欧李多功能PGPR菌株筛选、鉴定及促生防病特性研究

Isolation and identification of multifunctional PGPR and characterization of growth-promoting and disease-prevention of Cerasus humilis

摘要:

【目的】从荒漠草原灌木欧李(Cerasus humilis)根际筛选具有优良促生防病特性的植物根际促生菌(plant growth promoting rhizobacteria，PGPR)。【方法】采用选择性培养基，筛选欧李根表面及根际土中细菌。通过乙炔还原法、Salkowski 法、钼锑抗比色法和平板对峙法分别测定菌株固氮酶活性、 分泌 IAA、溶磷和拮抗病原菌的能力。并利用形态学、革兰氏染色及分子生物学方法对筛选出的 10 株优良根际促生菌进行初步鉴定 。【结果】分离出的 31 株细菌 ，固氮酶活性在 16. 22~328. 35 nmol C₂H₄/(h·mL)；分泌 IAA 量在 3. 85~60. 19 μg/mL；解有机磷量在 10. 66~118. 76 μg/mL；溶无机磷量在 1. 42~289. 93 μg/mL；菌株 WGB2 对茄病镰刀菌(Fusarium solani)、麦根腐平脐蠕孢(Bipolaris soro- kiniana)、尖突赤霉菌(Gibberella acuminata)、禾谷镰刀菌(Fusarium graminearum)和串珠赤霉菌(Gib- berella moniliformi)均具拮抗作用，抑菌率分别为 11. 85%、39. 91%、27. 64%、59. 84% 和 26. 22%。初步鉴定 10 株优良根际促生菌菌株分属于 Chryseomicrobium、动性球菌属(Planomicrobium)、假单胞菌属(Pseudomonas)、节杆菌属(Arthrobacter)、农杆菌属(Agrobacterium)和类芽孢杆菌属(Paenibacil- lus)。【结论】欧李 PGPR 菌株数量表现出根表面显著高于根际土，且菌株具有丰富的促生防病特性，可为后期微生物肥料的开发提供优质的菌种资源。

Abstract:

【Objective】 The aim of this research was to screen plant growth promoting rhizobacteria (PGPR) from the rhizosphere of the desert steppe shrub Cerasus humilis with excellent growth‐promoting and disease‐prevent‐ ing properties. In this study， selective media were used to screen the bacteria on the root surface and in the rhizo‐ sphere soil of the Cerasus humilis. Acetylene reduction method，Salkowski method， molybdenum antimony colorimet‐ ric method and plate confrontation method were used to determine the nitrogenase activity，secretion of IAA， phos‐ phorus and antagonism. Using Morphology， gram staining and molecular biology methods，10 strains with excellent rhizosphere growth ‐ promoting were preliminarily identified. The results from 31 strains of bacteria which were screened showed that： the nitrogenase activity was 16. 22~328. 35 nmol C2H4/(h·mL)； the amount of IAA se‐ creted was 3. 85~60. 19 μg/mL；the amount of dissolved organic phosphorus was 10. 66~118. 76 μg/mL；the amount of dissolved inorganic phosphorus was 1. 42~289. 93 μg/mL； strain WGB2 was effective against Fusarium solani，Bipolaris sorokiniana，Gibberella acuminata，Fusarium graminearum and Gibberella moniliformi，and the in‐ hibition rates were 11. 85%，39. 91%，27. 64%，59. 84%，and 26. 22%，respectively. PGPR of Cerasus humilis showed that the number of bacteria on the root surface was significantly higher than that of the rhizosphere soil. Ten strains were preliminarily identified as belonging to Chryseomicrobium，Planomicrobium，Pseudomonas， Arthrobac- ter， Agrobacterium and Paenibacillus.