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CN-121991832-A - Plant rhizosphere growth-promoting bacterium SPN5 and application thereof

CN121991832ACN 121991832 ACN121991832 ACN 121991832ACN-121991832-A

Abstract

The invention relates to the technical field of microorganisms, and particularly provides a plant rhizosphere growth-promoting bacterium SPN5 and application thereof. The strain is isolated from rhizosphere soil of rubber tree in Hainan province and is preserved in the microorganism strain collection in Guangdong province with the preservation number of GDMCC NO:66466. The SPN5 is a potential new species in pantoea, has various plant growth promotion capacities of phosphate dissolving, potassium dissolving, nitrogen fixing, siderophore producing, cellulase producing, indoleacetic acid producing, ammonia producing and the like, and can well grow in the pH range of 5.0-9.0 under the salt concentration of 3 percent. Potted experiments show that SPN5 has obvious promotion effect on lettuce and rubber tree seedlings, can improve plant biomass, leaf chlorophyll content and crop quality, and can effectively promote the growth of rubber trees under the condition of reducing fertilizer application by 20% -40%. The strain is suitable for preparing microbial agents, and has good application prospect in the aspects of promoting crop growth and realizing fertilizer decrement and synergy.

Inventors

  • PENG WENTAO
  • ZHAO CHUNMEI
  • Fu Yingge
  • CHENG LINLIN
  • WANG JIKUN
  • ZHOU LIJUN

Assignees

  • 中国热带农业科学院橡胶研究所

Dates

Publication Date
20260508
Application Date
20251230

Claims (10)

  1. 1. A Pantoea (Pantoea) strain SPN5, wherein the strain SPN5 is designated Pantoea sp. GDMCC NO:66466, deposited on the microorganism strain collection in Guangdong province at 4/6/2024.
  2. 2. The strain SPN5 of claim 1, wherein the sequence of 16S rDNA of the strain SPN5 is set forth in SEQ ID No. 1.
  3. 3. A fermentation broth or a bacterial suspension comprising the strain SPN5 as claimed in claim 1.
  4. 4. Use of the strain SPN5 of claim 1 or the bacterial suspension of claim 3, characterized in that the use is any of the following: A1 Use in promoting plant growth; A2 Use of the composition for the preparation of a product for promoting plant growth; The plant comprises lettuce and rubber tree seedlings.
  5. 5. A microbial agent comprising the strain SPN5 of claim 1.
  6. 6. A biological phosphate fertilizer comprising the strain SPN5 of claim 1.
  7. 7. A biological potassium fertilizer comprising the strain SPN5 of claim 1.
  8. 8. A biological nitrogen fertilizer comprising the strain SPN5 of claim 1.
  9. 9. A soil conditioner comprising the strain SPN5 of claim 1.
  10. 10. A method for promoting growth of lettuce or rubber tree seedlings, which is characterized in that the strain SPN5 in claim 1 is prepared into a bacterial suspension and applied to lettuce or rubber tree seedlings by a root irrigation mode; The preparation method of the bacterial suspension comprises the steps of inoculating bacterial strain SPN5 into LB liquid culture medium according to an inoculum size of 1%, culturing at 200 rpm and 30 ℃ for 48 h, centrifuging fermentation liquor 5000 rpm for 5min, discarding supernatant, washing bacterial precipitate with sterile water for 2 times, re-suspending, and diluting the bacterial precipitate with sterile water until the bacterial concentration is 1.0X10 8 cfu/mL, thus obtaining the bacterial suspension.

Description

Plant rhizosphere growth-promoting bacterium SPN5 and application thereof Technical Field The invention belongs to the technical field of microorganisms, and relates to plant rhizosphere growth-promoting bacteria SPN5 and application thereof. Background Plant rhizosphere growth promoting bacteria (PGPR) can directly or indirectly promote plant growth, increase crop yield and enhance stress resistance by colonizing around plant root systems. The action mechanism comprises biological nitrogen fixation, dissolving insoluble phosphorus and potassium, secreting plant growth hormone (such as indoleacetic acid), producing siderophore, inducing systemic resistance and the like. The development of microbial inoculants by utilizing PGPR is one of important ways for promoting green development of agriculture and realizing the reduction and synergy of chemical fertilizer and pesticide. At present, PGPR strain resources applied to agricultural production are still relatively limited, and a plurality of strains have the problems of single function, strong host specificity, narrow environmental adaptability and the like. For example, some strains only have a single function of fixing nitrogen or dissolving phosphorus, and the like, and it is difficult to stably exert comprehensive pro-active effects in a practical complex farmland environment. In addition, PGPR isolated and screened from the rhizosphere of a specific crop tends to exhibit better colonization ability and growth promoting effect due to its good adaptability to the rhizosphere microenvironment of the primary crop. Therefore, aiming at important cash crops (such as rubber trees), the system digs the special and multifunctional rhizosphere growth-promoting strain resources, and has important significance for developing high-efficiency special microbial fertilizers. On the other hand, long-term excessive application of chemical fertilizers has resulted in a series of soil degradation problems, such as hardening, acidification, salinization, and nutrient imbalance. The pushing of fertilizer decrement application has become a national strategy for sustainable development of agriculture in China. Under the background, a need exists for a microbial solution that can ensure crop nutrient supply and promote healthy growth of crops through various biological pathways under the condition of lower fertilizer input. However, most of the existing microbial fertilizer products often cannot fully maintain the nutritional requirements of crops due to single functions under the condition of greatly reducing the application of chemical fertilizers, so that the promotion effect is unstable, and the wide application of the microbial fertilizer products in actual production is limited. Therefore, the novel PGPR strain which has various growth promoting functions and wide environmental adaptability and can particularly stably exert the growth promoting effect under the condition of fertilizer application reduction is separated and screened from the rhizosphere environment of specific crops, and is developed into a corresponding microbial inoculant or biofertilizer, so that the novel PGPR strain has important practical value and application prospect for enriching an agricultural microbial germplasm resource library, supporting fertilizer reduction action and promoting development of ecological agriculture. Disclosure of Invention Aiming at the problems of lack of special growth promoting bacteria agent for rubber trees and insufficient efficient growth promoting strain in a fertilizer application reducing scene in the prior art, the invention provides a Pantoea (Pantoea) potential new species SPN5, which has comprehensive plant growth promoting function and strong adaptability, can effectively promote crop growth under the conditions of medium and low fertility or fertilizer application reducing, and realizes the dual aims of yield increase, quality improvement and fertilizer reduction. The invention provides the following technical scheme: Basic information of Strain The plant rhizosphere growth promoting bacterium is Pantoea (Pantoea) SPN5 which is preserved in the microorganism strain collection center of Guangdong province, and the address is No. 100 laboratory building 5 in Xiuzhou Yuxiu martyr of Guangdong province, the postal code is 510075, and the telephone is 020-37656629. The classification was designated Pantoea sp. With deposit number GDMCC NO:66466 and with a deposit date of 2024, month 6 and 4, isolated from the rhizosphere soil of rubber trees in Hainan gum garden. (II) Strain characterization 1. The morphological characteristics are that after culturing for 48 hours on LB solid medium at 30 ℃, single colony is light yellow, round convex, smooth and moist on the surface, the diameter is 1.5-3.0 mm, the thallus is short round rod-shaped, the size is about 0.8-1.2 multiplied by 1.2-2.5 mu m, and the thallus has flagellum and gram staining negative. 2. The physiologica