QTL Analysis For Yield Traits Using SL-RIL Population In Wheat

Wheat?Triticum aestivum L.?is an important food and cash crop.As an important part of world food security,the cultivation of high-yield wheat varieties is one of the most basic and feasible ways to ensure world food security.In this study,a recombinant inbred line?RIL?population derived from the cross of “Shannong 0431× Lumai 21”?SL-RIL?was used as the material.A genetic map basis the unigene positon in wheat genome was constructed.QTL analysis for 11 yield-related traits was carried out,aiming to lay a foundation for molecular marker assisted selection?MAS?and gene cloning of wheat yield-related traits.The main results are as follows:?1?Based on the v1.0 version of Chinese Spring Wheat Genome,the genetic map of SL-RIL population was constructed based on the physical location.The final map covered 21 chromosomes,including 20988 unigenes,with a total length of 54717.5 cM,and an average density of 2.61 cM.?2?The large variation range were showed for the 11 traits in eight environments?including average value,AV?.The variation coefficient for the number of top sterile spiklet per spike?TSSS?in ZBD14 is the largest,which is 210.44%;The variation coefficient of total spikelets per spike?TSS?in AVD was the smallest,4.27%.The heritability of different traits were ranged form 96.10% for plant height?PH?to 58.61% for theoretical grain yield?TGY?.According to the analysis of variance?ANOVA?,the differences between genotypes and environments of all the 11 yield traits reached the significant level of P?0.001,indicating that the genotypes and environments had significant effected the trait variation.The correlation between most traits was significant.?3?A total of 595 additive QTLs?757 single-environment QTLs?were detected for the 11 traits under 8 environments,distributing on all 21 wheat chromosomes.The additive effect of 282 QTLs was negative,indicating that male parent Lumai 21 were the source of increasing effects of QTLs;whereas the additive effect of 313 QTLs were positive,indicating that female Shannong 0431 was the source of increasing effects.The phenotypic variation of a single QTL was 4.02-32.46%.Among them,211 QTLs on 21 chromosomes were related to yield and its components,explaining 4.02-23.07% of the phenotypic variation for a single QTL;and There were 384 QTLs on 21 chromosomes were related to plant height and panicle traits,explaining 4.03-32.46% of the phenotypic variation.?4?A number of 27 RHF-QTL were found on 19 chromosomes except for 3D?5D?,containing the traits of bottom sterile spikelets per spike?BSSS?,fertile spikelets per spike?FSS?,plant height?PH?,spike length?SL?,1000-grain weight?TGW?,the total spikelets per spike?TSS?.The RHF-QTLs can explain the phenotypic variation was 4.03%-32.46% 0f these,17 RHF-QTLs showed positive additive effects,indicating that mother parent Shannon 0431 was the source of the increasing effects;whereas 10 RHF-QTLs showed negative additive effects,indicating that the increasing effects were caused by the parent Lumai 21.The average contribution rate of 11 RHF-QTLs were more than 10%,which were major RHF-QTLs.?5?A total of 2 QTL clusters?C1-C2?were obtained,involving 4 RHF-QTLs,which were located on the marker ranges of 0072925^S₀332902 and S₀903283^S₀903413 of chromosomes 2D and 6B,respectively.