玉米相对饱和遗传连锁图谱构建与一种新的AFLPs共显性分析方法探讨

利用一个F2作图群体(X178×B73),首先构建了一个含有130个SSRs的玉米连锁框架图,然后用119个AFLPs位点增加图谱密度,得到一个全长1659·3cM,标记间平均间距6·66cM的玉米相对饱和连锁图。同时,对SSRs和AFLPs的一些遗传特性进行了分析,探讨了AFLP标记进行共显性分析的一种新方法。分析表明SSRs和AFLPs分子标记具有多态性和可靠性高等特点,是构建高密度分子标记遗传连锁图的有效技术。加密的玉米遗传连锁图谱为比较基因组研究、数量性状位点(quantitativetraitloci,QTLs)克隆、杂种优势机理研究以及标记辅助选择等提供了技术基础。

Towards an Expanded Linkage Map and Exploration on Co-dominant Scoring of AFLPs in Maize

Simple sequence repeats (SSRs) and amplified fragment length polymorphisms (AFLPs) have become the most important markers for molecular mapping.Primarily based on restriction fragment length polymorphism (RFLP) markers,extensive linkage maps of maize had been developed.To construct a near-saturated genetic linkage map,an expanded maize genetic linkage map was constructed using a population of 234 F2 individuals derived from a cross of X178 and B73 base on an essential SSR framework map of maize.The level of polymorphisms and genetic properties of SSR and AFLP markers were characterized.A total of 249 markers consisting of 130 SSRs and 119 AFLPs have been landed on 10 chromosomes of maize.The 249-locus map spanned 1 659.3 centi-morgans (cM) and had a mean density of 6.66 cM.This mapping population and related information should connect further research involving analysis of quantitative trait loci,comparative genomics,and heterosis.Moreover,in many studies,AFLPs were analyzed on the basis of the presence or absence of a band on the electrophoresis gels.A new method based on double polymorphic bands of co-dominant scoring of AFLPs was explored according to the similarity of loci amplified from AFLP enzyme combination.