玉米自交系08-641不同选择方向回交改良后代的遗传变异

摘要

In this study ,SSR molecular markers were used to analysis the genetic variation of 79 backcross modi-fied lines of the maize inbred line 08-641(R08).The result showed that a total of 272 alleles were detected in the im-proved lines and R08,and 123 of them were detected in the modified lines but discarded in R 08.The modified line se-lected based on simialry in the shape and corlor of seeds to R 08 have lower genetic similary between R 08 than that between the lines selected based on dissimialry in the shape and corlor of seeds and R 08,and the genetic varioation of theses lines were wider .It conduvted that when the backcross breeding were used to improve the maize inbred lines , multidirectional selection based on phenotypic value were contribute to create and keep genetic variation .%利用SSR分子标记对玉米自交系08-641（ R08）不同选择方向回交改良得到的79个BC2 F4后代的遗传多样性进行分析。结果表明，利用44对具有清晰多态性的引物共检测到272个多态性等位基因位点，其中有123个位点在回交后代株系中被检测到而在轮回亲本中缺失；以种子形状和颜色不像R08为标准选择得到的回交后代株系，基因型与R08的相似程度总体低于以种子形状和颜色类似R08为标准选择得到的回交后代株，且其变异范围更广。可见不同选择方向所得回交后代选系的遗传变异存在一定的差异。因此，在回交过程中采用多向选择的策略，可能有利于提高回交改良的育种效率。