A Technology Established For Screening Resistant Genes To Sheath Blight And Verification Of R-PCR Technology

Maize(Zea mays L.)is one of the most important cereal crops in the world agricultural economy as food.Maize sheath blight is a very destructive disease that usually causes losses in grain yield ranging from11.0%to40.0%percent or to some content even over90.0%.Subgroup AG1IA of Rhizoctonia solani is the most major pathogen that causes maize sheath blight.In spite of several years of research in this area,the genetics of inheritance of resistance to Maize Sheath Blight is still unclear.This causes a major bottle neck in breeding of maize cultivar resistance Maize Sheath Blight,and also very limited sources of germplasm are available or the resistant sources can’t offer a high level and duriable resistance to this disease.We collect107plants belonging to48families from Wuhan area.An inoculation of plant pathogen R. solani on these plant’s leafs indicates that there are56plants belonging to34families showing a severe disease while51plants belonging to14families showing a slight disease or no disease.According to this result,we comfirm that R. solani can’t cause a disease on the two plants of Pinellia pedatisecta and Pinellia ternata and also we colone the lectin ofP. pedatisect、P.ternata and Gastrodia elata Bl.These provide us an opportune to further research the resistance of maize to R. solani.We construct cDNA library of P.pedatisectawhich is a resistant resource to R.solaniour inoculation expriment. We establish a system based on agrobacterium-mediated delivery of heterologous genes to express in tobacco.This system is an easy and efficient method to study unknown genes function.Blumeria graminis f. sp. tritici (Bgt) and Blumeria graminis f. sp. hordei (Bgh) are two world spread plant pathogens causing powdery mildew specifically in wheat and barley. While belonging to the same species Blumeria graminis(DC) Speer, and having the same lifestyle, they possess a strict host-specialization for wheat and barley, respectively. These properties provide us an obviously convenient opportunity to research the molecular basis of non-host resistance. R-PCR technology established by our laboratory is used in screening of the discrepant genes among Bht and Bgh. Using this technology on the level of genome, we obtain several interesting genes from Bgt and Bgh. A further research on these genes will unveil some possible reasons that determine a series of differences between Bht and Bgh.