水稻促生菌的筛选、鉴定及其促生效果

Screening and identification of rice growth-promoting strains and their effects on rice growth

摘要:

【背景】微生物在促进水稻生长上潜力巨大，利用水稻促生微生物是减少水田化肥施用、保障水稻安全高效生产的有效途径之一。【目的】筛选并获得能显著促进水稻生长的微生物，为水稻微生物肥料提供优质菌种资源。【方法】从水稻根围微生物中筛选具有高效固氮、溶磷、解钾、产铁载体和吲哚乙酸(indole acetic acid，IAA)的微生物菌株，并对其进行初步鉴定，分析其对水稻种子萌发和植株生长的影响。【结果】从394株水稻根围细菌中筛选并获得了6株在固氮或溶解有机和无机磷、钾或产铁载体和IAA综合水平较高的菌株，分别为菌株C7-1、L26、C10-19、S11-11、GYM_bt5和20-10，根据16S rRNA基因序列初步鉴定这些菌株为嗜线虫沙雷氏菌(Serratianematodiphila)、阿耶波多氏芽孢杆菌(Bacillus aryabhattai)、别氏不动杆菌(Acinetobacter bereziniae)、蒙氏假单胞菌(Pseudomonas monteilii)和贝莱斯芽孢杆菌(Bacillus velezensis)。促生试验结果表明，除别氏不动杆菌C10-19外，其他5株菌处理‘晶两优华占’水稻种子后均能显著促进水稻种子萌发和根系发育，种子萌发率可提高25%−43%，水稻幼苗在培养的第14天根长增长最显著，比对照增加了18%−42%。溶有机磷水平最高的菌株C7-1对根长的影响最显著，其次为菌株20-10，而菌株S11-11对茎的生长和分蘖促进作用最显著。【结论】菌株C7-1、20-10和S11-11对水稻促生作用显著，可用于水稻微生物肥料的研制。

Abstract:

[Background] Microorganisms have great potential in promoting rice growth. It is one of the effective ways for reducing the application rate of chemical fertilizers and ensuring safe and efficient rice production to apply rice growth-promoting microorganisms. [Objective] To screen rice growth-promoting microorganisms for the preparation of microbial fertilizers for rice production. [Methods] Strains with high efficiency in fixing nitrogen, solubilizing phosphate and potassium, or producing siderophore and indole acetic acid (IAA) were screened from rice rhizosphere and identified and their effects on seed germination and plant growth of rice were analyzed. [Results] A total of 6 strains (C7-1, L26, C10-19, S11-11, GYM_bt5 and 20-10) with high efficiency in fixing nitrogen, solubilizing organic and inorganic phosphate or potassium, or producing siderophores and IAA, were screened out from the 394 bacterial strains in rice rhizosphere, which were identified as Serratia nematodiphila, Bacillus aryabhattai, Acinetobacter bereziniae, Pseudomonasmonteilii, and Bacillus velezensisbytheir 16S rRNA gene sequences, respectively. The strains, except C10-19, all can significantly promote the seed germination and root development of ‘Jingliangyouhuazhan’. With the help of the 5 strains, the seed germination rate was 25%−43% higher and the root length (14th day of seedling culture) was 18%−42% larger than that of the control, respectively. Particularly, strain C7-1 with the highest level of solubilizing organic phosphate, had the most significant effect on root length, followed by strain 20-10, while strain S11-11 had the most significant effect on the growth and tillering of stems. [Conclusion]StainsC7-1,20-10 andS11-11 significantly promotes rice growth, which can be used for the preparation of rice microbial fertilizers.