| 1.17×103~11.16×103CFU/g (fresh weight) endophytic bacteria were obtained from the plants of solanaceae isolated by the surface sterilized with 0.1% mercury bichloride, 2.28xl03~17.80xl03 CFU/g (fresh weight) from roots, 1.52xl03~19.68 x103CFU/g (fresh weight) from stems, 0.70xl03~11.00x103 CFU/g (fresh weight) from leaves and 0.1xl03~0.92x103 CFU/g (fresh weight) from fruits. Of 523 endophytic bacteria isolates, 28.3% and 16.3 %, had inhibitory activity to Fusarium oxysporum f.sp.cucumberinum and Ralstonia solanacearum in vitro respectively.Nineteen isolates inhibiting Phytophthora capsici were screened out from 168 isolates which obviously antagonized against the growth of F. oxysporum f.sp. cucumerinum or R. solanacearum. Among them, seven isolates, 2, 13, 20, TL6, TMS2, TB2 and QEL1 could inhibit the growth of the three pathogens, while six isolates 20, 22, TL6, TB1, TB2 and EPL8 could live in capsicum and tomato plant and, promote the growth of tomato and control the fruits pepper phytophthora blight of capsicum. The six endophytic bacterial isolates were identified as Bacillus sp.. 16S rRNA gene sequence analysis showed they belonged to relative species of B. subtilis. Strain 22 and EPL8 were identified as B. subtilis by VITEK-32 system and strain TB2 was identified as B. amyloliquefaciens by Biolog system.The six endophytic antifungal bacterial strains were used to control pepper phytophthora blight. The results showed that the pepper phytophthora blight of the capsicum seedlings and fruits were controlled effectively by endophytic antifungal bacterial strains. Tests showed that the disease occurrence was delayed and the disease rate was decreased by endophytic bacteria. Seed coating and seed coating plus root drenching with these strains cultures gave 17.8-74.6 % and 30.8-80.4 % control efficacies respectively, on capsicum seedlings 20 d after inoculation of the pathogen P. capsici,. These strains also gave 53.5~82.9% control efficacies to the fruit phytophthora blight 14 d after inoculating the pathogen by spraying on fruits. Endophytic B. amyloliquefaciens strain, TB2, isolated from stem of tobacco was an efficient biological control agent to control pepper phytophthora blight. Seed coating and root drenching with TB2 cultures gave 70.0% and 88.1% control efficacies respectively, on capsicum seedlings 20 d after inoculation of the pathogen P. capsici, While spraying on fruits gave 65.2% control efficacy to the fruit phytophthora blight 14 d after inoculating the pathogen.The growth of tomato and cabbage were significantly promoted by dipping seeds with cells suspensions of the six strains. The TB1 and TB2 strains also promoted the growth of tobacco and capsicum. Compared with the water control, the dry weight of the 12 d old tomato seedling, 35 d old capsicum and 40 d old tobacco seedling were increased by 31.3%, 91.3% and 172.6% respectively tested in the pots and the dry weight of 30 d old cabbage was increased by 28.3% in field test by TB2 strain.The six strains were proved to be able to colonize in the plant of eggplant, tomato,capsicum and tobacco by watering roots with rifampicin mutant strains cultures. The result indicated that the colonization was not host specialization but the colonization levels were related to the original host. The results also showed that the TB2 strain was able to live and move from root to leaf in the plants of capsicum and tobacco for long time.The research on biological control mechanisms showed that the TB2 strain could inhibit the mycelial growth and reduce the sporangia and zoospores production of P. capsici. The treatment with TB2 strain considerably increased the SOD and POD activities in the capsicum fruits. Inoculation with P. capsici on fruit also significantly increased the MDA content and SOD, POD and CAT activities. However, the MDA content and SOD, POD and CAT activity of the capsicum fruits co-inoculated with the strain TB2 and P. capsici at the same time did not remarkably change comparing with fruits inoculating with sterile water. The O2- pr...
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