Multiple genetic pathways for seed shattering in the grasses
Multiple genetic pathways for seed shattering in the grasses
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DOI：
10.1007/s10142-005-0015-y
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发表时间：
2006-10-01
影响因子：
2.9
通讯作者：
Gill, Bikram S.
中科院分区：
文献类型：
--
作者：
Li, Wanlong;Gill, Bikram S.
破碎是野生物种中重要的种子传播机制。据信，直系同源基因座的独立突变导致谷类作物的趋同驯化。为了研究小麦科破碎基因与其他禾本科植物的遗传关系，我们绘制了小麦及其野生近缘种的穗型、桶型（B型）和楔型（W型）小穗断节基因。用于W型脱节的Br1基因被定位到由Xpsr598和Xpsr1196界定的区域，该区域位于Triticum timopheevii的染色体3A和Aegilops speltoides的3S染色体的短臂上。刺突型和 W 型断节基因在伊蚊中的 Br1 处是等位基因。拼写。 B型脱节基因，命名为Br2，定位于普通小麦D基因组供体节节山羊草3D染色体长臂上Xmwg2013和Xpsr170之间4.4 cM的间隔。因此，B 型和 W 型脱节由 3 组染色体上的两个不同的直系同源基因座控制。根据图谱位置，在大麦、玉米、水稻和高粱中未检测到 Br1 和 Br2 的直系同源物，表明禾本科植物中存在多种碎裂遗传途径。讨论了绘图结果对多倍体小麦进化和谷物驯化的影响。
Shattering is an essential seed dispersal mechanism in wild species. It is believed that independent mutations at orthologous loci led to convergent domestication of cereal crops. To investigate genetic relationships of Triticeae shattering genes with those of other grasses, we mapped spike-, barrel- (B-type), and wedge-type (W-type) spikelet disarticulation genes in wheat and its wild relatives. The Br1 gene for W-type disarticulation was mapped to a region delimited by Xpsr598 and Xpsr1196 on the short arm of chromosomes 3A in Triticum timopheevii and 3S in Aegilops speltoides. The spike- and W-type disarticulation genes are allelic at Br1 in Ae. speltoides. The B-type disarticulation gene, designated as Br2, was mapped to an interval of 4.4 cM between Xmwg2013 and Xpsr170 on the long arm of chromosome 3D in Aegilops tauschii, the D-genome donor of common wheat. Therefore, B- and W-type disarticulations are governed by two different orthologous loci on group-3 chromosomes. Based on map position, orthologs of Br1 and Br2 were not detected in barley, maize, rice, and sorghum, indicating multiple genetic pathways for shattering in grasses. The implications of the mapping results are discussed with regard to the evolution of polyploid wheat and domestication of cereals.