二倍体及四倍体枳橙DNA甲基化变异的MSAP分析

MSAP Analysis on DNA Methylation Diversity of Diploid and Tetraploid of Citrange

为探讨染色体加倍对四倍体枳橙(Citrus sinensis (L.) Osb.×Poncirus trifoliate (L.) Raf.)叶片基因组DNA甲基化修饰的影响,明确四倍体枳橙基因组DNA甲基化水平及模式的变化特征。本研究以枳橙二倍体为对照,利用MSAP分子标记技术对同源四倍体枳橙叶片基因组DNA甲基化水平及模式变化进行分析。结果表明,10对选择性扩增引物共扩增出775条条带,二倍体和同源四倍体枳橙扩增带数分别为391条和384条,对应的总甲基化率分别为31.97%(含全甲基化率16.37%,半甲基化率15.6%)和31.25%(含全甲基化率18.49%,半甲基化率12.76%);MSAP扩增条带统计表明,同源四倍体的总甲基化率变化较小,全甲基化率高于二倍体,半甲基化率较二倍体均有所降低,相比二倍体对照,四倍体枳橙叶片基因组DNA主要发生了甲基化模式的变化。

In order to investigate the effects of chromosome duplication on the genomic DNA methylation modification of tetraploid citrange(Citrus sinensis(L.)Osb.×Poncirus trifoliate(L.)Raf.),leaves,the changes of DNA methylation levels and patterns of tetraploid citrange genomic DNA were identified.In this study,MSAP molecular marker was used to analyze genomic DNA methylation levels and pattern changes of autotetraploids citrange leaves with diploid as the control.The results showed that 775 bands were amplified by the 10 pairs of selective amplification primers;the number of amplified bands of diploid and autotetraploid was 391 and 384 respectively;the corresponding total methylation rates were 31.97%(including 16.37%total methylation and 15.6%hemimethylation)and 31.25%(including 18.49%total methylation and 12.76%hemimethylation).In comparison with the diploids,the change in total methylation level was minor in the autotetraploids,while the full methylation rate of autotetraploid was higher and the hemimethylation rate was lower than that of diploid.The change of DNA methylation pattern in the CCGG loci was the main type of epigenetic variation in autotetraploids of citrange.