圆锥小麦四排穗性状基因的遗传及分子标记分析  

Inheritance and Mapping of Gene Controlling Four-Rowed Spike in Tetraploid Wheat (Triticum turgidum L.)

作　　者：张瑞奇[1] 王秀娥[1] 陈佩度[1] 

机构地区：[1]南京农业大学,作物遗传与种质创新国家重点实验室,细胞遗传研究所,江苏南京210095

出　　处：《作物学报》2013年第1期29-33,共5页Acta Agronomica Sinica

基　　金：南京农业大学青年科技创新基金项目(KJ2011002)资助

摘　　要：四排穗(four-rowed spike,FRS)性状是超数小穗(supernumerary spikelets,SS)性状的一种类型,表现为在一个穗轴节片上近垂直地着生2个无柄小穗,从而增加了小穗数和穗粒数,对提高产量有一定的潜力。为了解圆锥小麦0880 FRS性状的遗传特征,将0880与正常穗(normal spike,NS)圆锥小麦0879杂交,构建了遗传群体,并对0880(FRS)×0879(NS)与0879(NS)×0880(FRS)F1、F2及F2:3植株的穗部性状进行了调查。结果显示,正反交组合的F1植株均表现为正常穗,F2群体中正常穗与四排穗符合3∶1的分离比例,表明0880的四排穗性状由隐性单基因控制,将该基因定名为frs1;细胞质对frs1无显著影响。采用已定位于普通小麦A组与B组的SSR分子标记并结合混合分组分析法(BSA),筛选出32个在双亲及F2单株构建的四排穗型池和正常穗型池都具有多态性的SSR分子标记,利用JoinMap4.0软件构建了与frs1连锁的2A染色体11个SSR分子标记遗传图谱,其中SSR标记Xwmc598和Xwmc522位于frs1基因两侧,与该基因的遗传距离分别为4.0cM和2.4cM。利用2A染色体缺失系对这11个SSR进行物理定位,Xwmc598和Xwmc522均被定位在2A染色体短臂FL0～0.78区域。本研究的结果为frs1基因的精细定位及分子标记辅助选择奠定了基础。In hexaploid wheat and tetraploid wheat the spike normally bears one spikelet per rachis node, and the appearance of supernumerary spikelets is rare. The morphological characteristic of four-rowed spikes （FRS） is one type of the supernumerary spikelets traits, presenting as two spikelets per rachis node. Thus, the grain yield of FRS plants can be enhanced because the num- bers of spikelets and seeds of FRS are increased. To understand the genetic basis of FRS trait, the tetraploid FRS cultivar 0880 was crossed reciprocally to normal-spike （NS） cultivar 0879. The phenotypic evaluation of F1, F2, and F2：3 generations was con- ducted under greenhouse condition. The results indicated that all F1 plants of the reciprocal crosses showed normal spike, indicat- ing that the FRS trait was recessive to normal spike. In the reciprocal F2 populations, the ratios of normal spike to four-rowed spike were 3：1 according to Chi-square test. This indicates that FRS trait is controlled by a recessive allele without cytoplasm effect, and the data from reciprocal crosses could be pooled. This single recessive allele of the FRS trait was designated frsl. A total of 600 SSR markers located on A and B genomes of common wheat were used to amplify the 0880, 0879, four-rowed pool, and normal-spike pool. Among them, 32 SSR markers showed polymorphism between the four-rowed-spike pool and the nor- mal-spike pool. Eleven markers were identified to be linked with the frsl locus in a genetic map of chromosome 2A. Markers Xwmc598 and Xwmc522 were located on both sides offrsl with genetic distances of 4.0 cM and 2.4 cM, respectively. The placement of flanking microsatellite loci into chromosome deletion bin 2AS5 （FL 0--0.78） delimited the physical location offrsl to this region. This map provides a basis for fine mapping offrsl and marker-assisted selection of FRS trait.

关 键 词：圆锥小麦 超数小穗 四排穗 基因定位 

分 类 号：S512.1[农业科学—作物学]