Method for promoting rice seedling raising quality improvement by using China-hemp roots and endophytes and application of method

Abstract

The invention provides a method for promoting rice seedling raising quality improvement through China-hemp roots and endophytes and application of the method. The method specifically comprises the steps that waste China-hemp roots are smashed to prepare a seedling raising substrate, meanwhile, endophytic fungi YH1-1 from China-hemp plants are used in cooperation for seed soaking or spraying treatment, the quality of a rice seedbed and seedlings is remarkably improved, seed soaking of China-hemp root powder and seed soaking of the endophytic fungi YH1-1 can remarkably promote the germination rate and the germination potential of rice respectively, and the germination rate and the germination potential of the rice are improved by 15.91% and 13.64% respectively; the radicle length of the YH1-1 + root powder combined treatment is increased by 33.9% compared with that of a control group. Besides, YH1-1 bacteria are combined for rice seed soaking, then the seeds are sown in a YH1-1 + (the ratio of root powder to soil is 1: 9) matrix, and the plant height, the root length and the total dry weight of the rice after 21 days of treatment are remarkably increased and are increased by 21%, 29.63% and 20.45% respectively compared with those of a control group. The method not only can effectively solve the problem that the waste China-hemp roots are difficult to utilize, but also can solve the actual production problem that the rice seedling raising substrate is high in cost, develops the utilization channel of the waste China-hemp roots, provides an excellent seedling raising substrate and a seedling strengthening technology for intensive rice seedling raising, and reduces the problem of environmental pollution caused by the use of a rice fertilizer.

Description

Technical Field

[0001] The present invention relates to the field of bio-agriculture, and particularly to a method for promoting the improvement of rice seedling raising quality by using hemp roots and endophytes and its application. Background Art

[0002] Hemp is an important medicinal plant resource in Heilongjiang Province, China. Currently, hemp varieties with a tetrahydrocannabinol content of less than 0.3% are also called industrial hemp in China. The stems and seeds of industrial hemp are superior raw materials for papermaking, textiles, non-toxic materials, glazing agents, lubricating oils, etc., but their roots are usually discarded and not fully utilized.

[0003] Mechanized transplanting of rice includes two links: seedling raising and transplanting, and seedling raising is the key. Research shows that intensive seedling raising can improve the quality and uniformity of seedlings and improve the effect of machine transplanting, but it also consumes soil and is prone to soil-borne diseases. Therefore, many researchers have begun to focus on using agricultural waste, which can not only recycle resources but also solve the problem of waste treatment. Although these wastes are rich in nutrient elements, their physical structure is rough. Direct application to farmland may affect seed germination and emergence, and is not conducive to soil moisture retention and aeration. At the same time, the nutrient elements in the waste are unevenly distributed, making it difficult to meet the overall requirements of the seedling raising substrate. Therefore, it is necessary to explore a suitable blending method to adjust the structure and nutrient distribution of agricultural waste, optimize the performance of the seedling raising substrate, and improve the quality of seedling raising. Plant endophytes refer to those that live in the tissues or cells of healthy-growing plants at a certain stage or throughout their life cycle. The plant provides the nutrients required for the growth and development of endophytic fungi. At the same time, the metabolites produced by endophytic fungi enable the host plant to cope with various abiotic and biotic stresses. Endophytic fungi can play an important role in the process of plant growth by synthesizing various plant hormones, and have important application potential and prospects in reducing the use of conventional fertilizers and improving quality and increasing production. Summary of the Invention

[0004] Object of the Invention: The present invention provides a method for promoting the improvement of rice seedling raising quality by using hemp roots and endophytes and its application. Specifically, it includes using crushed hemp waste roots to make a seedling raising substrate, and at the same time, soaking seeds or spraying with endophytic fungus YH1-1 from hemp plants can significantly improve the quality of the rice seedbed and seedlings. The invention can not only effectively solve the problem of difficult utilization of hemp waste roots, but also solve the actual production problem of high cost of the rice seedling raising substrate, open up the utilization channels of hemp waste roots, provide excellent seedling raising substrates and strong seedling technologies for intensive rice seedling raising, and reduce the environmental pollution problems caused by the use of chemical fertilizers in rice.

[0005] Technical Solution:

[0006] The Fusarium endophytic fungus YH1-1 isolated from Cannabis sativa was registered and preserved in the China General Microbiological Culture Collection Center on January 22, 2024. The preservation number is: CGMCC 41048 (YH1-1), and the address of the preservation unit is the Institute of Microbiology, Chinese Academy of Sciences.

[0007] The plant endophytic fungus described in the present invention can be cultured by conventional microbial solid fermentation or liquid fermentation methods, and a microbial fertilizer with the plant endophytic fungus described in the present invention as the main component can be prepared; the optimal growth temperature of this fungus is 25 °C, and the optimal pH is 6-7. It can be cultured using solid fermentation tanks and mechanical stirring fermentation tanks in general fermentation industries, and formulated into dosage forms such as aqueous solutions and powders.

[0008] 1. Promoting effect of YH1-1 and Cannabis sativa root powder on rice germination

[0009] Rice seeds were soaked and rinsed with running water for 12 h, washed with sterile water, and set aside; double-layer sterilized filter paper was placed at the bottom of a glass dish, and 5 mL of root powder suspension, bacterial suspension, or combined suspension was added to different groups. Preparation of bacterial suspension: The mycelium grown on PDA was scraped off and crushed, and suspended in 5 ml of sterile water; Preparation of root powder suspension: The discarded roots of Cannabis sativa were ground into powder with an electric grinder, with a particle size of 100 μm - 350 μm. 0.2 g of Cannabis sativa root powder was weighed and added to 5 ml of sterile water. Healthy rice seeds were selected and placed in a culture dish, and cultured in a 25 °C incubator under light, with a light intensity of 2000 Lx. After 2 days of culture, the germination of the seeds was recorded, and the radicle and plumule lengths of the rice seeds at 2 days and 5 days were measured, and the germination potential, germination rate, average root length, and average bud length were statistically analyzed. Germination rate = number of germinated seeds / number of tested seeds; Germination potential = germination rate after 2 days of culture.

[0010] 2. Regulatory effect of the interaction between Cannabis sativa root powder-based rice seedling raising substrate and YH1-1 on the growth of rice seedlings

[0011] Rice seeds were divided into two groups, one group was added with sterile water, and the other group was added with an equal volume of YH1-1 bacterial solution. Preparation of bacterial solution: The endophytic fungus YH1-1 of Cannabis sativa was inoculated on a PDA plate medium and grown for 5 - 7 d until the colony covered the plate ( Figure 1 ), 6 bacterial cakes (diameter 0.8 cm) were taken from the petri dish with a puncher and placed in a triangular flask containing 250 mL of PDB medium for culture. Culture conditions: The shaking speed of the shaker was 160 rpm / min, the culture temperature was 23 - 25 °C, and the culture time was 7 - 9 days. The seeds were soaked in the bacterial solution for 12 h - 16 h and set aside, or the leaves were sprayed 2 - 3 times during the critical growth periods (seedling emergence stage, tillering stage, jointing stage) after the rice seedlings emerged.

[0012] According to different materials (hemp root powder, rice husk, residue after extraction of hemp phenolic substances) mixed with peat soil in different ratios (1:3, 1:9, 1:12), stir evenly. In the substrate, adding rice husk and hemp residue (residue remaining after extraction of hemp phenolic substances) (both with a ratio of 1:3 to the soil) are set as T1 and T5 respectively; T2, T3, and T4 respectively represent the ratios of hemp root powder to soil of 1:3, 1:9, and 1:12. At the same time, pure soil without adding other substrates is used as the blank control T0. Rice seeds are soaked in clean water for 12 - 16 h and then sown. At the same time, on the basis of different treatments, rice seeds soaked in YH1 - 1 for 12 - 16 h are sown, and are respectively recorded as T0+, T1+, T2+, T3+, T4+ and T5+; a total of different material treatments are divided into 12 groups. Then, different treatments are filled into seedling pots, and the above - mentioned rice seeds soaked in the endophyte YH1 - 1 bacterial solution are sown in each hole. The sown seedling pots are placed on a cultivation rack at 23 - 25 °C, and watered equally during the cultivation period. Description of the Drawings

[0013] Figure 1 Waste hemp roots and their powders

[0014] Figure 2 Effects of YH1 - 1 and hemp root powder on the germination rate of rice seeds

[0015] Figure 3 Effects of YH1 - 1 and hemp root powder on the growth of radicles and plumules of rice seeds Detailed Implementation Modes

[0016] The experimental methods used in the following examples are all conventional methods unless otherwise specified.

[0017] The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0018] Example 1: Effects of YH1 - 1 and hemp root powder on rice germination

[0019] The root tissue of hemp contains rich natural products (phenols, terpenoids) and polysaccharides, which may play a regulatory role in crop growth. In order to explore the effects of hemp root powder (RP) and hemp endophytic fungus YH1-1 on rice germination, a rice germination experiment was carried out in a petri dish. The germination rate, germination potential, plumule length and radicle length of rice were counted. After counting, it was found that the discarded hemp root powder, hemp endophytic fungus strain YH1-1, and XG9 endophytic fungus all promoted the rice germination rate and germination potential to varying degrees. The germination potential of the YH1-1 and hemp root powder treatment groups increased by 15.91% and 13.64% compared with the control group; the germination rate of the YH1-1 treatment group increased by 18.75% compared with the control group; on the 10th day, the radicle lengths of the YH1-1+RP group and the RP group were increased by 33.9% and 22.9% respectively compared with the control group, indicating that both the root powder and the endophyte effectively promoted the growth of rice roots, and the interaction between the two treatments was most beneficial to rice budding and root elongation( Figure 2 and Figure 3 ).

[0020] Example 2: Regulatory effect of the interaction between hemp root powder-based rice seedling raising substrate and YH1-1 on the growth of rice seedlings

[0021] According to different materials (hemp root powder, rice husk, residue after extraction of hemp phenolic substances) mixed with peat soil in different ratios (1:3, 1:9, 1:12), stir evenly. In the substrate, rice husk and hemp residue (residue remaining after extraction of hemp phenolic substances) are added, and the ratio to soil is 1:3 for both, which are set as T1 and T5 respectively; T2, T3, and T4 respectively represent the ratios of hemp root powder to soil of 1:3, 1:9, and 1:12. At the same time, pure soil without adding other substrates is used as the blank control T0. Rice seeds are soaked in clean water for 12 - 16 h and then sown. At the same time, on the basis of different treatments, rice seeds soaked with YH1-1 for 12 - 16 h are sown, which are respectively recorded as T0+, T1+, T2+, T3+, T4+ and T5+; a total of 12 groups of different material treatments are divided. Samples are taken at different times after rice sowing. Each time, 10 seedlings are taken from each group to measure their germination rate, root length, plant height, chlorophyll content, nitrogen content, and total dry weight. After 21 days of seedling growth, the results show that in the treatment group of YH1-1+ (root powder: soil = 1:9), the plant height, root length, and total dry weight are all significantly increased, which are 21%, 29.63%, and 20.45% higher than the control group respectively; compared with T1 (rice husk: soil = 1:3 treatment group), they are 34.78%, 54.99%, and 24.23% higher respectively; compared with T5 (hemp residue: soil = 1:3 treatment group), they are 40.53%, 105.43%, and 107.35% higher respectively. In addition, it is found through analysis that the root length of T2 (root powder: soil = 1:3 treatment group) is the most significant, which is 58%, 89.35%, and 151.01% higher than T0, T1, and T5 respectively; and the chlorophyll content of the T2+ treatment group is 87.9 SPAD and the nitrogen content is 25.4 mg / g, which are 55% and 51% higher than T0 respectively, 52.07% and 44.73% higher than T1 respectively, and 60.75% and 42.29% higher than T5 respectively.

[0022] The above results show that: the treatment group of YH1-1+ (root powder: soil = 1:9) has the most significant effect on increasing plant height and total dry weight. Therefore, selecting the root powder mixed with soil at a ratio of 1:9 as the rice seedling raising substrate formula and treating the seeds with the endophytic fungus YH1-1 of hemp can significantly increase the plant height, root length, and total dry weight of rice seedlings, significantly improve the quality of rice seedling raising, can be applied on a large scale in production, is green and environmentally friendly, reduces the cost of seedling raising, and improves the quality of seedling raising.

Claims

1. The present invention provides a method for improving the quality of rice seedling cultivation by using hemp roots and endophytes and its application. It is characterized in that: Waste hemp roots are crushed to make a seedling medium, wherein hemp root powder is mixed with soil in different proportions, and endophytic bacteria are used to soak rice seeds before sowing or spray them after sowing; the endophytic bacteria is Fusarium oxysporum, and the preservation number is CGMCC No. 41048 (YH1-1).

2. According to the application described in claim 1, hemp waste roots are crushed to make a rice seedling medium, and the root powder particle size is 100μm-350μm. At the same time, the endophytic fungus YH1-1 from hemp plants is used for seed soaking or spraying to significantly improve the quality of rice seedbeds and seedlings.

3. The use according to claim 2, wherein the quality of the rice seedling bed and seedlings, including the rice germination rate and germination potential, the rice plant height, root length, chlorophyll, N content, and total dry weight are significantly increased.

4. The use according to claim 1, wherein the hemp root powder and soil in the rice seedling medium are mixed in different proportions, including 1:3 to 1:12, among which 1:9 has the best effect. 21 days after treatment, the rice plant height, root length and total dry weight are significantly increased, which are 21%, 29.63% and 20.45% higher than those of the control group, respectively.

5. The use according to claim 1, the endophytic fungus YH1-1 of hemp plant can use mycelial aqueous solution or YH1-1 fermentation liquid or fermented mycelial extract. The treatment method is to soak the rice seeds for 12-16 hours before sowing, or spray the leaves 2-3 times in the key growth period (seedling stage, tillering stage, jointing stage) after the rice seedlings emerge.

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