中国花生品种更替引发的SSR位点遗传多样性变化趋势分析

Analysis the Genetic Diversity Variation Trends of Peanut Elite Cultivars in China using SSR Markers

【目的】旨在了解自20世纪50年代以来我国花生品种更替所引发的SSR位点遗传多样性变化,以期为花生育种提供参考。【方法】选用154对SSR引物对68个大面积推广种植品种进行检测。【结果】共获得173个位点,检测到872个等位变异,平均为5.04个等位变异/位点,遗传多样性指数的变化范围为0.014~0.881,平均0.477。20条染色体中,b07遗传多样性最高,染色体a04最低。品种更替过程中,20世纪80年代品种更替对SSR位点遗传多样性影响最为显著,与20世纪70年代及以前品种相比,表现为等位基因遗传丰富度增加、多样性指数增加、品种间遗传距离略有降低。20世纪80年代以后,SSR位点的等位基因丰富度增加、多样性指数和品种间遗传距离均无明显变化。检测到5个等位变异数随年代增加减少的SSR位点。聚类分析结果显示类群分布与系谱及地理来源相关,与品种更替年代无关。【结论】本研究结果表明,在花生品种更替过程中,主栽品种等位基因丰富度增加,而等位基因分布均匀度尚未产生显著性改变。

【Objective】The objective of this study was to detect the genetic diversity in China peanutcultivar replacement since1950s based on SSR marker in order to provide references for peanutbreeding.【Method】The genotype of68elite varieties was screened using154SSR markers.【Results】As results,173loci and872alleles were detected.The mean number of allele per locus was5.04.Thepolymorphism information content(PIC)value ranged from0.014to0.881,with average0.477.Among20chromosomes,b07had highest PIC value while a04had lowest one.The peanut cultivar evolution in1980s had the most significant impact on genetic diversity.The varieties that released in this stage hadmore allele,higher PIC value and similar genetic distance compared with the varieties that releasedbefore1980s.The varieties that released after1980s has more allele number than others,but whichhad no significant impact on PIC value and genetic distance.Furthermore,the allele number of5SSR loci showed significant decrease with cultivar evolution.The varieties with related pedigree orgeographic origin were assigned into same group,while cluster result had no relationship with releasedyear of varieties.【Conclusion】Our results showed that the allele number had increased while theevenness did not change in the past50years.