Molecular Mapping Of QTL For Resistance To Soybean Mosaic Virus (SMV) Strain SC-3and Functional Prediction Of Candidate Genes In Soybean

Soybean mosaic virus （SMV） in soybean [Glycine max （L.） Merr.] is one of the most commondiseases in soybean-producting countries worldwide. It causes severe yield loss and a reduction in seedquality. The resistance in infection and resistance in development of soybean to SMV are two differentkinds of resistance mechanism. The resistance in infection is special to the strain. Some resistantcultivars will be risk of loss resistance to SMV due to the change of the strain. It’s of great importanceto study the non-specialized resistance in developmen to control SMV.A recombinant inbred line （RIL） population derived from Zhongdou No.29×Zhongdou No.32was inoculated with the SMV strain SC-3. A sample of156lines was evaluated for diseased rate（I）,diseased rank（S）, lantent period（LP） and rate of disease development（R） in order to study theperformance of two kinds of resistance to soybean mosaic virus in soybean. The performance of the fourresistance components were significantly different between lines. These results demonstrated theexistence of two kinds of resistance to SMV in soybeans.Genetic segregation analysis for disease index（DI） were conducted by using major gene pluspolygenes mixed inheritance models and joint analysis method of P1, P2and recombinant inbred line（RIL） population. Resistance in development to SMV was controlled by two major gene with additiveeffect of-18.19at a site，with additive effect of-7.85at b site，and a heritability of85.05%for themajor genes.Based on the RIL population, a genetic linkage map of soybean genome was constructed, whichconsisted of31chromosomes with264simple sequence repeat （SSR） markers, covering1260cM. Twomajor QTLs （qF-1and qF-2）were detected on F linkage group for disease index or disease rank usingcomposite interval mapping （CIM）. Closest markers locating two sides of qF-1respectively wereSat₁97and Satt554. Closest markers locating two sides of qF-2respectively were Satt522andAW756935. qF-1and qF-2explained24.1%and22.5%of phenotypic variation respectively. Eighteenpolymorphic markers were mapped to the confidence interval of SMV resistant QTL. One majorresistant QTL was detected within F linkage group after adding markers, explaining28.9%ofphenotypic variation.The analysis of bioinformatics of the candidate genes in the resistant QTL region indicated thatfine genes （Glyma13g38890, Glyma13g38900, Glyma13g38950, Glyma13g38980andGlyma13g39110）maybe involved in resistance to SMV strain SC-3in soybean.