Strains Identification Of Soybean Mosaic Virus In Huang-Huai And The Middle And Lower Changjiang River Valleys And The Resistant Sources As Well As The Inheritance Of Resistance In Soybeans

Soybean Mosaic Virus (SMV) is one of the most serious diseases in soybean production all over the world. Studies on identification of strains screening for resistant germplasm, inheritance of resistance, genetic improvement of resistance and molecular marker of genes resistant to SMV strains in soybeans had been conducted. In the present study, specimens of soybean virus collected from Huang-Huai and the Middle and Lower of Changjiang river valleys were used to study the identification, distribution and change of SMV strains in these areas, and to screen for germplasm resistant to the newly identified SMV strains. Meanwhile, the soybean cultivars clearly resistant or susceptible to SMV strain were used to analyze the inheritance of resistance to SMV strain in multiple generations, in order to provide some useful information for soybean breeding for disease resistance arid to make preparations for the mapping and cloning of resistance genes. Eighty-one specimens of soybean mosaic virus (SMV) were identified and classified into eight stain groups as SC-I C-S based on disease reaction on twenty-five soybean cultivars. From these the nine cultivars including Nannong 1138-2, Qihuang No.10, 8101, Tiefeng No.25, Davis, Buffalo, Zaoshu 18, Kwanggyo, and Qihuang No.1 were selected as a set of differential hosts to identified the SMV strain groups. The comparison of SMV strains SC-I C-S with SMV-American strains G,7, SMV-iiangsu strains Sah, SMV-Hubei strains S1---S2, SMV-Northeast of China strains Sl-1M-S3-3N and SMV-Shandong strains y1----y, showed that only the SC-l and SC-2 had the same reactions on most but not complete differential hosts with the SI-1M, S2-IN, and S2-1M, the same to the SC-3 and Sf, the SC-8 and y~. Reactions of the rest of them on the differetials were obviously different. Twenty-one cultivars and lines with elite resistance to SMV strains were selected through inoculation by isolated with the mixture of SC-i C-8 strain groups and subsequently with the SC-I and SC-8 respectively The responses of P1. P,, F2.3, and F7:10 lines to the SC-S strain group in the cross between Kefeng No. I and 1138-2 were investigated to examine the inheritance of resistance to SC-S. The results showed that the resistance to SC-S in Kefeng No. I was controlled by a dominant gene which was denoted here as R58 temporary.