四川高效白三叶根瘤菌筛选及16S rDNA鉴定

Screening Efficient Rhizobia Strains Isolated from White Clover and Identification of 16S rDNA in Sichuan Area

为了筛选出与白三叶(Trifolium repens)共生匹配效果优异的根瘤菌菌株,从四川野外采集到80余份白三叶根瘤样品并从中成功分离出了72株。经菌落形态观察,革兰氏染色镜检初步检验后,对所分离的菌株进行水培法和砂培法结瘤试验筛选高效菌株。结果表明,接种根瘤菌显著提高了白三叶的结瘤数、株高、鲜重、干重、叶绿素和全氮含量(P<0.05),其中以菌株YA1121和CD1105为最佳。同时,采用16SrDNA序列鉴定菌株YA1121和CD1105,属于三叶草根瘤菌,为四川白三叶根瘤菌遗传多样性及系统发育研究奠定了基础。

In order to select out superior rhizobia strains matching with white clover symbiotic efficiently,seventy-two rhizobia strains were successfully isolated from more than eighty samples of white clover root nodules collected in Sichuan province.After initial inspection of colonial morphology observation and gram staining microscopy on all the separation of strains,nodulation experiment was carried out with hydroponics（water culture）and quartz sand culture method to choose out the efficient strains.The results showed that the inoculation of rhizobia significantly improved the nodules,height,fresh weight,dry weight,chlorophyll and total nitrogen contents of white clover.YA1121 and CD1105were the best strains among all tested strains.The 16 SrDNA sequence analyses indicated that both YA1121 and CD1105strains belonged to Rhizobium leguminosarum bv.Trifolii.These results will lay the foundation for the genetic diversity and phylogenetic study of rhizobia isolated from white clover in Sichuan area.