| In order to discover new quantitative trait loci (QTL) for Fusarium head blight (FHB) resistance,a total of 2 018 simple sequence repeats (SSRs) and sequence tagged site (STS) markers were analyzed between parents N553 and Yangmai 13 for genetic map construction and QTL scanning. In this research, 217 polymorphic markers were identified and used to screen a population of 184 recombinant inbred lines (RILs) derived from a cross between N553 and Yangmai 13. Results showed that, five QTLs were found for FHB resistance using WinQTLcart 2.5 software. Among them, two QTLs were contributed by N553 and the other three were contributed by Yangmai 13. A stable major QTL, QFhb.jaas-2DS,was detected on the short arm of chromosome 2D, which could explain 8.17% to 11.42% of phenotypic variation for FHB resistance. A second stable major QTL, QFhb.jaas-3BS, was identified to be located between marker barc102 and gwm493, which could explain 5.33% to 42.96% of phenotypic variation for FHB resistance. Besides, three other minor QTLs on chromosome 2BS, 3BL and 4AS with less than 10% explanation of phenotypic variations in individual experiments were detected. The polymerization of these two major QTLs ( QFhb.jaas-2DS and QFhb.jaas-3BS) was proved to significantly increase the resistance to FHB. At the same time, one QTL related to spikelet compactness (SC) was mapped on chromosome 3B, explaining 5.36% to 6.08% of phenotypic variation; five QTLs associated with plant height (PH) were mapped on chromosomes 4A, 7A, 5B, 6B, explaining 5.2% to 8.93% of phenotypic variation.Correlation analysis showed that spikelet compactness had a significantly positive correlation with FHB resistance, while plant height had a significantly negative correlation with resistance to infection of FHB, and no significant correlation with resistance to spread of FHB.Combined with the result of QTL detection and correlation analysis,we know that QFhb.jaas-3BL may not be the locus of FHB resistance.Therefore,three QTLs related to FHB resistance and detected in a single environment,with a contribution rate less than 10%,need to be fureber tested in multi-site experiments for many years. |
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