基于中国樱桃转录组的SSR分子标记开发与鉴定

Development and Validation of SSR Markers Based on Transcriptomic Data of Chinese Cherry(Prunus pseudocerasus)

对中国樱桃（Prunus pseudocerasus Lindl.）休眠芽转录组数据进行了SSR位点搜索和分析,发现了7 197个SSR位点,总的发生频率为15.62%。SSR重复类型以二核苷酸发生频率最高（58.65%）,三核苷酸次之（34.72%）。利用8对多态性引物在24份樱桃种质中进行了引物有效性验证和遗传多样性分析,结果表明有效等位基因数最大值为2.92（Pp SSR2）,最小值为1.09（Pp SSR8）,平均值为1.73;香农多样性指数变化范围是0.202~1.290,平均值为0.755。观察杂合度和期望杂合度的变化范围分别是0.083~0.917和0.082~0.671;平均值分别为0.391和0.384。香农多样性指数、观察杂合度和期望杂合度3个多样性指数最大值均出现在位点Pp SSR2,最小值出现在位点Pp SSR8。基于SSR标记的24份樱桃种质的聚类结果与经典的形态学分类不完全一致,但聚类结果清晰地划分出5个不同组别,说明浙江省的中国樱桃种质资源遗传多样性丰富。两个龙泉地方品种与其他的浙江樱桃种质资源明显不同,它们与山樱和浙闽樱有着更紧密的遗传关系,该地方品种可以作为樱桃新品种选育的优良材料,有利于拓宽现有樱桃栽培品种的遗传背景。

Simple sequence repeat（SSR） loci were searched and analyzed transcriptomic data of Prunus pseudocerasus dormancy buds.A total of 7 197 SSR loci were detected which accounted for15.62%of total unigenes.Dinuclotide repeat were the most abundant SSR type with a frequency of58.65%,followed by trinucleotide repeat（34.72%）.The availability and polymorphism of selected 8primers were checked by using 24 cherry accessions.The results showed that average number of effective alleles was 1.73,ranged from a minimum of 1.09（PpSSR8） to a maximum of 2.92（PpSSR2）.Shannon＇s indexes ranged from 0.202 to 1.290,with an average of 0.755.The observed heterozygosity and expected heterozygosity were from 0.083 to 0.917 and from 0.082 to 0.671,respectively.The average value of observed heterozygosity was 0.391,and of expected heterozygosity was 0.384.The maximum and minimum values of observed heterozygosity,expected heterozygosity and Shannon＇s index were observed at locus PpSSR2 and locus PpSSR8,respectively.Genetic relationship of 24 cherry accessions based on the polymorphic primers were not fully in accordance with morphological evidences.Nevertheless,the cherry germplasms were clearly clustered into 5 clades,which indicated an abundant genetic diversity of P.pseudocerasus gathered from Zhejiang Province.Two landraces sampled from Longquan were dramatically different with other cherry accessions.They are genetically more closed to P.serrulata and P.schneideriana.These landraces could be used as parental lines in cherry breeding and were helpful to enlarge the genetic background of cherry cultivars.