中国主要农区稻田稗草分类与多样性研究

将采自中国15个省和1个直辖市的206份稗属（Echinochloa）植物种子分别播种在相同栽培条件下,获得了206份子代样本及其21项形态性状数据,基于这些形态性状对206份稗属植物样本进行了聚类和主成分分析。结果表明：（1）从206份稗属植物样本中鉴别出了形态性状相对一致的8个分类群（G1-G8）,依次对应于湖南稗子（Echinochloa frumentaceae,2份样本）、水田稗（E.oryzoides,5份）、细叶旱稗（E.crus-galli var.praticola,6份）、硬稃稗（E.glabrescens,14份）、光头稗（E.colona,2份）、长芒稗（E.caudata,16份）、孔雀稗（E.cruspavonis,8份）、稗复合群（稗原变种E.crus-galli var.crus-galli、稗的变种无芒稗var.mitis、短芒稗var.breviseta和西来稗var.zelayensis,共150份）,还有3份样本没有聚合成组。它们依次占总样本量的0.97%、0.97%、2.42%、2.91%、3.88%、7.77%、6.80%、72.81%和1.46%,反映出中国主要农区稻田稗属植物主要以稗及其变种为主;（2）单因素方差分析表明,9个数量性状,包括叶长、叶宽、圆锥花序长度、总状花序长度、小穗芒长、小穗长度、第1颖长度/小穗长度、主茎直径和株高,在稗属植物的8个分类群（G1-G8）之间有显著差异;（3）根据8个分类群之间的形态性状特点及差异,给出了鉴别中国主要农区稻田稗属植物的分种检索表;（4）由于细叶旱稗具有总状花序简单、小穗无芒、叶较宽、植株高大、小穗紫黑色等独特形态性状,在206份稗属植物样本的聚类图上单独聚成一组,故建议将细叶旱稗作为独立种处理。

Classification and Diversity of Echinochloa in Paddy Fields of Main Agricultural Regions in China

The seeds of 206 Echinochloa samples from paddy regions of 15 provinces and one municipality of China were sown in the same cultivation environment and their offspring were obtained. We measured 21 morphological traits of the 206 Echinochloa offspring samples.Based on these 21 traits,cluster analysis and principal component analysis（ PCA） were conducted. Results showed that：（ 1） Eights groups were identified from these 206 samples,corresponding to E. frumentaceae（ 2 samples）,E. oryzoides（ 5 samples）,E. crus-galli var. praticola（ 6 samples）,E. glabrescens（ 14 samples）,E. colona（ 2 samples）,E.caudate（ 16 samples）,E. cruspavonis（ 8 samples）,E. crus-galli complex（ 150 samples including E. crus-galli var. crus-galli,var. mitis,var. breviseta and var. zelayensis） and three other samples,accounting for 0. 97%,0. 97%,2. 42%,2. 91%,3. 88%,7. 77%,6. 80%,72. 81% and 1. 46%,respectively. Echinochloa crus-galli and its varieties were the main taxa of the genus in the main paddy regions of China;（ 2） Analysis of variance showed that the main quantitative traits for identifying the eight groups of Echinochloa included leaf length,leaf width,panicle length,raceme length,awn length of spikelet,spikelet length,length of first glume /spikelet length,diameter of main stem,and individual height;（ 3） A key to the eight groups was given based on their morphological differences;（ 4） Taxonomically,E. crus-galli var. praticola was suggested as an independent species from the E. crus-galli complex due to its simple racemes,awnless spikelets,wider leaves,higher individuals,and purple spikelets.