云南水稻地方品种月亮谷的群体多样性分析

月亮谷是云南元阳梯田种植历史悠久、种植面积最大的优良水稻地方品种之一,当地少数民族具有引种或换种的稻作习惯。为揭示这种稻作习惯对月亮谷群体遗传多样性的影响,本研究对该品种群体内和群体间进行了遗传多样性的比较和分析,目的是为更好地了解月亮谷的群体遗传结构,为持久利用地方品种提供理论依据。首先采用分层随机取样的策略从元阳梯田不同海拔获得24个原位栽培群体,采用形态指数分类法和抗病性测定对24个群体共720个单株样品的月亮谷进行形态学分类和稻瘟病抗性鉴定,并分析了这些单株材料在48个SSR位点的遗传多样性。研究结果表明,形态上月亮谷属于栽培稻的籼稻类型,其群体对稻瘟病具中抗水平,但无论是在群体内还是群体间,均普遍表现出明显差异,说明不同来源的月亮谷存在抗病功能表型上的变异;遗传多样性分析显示,48对SSR引物共检测出91个多态位点,多态性位点百分率为77.08%,Nei多样性指数平均值为0.064,变幅为0~0.4302。24个群体之间的遗传相似系数在0.9753~0.9866之间,群体内个体之间的遗传相似系数在0.86~1.00之间;AMOVA分析显示,以地理村寨作为自然居群单位,居群间的变异为3.36%,居群内群体间的变异为33.15%,居群内的变异为63.49%;聚类分析显示,村寨群体间的遗传多样性与村寨间的地理空间距离有一定相关性。

Population characterization of rice landrace Acuce from Yunnan Province through phenotyping and genotyping

Acuce, one of the rice landrace has being cultivated at Yuanyang Hani terrace more than one hundred years. For the purpose of intensively elucidating its population genetic characters under local rice production patterns, at present research, 24 populations were collected from local peasant household with stratified random sampling method. The intra- and inter- population of Acuce was analyzed through morphological traits and genetic diversity evaluation. The results showed that Acuce was classified into subspecies Oryzae indica, and displayed moderate resistance (MR) to Magnoporthe oryzae, the pathogenic fungi caused rice blast worldwide. Whatever intra- or inter-population, it showed blast resistance variation within all of the populations. For the reason of landrace harboring high frequent intra-heterogeneity, 30 single plants of each population were sampled and analyzed on 48 SSR loci which evenly distributed on 12 chromosomes of rice genome. The results showed that, whatever intra- or inter-population, 720 samples obtained 91 polymorphic alleles with polymorphic allele percentage 77.08%, and the mean of Nei diversity index 0.064 with the range 0-0.4302. Through cluster analysis, it indicated that genetic similarity coefficient range from 0.98-0.99 within 24 populations, and coefficient 0.86-1 between single plants within individual population. Taking Acuce source village as natural population, AMOVA results showed that it consisted of inter-village variation 3.36%, inter-population within village 33.15% and intra-village contributed 63.49% variation. Further, the cluster analysis result indicated that the inter-village genetic similarity correlated with geographical distance between villages.