吉林省杂草稻遗传多样性及起源的研究

摘要

In recent years, weedy rice is increasingly becoming a serious problem in rice production. On the other hand, weedy rice can be used as new germplam resources for rice breeding. This paper reports a study on the botanical characteristics of weedy rice found in Jilin Province of Northeast China. Phylogenetic origin of weedy rice was estimated based on polymorphic banding patterns derived from 26 pairs of SSR primers. For the botanical traits, the majority of the weedy forms were taller than the cultivated rice; glume color was straw yellow, reddish brown, yellow, dark brown, purple black, grayish black or yellow brown; pericarp was mostly red colored; awn appeared in straw yellow and reddish brown color; and the plants were prone to seed shattering and lodging. Polymorphism were identified in 21 (80.77%) out of the 26 SSR loci. The Shannon polymorphism index (I) ranged from 0.2237 to 1.6357 with the average of 0.8402. The expected heterozygosity (He) ranged from 0.1107 to 0.7812 with the average of 0.4840. Among the five clusters based on botanical diversity, weedy rice was found to be more closely related to the local Japonica rice varieties, but more distant from the lndicaJJaponica rice in neighbor provinces as well as wild rice. Similar relationship was also shown in the UPGMA analysis based on genetic distance among weedy, cultivated and wild rice species. In conclusion, Jilin weedy rice is mostly likely evolved from the local Japonica varieties as a degenerative form with seed shattering trait.%近年来,杂草稻在中国北方稻区的危害越来越大,杂草稻也被认为是一种新的育种资源.利用在中国东北地区吉林省采集到的杂草稻为试验材料,调查了吉林省杂草稻的植物学性状,采用26对SSR引物对吉林杂草稻进行了DNA水平的多态性检测,分析了杂草稻的起源.结果表明:吉林省大部分杂草稻植株高于当地栽培稻,颖壳色共有7种表型,其中以秆黄色居多,赤褐色、黄色、黑褐色、紫黑色、灰黑色和黄褐色相对较少,果皮色以红色果皮为主；大部分杂草稻有芒,芒色以秆黄和赤褐为主;大部分杂草稻易落粒且易倒伏.SSR分子标记结果表明:26个位点上有21个具多态性,占80.77％.Shannon多样性指数(Ⅰ)的变异范围在0.2237～1.6357,平均为0.8402.遗传多样性指数(He)的变异范围在0.1107～0.7812,平均为0.4840.通过聚类分析,可将吉林杂草稻与栽培稻、野生稻分成5大类群.聚类分析结果表明,吉林省杂草稻与当地粳型栽培稻有着较近的亲缘关系,与籼型栽培稻、临近省区粳型栽培稻、野生稻的亲缘关系较远.吉林省杂草稻很可能起源于当地粳型栽培稻,是栽培稻个体间自然杂交等产生的具有落粒特性的退化类型.