Nutrient solution and hydroponic rejuvenation method for sweet potato germplasm resource endangered variety

Abstract

The invention relates to the technical field of plant germplasm resource rejuvenation, in particular to a nutrient solution for sweet potato germplasm resource endangered varieties and a water culture rejuvenation method. The nutrient solution comprises potassium nitrate, boric acid and other components, and stems of the sweet potato germplasm resource endangered variety are subjected to water culture in the nutrient solution. The weak seedlings are good in rooting property after being subjected to water culture, 71.1% of varieties have 2-9 roots per plant, and 92.6% of varieties have the average root length ranging from 0.4 cm to 3.1 cm; 20 days after transplanting, the survival rate of 135 varieties reaches 82.2%. After the sweet potato seedlings are transplanted for 5 months, the survival varieties with the average vine length larger than 30 cm account for 96%, the varieties with more branches and the average stem diameter larger than 3.0 mm account for 91%, the requirement for weak seedling rejuvenation is met, and a feasible method is provided for preservation of the sweet potato resource dangerous weak seedlings.

Description

Technical Field

[0001] The invention relates to the technical field of plant germplasm resource rejuvenation, in particular to a nutrient solution and a hydroponic rejuvenation method for endangered varieties of sweet potato germplasm resources. Background Art

[0002] Sweet potato is an important crop for food, feed, energy and industrial raw materials in the world. China is the world's largest producer and consumer of sweet potato. Sweet potato is the second largest food crop in Guangdong Province. In recent years, the benefits of sweet potato planting have been continuously improved. The sweet potato industry has been rejuvenated and has gradually become an economic crop with profit-oriented advantages. Guangdong Province is one of the earliest birthplaces of sweet potato introduced from abroad, cultivated and improved in China. Guangdong has now become the largest fresh-eating sweet potato planting area and distribution center in the country. Due to the climatic characteristics, most sweet potato varieties can bloom and bear fruit naturally in Guangdong, with a lot of natural variation, resulting in a group of local resources with very rich ecological types. Guangdong's local sweet potato varieties account for more than 80% of the country. In 1990, the state established the "National Germplasm Guangzhou Sweet Potato Nursery" in Guangdong Province, where sweet potato germplasm resources are concentrated.

[0003] The preservation time span of sweet potato resources is relatively long, and some resources were collected and preserved decades ago. Existing preservation technologies include greenhouse potted preservation, field cultivation and seed potato preservation, and in vitro test tube seedling preservation. Among them, greenhouse potted preservation, field cultivation and seed potato preservation are conventional preservation methods. After long-term preservation, there are situations such as variety degeneration, infection with pests and diseases, and uneven growth. For vulnerable varieties of plants, in vitro test tube seedlings can be preserved. The in vitro test tube seedling preservation adopts the technology of virus-free tissue culture, but the cycle of virus-free tissue culture method is relatively long, and the worse the quality of the seedlings, the lower the success rate of tissue culture. Therefore, it is particularly important to rejuvenate vulnerable plants before tissue culture. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a nutrient solution and a hydroponic rejuvenation method for endangered varieties of sweet potato germplasm resources. The nutrient solution provided by the present invention can enable weak seedlings to take root quickly in a hydroponic manner, thereby ensuring the survival of endangered germplasm resources as much as possible. At the same time, through hydroponic transplanting and rejuvenation, the success rate of virus-free tissue culture is increased.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The invention provides a nutrient solution for an endangered variety of sweet potato germplasm resources. The nutrient solution takes water as a solvent and comprises the following components: 506 mg / L of KNO3, 6.2 mg / L of H3BO3, 80 mg / L of NH4NO3, 16.9 mg / L of MnSO4·H2O, 136 mg / L of KH2PO4, 8.6 mg / L of ZnSO4·7H2O, 241 mg / L of MgSO4, 0.25 mg / L of Na2MoO4·2H2O, 36.7 mg / L of FeNaEDTA, 0.025 mg / L of CuSO4·5H2O, 0.83 mg / L of KI, 0.025 mg / L of CoCl2·6H2O and 945 mg / L of Ca(NO3)2·4H2O, and the pH value is 5.8±0.1.

[0007] The invention provides a hydroponic rejuvenation method for endangered varieties of sweet potato germplasm resources, comprising the following steps: hydroponically cultivating stem segments of the endangered varieties of sweet potato germplasm resources in the nutrient solution described in the technical solution.

[0008] Preferably, the length of the stem segment is 10 to 15 cm.

[0009] Preferably, the hydroponic conditions include: light intensity of 2480 Lux, temperature of 25° C., and lighting time of 6:00-18:00 every day.

[0010] Preferably, the hydroponic culture time is 5 to 21 days.

[0011] Preferably, the hydroponic culture time is 8 to 11 days.

[0012] Preferably, the screening criteria for endangered varieties of sweet potato germplasm resources include:

[0013] Grade Ⅰ: slightly curled or wrinkled leaves;

[0014] Level II: curled or wrinkled leaves, few branches, and short plants;

[0015] Level III: The leaves are wrinkled, the branches are very few, and the plants are extremely short.

[0016] Preferably, the stem segments are hydroponically grown in an artificial climate chamber MGC-300H.

[0017] Preferably, the nutrient solution is replaced every 7 days.

[0018] Beneficial effects of the present invention:

[0019] The weak seedlings had good rooting ability after hydroponics, with 71.1% of the varieties having 2 to 9 roots per plant, and 92.6% of the varieties having an average root length of 0.4 to 3.1 cm; 20 days after transplanting, the survival rate of 135 varieties reached 82.2%. Five months after transplanting, 96% of the surviving varieties had an average vine length of more than 30 cm, and 91% of the varieties had more branches and an average stem diameter of more than 3.0 mm, meeting the requirements for weak seedling rejuvenation, and providing a feasible method for the preservation of weak seedlings of sweet potato resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0021] Figure 1 This is a schematic diagram of hydroponic treatment;

[0022] Figure 2 This is a schematic diagram of potted cultivation;

[0023] Figure 3 This is the number of roots grown on the 5th day of hydroponics;

[0024] Figure 4 This is the number of roots on the 8th day of hydroponics;

[0025] Figure 5 The number of roots for the 11th day of hydroponics;

[0026] Figure 6 The number of roots grown in hydroponics on the 21st day;

[0027] Figure 7 The average root length on the 5th day of hydroponics;

[0028] Figure 8 The average root length on the 8th day of hydroponics;

[0029] Fig. 9 The average root length on the 11th day of hydroponics;

[0030] Fig.10 The average root length on the 21st day of hydroponics;

[0031] Fig.11 is the survival rate 20 days after transplanting;

[0032] Fig.12 is the percentage of the longest vine length to the total number of varieties;

[0033] Fig.13 is the number of branches and the percentage of the total number of varieties;

[0034] Fig.14 It is the percentage of stem diameter to the total number of varieties. DETAILED DESCRIPTION

[0035] The invention provides a nutrient solution for endangered varieties of sweet potato germplasm resources, which uses water as a solvent and comprises the following components: 506 mg / L KNO3, 6.2 mg / L H3BO3, 80 mg / L NH4NO3, 16.9 mg / L MnSO4·H2O, 136 mg / L KH2PO4, 8.6 mg / L ZnSO4·7H2O, 241 mg / L MgSO4, 0.25 mg / L Na2MoO4·2H2O, 36.7 mg / L FeNaEDTA, 0.025 mg / L CuSO4·5H2O, 0.83 mg / L KI, 0.025 mg / L CoCl2·6H2O and 945 mg / L Ca(NO3)2·4H2O. The components of the nutrient solution are configured according to the nutrient component ratio required for the growth of the sweet potato, can provide the necessary nutrients for the plant, and greatly improve the rooting condition. In Comparative Example 1 where no nutrients were added, the plants had poor rooting due to lack of nutrients (Table 4).

[0036] The present invention also provides a hydroponic rejuvenation method for endangered varieties of sweet potato germplasm resources, comprising the following steps: hydroponically cultivating stem segments of the endangered varieties of sweet potato germplasm resources in the nutrient solution described in the above technical solution.

[0037] In the present invention, the length of the stem segment is preferably 10 to 15 cm. In the present invention, the conditions for hydroponic culture preferably include: light intensity of 2480 Lux, temperature of 25° C., and lighting time of 6:00-18:00 every day. In the present invention, the culture time of hydroponic culture is preferably 5 to 21 days. Comparative Example 2, which was not cultured in an incubator, was affected by culture conditions such as cold waves, high temperatures or insufficient light, resulting in weak seedlings or dead seedlings (Table 5). In the present invention, the culture time of hydroponic culture is preferably 8 to 11 days.

[0038] In the present invention, the screening criteria for the endangered varieties of sweet potato germplasm resources preferably include:

[0039] Grade I is slightly curled or shrunken leaves; Grade II is curled or shrunken leaves, few branches, and short plants; Grade III is shrunken leaves, very few branches, and very short plants. In the present invention, the nutrient solution is preferably replaced every 7 days.

[0040] In the present invention, the stem segments are preferably hydroponically cultivated in an artificial climate chamber MGC-300H.

[0041] In the present invention, the sweet potato germplasm resources are transplanted into a greenhouse potted culture after 21 days of hydroponics. In the present invention, the potting medium formula is: 50% loam + 20% sand + 30% peat soil.

[0042] In the present invention, the potted cultivation method is: the rooted plants are planted into a substrate, watered by sprinkling irrigation, and immediately after transplanting, the substrate is evenly moistened by sprinkling irrigation, and then the sprinkling irrigation is set once every 2 days, each time for 15-20 minutes until the substrate is evenly moistened. In the present invention, the sprinkling irrigation time is preferably 15:00 in the afternoon.

[0043] In order to further illustrate the present invention, the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0044] Example 1

[0045] (1) Screening criteria for endangered sweet potato germplasm resources:

[0046] The experimental materials come from the National Sweet Potato Germplasm Resource Nursery (Guangzhou). The screening criteria for vulnerable plants of endangered varieties are divided into three levels according to symptoms.

[0047] Screening criteria for endangered sweet potato germplasm resources:

[0048] Grade Ⅰ: slightly curled or wrinkled leaves;

[0049] Level II: curled or wrinkled leaves, few branches, and short plants;

[0050] Level III: The leaves are wrinkled, the branches are very few, and the plants are extremely short.

[0051] (2) Hydroponic treatment of nutrient solution for endangered species:

[0052] (2.1) Hydroponic treatment method

[0053] Take 10-15 cm stem segments of weak plants of endangered species, select 3 plants of each species, and transfer them into glass culture bottles filled with nutrient solution.

[0054] (2.2) Culture conditions:

[0055] Artificial climate chamber MGC-300H, light intensity is 2480Lux, 25℃, lighting time: 6:00-18:00.

[0056] (3) Nutrient solution:

[0057] (3.1) Nutrient solution formula

[0058] Table 1 Nutrient solution formula (mg / L)

[0059]

[0060] (3.2) Addition and replacement of nutrient solution:

[0061] The nutrient solution was treated on the day of transplanting and replaced every 7 days. After 21 days, the plants were transplanted into greenhouse pots for cultivation.

[0062] Potting medium formula: 50% loam + 20% sand + 30% peat soil.

[0063] Potted cultivation method: plant the rooted plants into the substrate and water them by sprinkling. Immediately after transplanting, sprinkle water until the substrate is evenly moistened. Then set the sprinkling irrigation to be once every 2 days, and sprinkle for 15-20 minutes each time until the substrate is evenly moistened. The sprinkling irrigation time is 15:00 in the afternoon.

[0064] (4) Identification method of plants after hydroponic rejuvenation:

[0065] (4.1) Rooting statistical method

[0066] On the 5th, 8th, 11th and 21st days of hydroponics, the number of roots and the average root length of each variety were counted.

[0067] (4.2) Survival rate calculation formula

[0068] After 21 days of hydroponics, the seeds were transplanted into greenhouse potted plants for cultivation. 20 days after transplanting into potted plants, the survival rate of each variety was counted.

[0069] Survival rate calculation formula:

[0070] Survival rate = number of surviving plants / number of transplanted plants;

[0071] Average root length = total root length per plant / number of roots.

[0072] (4.3) Growth status identification indicators:

[0073] The growth status of the plants was identified 5 months after transplanting into pots.

[0074] Growth status identification indicators:

[0075] Longest vine length: Measure the length from the point where the base of the plant contacts the soil to the tip of the stem. The length of the longest branch vine is the longest vine length.

[0076] Number of branches: measure the number of branches 10-30 cm above the base of the plant;

[0077] Stem diameter: Measure the thickness of the stem segment between the 6th to 10th leaves from the stem tip.

[0078] 1. Screening of endangered sweet potato germplasm resources

[0079] According to (1) the screening criteria for endangered varieties of sweet potato germplasm resources, 135 endangered variety resources were screened out. The 135 endangered varieties were divided into 135 groups of examples, each group of examples contained biological replicates of 3 plants.

[0080] Table 2 Example grouping table

[0081]

[0082]

[0083]

[0084]

[0085] 2. Statistics on rooting of hydroponic plants

[0086] 135 groups of examples were processed according to (2.1) hydroponic treatment method in (2) nutrient solution hydroponic treatment method for endangered species.

[0087] According to the culture conditions (2.2), 135 groups of examples were cultured in an artificial climate chamber MGC-300H, with a light intensity of 2480 Lux, 25° C., and a lighting time of 6:00-18:00.

[0088] Prepare the nutrient solution according to the nutrient solution formula (3.1) in (3) nutrient solution.

[0089] According to (3.2) Addition and replacement of nutrient solution, nutrient solution treatment should be started on the day of transplanting, and the nutrient solution should be replaced every 7 days.

[0090] According to the rooting statistics method (4.1) in (4) the identification method of plants after hydroponic rejuvenation, the number of roots and the average root length of the 135 groups of examples were counted on the 5th, 8th, 11th and 21st days of hydroponic cultivation.

[0091] According to the rooting statistics method (4.1) in (4) the identification method of plants after hydroponic rejuvenation, after 5 days of hydroponic cultivation, the number of roots and the average root length of 135 groups of embodiments were counted. The results are as follows: 112 groups of embodiments have taken root, with a rooting rate of 83%. Among them, 77% of the embodiments have 1 to 6 roots per plant, 5.9% of the embodiments have 7 to 14 roots per plant, 76.3% of the embodiments have an average root length of 0.1 to 0.9 cm, and 6.7% of the embodiments have an average root length of 1.0 to 1.6 cm;

[0092] According to the rooting statistics method (4.1) in (4) the identification method of plants after hydroponic rejuvenation, after 8 days of hydroponic cultivation, the number of roots and the average root length of 135 groups of examples were counted. The results were: 125 groups of examples had rooted, with a rooting rate of 92.6%, of which 85.2% of the examples had 1 to 9 roots per plant, 7.4% of the examples had 10 to 22 roots per plant, 95.6% of the examples had an average root length of 0.1 to 1.7 cm, and 5.9% of the examples had an average root length of 1.8 to 2.6 cm;

[0093] According to the rooting statistics method (4.1) in (4) the identification method of plants after hydroponic rejuvenation, after 11 days of hydroponic cultivation, the number of roots and the average root length of 135 groups of examples were counted. The results were: 130 groups of examples had rooted, with a rooting rate of 96.3%, of which 86.7% of the examples had 1 to 10 roots per plant, 9.6% of the examples had 11 to 23 roots per plant, 90.4% of the examples had an average root length of 0.1 to 1.7 cm, and 5.9% of the examples had an average root length of 1.8 to 2.6 cm;

[0094] According to the rooting statistics method (4.1) in the identification method of plants after hydroponic rejuvenation (4), after 21 days of hydroponic cultivation, the number of roots and the average root length of 135 groups of examples were counted. The results were: 130 groups of examples had rooted, with a rooting rate of 96.3%, 75.6% of the examples had 1 to 10 roots per plant, 20.7% of the examples had 11 to 23 roots per plant, 93.3% of the examples had an average root length of 0.3 to 3.1 cm, and 3.0% of the examples had an average root length of 3.8 to 5.7 cm.

[0095] Table 3 Varieties that did not take root at different times

[0096]

[0097]

[0098] 3. Transplant survival rate statistics

[0099] According to the survival rate calculation formula (4.2) in the identification method of plants after hydroponic rejuvenation (4), the plants were transplanted into potted plants in a greenhouse for 21 days after hydroponic cultivation. After 20 days after transplanting into potted plants, the survival rates of 135 groups of examples were calculated. The results were as follows: 17.8% of the examples failed to survive, 82.2% of the examples survived, of which 21.5% of the examples had a survival rate of less than 50%, 60.7% of the examples had a survival rate of more than 50%, and 13.3% of the examples had a survival rate of 100%. The varieties that did not survive include: Xu Shu 24, Xu 033115, Chuan Shu 4-11-12, sweet potato, 106861.3, 187004.2LM87.045, E3588, Hainan Company No. 2, Zhanjiang White, Egg Fanzhu, Fragrant potato, sweet potato, white-fleshed sweet potato, F3, sweet potato, C315, sweet potato, white-skinned millet, China 28, Nonglin No. 5, Taiwan potato, Ningyin potato, triangular leaf potato, Zhejiang 3481.

[0100] 4. Identification of growth status after transplanting

[0101] According to the growth status identification index (4.3) in the method for identifying plants after hydroponic rejuvenation in technique (4), 5 months later, the growth status of the embodiments that were transplanted into the greenhouse potted culture and survived was identified. The results were as follows: there were only 3 groups of embodiments with an average vine length of less than 30 cm, 58% of the embodiments had an average vine length between 30 and 60 cm, 26% of the embodiments had an average vine length between 60 and 90 cm, and 12% of the embodiments had an average vine length greater than 90 cm; 22% of the embodiments had an average number of branches of 1, 78% of the embodiments had an average number of branches greater than 1, with 2 and 3 branches being the most numerous; 9% of the embodiments had an average stem diameter of 2 to 3 mm, and 91% of the embodiments had an average stem diameter greater than 3 mm.

[0102] Comparative Example 1

[0103] The species grouping of Comparative Example 1 is the same as that of the embodiment.

[0104] The hydroponic solution of Comparative Example 1 was H2O without any nutrient components. Other culture conditions were consistent with those of the embodiment.

[0105] The number of roots of Comparative Example 1 without adding nutrients on the 5th, 8th, 11th and 21st days were significantly lower than those of the examples with added nutrients (Table 4).

[0106] Table 4 Rooting in hydroponics with and without nutrient solution

[0107] deal with Number of roots on the 5th day Number of roots on day 8 Number of roots on day 11 Number of roots on day 21 Comparative Example 1 (without nutrient solution) 1.6±0.7b 2.4±0.3b 4.2±0.2b 6.8±0.5b Embodiment (with nutrient solution) 4.4±0.9a 7.0±1.1a 8.3±1.1a 16.2±2.1a

[0108] Comparative Example 2

[0109] The species grouping of Comparative Example 2 is the same as that of the embodiment.

[0110] The culture conditions of Comparative Example 2 were open-air culture, and other culture conditions were consistent with those of the embodiment.

[0111] Due to the influence of culture conditions such as cold waves, high temperature or insufficient light, the survival rate of Comparative Example 2 was significantly lower than that of the embodiment (Table 5).

[0112] Table 5 Survival rate of hydroponics with and without incubator

[0113] deal with Survival rate Comparative Example 2 (without incubator) 25％±11％b Example (with incubator) 87％±24％a

[0114] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A nutrient solution for endangered varieties of sweet potato germplasm resources, characterized in that: Water is used as the solvent, and the following components are included: KNO3 506 mg / L, H3BO3 6.2 mg / L, NH4NO3 80 mg / L, MnSO4·H2O 16.9 mg / L, KH2PO4 136 mg / L, ZnSO4·7H2O 8.6 mg / L, MgSO4 241 mg / L, Na2MoO4·2H2O 0.25 mg / L, FeNaEDTA 36.7 mg / L, CuSO4·5H2O 0.025 mg / L, KI 0.83 mg / L, CoCl2·6H2O 0.025 mg / L and Ca(NO3)2·4H2O 945 mg / L, and the pH value is 5.8±0.

1.

2. A hydroponic rejuvenation method for endangered varieties of sweet potato germplasm resources, characterized in that: The following steps are involved: The stem segments of the endangered variety of sweet potato germplasm resources are hydroponically cultured in the nutrient solution of claim 1.

3. The hydroponic rejuvenation method according to claim 2, characterized in that: The length of the stem segment is 10 to 15 cm.

4. The hydroponic rejuvenation method according to claim 2, characterized in that: The hydroponic conditions include: light intensity of 2480 Lux, temperature of 25° C., and light time of 6:00-18:00 every day.

5. The hydroponic rejuvenation method according to claim 2, characterized in that: The hydroponic culture time is 5 to 21 days.

6. The hydroponic rejuvenation method according to claim 2 or 5, characterized in that: The hydroponic culture time is 8 to 11 days.

7. The hydroponic rejuvenation method according to claim 2, characterized in that: The screening criteria for endangered varieties of sweet potato germplasm resources include: Grade Ⅰ: slightly curled or wrinkled leaves; Level II: curled or wrinkled leaves, few branches, and short plants; Level III: The leaves are wrinkled, the branches are very few, and the plants are extremely short.

8. The hydroponic rejuvenation method according to claim 2, characterized in that: The stem segments were hydroponically cultured in an artificial climate chamber MGC-300H.

9. The hydroponic rejuvenation method according to claim 2, characterized in that: The nutrient solution was replaced every 7 days.

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