披碱草属及其近源属植物种子胚乳细胞多样性研究

摘要

Elymus L.is not only an important gene pool for crops,such as wheat and barley,but also an important part of fine forages.The endosperm is a important part to seeds of cereal crops and the weight of endosperm is more than 90% in cereal crops seeds.The endosperm characteristics is a relatively stable genetic character,which can be used as a indicator to research plant classification and phylogenetic relationships.As the kind of micro morphological characteristics of plants,the endosperm characteristics is valuable in phylogeny of Triticeae .To provide evidence of the endosperm cells for reveal the phylogenetic relationships of Elymus species,as well as accumulate data for use the genus improve the quality of wheat and barley.The endosperm cells of 11 Triticeae species which belong to 6 Elymus species,2 Pseudoroegneria species,1 Hordeum species or 2 Agropyron species,were surveyed in this pa-per.The results were as follows:(1)Significant variations existed in the size,forms and quantity of endosperm cells in those species;(2)The cell shape and size existed small variations in Agropyron cristatum (P),A .mongolicum (P)and Pseudoroegneria libanotica (St),P .spicata (St),respectively;(3)The differences in genera were smal-ler than those in species,indicating that the characters of endosperm cells had less value in the systematic studies of those genera than in the studies of those species in Triticeae .%披碱草属不仅是小麦、大麦等作物的重要基因库，也是优良牧草的重要组成部分.胚乳是麦类作物种子的重要组成部分，其重量占籽粒重量在90％以上.胚乳特性是一个相对稳定的遗传性状，可以将胚乳特性作为植物分类和系统关系的一个指标.胚乳细胞特征作为植物的一类微形态特征，在麦类植物系统分类与进化研究中具有一定的价值.该研究对小麦族的6个披碱草属(Elymus )物种、2个拟鹅观草属(Pseudoroeg-neria )物种、1个大麦属(Hordeum )物种和2个冰草属(Agropyron )物种，共4属11份材料的胚乳细胞特征进行解剖观察并测量相关指标.结果表明：(1)不同属、种的植物种子胚乳细胞之间存在丰富的多样性，属间差异大于属内种间差异；(2)同样具有 P 染色体组的 Agropyron cristatum 和 A ．mongolicum 与同样具有 St染色体组的 Pseudoroegneria libanotica 和 P ．spicata 各自在细胞形状和大小上的差异很小；(3)不同物种的胚乳细胞在大小、形状和数量上均表现出差异，但不能很好地反映属以及基因组间的差异，研究结果为揭示披碱草属植物的系统关系提供了胚乳细胞方面的证据，同时也为利用该属植物改良麦类作物品质积累资料.