高粱子粒单宁含量和颜色QTL分析

QTLs Analysis of Tannin Content and Color of Grain in Sorghum

高粱在我国酿酒行业和农业结构调整中均有重要作用。子粒单宁含量和粒色是高粱两个重要的品质性状,但有关高粱子粒单宁和粒色分子遗传的报道还较少。本研究用白粒低单宁的BTx623与浅粉高单宁Rio两个品种为亲本,构建了含325个株系的重组自交系基因定位群体,开展高粱子粒单宁和粒色基因定位研究。筛选出118个SSR标记和8个INDEL亲本多态性标记用于定位群体株系的基因型检测,结合亲本和定位群体子粒单宁和粒色2年测定数据,采用QTL Ici Mapping 4.1软件中的完备区间作图法,对高粱子粒单宁和粒色2个性状进行QTL定位,共检测到3个与单宁含量相关和6个粒色相关的QTL位点。与单宁含量相关的QTL qTan4-1即为已克隆的Sb04g031730,另外检测到新的qTan1-1(txp11~txp279,贡献率1.29%)和qTan2-1(txp298~SB1292,贡献率1.28%),但2014年未检测到。控制粒色的6个QTL中,qGC1-1(贡献率1.00%和12.03%)在txp11~txp279之间;qGC1-2(贡献率2.64%和16.96%)在txp43~txp11之间;qGC1-3(2014年贡献率22.81%)在1d1A3~sam44127标记之间;qGC2-1(2014年贡献率1.00%)在txp72~txp298之间;qGC2-2(贡献率1.19%和3.66%)在txp298~SB1292之间;qGC6-1(2015年贡献率15.08%)在txp57~sam43683之间。本研究为高粱子粒单宁和粒色2个性状的精细定位、基因克隆和分子标记辅助选择研究奠定了基础。

Sorghum plays an important role in brewing liquor and adjustmenting crops planted in agriculture in China. The tannin and the color of grain are two important quality traits,but less molecular genetic researches of these two traits were reported. In this study,recombinant inbred lines with 325 lines were constructed using BTx623（ white grian and low tannin） and Rio（ pink grain and high tannin） as parents for gene mapping of tannin and color of sorghum grain. Total 126 markers（ 118 SSRs and 8 Indel） were screened to identify population genotypes,and used two years measured phenotype data to map genes through inclusive composite interval mapping（ ICIM） method.Totally 3 and 6 QTLs were mapped with related to content of grain tannin and seed color respectively. For tannin content,one known tannin regulated gene Sb04 g031730 were located in the QTL qTan4-1,and the other two QTLs,qTan1-1（ txp11-txp279,rate of contribution 1. 29%） and qTan2-1（ txp298-SB1292,rate of contribution 1. 28%）,were new loci related with sorghm tannin content. In grain color QTL analysis,qGC1-1（ rate of contribution 1. 00%and 12. 03%）,qGC1-2（ rate of contribution 2. 64% and 16. 96%）,qGC1-3（ 2014,rate of contribution 22. 81%）,qGC2-1（ 2014,rate of contribution 1. 00%）,qGC2-2（ rate of contribution 1. 19% and 3. 66%） and qGC6-1（ 2015,rate of contribution 15. 08%） were mapped between txp11-txp279,txp43-txp11,1 d1 A3-sam44127,txp72-txp298 and txp298-SB1292,txp57-sam43683（ chr6） respectively. Our study laid the foundation and provided new data for genetic regulation of grain tannins and color and foundation for gene cloning.