小麦淀粉RVA特性的QTL定位及效应分析

QTL Mapping and Effect Analysis of RVA Characteristics of Wheat Starch

小麦淀粉糊化(RVA)特性是评价小麦加工品质重要指标之一。为进一步挖掘优质小麦淀粉糊化特性相关数量性状位点(QTL)及位点间效应差异,以周麦23/郑麦366的F8代重组自交系(RIL)群体的237个家系及其亲本为试验材料,利用55K核苷酸多态性(SNP)芯片构建高密度遗传图谱,根据2年3点5个环境下的数据对小麦淀粉RVA参数进行QTL定位分析。结果表明,共检测到96个QTL位点,位于21条染色体上,稳定位点共有8个,其中调控峰值黏度的Qpv.hau-4A.1和Qpv.hau-6A.1以及调控崩解值的Qbd.hau-4A.1和Qbd.hau-6A.1能够同时在2个以上的环境中检测到,分别解释了2.55%~24.23%、2.60%~6.00%、11.50%~48.30%和3.86%~8.09%的表型变异,调控峰值黏度的Qpv.hau-6A.1可能为新的QTL位点,其增效等位基因来源于优质强筋小麦品种郑麦366,对峰值黏度具有显著的增效作用,与面条的弹性和韧性有关。QTL聚合效应分析结果发现,Qpv.hau-4A.1和Qpv.hau-6A.1能极显著提高峰值黏度,且两者对峰值黏度具有显著的累加效应。此外,在4A和6A染色体上存在QTL富集区或者一因多效现象。这些重要区段和QTL位点为优质小麦淀粉糊化特性的分子标记辅助选择提供了重要的信息。

Wheat starch pasting property is one of the important indicators of processing quality in wheat.In order to further explore the QTL for starch pasting property,237 lines of the F8 RIL population derived from Zhoumai 23/Zhengmai 366 and their parents were used and a high-density genetic map was conducted by the wheat 55K SNP array.Combining the data of pasting property from 5 environments(three locations in two years),a total of 96 QTLs were mapped,which located on 21 chromosomes.There are 8 QTLs identified consistently in multiple environments.Among which,Qpv.hau-4A.1 and Qpv.hau-6A.1 regulating the peak viscosity,and Qbd.hau-4A.1 and Qbd.hau-6A.1 regulating the disintegration value accounted for 2.55%~24.23%,2.60%~6.00%,11.50%~48.30%and 3.86%~8.09%of the phenotypic variances,respectively.The QTL Qpv.hau-6A.1 may be a new locus for peak viscosity,its enhancing allele was derived from the highquality gluten wheat cultivar Zhengmai 366 and had significant synergistic effect on the peak viscosity,which was related to the elasticity and toughness of noodles.QTL polymerization effect analysis found that Qpv.hau-4A.1 and Qpv.hau-6A.1 have significant cumulative effect and can significantly improve the peak viscosity.In addition,there were QTL-rich regions or pleiotropism effects on chromosomes 4A and 6A.These important regions and QTL provided important information for improving starch pasting properties in high-quality wheat.