关键词: 稗, 形态性状, ISSR, 地理背景, 变异, 模糊均值聚类分析

Abstract: Thirty-three seeds of Echinochloa crus-galli(L.) P. Beauv. from paddy regions of nine provinces(Autonomous Region) of China were sampled and sown in the same environment. Their offspring were obtained. Sixteen morphological traits of their offspring were measured. Nine ISSR primers with good repeatability were selected and 109 ISSR loci were amplified from thirty-three E.crus-galli samples. Based on morphological traits and locus information, cluster analysis and principal component analysis on these thirty-three populations were conducted. The main results are as follows:(1)Four morphological groups were identified from these populations, among them are E.crus-galli var. zelayensis(Kunth) Farw., E.crus-galli var. mitis(Pursh) Peterm. and E.crus-galli var. praticola Ohwi; (2)Six groups were also identified from these samples by using cluster analysis based on ISSR locus data, which corresponds well with the morphological groups, especially for E.crus-galli var. praticola; (3) Obvious genetic differentiation existed among these thirty-three populations, which is obviously influenced by the geographical locations(r=0.684, n=33, P<0.001). Their morphological variation, however, is weakly affected by the geographical locations(r=0.245, n=33, P<0.2); (4) Both the morphological data and the ISSR data separated the populations of E.crus-galli var. praticola from the other populations. Therefore, the variety was suggested to elevate to species level:Echinochloa praticola(Ohwi) Guo S L, Lu Y L, Yin L P & Zou M Y.

Key words: Echinochloa crus-galli, morphological traits, ISSR, geographic background, variation, Fuzzy C-means cluster analysis