中国境内稗(Echinochloa crus-galli)形态变异及其遗传和地理背景分析

采集了浙江、福建、江苏、湖南、湖北、四川、重庆、黑龙江、河南9个省的稗（Echinochloa crus-galli（L.）P.Beauv.）及其变种的33份种子，分别播种在相同的环境下，获得33个种群，测定了种群的16个形态性状，筛选出重复性好的9条ISSR引物，从33个种群中扩增出了109个位点。基于这些形态性状和ISSR位点信息，对33个种群先进行主成分分析，在此基础上再进行模糊均值聚类分析，探讨了它们的形态和遗传变化特点，及其与形态-遗传-地理背景三者之间的关系。主要结论如下：（1）33个种群可以鉴别出形态性状相对一致的4组，能够识别出西来稗（E.crus-galli var.zelayensis（Kunth）Farw.）、无芒稗（E.crus-galli var.mitis（Pursh）Peterm.）、细叶旱稗（E.crus-galli var.praticola Ohwi）；（2）基于109个位点信息对33个种群进行聚类分析得到了6组，部分组与形态聚类分组有一定的对应性；（3）33个稗草种群的遗传分化受地理背景因素的影响（r=0.684，n=33，P<0.001）；形态变异也有较明显的遗传背景因素（r=0.425，n=33，P<0.02）。在相对一致的稻田生境中，可能存在着形态上的趋同适应，使遗传上分化的组间在形态上又往往有交叉过渡，致使稗原变种（E.crus-galli var.crus-galli）、西来稗、无芒稗、短芒稗（E.crus-galli var.breviseta（Döll）Podp.）在形态上难以区别；（4）基于遗传和形态数据分析，发现细叶旱稗无论在形态上，还是遗传上，均形成了明显的一组，推测与该种长期适应于干旱生境有关，建议将细叶旱稗提升为种的水平，并将其命名为Echinochloa praticola（Ohwi）Guo S L，Lu Y L，Yin L P&Zou M Y。

Morphological Variations,Genetics and Geographic Background of Echinochloa crus-galli in China

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.