江西山药种质资源遗传多样性及其组培苗遗传稳定性的RAPD检测

目的 对来自江西的11份山药种质资源进行遗传多样性分析,并对其组培苗的遗传稳定性进行检测。方法 采用RAPD-PCR技术。结果 试验筛选出20条引物,共扩增出238个条带,其中234个为多态性带,平均每个引物扩增出多态性带11.7条,多态性条带比率为98.32%,材料间遗传相似系数为0.575 6~0.970 6,平均相似系数为0.723 1。根据UPGMA聚类分析结果,可在0.634 8的遗传相似系数上,将11份山药种质资源聚成5大类群(类群I~V)。其中第I类群只包含黄独;第II类群只包含瑞昌山药;第III类群包括南城淮山药1、千金薯、信州山药、永丰淮山药和铁棍山药,说明南城淮山药1、千金薯、信州山药、永丰淮山药与来源于河南焦作市温县的铁棍山药亲缘关系较近;第IV类包括南城山药、南城淮山药2、广丰药薯;第V类只包括泰和竹篙薯。这个结果表明江西山药种质资源遗传多样性还是比较丰富的。同时,江西山药带芽茎段连续继代6次后的组培苗(处理组)及其微型块茎实生苗(对照组)的RAPD分析结果也表明,11份山药品种均扩出126~179条可辨认的条带,每个品种的处理组和对照组均出现了5~18条变异条带数,表明江西山药各个品种带芽茎段连续继代6次后的组培苗存在着一定的体细胞无性系变异,但它们与微型块茎萌发实生苗的遗传相似系数还是比较高,说明它们的遗传性状还是比较稳定的,并未影响到其基因型。结论 本实验结果可为江西山药引种育种、资源改良、品种鉴定、种质保存及其种苗培育提供可靠依据。

RAPD analysis of genetic diversity of Dioscorea opposita germplasm resources from Jiangxi and genetic stability of their plantlets

Objective To analyze the genetic diversity of 11 varieties of Dioscorea opposita germplasm resources from Jiangxi, and detect the genetic stability of the tissue cultured plantlets. Methods RAPD-PCR was applied. Results Twenty primers were screened out, 238 bands were amplified, 234 of them were polymorphic bands, the average amplified polymorphic bands were 11.7, and the ratio of polymorphic bands was 98.32%. The genetic similarity coefficient was 0.575 6-0.970 6 and the average similarity coefficient was 0.723 1. According to the results of UPGMA clustering analysis, the 11 D. opposita germplasm resources from Jiangxi province were divided into five categories:The first class included D. bulbifera. The second class included D. opposita. The third class included D. opposita Nancheng 1, D. opposita, D. opposita, D. opposite, and D. opposita, which showed that D. opposita 1, D. opposita, D. opposita and D. opposite, had closer relationship with D. opposita came from Wenxian County, Jiaozuo City, Henan province. The fourth class included D. opposita, D. opposita Nancheng 2 and D. opposita. The fifth class included D. opposita. The RAPD analysis results of plantlets subcultured for six times by in vitro rapid propagation method of stem segment with a bud of D. opposita L. germplasm resources from Jiangxi province (treatment group) and their seedlings germinated from microtuber (control group) also showed that 11 yam varieties were spread out 126-179 identifiable bands and each variety appeared 5-18 mutation bands, which indicated plantlets subcultured for six times by in vitro rapid propagation method of stem segment with a bud of D. opposita. germplasm resources from Jiangxi province existed somaclonal variation, but their genetic similarity coefficient compared with their seedlings germinated from microtuber was still relatively high, illustrating that their genetic traits were still relatively stable and did not affect their genotype. Conclusion The experimental results can provide the reliable basis for introduction breeding, resource improvement, variety identification, germplasm conservation, and their plantlet culture of D. opposita germplasm resources from Jiangxi province.