seedlings that have grown to 4-5 compound leaves, and after grafting, a self-made fog culture device is used for fog culture management, and cold-resistant germplasm with oblong potatoes is screened, so that new cold-resistant potato germplasm with oblong potatoes can be bred, which meets production and market needs. Among them, when the present invention screens cold-resistant germplasm with oblong potatoes, multiple generations of grafting are first performed to screen out potato germplasm with oblong potatoes. Due to the grafting transmission effect, the oblong potato germplasm has the cold-resistant gene transmitted by "Guinongshu No. 1", but the expression amount is low. Then, through low-temperature treatment, the cold-resistant gene in the potato germplasm with oblong potatoes is fully expressed, and then the new potato germplasm with oblong potatoes and stable traits and cold resistance is bred, which is more conducive to production and application. In addition, the mist culture device can reduce the contact between the grafted wound and the water vapor coming out of the box by providing an annular rubber gasket on the planting board, reduce the phenomenon of disease and rot, and improve the survival rate of the grafted seedlings; the nutrient solution nozzle extends about 15 cm from the bottom of the planting board and the junction of the box at an angle of 30-45 degrees. On the one hand, it prevents the nozzle from directly spraying into the planting holes on the planting board and causing contamination of the grafting port. On the other hand, it can spray at a close distance and spray more evenly on the roots, allowing the roots to absorb nutrients more efficiently, promoting faster healing of the grafting port and plant growth.

[0092] The foregoing descriptions of specific exemplary embodiments of the present invention are for the purpose of explanation and illustration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is obvious that many changes and variations can be made based on the above teachings. Although an embodiment of the present invention has been shown and described, this specific embodiment is only an explanation of the present invention and is not a limitation of the invention. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can make modifications, substitutions, variations and various selections and changes to the embodiments without creative contribution as needed without departing from the principles and purpose of the present invention after reading this specification, but they are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for changing potato shape by intraspecific grafting, characterized in that: The steps include: (1) Cultivation of potato seedlings: The germinated virus-free "Guinongshu No. 1" and "Feureta" seed potatoes were planted in pots covered with seedling substrates, and grown to 4-5 compound leaves under natural light conditions. Then, they were cut from the connection of the seed potatoes, 2-3 compound leaves were retained, and soaked in rooting liquid for 25-35 minutes. They were transplanted into a self-made aeroponic device. Before they took root, only rooting liquid with rooting powder was sprayed. When the roots were 1-2 cm long, nutrient solution was sprayed, and conventional aeroponic management was carried out to cultivate the plants. (2) Mutual rootstock-scion grafting: using "Guinongshu No. 1" as the rootstock and "Feiwu Ruita" as the scion, or using "Feiwu Ruita" as the rootstock and "Guinongshu No. 1" as the scion; The grafting operation includes: the method is a cleft grafting method, that is, the stock stem is cut at the thick part under shading conditions, and a 1-2 cm opening is split from the middle, then the lower end of the scion with similar thickness is cut off, 1-2 functional leaves are retained, the scion stem segment is cut into a gentle slope, the two sides are kept symmetrical and the length is equal to the stock opening, and then the scion is inserted into the stock so that the stock cut surface is closely fitted with the scion cut surface, and fixed with a grafting clamp; (3) Treatment of grafted plants: The grafted "Guinongshu No. 1" / "Feiwu Ruita" (scion / stock) grafted seedlings or "Feiwu Ruita" / "Guinongshu No. 1" grafted seedlings are further cultivated in the aeroponic device, and the ambient temperature of the aeroponic device is controlled at 20-24°C and the relative humidity is 60-70% to prevent the grafted seedlings from dehydration and death. In the first week, they are covered with a sunshade net with a shading rate of 70-80%, and then exposed to natural light. The seedlings are cultivated for 3-4 weeks, during which all the long runners are cut off to obtain grafted seedlings 1; (4) Screening of germplasm with oblong potato shape and cold resistance: S1, cultivating the grafted seedling 1 at a temperature of 20-24° C., with a light period of 14-16 hours and a dark period of 8-10 hours, during which the runners and grown tubers are retained, and tubers are harvested in due time, and tubers with an oblong shape are selected to obtain tubers 1; S2, using the tuber 1 to replace "Guinongshu No. 1" and cultivating and grafting according to the method of steps (1) to (3) above to obtain grafted seedlings 2, and then managing according to the method of S1, selecting tubers with oblong shapes to obtain tubers 2; S3, repeating step S2 2-4 times with the tuber 2 to harvest oblong tubers, and obtaining new potato germplasm with an oblong tuber shape; S4, subjecting the new potato germplasm with an oblong potato shape to low temperature treatment, selecting low temperature resistant plants for potting, and harvesting them in due time to obtain a new potato germplasm with an oblong potato shape and cold resistance.

2. The method for changing potato shape by intraspecific grafting according to claim 1, characterized in that: In step (1), the aeroponic device comprises: a first aeroponic box, a second aeroponic box, a first spray system, a second spray system, a planting plate and an annular rubber gasket; The first aerosol box is arranged above the second aerosol box, and the first aerosol box and the second aerosol box are connected through the planting plate; the top of the first aerosol box is set as an opening; the first spray system is arranged in the first aerosol box, and the second spray system is arranged in the second aerosol box; planting holes are arranged at intervals on the planting plate, and the annular rubber gasket is arranged above the planting plate and corresponds to the position of the planting holes up and down; the annular rubber gasket includes a stacked first gasket and a second gasket, the first gasket is arranged above the second gasket, the inner diameter of the first gasket is smaller than the inner diameter of the second gasket, and the inner circles of the first gasket and the second gasket are provided with easy-tear openings.

3. The method for changing potato shape by intraspecific grafting according to claim 2, characterized in that: The annular rubber gasket also includes a third gasket, which is stacked between the first gasket and the second gasket. The inner diameter of the third gasket is larger than the inner diameter of the first gasket and smaller than the inner diameter of the second gasket. The inner circle of the third gasket is also provided with an easy-tear notch.

4. The method for changing potato shape by intraspecific grafting according to claim 2, characterized in that: The nozzle of the second spray system extends downward by 10-20 cm from the junction of the bottom of the planting plate and the second aerosol culture box at an angle of 30-45 degrees for spraying.

5. The method for changing potato shape by intraspecific grafting according to claim 1, characterized in that: In step (2), the grafting time is selected within one week before or after New Year's Day.

6. The method for changing potato shape by intraspecific grafting according to claim 1, characterized in that: In S4 of step (4), the low temperature treatment is as follows: the oblong potato germplasm is cultivated according to step (1), and after the plants are cultivated under conventional aeroponic management for 3 weeks, the aeroponic device is cooled to 16-20°C for 3-5 days, then cooled to 10-15°C for 5-7 days, and finally cooled to 3-6°C for 5-10 days; the air humidity is maintained at 70-80%, the light intensity is 10000-20000Lux, and the light is illuminated for 16 hours and the dark culture is carried out for 8 hours every day.

7. The method for changing potato shape by intraspecific grafting according to claim 1, characterized in that: In S4 of step (4), the low temperature resistant plants are plants whose leaves do not become lighter or yellower, and whose edges and tips do not turn brown.

8. The method for changing potato shape by intraspecific grafting according to claim 1, characterized in that: The mist cultivation device is placed in a temperature-controllable air-conditioned room for temperature and humidity control, and / or a temperature control device, a light control device and a humidity sensor are provided in the first mist cultivation box, the temperature control device comprises a temperature probe, a heating tube and a temperature controller, the temperature probe and the heating tube are electrically connected to the temperature controller respectively, and the temperature in the first mist cultivation box is controlled by the temperature controller; the light control device comprises an LED lamp and a time controller, the LED lamp and the time controller are connected, and the illumination time in the first mist cultivation box is controlled by the time controller; the humidity sensor is connected to the first spray system to control the air humidity in the first mist cultivation box.

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