Abstract: Alfalfa(Medicago sativa L. 2n=32)and M. falcata are important forage and wild genetic resources for alfalfa improvement. Molecular karyotype comparisons were conducted using fluorescence in situ hybridization (FISH) to detect genetic relationship. Three different repetitive sequences (5S Rdna, 45S rDNA and C₀t-1 DNA) were adopted as FISH probes. Result showed that 32 chromosomes of alfalfa could be charaterized as 16 pairs with pobe combinations. FISH pattern comparisons of individual chromosomes between M. sativa and M. falcata revealed high similarity. There were no significant karyotype differences between M. sativa and M. falcata in this study.

Key words: Medicago sativa, M.falcata, Molecualr karyotype, Fluorescence in situ hybridization (FISH)

摘要： 黄花苜蓿(Medicago falcata L. 2n=32)是一种重要的野生豆科牧草,由于其突出的抗逆特性,被认为是用来进行苜蓿改良的优异遗传资源。本研究利用染色体荧光原位杂交技术(FISH),以不同荧光物标记的3种重复序列(5S rDNA,45S rDNA和C₀t-1 DNA),对黄花苜蓿和和紫花苜蓿(Medicago sativa L. 2n=32)染色体进行了FISH分析和分子核型比较,以期在染色体水平上揭示二者之间的亲缘关系。结果表明:利用上述重复序列可以较好的将苜蓿32条染色体区分为16对特征不同的染色体。黄花苜蓿和紫花苜蓿绝大多数染色体FISH杂交特征表现一致或高度相似性,分子核型无显著区别,因此二者间在遗传上具有高度的相似性。

关键词: 黄花苜蓿, 紫花苜蓿, 分子核型, 染色体荧光原位杂交技术