Abstract: The demand for high quality forage species is increasing in the southern tropical regions of China,and comprehensive evaluation of the morphological characteristics among the existing accessions is a prerequisite for the excellent variety selection. 32 botanical characters of 76 Desmodium Des. accessions from 9 species were observed,and the morphological genetic diversity was studied. The results showed that:Among the 32 botanical characters,the coefficient of variation of pod shape and hair type of stems were relative higher,which was 60.72% and 50.45%,respectively,indicating rich genetic diversity in Desmodium Des. accessions; Cluster analysis showed that,76 germplasm can be divided into 7 categories at the Euclidean distance of 17,Desmodium heterocarpon var. strigosum Vaniot Meeuwen ‘071221227’,Desmodium cinereum ‘CIAT46561’,Desmodium heterocarpon ‘061002029’,Desmodium heterocarpon ‘081229011’,Desmodium heterocarpon ‘071221025’,Desmodium heterocarpon ‘070302002’,Desmodium ovalifolium ‘CIAT350’,Desmodium heterocarpon ‘041104057’ and Desmodium heterocarpon ‘070117039’ in the first category had larger leaf in pod shapes,wider central leaflets and few hairs,these accessions potentially have high yield and high quality,should be the candidate accessions for breeding. Through this study,characteristics of inter-specific morphological genetic diversity among Desmodium Des. were clarified,which laid the foundation for the breeding of Desmodium Des.

Key words: Leguminous forage, Morphological marker, Breeding, South tropics

摘要： 南方热区对高品质牧草品种的需求不断增加，而形态特征综合评价是优良品种选育的前提。本试验以9种76份山蚂蝗属（Desmodium Des.）种质为材料，对32个植物学性状进行观测，研究其形态学遗传多样性。结果表明：32个植物学性状中荚果形状和茎毛类型变异系数最大，分别为60.72%和50.45%，说明山蚂蝗属具有丰富的遗传多样性；聚类分析表明，在欧氏距离17处可将76份种质分为7类，其中第一类中糙毛假地豆071221227、灰色山蚂蝗CIAT46561、假地豆061002029，081229011，071221025，070302002、卵叶山蚂蝗CIAT350、异果山绿豆041104057，070117039叶形及果形大、中央小叶较宽、被毛少，具有高产优质特点，可作为育种的候选材料。本研究明确了山蚂蝗种间形态学遗传多样性特点，获得的9份材料为山蚂蝗育种奠定基础。

关键词: 豆科牧草, 形态学标记, 育种, 南方热区