二倍体和四倍体野生黄花苜蓿形态特征比较研究

Comparative Studies on the Morphological Characteristics of Diploid and Tetraploid of Wild Sickle Alfalfa

为了解野生黄花苜蓿(Medicago falcataL.)的种质特征与特性,对来自我国新疆、内蒙古和俄罗斯的二倍体和四倍体野生黄花苜蓿的19项形态指标进行比较研究。结果表明:二倍体和四倍体的形态特征存在不同程度差异,其中营养器官的差异比生殖器官显著;二倍体植株的花为桔黄色,茎主要为紫-绿色,叶片明显较四倍体窄小,叶形以倒披针形和线形为主,叶片毛被多为上下密集型;四倍体植株的花主要为黄色,茎多为绿色和紫-绿色,叶片明显较二倍体宽大,叶形以倒披针形和倒卵形居多,叶片毛被多为上面光滑下面稀疏型;四倍体黄花苜蓿与二倍体相比,具有植株高大,生长繁茂,叶片增大等特征;聚类分析可将供试材料明显分为二倍体和四倍体2类,四倍体材料间表现出相似生境的聚类趋势,不同染色体数目间的形态学差异远比相同染色体数目而生境不同材料间的形态差异明显。

Nineteen morphological characters were compared between diploid and tetraploid plants of wild sickle alfalfa （Medicago falcata L. ） collected from Xinjiang Uygur Autonomous Region, Inner Mongolia Autonomous Region, and Russia. Results show that there were significant differences in morphological characters between the two plants. Differences in vegetative organs were more obvious than those in reproductive organs. Diploid plants had orange colored flowers, purple-green stems, oblanceolate or linear leaves, dense hairs on both sides of leaves; tetraploid plants had yellow flowers, green stems, oblanceolate or obovate leaves, smooth leaf surface and sparse hairs on the underside of leaves. In comparison with diploid plants, tetraploid plants appeared as more vigorous growth. The two types of plants could be distinguished easily by cluster analysis based on six morphological characters. Plants of the tetraploid group could be further classified into different categories based on the habitat characters. Morphological differences between different ploidy groups were more obvious than those among the plants of same ploidy groups from different habitats.