何首乌根际促生菌的筛选及其对何首乌种子萌发的影响

Screening of plant growth-promoting rhizobacteria and its effect on seed germination of Polygonum multiflorum

该研究以何首乌根际细菌和放线菌为实验对象,采用Salkowski法筛选具有产吲哚乙酸(IAA)能力的菌株,铬天青S(CAS)平板法筛选具有产铁载体能力的菌株,PKO无机磷培养基筛选具有溶解无机磷能力的菌株,从形态学、生理生化以及16S rDNA序列分析等方法来确定菌株的分类学地位,并研究促生菌株对何首乌种子发芽和生长的影响。结果从196株菌株中得到2株同时具有产IAA、产铁载体和溶解无机磷的菌株F17、F42。菌株F17、F42产IAA的能力分别为38.65、33.64 mg·L-1;产铁载体的能力(As/Ar)分别为0.85、0.49;溶解无机磷的能力(D/d)分别为1.35、1.70。综合分析结果显示,菌株F17、F42分别鉴定为不解糖假苍白杆菌Pseudochrobactrum asaccharolyticum和阿氏芽孢杆菌Bacillus aryabhattai,并且发现2种菌株均对何首乌种子的萌发具有显著的促进作用。

In this study,the rhizobacteria and actinomycetes of Polygonum multiflorum were screened for the strains with indole acetic acid(IAA)-producing capacity by Salkowski method,the siderophore-producing strains by Chrome Azurol S(CAS)assay,and the strains with inorganic phosphorus-solubilizing capacity by PKO inorganic phosphorus medium.The strains were identified by morphological identification,physiological and biochemical characteristics,and 16S rDNA sequences.Furthermore,the effect of growthpromoting strains on the seed germination and development of P.multiflorum was tested.The results showed that among 196 strains,two strains F17 and F42 were found to be capable of producing IAA and siderophore and solubilizing inorganic phosphorus simultaneously.For F17 and F42,the results are listed below:38.65 and 33.64 mg·L-1 for IAA production,0.85 and 0.49 for siderophoreproducing capacities(As/Ar),and 1.35 and 1.70 for inorganic phosphorus-solubilizing capacities(D/d),respectively.Comprehensive analysis revealed that strains F17 and F42 were identified as Pseudochrobactrum asacharolyticum and Bacillus aryabhattai,respec-tively,and both could significantly promote the seed germination of P.multiflorum.