Molecular evolution of shattering loci in U.S. weedy rice.
Molecular evolution of shattering loci in U.S. weedy rice.
复制标题
DOI：
10.1111/j.1365-294x.2010.04708.x
复制
发表时间：
2010-08
影响因子：
4.9
通讯作者：
Caicedo AL
中科院分区：
文献类型：
--
作者：
Thurber CS;Reagon M;Gross BL;Olsen KM;Jia Y;Caicedo AL
杂草稻是栽培稻（Oryza sativa L.）的同种杂草，在世界范围内的栽培稻田中普遍存在。杂草稻的持久性部分归因于其在作物收获前粉碎（分散）种子的能力。在美国，单独进化的杂草稻群体已被证明与外来驯化品种共享基因组身份。在这里，我们调查了一系列美国杂草稻品种以及野生和栽培近缘种的破碎表型。我们发现，所有的美国杂草稻组粉碎种子容易，尽管有多个来源，并在相反的粉碎能力下降，看到在栽培群体。我们评估了杂草稻中主要落粒位点sh 4的等位基因身份和多样性;我们发现，所有栽培稻和杂草稻，无论人口如何，在sh 4都有相似的单倍型，并且都含有一个与落粒减少相关的单一衍生突变。我们的数据构成了迄今为止杂草从驯化背景进化的最有力的证据。共同的栽培品种sh 4等位基因和高度落粒表型的组合表明，美国杂草稻在通过替代遗传机制与其祖先分化后重新获得了落粒性状。
Cultivated rice fields worldwide are plagued with weedy rice, a conspecific weed of cultivated rice (Oryza sativa L.). The persistence of weedy rice has been attributed, in part, to its ability to shatter (disperse) seed prior to crop harvesting. In the United States, separately evolved weedy rice groups have been shown to share genomic identity with exotic domesticated cultivars. Here, we investigate the shattering phenotype in a collection of U.S. weedy rice accessions, as well as wild and cultivated relatives. We find that all U.S. weedy rice groups shatter seeds easily, despite multiple origins, and in contrast to a decrease in shattering ability seen in cultivated groups. We assessed allelic identity and diversity at the major shattering locus, sh4, in weedy rice; we find that all cultivated and weedy rice, regardless of population, share similar haplotypes at sh4, and all contain a single derived mutation associated with decreased seed shattering. Our data constitute the strongest evidence to date of an evolution of weeds from domesticated backgrounds. The combination of a shared cultivar sh4 allele and a highly shattering phenotype, suggests that U.S. weedy rice have re-acquired the shattering trait after divergence from their progenitors through alternative genetic mechanisms.