Colonization And Adjusted Effect Of Inoculating With Antagonistic Strains Y13on Microbe In Camellia Oleifera

Camellia oleifera anthracnose is one of the major diseases in China’s Camellia Produeing areas. It damages fruits、leaves、shoots and buds of Camellia oleifera, and seriously affect total yield. The study found endophytic Bacillus subtilis strain Y13which was obtained from oil-tea leaves through isolation and screening, possess better control effect to camellia anthracnose. But its control effect is not stable in the fields experiment. So in order to effectively take advantage of the strain Y13, this paper mainly studies colonization of Bacillus subtilis Y13and adjusted effect of inoculating with strains Y13on microecology in camellia oleifera. The main results were as followed:(1) Colonization dynamics of endophytic antagonistic bacteria Y13in Camellia oleifera. We screeninged Y13Rmarked with300μg/mL rifampicin, inoculated of camellia seedlings with strains Y13R by root drenching, leaf spraying, stem injecting and leaf puncturing methods, and investigate the colonization capacity of strains Y13R in camellia oleifera, the results showed that strains Y13could invade camellia oleifera tissues by natural orifice or a wound, reproduce and transfer in camellia oleifera tissues in camellia oleifera. Strains Y13R of different concentrations could colonize in camellia oleifera, but when the Y13R concentration increased, colonization time gradually extended and the quantity of strains Y13Ralso increased accordingly. The best concentration of inoculating with strains Y13R was109cfu/mL, and the best method of inoculating was leaf puncturing. The quantity of strains Y13R by leaf puncturing showed a trend "fist increasing then decreasing",20days after inoculation,3.59X103cfu/g strains Y13R could be detected in Camellia oleifera leaves.(2) Microflora difference between healthy and diseased Camellia oleifera. Microflora of healthy and diseased camellia oleifera consisted of bacterium and fungi, no actinomyces. Endophytic bacteria belong to5genera of7species and endophytic fungi belonged to9genera of7species.The community composition of endophyte and predominant species had evident distinction in healthy and diseased camellia oleifera. The bacterial species in diseased tissues were more than those in healthy tissues. Bacillus subtilis^Lysinibacillus sphaericus and Bacillus cereus were the same dormant bacteria in healthy and diseased camellia oleifera; Bacillus anthracis、Sphingomonas spp. and Klebsiella pneumonia were the domiant bacteria only in diseased camellia oleifera. The bacterial quantity were significantly higher than fungi’s in healthy and diseased leaves (p<0.05). The bacterial quantity in diseased leaves was1.12-26.63times of that in healthy leaves. The fungi quantity in healthy leaves was1.33-2.40times of that in diseased leaves. The diversity and equality of microbial community in healthy and diseased leaves was analyzed, and the results showed that the diversity and equality of microbial community in healthy leaves were higher than that in diseased leaves.(3) Adjusted effect of inoculating with antagonistic strains Y13on microbe in Camellia oleifera. Strains Y13R displayed good colonization in healthy and diseased leaves, and colonization ability was stronger. After inoculation with strains Y13R, the bacterial quantity increased by32.81%-902.59%, and the fungi quantity in diseased leaves decreased by4.36%～39.30%in healthy leaves.3d and20d after inoculation, the bacterial quantity increased by162.85%and138.98%accordingly, and the rest are lower than the control group. The fungi quantity increased by44.41%～109.42%in diseased leaves. The quantity of predominant species had evident distinction in different treatments. After inoculation with strains Y13R, the quantity of Bacillus subtilis increased by87.71%～5358.54%in healthy and diseased leaves; the quantity of Colletotrichum gloeosporioides decreased by18.45%～79.48%in healthy and diseased leaves. Camellia oleifera’s disease index in four treatments had the significant difference (P<0.05), and the control effects of strains Y13R for healthy and diseased Camellia oleifera were71.85%and64.84%respectively.