人工老化紫花苜蓿种子活力变化与ISSR标记

Vigor Change of Artificial Aging Alfalfa Seeds and ISSR Markers

应用ISSR分子标记对经过老化处理（在45℃和RH100%条件下处理48~132h）的紫花苜蓿种子进行遗传完整性检测,通过发芽率、遗传相似性系数、多态性位点百分率等指标分析其遗传完整性的变化,以探讨不同老化种子的发芽率与其遗传完整性变化的关系,为苜蓿种质资源的安全贮存及繁殖更新提供依据。结果表明：老化处理96h可明显促进紫花苜蓿种子的劣变,至132h时完全失去活力。ISSR标记图谱显示,种子老化引起的DNA片段变化集中在高分子量和低分子量区域,DNA片段颜色渐浅、消失或出现特异DNA片段。当苜蓿种子ISSR标记的遗传相似系数出现显著性变化时,发芽率为75%,可以考虑作为紫花苜蓿种子繁殖更新的发芽率标准。

ISSR molecular markers were used to test alfalfa seeds genetic integrity in this study.Before the test,the alfalfa seeds were aged under the condition of 45℃ and 100%RH with 48~132h.Then the changes of genetic integrity were analyzed by germination percentage,polymorphism loci,and genetic similarity coefficient.This study aims to make a deeper understanding of seeds aging rules and DNA damage degree of alfalfa seeds in storage.The results showed as followings：（1）The aging treatment for 96 hcan significantly promote（P〈0.05）the deterioration of alfalfa seeds,and completely lost the vigor until 132 h.（2）ISSR marker maps showed that the changes of DNA fragments of artificial aging seeds concentrated on the regions of high molecular weight and low molecular weight,DNA fragments gradually became light in color,disappeared,or had specific DNA fragments.（3）When the genetic similarity coefficients changed significantly,the germination percentage was 75%,it could be considered as the standard of germination percentage for renewing alfalfa seed by reproduction.