基于分子标记的野生棉遗传关系研究

利用RAPD技术研究了野生棉种间遗传关系。采用45条随机引物获得758个条带,根据UP GMA聚类分析将16个野生棉种分为5组。第1组包括B组染色体的4个棉种,其中异形棉(G.anomalum)与三叶棉(G.triphyllum)相似系数高达0.96。第2组包括瑟伯氏棉(G.thurberi)等7种,长萼棉(G.longicalyx)、比克氏棉(G.bickii)分别单独构成第4,5组,斯特提棉(G.sturtianum)、澳洲棉(G.australe)和细毛棉(G.pilosum)组成第3组。

Genetic Relationships among Wild Cotton Species Analyzed by Molecular Markers

The genetic relationships among wild cotton species has been analysed by randomly amplified polymorphic DNA (RAPD) technique. A total of 758 amplified bands were observed using 45 random sequence decamer primers. The genetic distances, which reveal genetic diversity among the species, were estimated from the binary data matrix. The dendrogram produced by Unweighted paired group method of arithmetic means (UPGMA) clustering method assigned the 16 wild species in to five groups. Group I consisted of 4 species with G. anomalum and G. triphyllum are closely placed in the dendrogram as they have similarity index of 0.96 since they are also similar in most of the morphological characters. The other two are G. barbosum and G. capitis-viridis. Within the group II G. davidsonii and G. raimondii were clustered together and showed a very reasonable relationship with G. thurberi, G. harknessi and G. aridum. G. Klotzschianum and G. davidsonii are closely related but varies in the nature of the stem tip, which is glabrous whereas G. davidsonii has light, hairy stem tip and petal spot. G. longicalyx (F genome) is a perennial crawling shrub and G.bickii (G genome) spreading shrub was apart from each other in the dendrogram and form the IV and V group. Group III in the dendrogram of the species studied was clustered together in which G.sturtianum and G. australe differ in flower colour.