高粱黄色籽粒基因Yellow Seed 2的定位及候选基因分析

Genetic Mapping and Candidate Gene Analysis of Yellow Grain Gene Yellow Seed 2 in Sorghum

高粱在我国农业结构调整和酿酒行业中具有重要的作用。籽粒颜色是高粱重要的性状之一,但有关高粱籽粒颜色的研究并不多。本研究观察了高粱黄色籽粒材料GLB41的籽粒发育过程,花后1~16 d为快速生长期,17~24 d进入缓慢膨大期,第25天开始进入转色期,绿色逐渐褪去,籽粒颜色由乳白色或苍白色逐渐变成浅黄色,随后颜色加深,40 d后籽粒颜色变为深黄色。利用黄色籽粒GLB41和白色籽粒6E16两个材料构建的群体,使用重测序BSA方法,将控制黄色籽粒性状的基因初定位在1号染色体15.6 Mb区间内,利用3215株分离个体将该基因定位在BR13和P2两个标记之间,区间内有7个候选基因,对这些基因的功能注释进行分析并测序,结果表明GLB41、6E16两个材料中未被报道过的基因Yellow Seed 2(Sobic.001G397900)的编码区内第619~621位插入CTG 3个碱基,导致增加了1个Leu(亮氨酸),第819位C突变为G,导致Cys(半胱氨酸)突变为Trp(色氨酸);第912位C突变为T,但氨基酸序列无变化。因此推测Yellow Seed 2可能参与这两份亲本材料籽粒颜色的形成。本研究为高粱籽粒颜色性状的研究提供了新的基因。

Sorghum plays an important role in agricultural farming and brewing industry of China.The grain color is one of the important traits,while its genetic basis remains largely unclear.By observing the grain development process using yellow grain material GLB41,we found that on 1 to 16 days after flowering the grain grew rapidly,followed by the slow expansion on 17~24 days,and the coloring on 25 days after flowering.At the coloring stage,the green color gradually faded,the grain color gradually changed from milky white or pale white to light yellow,and then the color deepened,and the grain color changed to dark yellow after 40 days.The genetic locus controlling the yellow grain trait was initially mapped to a 15.6 Mb interval on chromosome 1,and was further delimited between two markers BR13 and P2 by fine mapping in 3215 individuals.The functional annotation suggested seven candidate genes.Through Sanger sequencing of the candidate genes in GLB41(yellow grain)and 6E16(white grain),we found three sequence variations(insertion at 619’-621’,CTG/Leu;mutation at 819’,Cys to Trp;synonymous mutation at 912’,C to T)at the unreported gene Yellow Seed 2(Sobic.001G397900).Therefore,it is speculated that Yellow Seed 2 may be involved in the formation of the grain color of these two parent materials,as a new gene for further deciphering the functional mechanism of grain color in sorghum.