马铃薯不同基因型试管薯形成能力比较及遗传位点分析

Evaluation of in Vitro Tuberization in Different Genotypes of Potato(Solanum tuberosum L.)Based on Phenotype and Genetic Loci

因病毒引起的种薯退化是马铃薯生产面临的主要问题之一,生产脱毒种薯是解决这一问题的主要途径,而试管薯是脱毒种薯生产的首要环节。然而,不同基因型马铃薯的试管薯形成能力差异较大,阻碍了试管薯的应用。比较了4个杂交组合后代共222个基因型材料(Solanum tuberosum L.)在短日照(8 h光照/16 h黑暗)诱导条件下的试管薯形成情况。结果显示,4个组合在结薯方式、结薯时间、结薯率及单薯重等方面均存在显著差异,表明马铃薯试管薯形成受亲本遗传基础影响十分明显。进一步比较各个组合内不同基因型的试管薯形成情况,发现组合内差异大于组合间差异,差异程度也因组合而异。此外,基于SSR分子标记与试管薯形成性状的相关性分析,发现4个组合中与结薯时间、结薯率及单薯重相关的遗传位点差异明显。同一性状在不同组合中仅存在个别共有位点,同一组合中不同性状之间的遗传相关性则因组合而异。结果从群体层面上结合表型和遗传位点,进一步证实了遗传基础对马铃薯试管薯形成的决定性影响,为马铃薯新品种培育提供了理论基础。

The degeneration caused by viral diseases of the seed potato is the key factor to cause low yield and benefit of potatoes,and it is also the most important constrain of potato production in China.The production of virus-free seed potato based on in vitro tuberization has greatly alleviated this problem.But,in vitro tuberization of potatoes are totally different among genotypes which limits the use of it.In this study,the microtubers were induced under the short photoperiod(8 h light/16 h dark)from four crosses including 222 genotypes of potato(Solanum tuberosum L.).These four crosses showed significant difference in the mode of tuberization,the initialization of tuberization,the percentage of tuberization and the average weight of tubers.Further analyses of the offspring of each cross revealed the greater difference among individual genotypes within a cross than crosses,and the degree of difference varied with cross.In addition,the SSR loci associated with tuberization traits were also identified.For the same trait,there were few loci to be shared in different crosses.But among different traits,whether or not there was the same locus to be shared varied in different crosses.All of the results indicate that the in vitro tuberization of potatoes is affected obviously by their genetic backgrounds.It provides a theoretical basis for the breeding of new potato varieties.