梨AFLP分子连锁图谱的构建与分析

Construction and Analysis of AFLP Molecular Linkage Map in Pear

遗传图谱是数量性状基因定位、基因图位克隆及分子辅助育种等研究的基础,而目前国内在梨树上这方面的研究尚属空白。试验以早美酥×八月红的杂交F192株实生苗为作图群体,采用了扩增稳定、多态性丰富的16对MseⅠ/EcoRⅠ引物组合,对分离群体进行AFLP多态性检测,共获得208条多态性带,其中偏离孟德尔遗传的比率29.8%（P〈0.01）。应用Joinmap 3.0软件且结合“双假测交”策略,对208个AFLP分子标记进行了遗传连锁分析,构建了一张包含145个AFLP标记,分属20个连锁群的梨分子遗传连锁图谱,每个连锁群包含4-20个标记,平均为9.06个标记,图谱总长度覆盖梨基因组618.7 cM,标记间平均图距为6.58 cM。此图谱为梨树基因定位、比较基因组学和重要农艺性状的QTL定位等研究奠定了基础。

Genetic linkage map was the foundation of locating quantitative trait loci, genes map-based cloning and marker assisted selection, while the research had done little on the pear. In order to accelerate the molecular breeding study on pear,a genetic map for pear（ Pyrus L. ）has been developed based on 92 F1 plants derived from an interspecific cross between the cuhivars Zaomeisu and Bayuehong. The linkage map was constructed based on 208 polymorphic AFLP markers and the ＂double pseudo-testcross＂ strategy by using Jionmap version 3.0 software. The map in this study covered 618.7 cM of pear genome harboring 145 AFLP markers on the twenty linkage groups,which the length of linkage group varied from 2.06 cM to 79.3 cM and an average genetic distance between adjacent markers was about 6.58 cM of Kosambi genetic distance. And also the markers on the linkage group varied from 4 to 20. Compared with the reports of pear genetic maps, the pear linkage map in this study was not saturated, but it was currently the first integrated linkage map in pear comprising 47 3 ： 1 and 98 1 ： 1 AFLP markers by using Joinmap 3.0 setting CP（cross pollination）type data.