| Stem rot disease of rapeseed caused by the ascomycetous fungus Sclerotinia sclerotiorum is a devastating plant pathogens worldwide, with incidence of 10% to 30%, and up to 80% in severe cases. This disease is not only detrimental to the yield and quality of rapeseed, but also influential in production safety of grain and oil. In this study, we isolated 96 S. sclerotiorum isolates from sclerotia collected from the main rapeseed stem rot disease area of Changde, Yiyang, Yueyang, Shaoyang, Huaihua, Hengyang, Loudi, Chenzhou, and tested their pathogenicity on detached leaves of rapeseed. The results showed visible difference in lesion sizes resulting from different fungal strains, after being inoculated for 60h. They are distinct pathogenicity differentiation among the S. sclerotiorum population in Hunan planting region. Strains collected from Changde and Yiyang are highly pathogenic, contrary to that from Yueyang and Chenzhou, on rapeseed leaves. With an attempt to screen actinomyces strains potential for biocontrol of S. sclerotiorum, we cultured the 24 actinomyces strains isolated previously and conducted a confront culture and culture filtrate antifungal tests. A strain named H02 displayed evident antifungal activity up to 72.31%. H02 has been identified as Streptomyces anulatus according to its incubation traits, morphology, physiological and biochemical identification along with the 16S rRNA sequences analysis. Antifungal spectrum research of H02 showed that it also has less obvious antifungal activity, at rate from 10.77% to 14.17%, to a variety of plant pathogens. In conclusion, the results provided scientific basis for biocontrol of rapeseed stem rot disease. |
PDF Full Text Request