多子芋组培突变材料表型及SSR标记鉴定

Identification of Mutants from Tissue Culture in Multi-cormels Taro by Phenotypic Traits and SSR Markers

【目的】探究多子芋体细胞无性系变异材料(江芋4号)与亲本(江芋2号)间的性状变异及遗传差异,明确多子芋变异材料的育种潜力和生产利用价值。【方法】考察测定江芋2号及其组培后代稳定变异材料江芋4号间表型、产量及品质相关性状的变异,测定分析两材料间的染色体数目和倍性水平,并采用SSR标记技术和118份芋种质分析亲本及组培变异材料间的遗传差异。【结果】与亲本江芋2号相比,突变材料江芋4号植株地下部侧球茎(子、孙芋)不能正常膨大,突变为长棒状,且侧球茎总质量显著低于亲本,但生物产量与亲本差异不显著;江芋4号侧球茎中淀粉、纤维素、可溶性蛋白及Vc含量显著高于亲本。此外,通过常规压片和细胞流式分析表明江芋4号和江芋2号染色体数目和倍性一致。再者,通过38对SSR分子标记遗传聚类分析表明,江芋2号与江芋4号遗传距离最近,且遗传相似系数高达97%,确定江芋4号为江芋2号基因水平的变异。【结论】通过表型性状考察及分子鉴定,明确了多子芋江芋2号与其组培变异材料江芋4号的表型变异和遗传差异。突变材料江芋4号可作为进一步研究多子芋侧球茎膨大调控机制的独特材料,并可进一步开发为叶、花柄用或观赏用芋新品种。

[Objective]To explore the character variation and genetic difference between the parent(Jiangyu 2)and its somatic mutant(Jiangyu 4),and determine their breeding potential and utilization value for taro planting.[Method]In this study,the variation of phenotypic,yield and quality-related traits between Jiangyu 2 and Jiangyu 4 were investigated,the chromosome number and ploidy level of them were analyzed,and the genetic diversity of 72 taros including Jiangyu 2 and Jiangyu 4 were analyzed by SSR markers.[Result]Comparing to Jiangyu 2,the first and second grade cormels of Jiangyu 4 could not expand normally,the shape of first grade cormels mutated into sticks,and the total weight of cormels was less than Jiangyu 2,but the biological yield had no significantly difference between two material.In addition,the content of starch,cellulose,soluble protein and Vc in the first grade cormels of Jiangyu 4 were significantly higher than that of Jiangyu 2.Moreover,the chromosome number and ploidy level of Jiangyu 4 and Jiangyu 2 were consistent by traditional pressing method and flow cytometry analysis.Furthermore,the genetic clustering analysis of 38 pairs of SSR markers showed that Jiangyu 2 and Jiangyu 4 were clustered together,and the genetic similarity coefficient was as high as 97%,and Jiangyu 4 was identified as a gene level mutation.[Conclusion]The character variation and genetic difference between Jiangyu 2 and Jiangyu 4 were uncovered by morphological identification,chromosome and SSR molecular markers analysis.Jiangyu 4 can serve as a unique material to study the regulatory mechanism of cormel expansion,and also further could be developed into new edible or ornamental variety of taro.