Application of Streptomyces murinus JKTJ-3 in strawberry seedling raising

Abstract

The application discloses application of Streptomyces murinus JKTJ-3 in strawberry seedling raising, and the number of streptomyces spores prepared by the application reaches 10 9 cfu.g ‑1 ~10 12 cfu.g ‑1 The obtained streptomyces murinus JKTJ-3 inoculum is applied to strawberry seedling raising, so that the plant height, stem diameter, root length, leaf number and biomass of strawberry mother plant seedlings can be significantly increased, and during the period of transplanting and expansion of the strawberry mother plants, the time for the mother plants cultivated by using the streptomyces murinus JKTJ-3 inoculum to sprout is shortened, and the number of sprouts and the number of seedlings are significantly increased. It can be seen that the application of the streptomyces murinus JKTJ-3 to the cultivation of the strawberry mother plant seedlings has a remarkable effect on improving the reproduction efficiency of the strawberry mother plants, and fills the blank of the microbial method in the strawberry seedling raising.

Description

Technical Field

[0001] This invention belongs to the field of strawberry seedling technology, specifically involving the application of Streptomyces oryzae JKTJ-3 in strawberry seedling cultivation. Background Technology

[0002] Since the 1950s, chemical fertilizers and growth regulators have played a vital role in agricultural production. However, the widespread use of these traditional agricultural inputs has led to a series of problems, including soil pollution, ecological imbalance, and environmental degradation. Therefore, developing more environmentally friendly and sustainable agricultural solutions has become a key research focus for scientists worldwide. In recent years, microbial inoculants and microbial fertilizers, with microorganisms at their core, have gradually emerged as new green inputs and are attracting increasing attention.

[0003] Streptomyces are a type of higher actinomycetes. Due to their high spore production and long spore survival time, they are easily formulated into live cell preparations, including spore powders, seed dressings, and mycelial cultures, which are used in agricultural production. Compared with other microorganisms, Streptomyces possess a rich and diverse capacity for producing bioactive substances. They can secrete plant growth regulators such as auxins or gibberellins, effectively promoting plant growth and becoming a high-quality source of plant growth-promoting inoculants. Studies have shown that Streptomyces can effectively inhibit the mycelial growth of pathogenic fungi by secreting extracellular chitinase and glucanase. For example, *S. plicatus* 101 inhibits the mycelial growth of some pathogenic fungi by secreting extracellular chitinase, thereby indirectly promoting plant growth.

[0004] In addition, Streptomyces secrete hematophiles through nutrient competition, enhancing plant absorption of iron ions from the soil while limiting competition for iron ions from pathogens, thus reducing disease occurrence. Reports indicate that Streptomyces can increase the dry weight of plants such as corn, cucumber, and tomato by secreting growth hormones. For example, *S. hygroscopicus* can produce various hormone analogs that promote plant growth. Streptomyces can also promote plant growth by increasing the absorption of mineral nutrients and the synthesis of organic matter. For instance, *Streptomyces hygroscopicus* can increase the nitrogen, phosphorus, and potassium content in broad beans and promote protein accumulation. *S. lydicus* can promote tomato growth, increase the number of leaves, enhance photosynthesis, and increase the content of plant growth regulators such as abscisic acid and deionized salicylic acid in tomatoes.

[0005] In strawberry production, the application of Streptomyces is mainly focused on disease control, such as the control of strawberry root rot by *Streptomyces whitethornii* and strawberry gray mold by *Streptomyces hygroscopicus*. In addition, some studies have shown that Streptomyces can improve strawberry quality; for example, *Streptomyces hygroscopicus* can increase the vitamin C content and sugar-acid ratio in the fruit. However, high-quality strawberry seedlings are a key link in the green, high-quality, and efficient production of strawberries, and currently there is little research and application on the role of Streptomyces in promoting the growth of strawberry mother plants and increasing the strawberry propagation coefficient.

[0006] Currently, strawberry seedling cultivation mainly relies on the application of chemical fertilizers, humic acid, and plant growth regulators to promote the growth of strawberry mother plants and increase the number of runners and daughter plants. However, research and reports on the use of microorganisms, especially Streptomyces, to promote strawberry seedling cultivation (runner propagation) are still very scarce. Therefore, it is necessary to further study the application potential of Streptomyces in strawberry seedling cultivation to achieve innovation in strawberry seedling technology. Summary of the Invention

[0007] Based on the above-mentioned prior art, the present invention provides the application of Streptomyces oryzae JKTJ-3 in strawberry seedling cultivation. The present invention is the first to discover that applying Streptomyces oryzae JKTJ-3 to strawberry seedling cultivation can effectively promote the propagation of strawberry runners and increase the propagation coefficient of strawberry mother seedlings.

[0008] The technical solution adopted to achieve the above-mentioned objectives of this invention is as follows:

[0009] Application of Streptomyces oryzae JKTJ-3 in strawberry seedling cultivation (promoting the propagation of strawberry runners).

[0010] A Streptomyces oryzae JKTJ-3 inoculant, the active ingredient of which is Streptomyces oryzae JKTJ-3 and its fermentation products.

[0011] Furthermore, the number of spores of Streptomyces griseus JKTJ-3 in the bacterial agent is 10. 9 cfu·g -1 ~10 12 cfu·g -1 .

[0012] Application of Streptomyces griseus JKTJ-3 inoculum in strawberry seedling cultivation (promoting the propagation of strawberry runners).

[0013] Compared with the prior art, the beneficial effects and advantages of the present invention are as follows:

[0014] This invention utilizes *Streptomyces griseus* JKTJ-3 to prepare *Streptomyces* spores with a quantity reaching 10. 9 cfu·g -1 ~10 12 cfu·g -1The *Streptomyces oryzae* JKTJ-3 inoculant was applied to strawberry seedling cultivation. This significantly increased the height, stem diameter, root length, number of leaves, and biomass of strawberry mother plant seedlings. Furthermore, during the subsequent transplanting and propagation period, mother plants cultivated using *Streptomyces oryzae* JKTJ-3 exhibited earlier runner emergence and a significantly increased number of runners and daughter plantlets. Therefore, this invention demonstrates that applying *Streptomyces oryzae* JKTJ-3 to strawberry mother plant seedling cultivation is highly effective in improving the propagation efficiency of strawberry mother plant seedlings, filling a gap in microbial methods for strawberry seedling cultivation. Attached Figure Description

[0015] Figure 1 Photos of strawberry mother plant seedlings grown in different seedling substrates.

[0016] Figure 2 Photos of strawberry mother plants propagating daughter plants from different seedling substrates at the onset of runner development.

[0017] Figure 3 Photos of strawberry mother plants propagated from different propagation substrates at the time of stolon emergence. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific embodiments.

[0019] Unless otherwise specified, the raw materials used in the following examples are from the following sources:

[0020] Strain: Streptomyces murinus JKTJ-3 (Mihong Ge, Xiang Cai, Dehuan Wang, et al. Efficacy of Streptomyces murinus JKTJ-3 in Suppression of Pythium Damping-Off of Watermelon. Microorganisms, 2023, 11, 1360.).

[0021] Fermentation raw materials: peat moss and wheat bran, which were purchased from the market.

[0022] Example 1

[0023] 1. Inoculate Streptomyces murinus JKTJ-3 onto a plate containing ISP-2 medium, streak evenly, and incubate at 28℃ for 5 days until the spores are full to obtain an activated strain plate. Use a block puncher to punch holes in the activated strain plate to obtain activated blocks with a diameter of 8mm.

[0024] 2. Put peat moss and wheat bran into a 250mL Erlenmeyer flask at a mass ratio of 4:6. The total mass of coconut coir and wheat bran (solid matrix) is 20g. Add 24g of water to the Erlenmeyer flask (material-to-water ratio is 1:1.2) and stir well.

[0025] 3. Add 0.9g of carbon source glycerol (mannitol mass is 3% of the total mass of solid matrix) to the Erlenmeyer flask, stir well, and then sterilize at 121℃ for 40min to obtain the JKTJ-3 solid fermentation medium of Streptomyces oryzae (hereinafter referred to as medium JKTJ-3).

[0026] 4. Three activated bacterial blocks were inoculated onto culture medium JKTJ-3, and then incubated at 30℃ with the inoculum turned every 24 hours. After 7 days of fermentation, *Streptomyces griseus* JKTJ-3 inoculum (hereinafter referred to as inoculum JKTJ-3) was obtained. The number of spores produced by *Streptomyces griseus* strain JKTJ-3 inoculum JKTJ-3 (hereinafter referred to as strain JKTJ-3) was determined by the dilution plate method. The experiment was repeated 3 times, and the average number of spores produced by strain JKTJ-3 inoculum JKTJ-3 was calculated. After measurement and calculation, the average number of spores of strain JKTJ-3 was 7.73 × 10⁻⁶. 11 cfu·g -1 .

[0027] Example 1

[0028] 1. A common substrate (substrate CK, composed of peat moss and perlite in a volume ratio of 3:1) was used as the seedling substrate for the control group of strawberry mother plants. The microbial agent JKTJ-3 prepared in Example 2 was then added to the common substrate (the ratio of microbial agent JKTJ-3 to common substrate was 3 g / L) and mixed to prepare seedling substrate JKTJ-3 (hereinafter referred to as substrate JKTJ-3), which was used as the seedling substrate for the experimental group of strawberry mother plants. Substrate JKTJ-3 and substrate CK were separately placed into disposable seedling pots. Strawberry runners were cut and inserted into the seedling pots, and managed according to conventional mother plant seedling cultivation methods.

[0029] 2. After 70 days of cultivation, the following measurements were taken on the strawberry seedlings of the experimental group and the control group:

[0030] 1) Photographs were taken of strawberry mother plants and seedlings cultivated in different seedling substrates. The results are as follows: Figure 1 As shown.

[0031] 2) Measure the biomass indicators of strawberry mother plant seedlings cultivated in different seedling substrates, including plant height, stem diameter, root length, and number of leaves. The biomass indicators of strawberry mother plant seedlings cultivated in different seedling substrates are shown in Table 2 below:

[0032] Table 1. Effects of different seedling substrates on strawberry mother plant seedling biomass.

[0033]

[0034] From Table 2 and Figure 1 It can be seen that, compared with the control group, the biomass indicators of strawberry mother plant seedlings in the experimental group, such as plant height, stem diameter, root length and number of leaves, were significantly increased, which indicates that the fungal agent JKTJ-3 of the present invention has a good growth-promoting effect on strawberry mother plants.

[0035] 3) The nutrient content of elements such as P, K, Ca, and Mg in strawberry mother plant seedlings cultivated in different seedling substrates was measured. The nutrient content of elements in strawberry mother plant seedlings cultivated in different seedling substrates is shown in Table 2 below:

[0036] Table 2. Effects of different seedling substrates on nutrient content of strawberry mother plants and seedlings.

[0037]

[0038] As shown in Table 3, the substrate JKTJ-3 can promote the absorption and accumulation of nutrients in strawberry mother plant seedlings. The nutrient content of P, K, Ca and Mg in the experimental group of strawberry mother plant seedlings was significantly higher than that in the control group, especially the P content increased by 63.1% compared with the control.

[0039] 4) The contents of plant hormones IAA, GA, ABA, and ETH, as well as the activities of resistance-related enzymes SOD, POD, and CAT, were measured in strawberry seedlings cultivated in different seedling substrates. The contents of plant hormones and the activities of resistance-related enzymes in strawberry seedlings cultivated in different seedling substrates are shown in Table 4 below:

[0040] Table 3. Effects of different seedling substrates on the activity of hormones and resistance-related enzymes in strawberry seedlings.

[0041]

[0042] As shown in Table 3, compared with the control group, the experimental group of strawberry mother seedlings (cultivated in seedling substrate JKTJ-3) showed significantly increased levels of plant hormones IAA, GA, ABA, and ETH, as well as the activities of resistance-related enzymes SOD, POD, and CAT.

[0043] 3. The ordinary substrate (a mixture of peat moss and perlite in a 3:1 volume ratio) was placed into two sets of planting bags. The strawberry mother plants obtained in step 2 were used as experimental group mother plants and placed in one set of planting bags. The strawberry mother plants obtained in step 2 were used as control group mother plants and placed in the other set of planting bags. Measurements were taken as follows when the runners of the control group strawberry mother plants began to develop and when they ceased to grow:

[0044] 1) When 25% of the strawberry mother plants in the control group began to develop runners, photos were taken of the strawberry mother plants cultivated in different seedling substrates. The results are as follows: Figure 2 As shown.

[0045] 2) When 25% of the strawberry mother plants in the control group began to produce runners, the number of runners and the number of daughter plants produced by different seedling substrates were measured as reproductive indicators. The reproductive indicators of strawberry mother plants under different reproductive substrates are shown in Table 4 below:

[0046] 3) When the runners of 75% of the strawberry mother plants in the control group had ceased to develop, the propagation indicators of the strawberry mother plants cultivated in different seedling substrates were statistically analyzed, as shown in Table 4 below:

[0047] Table 4. Effects of different seedling substrates on the propagation of strawberry mother plants

[0048]

[0049] Depend on Figure 2 As shown in Table 4, the strawberry mother plants cultivated with seedling substrate JKTJ-3 exhibited earlier runner development and faster seedling formation. At the same time, the number of runners and daughter plants produced at different stages was significantly higher than that of the control group, indicating that the seedling substrate has a significant promoting effect on the propagation of strawberry daughter plants.

[0050] Example 2

[0051] 1. Use a common substrate (made of peat moss and perlite in a volume ratio of 3:1) as the seedling substrate for strawberry mother plants. Fill disposable seedling pots with the common substrate, cut strawberry runners, insert them into the seedling pots, and manage them according to the conventional mother plant seedling cultivation method.

[0052] 2. After 70 days of cultivation, strawberry mother plant seedlings are obtained.

[0053] 3. A common substrate (substrate CK, a mixture of peat moss and perlite in a 3:1 volume ratio) was used as the propagation substrate for the control group of strawberry mother plants. The microbial agent JKTJ-3 prepared in Example 2 was added to the common substrate (the ratio of microbial agent JKTJ-3 to common substrate was 1 g / L) and mixed to prepare propagation substrate JKTJ-3 (hereinafter referred to as substrate JKTJ-3), which was used as the propagation substrate for the experimental group of strawberry mother plants. Substrate CK was placed in one set of planting bags, and substrate JKTJ-3 was placed in another set of planting bags. The strawberry mother plant seedlings obtained in step 2 were planted as strawberry mother plants in the planting bags containing substrate JKTJ-3 (experimental group), and the strawberry mother plant seedlings obtained in step 2 were planted as strawberry mother plants in the planting bags containing substrate CK (control group). The following measurements were taken when the runners of the strawberry mother plants in the control group began to develop and when they ceased to develop:

[0054] 1) When 25% of the strawberry mother plants in the control group began to develop runners, photographs were taken of the strawberry mother plants cultivated in different propagation substrates. The results are as follows: Figure 3 As shown.

[0055] 2) When 25% of the strawberry mother plants in the control group began to produce runners, the number of runners and the number of offspring plantlets produced by the strawberry mother plants cultured in different propagation substrates were measured. The propagation indicators of strawberry mother plants cultured in different propagation substrates are shown in Table 6 below:

[0056] 3) When the runner development of 75% of the strawberry mother plants in the control group ended, the propagation coefficient of strawberry mother plants obtained from different propagation substrates was statistically analyzed, as shown in Table 5 below:

[0057] Table 5. Effects of different propagation substrates on the propagation of strawberry mother plants.

[0058]

[0059] right Figure 3 Analysis of the data in Table 5 leads to the following conclusions: Strawberry mother plants cultivated using propagation substrate JKTJ-3 exhibited earlier runner formation and faster seedling growth. Furthermore, at different growth stages, the number of runners and daughter plants was significantly higher than the control group, indicating that this propagation substrate has a significant promoting effect on strawberry propagation.

Claims

1. Application of Streptomyces oryzae JKTJ-3 in promoting the propagation of strawberry runners.

2. The application of a Streptomyces griseus JKTJ-3 inoculant in promoting the propagation of strawberry runners, characterized in that: The active ingredient of the microbial agent is the Streptomyces oryzae JKTJ-3 and its fermentation products as described in claim 1.

3. The application of the *Streptomyces griseus* JKTJ-3 inoculant according to claim 2, characterized in that: The bacterial agent contains 10 spores of Streptomyces griseus JKTJ-3. 9 cfu·g -1 ~10 12 cfu·g -1 .

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