中国西南区野生狗牙根抗寒相关性状与SSR标记关联分析

Association of SSR markers with cold-tolerance traitsin wild bermudagrass (Cynodon dactylon) ofsouthwest China

摘要:

利用SSR(Simple Sequence Repeat)标记对52份狗牙根(Cynodon dactylon)的抗寒相关性状进行关联分析。结果表明:狗牙根的抗寒性状变异丰富,其中半致死温度(LT₅₀)及恢复生长率的变异系数分别为40.69%、18.37%;形态性状中茎粗变幅最大,其次是叶长、叶色和株高,变异系数达20.00%以上;相关分析表明,枯黄期、绿期及恢复生长率与叶宽、株高间呈极显著正相关(P＜0.01),LT₅₀ 与叶宽、株高间呈显著负相关(P＜0.05),而叶宽与叶长、株高、叶色间呈极显著正相关(P＜0.01);群体结构分析表明52份材料可分为5个类群;利用一般线性模型(GLM)鉴定到10个与抗寒相关性状显著关联的标记,其中绿期与标记89显著相关(P＜2.71×10-5),恢复生长率与标记12显著相关(P＜2.71×10-5),解释率为19.94%~39.29%。该研究结果可早期发现优异种质,缩小筛选范围,降低筛选成本和工作量,加快狗牙根育种进程。

Abstract:

Using simple sequence repeat (SSR) markers to perform association analysis on 52 copies of bermudagrass (Cynodon dactylon) for cold resistance-related traits The results showed that the variation of cold-tolerant traits of bermudagrass were rich,and the coefficient of variation of semi-lethal temperature (LT₅₀) and recovery growth rate are 40.69% and 18.37%,respectively;the greatest variation had been observed in stem diameter,followed by leaf length,leaf color,and plant height,with a variation coefficient of more than 20.00%;the correlation analysis showed that there were the significant positive correlation (P＜0.05) between withering period,stolon regrowth rate,green period and leaf width ,plant height,leaf length,and leaf color (P＜0.01) ,LT₅₀ was significantly negatively correlated with leaf width and plant height (P＜0.05),while leaf width was extremely significantly positively correlated with leaf length,plant height, and leaf color (P＜0.01);the analysis of population structure shows that 52 materials can be divided into 5 groups;ten markers significantly associated with cold resistance were identified by general linear model (GLM), the green phase was significantly correlated with the primer 89 (P＜2.71×10-5),the recovery rate of growth was significantly correlated with primer 12 (P＜2.71×10-5),and the contribution rate ranged from 19.94% to 39.29%.The findings of this study can be useful for early germplasm evaluation,reduce selection range,decrease screening cost and workload,and accelerate the breeding process,respectively.