2014-2019年国家玉米区域试验参试组合DNA指纹检测及遗传多样性分析

DNA Fingerprinting and Genetic Diversity Analysis of National Maize Regional Trials in 2014-2019

随着我国玉米品种审定制度的改革和参试渠道的扩宽,近年来玉米参试组合年均近8 000份,为了解我国近几年育种水平、发展趋势和存在的问题,对2014-2019年共计2 949份国家玉米品种试验参试组合进行DNA指纹检测和遗传多样性分析。40个SSR位点,平均每个位点检测到14.55个等位变异,平均遗传多样性和PIC(多样性信息)分别为0.71和0.67。2014-2019年不同年份参试组合的遗传多样性基本一致,其中爆裂组遗传多样性最低,鲜食玉米组遗传多样性最高,生态种植区上从北向南多样性有上升趋势。遗传聚类结果表明,爆裂、鲜食、热带和亚热带、极早熟几个组别分别归属不同的亚类,遗传背景与其他组别差异较大,其他区组的遗传背景相互渗透,东华北和西北组之间遗传关系最近。DNA指纹真实性检测结果表明,参试组合与数据库比对筛查出DNA指纹差异位点在5个以内的样品数量逐年下降。近10 a来我国玉米区域试验参试组合遗传多样性日趋丰富,SSR技术在玉米品种区域试验中发挥了重要的作用,随着育种新技术的不断发展,建议加快SNP等新技术在区域试验中的研究和应用。

With the reform of maize variety approval system and the expansion of trial channels in China,nearly 8000 maize combinations are tested every year.In order to understand the breeding level,development trend and existing problems in recent years,2949 national regional trials combinations in 2014-2019 were analyzed for genetic diversity and DNA fingerprinting.With an average of 14.55 alleles per locus were detected in 40 SSR loci.The average gene diversity and PIC were 0.71 and 0.67,respectively.In 2014-2019,the genetic diversity of the trial combinations was basically the same,the lowest in the pop corn,and the highest in the fresh corn,and the increasing trend from north to south in the ecological planting area.The results of group heterotic grouping and principal coordinates analysis showed that the groups of pop corn,tropical and subtropical,fresh corn,early maturity and Southwest group belonged to different subclasses respectively.The genetic background of other groups mixed with each other,the genetic relationship between Northeast and Northwest was the closest.The results of DNA fingerprint authenticity test showed that the number of samples with less than 5 different loci compared between the combinations and database decreased year by year.In the past ten years,the genetic diversity of the combinations in the maize regional trials had been increasing,SSR technology played an important role in the regional trails,with the development of new breeding techniques,it is recommended to accelerate the research and application of new technologies such as SNP in regional trials.