Endophytic Fungi (Trichoderma Viride) On Biological Control Of Sclerotinia Stem Rot Of Oilseed Rape

Sclerotinia stem rot of oilseed rape is a disease in the world on five continents in more than 100 States had a popular place of its very wide geographic distribution. It consists of Sclerotinia sclerotiorum disease caused by a fungi. In China, the three major diseases of Sclerotinia stem rot of oilseed rape ranks first in the general incidence ratio of 10% to 30%, serious, up to 80%. In the Yangtze River middle and lower reaches and along the southeast coast of the rape of some major producing areas, including Jiangsu, Anhui, Shanghai, Hunan, Zhejiang, Jiangxi, Hubei and so particularly occurring disease has seriously affected China's rapeseed production. Therefore,S. sclerotiorum has been considerable research attention.In this study, from the maidenhair tree, tea tree and Ormosia hosiei soil rhizospheres and roots, stems and leaves fungi isolated were screened with antagonistic effect against S. sclerotiorum biocontrol fungi; interior antagonist, spore germination tests colonization and pot plant, disease prevention field experiment collected the antagonism of fungi on S. sclerotiorum biocontrol potential, made the following findings.1 The separation of fungal biocontrol agents, screening and identificationYa'an collected from the maidenhair tree, such as three kinds of Ormosia hosiei and tea tree's roots, stems, leaves, and endophytic fungi isolated species of rhizosphere soil fungi, endophytic fungi were isolated from 73 rhizosphere soil fungi 29; by S. sclerotiorum in the antagonistic test to screen out strong antagonistic effect of endophytic fungi a virgin. Through morphological identification, the endophyte was identified as Trichoderma viride.2 T. viride on the antagonism of S. sclerotiorum and the germination ratios of ascosporesUse of T. viride HJZ3 fermentation broth inhibited the growth of S. sclerotiorum mycelium were used to determine 90% inhibition ratio; using fermentation broth soaked S. sclerotiorum and joined the PDA plate of the two methods measured HJZ3, S. sclerotiorum germination inhibition on the rape ratio, fermentation broth diluted 2 times, and S. sclerotiorum germination inhibition ratios were 66%,60%; in diluted 5 times, on the germination of S. sclerotiorum inhibition when compared to diluted 2-fold decrease in inhibition ratios were reduced to 30%,34%. HJZ3 broth diluted 2 times,5 times,10 times, S. sclerotiorum ascospores germination ratios were 58.3%,85.8%,90.4%, HJZ3 strains diluted 2 times,5 times,10 times the germination of spores ratios were 6.9%, 23.1%,53.6%.3 T. viride in vivo colonization of rapeMarked by T.viride, rape plants in soil and rhizosphere colonization on plant capacity in vivo determination of test results proved that the screening of T. viride can indeed better in the rhizosphere of rape plants and in vivo colonization, strains directly after inoculation, root pouring handle section 3d, the bacteria isolated from seedling roots reached 204cfu/mg, significantly higher than stems and leaves, indicating strain easily into the body of rape seedlings. And3,5,8,11,15 days after inoculation of rape seedlings were taken randomly from 5 to mark the separation of bacteria, testing shows that bacteria can be marked HJZ3 rape rhizosphere soil and in vivo colonization, reproduction and transmission.4 T. viride on the growth of rapeSoaking the seed rape antagonistic bacteria germination ratio, plant growth significantly facilitated. Among them, the inoculation of the seed germination ratio compared with the control non-vaccinated increases 2.29 (P<0.05), and the emergence of orderly, rapid; plant height, dry weight were significantly higher than the water control, the difference reached a significant level (P<0.05) or highly significant (P<0.01).5 T. viride against Sclerotinia stem rot of oilseed rape control the interior and field resultsInterior pot experiment, the control lesion size is 23.4mm, the two tested chemical and biological control treatment of the lesion size of bacteria were between 5～10mm, compared to experimental results, filtering out bacteria antagonistic fungi on rapeseed tuberculosis indeed inhibited; in field trials, statistics S. sclerotiorum in field strain ratio as high as 94.2% in control, both chemical and biological control bacteria in the processing of the 50%～60%, control of the disease index was 71.7%,17.5% of biocontrol bacteria, both chemical and biological control of field efficiency against bacteria were 65%～70%, but the biocontrol bacteria deal with the disease before the interior pot experiment results have some differences, which may affect the complex of the natural environment, resulting in antagonistic bacteria in the rape plant colonization ability of the body affected.