Muskmelon stock grafting method

Abstract

The invention provides a muskmelon stock grafting method, which comprises the steps of stock selection, stock treatment, scion selection, grafting and management, and the stock treatment is as follows: at least one of biocontrol bacteria NBmelon-1 or Bc1-20 is adopted for shake cultivation to form a bacterial solution, and then root irrigation is performed on muskmelon stock seedlings. According to the method, the characteristics of the biocontrol bacterium NBmellon-1 and the biocontrol bacterium Bc1-20 are applied to grafting for the first time, the technical blank is filled, the new application of the biocontrol bacterium NBmellon-1 and the biocontrol bacterium Bc1-20 is developed, the stem diameter, the root length and the root number of the muskmelon stock are increased, and the problem that the grafted root system of the muskmelon stock is weak is solved.

Description

Technical Field

[0001] The invention relates to the field of agriculture, and in particular to a melon rootstock grafting method. Background Art

[0002] melon( Cucumis melo L.) is an annual vine herbaceous plant of the Cucurbitaceae family, with extremely high nutritional and edible value, and is deeply loved by consumers. However, the melon industry is currently deeply affected by the problems of continuous cropping and continuous cropping, resulting in an increasing trend of soil-borne diseases. Common chemical pesticides have high control costs, high control pressure, and are prone to drug resistance.

[0003] At present, grafting is one of the effective solutions to prevent and control soil-borne diseases. In production, melons are often grafted onto rootstocks such as gourd, pumpkin, wax gourd or gourd, but these rootstocks will have a negative impact on the taste and shape of the scion fruit to a certain extent. Choosing melon as the rootstock for melon grafting can avoid such problems. The melon rootstock has good affinity with melon grafting and has little effect on the quality of the scion fruit. However, if untreated melon is directly selected as the rootstock, its resistance is lower than that of the pumpkin rootstock, and the grafted root system is also weaker.

[0004] Biocontrol bacteria are a type of microorganism that has an antagonistic effect on pathogens and a growth-promoting effect on plants, such as Bacillus ( Bacillus spp.), Pseudomonas spp. Pseudomonas spp.) etc. The biocontrol bacterium NBmelon-1 is a polymyxa-bacillus, an important type of biocontrol bacterium. It mainly promotes plant growth by fixing nitrogen and dissolving phosphorus, producing IAA, etc. It can also inhibit pathogens by site competition, inducing plant systemic resistance and secreting antibacterial substances. The biocontrol bacterium Bc1-20 is Pseudomonas aeruginosa, a common Gram-negative bacterium with strong reproductive capacity. It can use nutrients in the soil to gain competitive advantages and inhibit a variety of pathogens. Biocontrol bacteria are usually used for disease control and plant growth promotion, and their application in grafting has not been reported.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a melon rootstock grafting method, which applies the characteristics of biocontrol bacteria NBmelon-1 and biocontrol bacteria Bc1-20 to grafting, so that the melon rootstock has significant improvements in stem thickness, root length and root number, improves the problem of weak root system of melon rootstock grafting, and enhances the resistance of the rootstock.

[0007] The technical solution of the present invention adopts the following concept: A melon rootstock grafting method includes rootstock selection, rootstock treatment, scion selection, grafting and management, and is characterized in that the rootstock treatment comprises: using at least one of the biocontrol bacteria NBmelon-1 or Bc1-20 to shake-cultivate a bacterial solution and then irrigating the roots of the melon rootstock seedlings.

[0008] As a method, on the 1st, 3rd, 5th, 7th, and 9th day after sowing the rootstock seeds, use 10 8 cfu / mL of the biocontrol bacteria NBmelon-1 or Bc1-20 solution were irrigated into the roots of melon seedlings, with 2 mL of the solution per seedling.

[0009] As a method, the preparation method of the bacterial solution of biocontrol bacteria NBmelon-1 or Bc1-20 is as follows: after the biocontrol bacteria NBmelon-1 or Bc1-20 is activated, it is inoculated into a 250 mL Erlenmeyer flask containing 100 mL NB culture medium, and placed at 28 °C and 180 r·min -1 After shaking culture for 24 h, the seed solution was obtained; The seed solution was inoculated into a flask containing 300 mL of NB medium at a volume fraction of 2% and incubated at 28°C and 180 r·min -1 After shaking culture for 24 h, the bacterial solution was obtained.

[0010] As a method, 'Zhentian No. 1' was selected as the rootstock; 'Bai Mei No. 1' was selected as the scion.

[0011] As a method, grafting is performed when the rootstock has been treated until the first true leaf is flattened to the second true leaf is half-expanded.

[0012] As a method, when grafting, remove the growth point of the rootstock, use a bamboo stick with a tapering end and the thickness of the scion hypocotyl to insert it from the rootstock where the growth point is removed, close to the base of the cotyledon on one side and 30-45 degrees to the other side to a 1 cm hole; When grafting scion seedlings, use a blade to cut downward at a distance of 0.5-1 cm from the growth point, cutting into a wedge shape with a length of 1±0.1 cm and a cut surface of 30-45 degrees; Finally, pull out the bamboo stick and insert the sharpened scion into the hole of the rootstock so that the rootstock and scion fit tightly together. At the same time, the cotyledons of the rootstock and the cotyledons of the scion are in the shape of a "cross". After grafting, fix them with a grafting clamp to complete the grafting.

[0013] As a method, rootstock selection and scion selection include the process of seed soaking and germination; the seed soaking steps are: soak the melon seeds in 40±2℃ water for 2-3 hours; The steps of germination are as follows: after taking out the soaked melon seeds, put them into a constant temperature box for germination; the germination temperature is 28~30℃, and after 24 hours, when the radicle of the seeds turns white or slightly elongates, the germination is completed.

[0014] As a method, the biocontrol bacteria NBmelon-1 or Bc1-20 are activated by streaking the biocontrol bacteria NBmelon-1 and Bc1-20 on NA plates, respectively, at 28°C for 24 h.

[0015] The present invention has the following advantages: 1. The method of the present invention applies the characteristics of the biocontrol bacteria NBmelon-1 and the biocontrol bacteria Bc1-20 to grafting for the first time, filling the technical gap and opening up new uses of the biocontrol bacteria NBmelon-1 and the biocontrol bacteria Bc1-20.

[0016] 2. The method of the present invention significantly improves the stem diameter, root length and root number of the melon stock by respectively irrigating the roots with the biocontrol bacteria NBmelon-1 and Bc1-20, improves the problem of weak root system of the melon stock grafted, enhances its resistance, and thus improves the survival rate and disease resistance of the grafted seedlings.

[0017] 3. The method of the present invention also promotes the growth rate of the scion, increases the single fruit weight of the scion fruit, and improves the quality of the fruit such as sugar content and vitamin C content. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0019] Figure 1 This is a real-life rendering of a melon rootstock treated with the biocontrol bacteria solution of the present invention.

[0020] Figure 2 These are the evaluation results of the morphological indicators of the melon rootstock tested in Experimental Example 1.

[0021] Figure 3 The following are the actual renderings of the grafted seedlings of Examples 1-2 and Comparative Example 1.

[0022] Figure 4 These are the morphological index evaluation results (AD) and survival rate (E) test results of the grafted seedlings on the 15th day in Experimental Example 1.

[0023] Figure 5 The following are actual pictures of the scion fruits of the grafted seedlings in Examples 1-2 and Comparative Example 1.

[0024] Figure 6The following are the test results of the incidence of grafted seedlings in Examples 1-2 and Comparative Example 1.

[0025] Figure 7 These are the test results of fruit unit weight (A), fruit thickness (B), fruit shape index (C), soluble solids (D), vitamin C content (E) and soluble sugar content (F) obtained from the grafted seedlings in Experimental Example 2. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment 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.

[0027] The biocontrol bacteria NBmelon-1 and Bc1-20 used in the present invention are isolated and preserved by the Vegetable Research Institute of Ningbo Academy of Agricultural Sciences. Hao Fangmin, Zang Quanyu, Ma Erlei, et al. Identification of antagonistic bacteria NBmelon-1 against multiple fungal diseases of melon and its growth-promoting and biocontrol effects[J]. Chinese Journal of Melon and Vegetables, 2021, 34(07): 14-19. Hao Fangmin, Dong Wenjie, Zang Quanyu, et al. Screening, identification and biocontrol effect of an antagonistic bacterium against melon wilt[J]. Chinese Vegetables, 2023, 36(12): 26-32. Example 1 A melon rootstock grafting method comprises the following steps: (1) Rootstock selection Select the rootstock 'Zhitian No. 1' with full grains; Pretreatment of rootstock seeds: Soaking seeds for germination. Place the seeds of 'Zhentian No. 1' in 55 ℃ water, stirring while soaking. When the water temperature drops to 40±2 ℃, stop stirring and soak for 2~3 hours. Then place the seeds in 28~30℃ environment for germination. After 24 hours, when the radicle of the seeds turns white or grows slightly, use a 50-hole plug tray to sow the seeds. Place the seeds flat with the radicle facing down, one seed per hole, and cover with a 1.5 cm thick substrate.

[0028] (2) Rootstock treatment On the 1st, 3rd, 5th, 7th and 9th day after rootstock sowing, use 10 8The rootstock seedlings were irrigated with 2 mL of the biocontrol fungus NBmelon-1 solution at a concentration of 100 cfu / mL, and each seedling was treated with 2 mL of the solution. Grafting can be performed when the first true leaf of the rootstock is flat and the second true leaf is half-expanded.

[0029] The preparation process of the NBmelon-1 bacterial solution was as follows: the NBmelon-1 was activated and inoculated into a 250 mL Erlenmeyer flask containing 100 mL NB culture medium, and then placed at 28 °C and 180 r·min -1 The seed solution was obtained by shaking the culture for 24 h. The seed solution was inoculated into a 300 mL NB medium flask at a volume fraction of 2%, and the culture was shaken at 28 °C and 180 r·min-1 for 24 h to obtain the bacterial solution.

[0030] (3) Scion selection Select the melon scion 'Bai Mei No. 1' with full grains. Place the scion seeds in 55 ℃ water, stir while soaking, and stop stirring when the water temperature drops to 40±2 ℃. Keep warm and soak for 2~3 hours. Then place the seeds in a 28~30 ℃ environment for germination. After 24 hours, when the radicle of the seeds turns white or grows slightly, use a 50-hole plug tray for sowing; (4) Grafting and management First, remove the growth point of the melon seedling rootstock, and use a bamboo stick with a tapering end and a thickness similar to the hypocotyl of the scion to remove the growth point of the rootstock, close to the base of the cotyledon on one side and 30 to 45 degrees from the other side. o The depth of the hole is about 1 cm. The depth should not break the hypocotyl epidermis, and the bamboo stick is faintly visible. For the scion seedling, use a blade to cut downward at a distance of 0.5~1 cm from the growth point to make a length of 1±0.1cm and a cut surface of 30~45 o Finally, pull out the bamboo stick, and then insert the sharpened scion into the hole of the rootstock, so that the cotyledons of the rootstock and the scion fit tightly together, and at the same time, the cotyledons of the rootstock and the scion form a "cross" shape. After the grafting is completed, fix it with a grafting clamp to complete the grafting; Grafting management: Grafting management is carried out after the grafting is completed.

[0031] Example 2 The only difference from Example 1 is that the root irrigation treatment with the bacterial solution of the biocontrol bacterium NBmelon-1 is replaced by the bacterial solution of the biocontrol bacterium Bc1-20. The preparation method of the bacterial solution of the biocontrol bacterium Bc1-20 is the same as the preparation method of the bacterial solution of the biocontrol bacterium NBmelon-1.

[0032] Comparative Example 1 The only difference from Example 1 is that the root irrigation treatment with the biocontrol bacteria NBmelon-1 solution in Example 1 was replaced with the root irrigation treatment with clean water. This is denoted as the CK group.

[0033] Test Example 1 Measurement of morphological indexes of melon rootstock Ten rootstocks of Examples 1-2 and Comparative Example 1 were randomly selected and evaluated for morphological indices such as rootstock stem thickness, true leaf size, and cotyledon size.

[0034] Rootstock stem diameter: measured using a vernier caliper.

[0035] Rootstock true leaf size: Use a steel ruler to measure the length and width of the largest true leaf.

[0036] Rootstock cotyledon size: Measure the length and width of the cotyledon using a steel ruler.

[0037] The test results are as follows Figure 2 shown.

[0038] according to Figure 2 It can be seen from the data that the stock treated with the biocontrol bacteria solution in Examples 1-2 of the present invention is significantly higher in stem thickness, length and width of cotyledons, and length and width of the largest true leaf than the stock treated with clean water in Comparative Example 1 (CK). It can be seen that the method of the present invention promotes the growth of the melon stock, improves the problem of weak root system, and is beneficial to the subsequent grafting operation.

[0039] Test Example 2 Measurement of morphological indexes of grafted seedlings Ten grafted seedlings of Examples 1-2 and Comparative Example 1 were randomly selected on the 15th day after grafting, and morphological indexes were evaluated and the survival rates were calculated.

[0040] Morphological indicators and their testing methods: Scion true leaf size: Use a steel ruler to measure the length and width of the largest true leaf.

[0041] Scion cotyledon size: Use a steel ruler to measure the length and width of the cotyledon.

[0042] Scion stem diameter: Measure using a vernier caliper.

[0043] Number and length of rootstock roots: measured using a vernier caliper.

[0044] The results are as follows Figure 4 shown.

[0045] according to Figure 4 It can be seen from the AD data that the rootstocks treated with biocontrol bacteria solution in Examples 1-2 of the present invention are significantly higher in scion stem thickness, cotyledon length and width, length and width of the largest true leaf, and number and length of rootstock than those in Comparative Example 1 (CK) in comparison with the rootstocks treated with clean water in Comparative Example 1.

[0046] according to Figure 4From the data in E, it can be seen that the survival rates of the grafted seedlings obtained from the rootstocks treated with biocontrol bacteria in Examples 1-2 of the present invention are 98.5% and 97.5%, respectively. Compared with the survival rate of 82.5% in Comparative Example 1 (CK), the survival rate of the grafted seedlings of the present invention is significantly increased.

[0047] It can be seen that the method of the present invention promotes the growth rate of melon scion, increases the number and length of roots of the rootstock, improves the problem of weak root system of melon grafting, and further improves the grafting survival rate.

[0048] Test Example 3 Grafted Plant Morbidity and Scion Fruit Data statistics were performed on the incidence of grafted plants and scion fruits of Examples 1-2 and Comparative Example 1.

[0049] The specific statistical data are: Incidence rate: Count the number of diseased plants in all grafted plants and calculate the incidence rate.

[0050] Single fruit weight: 10 fruits were randomly selected, weighed and the average value was calculated.

[0051] Fruit shape index: Randomly select 10 fruits and measure the longitudinal stem and transverse stem of the fruit with a vernier caliper. Fruit shape index = longitudinal stem / transverse stem.

[0052] Flesh thickness: randomly select 10 fruits, cut them longitudinally evenly, take one of them, measure it with a ruler at the top, middle and bottom, and take the average value as the flesh thickness.

[0053] Soluble solids: 10 fruits were randomly selected and measured using a handheld sugar meter to obtain the average value.

[0054] Soluble sugar: Five fruits were randomly selected and the soluble sugar content was measured using a soluble sugar content kit. Each treatment was repeated 3 times and the average value was taken.

[0055] Vitamin C: Five fruits were randomly selected and the vitamin C content was measured using a reduced ascorbic acid kit. Each treatment was repeated 3 times and the average value was taken.

[0056] The results are as follows Figure 6-7 shown.

[0057] according to Figure 6 From the data in, it can be seen that the incidence of the grafted seedlings in comparative example 1 (CK) is 16%, and the incidence of the grafted seedlings in embodiments 1-2 of the present invention are 6% and 8%, respectively. The incidence of the grafted seedlings in embodiments 1-2 of the present invention is significantly reduced.

[0058] according to Figure 7It can be seen from the data that the scion fruits of Examples 1-2 of the present invention are significantly higher than those of Comparative Example 1 (CK) in terms of unit weight, fruit thickness, soluble solid content, vitamin C content, and soluble sugar content. In terms of fruit shape index, there is no obvious difference compared with Comparative Example 1 (CK).

[0059] It can be seen that the grafting method of the present invention can significantly reduce the incidence of melon rootstock grafted seedlings, and at the same time significantly increase the weight of single scion melon, the thickness of the flesh and the sugar content, and the vitamin C content.

[0060] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for melon rootstock grafting, comprising rootstock selection, rootstock treatment, scion selection, grafting and management, characterized in that: The stock treatment comprises: using at least one of the biocontrol bacteria NBmelon-1 or Bc1-20 to shake and cultivate a bacterial solution, and then irrigating the roots of the melon stock seedlings.

2. The melon rootstock grafting method according to claim 1, characterized in that: On the 1st, 3rd, 5th, 7th and 9th day after sowing the rootstock seeds, use 10 8 cfu / mL of the biocontrol bacteria NBmelon-1 or Bc1-20 solution were irrigated into the roots of melon seedlings, with 2 mL of the solution per seedling.

3. The melon rootstock grafting method according to claim 1 or 2, characterized in that: The preparation method of the biocontrol bacteria NBmelon-1 or Bc1-20 solution is as follows: after the biocontrol bacteria NBmelon-1 or Bc1-20 is activated, it is inoculated into a 250 mL Erlenmeyer flask containing 100 mL NB culture medium, and placed at 28 °C and 180 r·min -1 After shaking culture for 24 h, the seed solution was obtained; The seed solution was inoculated into a flask containing 300 mL of NB medium at a volume fraction of 2% and the culture medium was incubated at 28 °C and 180 r·min -1 After shaking culture for 24 h, the bacterial solution was obtained.

4. The melon rootstock grafting method according to claim 1, characterized in that: Select 'Zhentian No. 1' as the rootstock; select 'Baimei No. 1' as the scion.

5. The melon rootstock grafting method according to claim 1, characterized in that: When the rootstock has been treated to the point where the first true leaf is flat and the second true leaf is half-expanded, grafting can be carried out.

6. The melon rootstock grafting method according to claim 1, characterized in that: When grafting, remove the growth point of the rootstock, and use a bamboo stick with a gradually pointed end and the thickness of the scion hypocotyl to insert it from the rootstock where the growth point is removed, close to the base of the cotyledon on one side and 30-45 degrees to the other side to a 1 cm hole; When grafting scion seedlings, use a blade to cut downward at a distance of 0.5-1 cm from the growth point, cutting into a wedge shape with a length of 1±0.1 cm and a cut surface of 30-45 degrees; Finally, pull out the bamboo stick and insert the sharpened scion into the hole of the rootstock so that the rootstock and scion fit tightly together, and at the same time, the cotyledons of the rootstock and the cotyledons of the scion are in a "cross" shape. After grafting, fix it with a grafting clamp to complete the grafting.

7. The melon rootstock grafting method according to claim 1, characterized in that: The rootstock selection and scion selection include the process of seed soaking and germination; the seed soaking steps are: soak the melon seeds in water at 40±2℃ for 2-3 hours; The steps of germination are as follows: after taking out the soaked melon seeds, put them into a constant temperature box for germination; the germination temperature is 28 ~ 30℃, and after 24 hours, when the radicle of the seeds turns white or slightly elongates, the germination is completed.

8. The melon rootstock grafting method according to claim 1, characterized in that: The activation method of the biocontrol bacteria NBmelon-1 or Bc1-20 is as follows: streak the biocontrol bacteria NBmelon-1 and Bc1-20 on NA plates respectively, and the culture conditions are 28° C. and 24 h.

Images