宁麦9号与扬麦158株高及其构成因素的遗传解析

Genetic analysis of plant height and its components for wheat(Triticum aestivum L.)cultivars Ningmai 9 and Yangmai 158

宁麦9号与扬麦158是我国长江中下游麦区的主栽品种和骨干亲本,长江中下游麦区近3年来审定品种中80%都是其衍生后代,研究其性状的遗传具重要意义。以宁麦9号与扬麦158为亲本构建的包含282个家系的重组自交系群体为材料,利用Illumina 90k芯片对群体进行基因型分析,建立高密度遗传图谱。连续3个生长季对株高及节间长度、穗长等株高构成因素进行测定,结合遗传图谱对株高及相关性状进行QTL定位,获得14个控制株高及其构成因素的稳定表达位点。通过进一步位置比对,聚焦到6个染色体区段,初步明确了各节间对株高的遗传调控机制。同时,将6个染色体区段中同源性较低的连锁标记转化为适用于高通量筛选的KASP标记,利用101份区域试验材料进行标记效应验证,结果显示聚合Qph-2D与Qph-5A.1两个位点具有较高的选择效率,继续聚合Q2A后,中选材料显著减少,可能降低选择效率;对Q2A与Q5A两个一因多效位点的选择建议以降低株高的等位变异为主;Qd1-5D可作为穗下节间(D1)的选择标记对株高展开优化选择。期望以上结果能为长江中下游麦区的小麦株高遗传改良提供帮助。

Ningmai 9 and Yangmai 158 are the main wheat cultivars and core parents in the middle and lower reaches of the Yangtze River in China.In the past three years,80%of the released varieties in the middle and lower reaches of the Yangtze River had the background of Ningmai 9 or Yangmai 158.To make better use of these two parents,the genetic mechanism of their traits need to be further clarified.A high-density genetic map was constructed by Illumina 90 k chip using 282 recombinant inbred lines(RILs)from the cross between Ningmai 9 and Yangmai 158.In this study,the traits including plant height,internode length,and spike length were determined in three consecutive growing seasons,and 14 stable QTLs were obtained by QTL mapping.By further position alignment,we focused on six chromosome intervals,which preliminarily revealed the genetic regulatory mechanism of the internode on plant height.KASP markers suitable for high-throughput analysis were developed based on the low-homology markers in the six chromosome intervals,and they were further validated in 101 wheat accessions.The polymerization of Qph-2 D and Qph-5 A.1 had high selection efficiency which might be decreased if further intruding Q2 A.It suggests that the selection of Q2 A and Q5 A should mainly focus on the alleles reducing plant height,and Qd1-5 D could be used in marker-assisted selection for internode length below spike(D1).The results in this study may provide assistance for wheat height genetic improvement in the middle and lower reaches of the Yangtze River.