Molecular Identification And Comparison Of Soybean Rsv3 Complex Locus Between Multiple Resistant/Susceptible Lines

Soybean mosaic virus (SMV) is a prevalent viral pathogen of soybean wherever it is grown. The virus, causing significant yield reduction and financial loss every year, belongs to the family Potyviridae and the genus Potyvirus. SMV can be divided into different strains according to different virulence, resulting in mosaic, necrosis or other symptoms on soybean.Up till now,3 genes that confer resistance to SMV in soybean have been identified, which are Rsvl, Rsv3 and Rsv4. Rsv3 was mapped to Molecular Linkage Group B2(Chromosome 14) between molecular markers A519 and M3Satt. There are 5 CC-NBS-LRR genes between the two markers, which are 14g38500,14g38510, 14g38540,14g38560,14g38590。In this research, we applied PCR techniques to amplify these 5 genes in several resistant soybean cultivars(Harosoy, Tousan140, L29, J05). Non-specific primers and specific primers were used and we got the sequences of 38500,38510,38540 and 38560 while 38590 is still being sequenced. Along with the sequences of susceptible cultivars that our lab has got, we compared and analyzed these CNL genes between resistant lines and susceptible lines. Results showed that 38500 and 38510 do not differ much between resistant and susceptible lines while 38540 and 38560 differ a lot and recombination events happened in the two genes. We inferred that 38540 and 38560 are the functional genes in Rsv3. But it needs to be verified through transgenic technology.In order to get the whole sequence of the Rsv3 locus, we constructed a BAC library of Zaoshul8. Using SSR molecular markers, we screened out three positive single clones that covers Rsv3 locus. Yet there are still two gaps between them, 14.13kb and 39kb, which needs to be complemented through PCR. The construction of Zaoshu18 BAC library provides a great foundation for future research of Rsvl and Rsv3.