四倍体紫花苜蓿遗传图谱的初步构建

Preliminary Construction of Genetic Map in Tetraploid Alfalfa

分别以早熟低产和晚熟高产苜蓿单株为父母本,通过人工杂交构建了四倍体紫花苜蓿(Medicago Sativa)F1遗传作图群体,采用单因子变量分析法,以降落式PCR和常规PCR结合的反应程序,建立了适宜于紫花苜蓿的分子标记扩增体系;应用130对SSR引物进行筛选,获得60对引物在父母本间存在多态性而被用于绘制遗传连锁图。采用PAGE电泳分析,对作图群体进行基因型分析。通过TetraploidMap软件对60个SSR标记进行连锁作图分析,有44个标记可以定位在8个连锁群上,占总标记数的33.8%,覆盖遗传距离979cM,两标记间平均图距为22.25cM,初步构建了四倍体紫花苜蓿遗传图谱的框架图,还需要进一步添加标记数量增大其饱和度,为重要性状的QTL定位奠定基础。

In this study,a F1 population of alfalfa was generated by crossing an early-maturing,low-yield plant（male parent）and a late-maturing,high-yielding plant（female parent）.And a system of PCR amplification for tetraploid alfalfa was established by analyzing the standard PCR reaction program or touchdown program.Total of 130 SSR markers were tested in the experiments,of which 60 markers gave polymorphic between two parents and were used to construct the genetic linkage map.Genotypes of the F1 mapping population were analyzed by PAGE electrophoresis.And a prelimary genetic linkage map was constructed by using Tetraploid Map software.The genetic map consists of 44 loci,spanning 979 cM and covering all of 8alfalfa chromosomes with an average genetic distance of 22.25 cM.More markers are still needed to be added to make a saturated genetic map.The study made a foundation for identifying important quantitative trait loci（QTL）for important agricultural traits.