Population Diversity And Plant Growth Promoting Activities Of The Cultivable Rhizosphere Microorganism And Endophyte From Dongxiang Wild Rice (Oryza Rufipogon Griff.)

In this study, To completely know the population diversity of cultivable microorganism from rhizosphere soil and plant tissue of Dongxiang wild rice and their plant growth promoting activities, The microbial community from rhizosphere soil and plant tissue of Dongxiang wild rice were studied with culture-dependent methods. The 147 rhizobacteria strains and 55 rhizosphere fungi strains of Dongxiang wild rice at different developmental stages were isolated. The 209 endophytic bacteria and 59 endophytic fungi from Dongxiang wild rice at different developmental stages were also isolated. All of these strains were investigated their plant growth promoting activities (PGPA) in prensent study.The results based on the morphological traits and sequence analysis of partial 16S rRNA gene indicated that a total of 147 bacteria isolates from rhizosphere were clustered into 6 groups and 13 genera: 29 ofα-Proteobacteria, 9 strains ofβ-Proteobacteria, 37 strains ofγ-Proteobacteria, 41 strains of Firmicutes, 2 strains of Aquificae, 19 of Actinobacteria. Among them, Bacillus (19%), Pantoea (16.3%) and Sphingomonas (15.6%) were the dominant genus. The total of 209 isolates from plant tissue were clustered into 6 groups and 16 genera: 31 ofα-Proteobacteria, 6 strains ofβ-Proteobacteria, 57 strains ofγ-Proteobacteria, 61 strains of Firmicutes, 50 of Actinobacteria, 4 strains of Aquificae. Among them, Bacillus (29.2%), Pantoea (11.5%) and Streptomyces, (11%) were the dominant genus.The cultivable bacterial diversity from rhizosphere soil and plant tissue of Dongxiang wild rice was abundant, and the Shannon-Wiener index was 1.494~2.954. The genera of the cultivable bacterial from rhizosphere soil and plant tissue were varied with the different developmental stages of Dongxiang wild rice.The results based on the morphological traits and sequence analysis of partial rRNA-ITS gene indicated that a total of 55 fungi isolates from rhizosphere were clustered into 2 groups and 9 genera: 51 of Deuteromycetes, 4 of Mastigomycotina. Three order of Deuteromycetes were isolates from rhizosphere of Dongxiang wild rice, Among them, Moniliales (29) was the dominant order , Penicillium (34.5%) was the dominant genus. The total of 59 endophytic fungi isolates from Dongxiang wild rice were clustered into 2 groups and 8 genera: 52 of Deuteromycetes, 7 of Mastigomycotina. Three order of Deuteromycetes were isolates from rhizosphere of Dongxiang wild rice, Among them, Moniliales (29) was the dominant order ,Penicillium (27.1%) and Fusarium(22%) were the dominant genus.The number of cultivable fungi from rhizosphere soil and plant tissue of Dongxiang wild rice was less, and the Shannon-Wiener index was 0.693~2.372. The genera of the cultivable fungi from rhizosphere soil and plant tissue were varied with the different developmental stages of Dongxiang wild rice.The results from PGPA analysis showed that the plant growth promoting bacteria (PGPB) with nitrogen-fixing, phosphorus-solubilizing, IAA-producing and siderophore-secreting bioactivities were abundant, and hereinto Pantoea was the dominant PGPR. Additionally, the total amount of PGPB of Dongxiang wild rice increased gradually at seedling stage, and reached its peak at heading stage, then decreased at grain filling stage. It were concluded that the cultivable microbial population diversity was abundant and there was a fascinating PGPR reservoir at the rhizosphere soil of Dongxiang wild rice. Our research made it is possible to further investigate the function of the rhizosphere microbes and their interaction with the rice plant.