苜蓿育种成效的大小在很大程度上取决于它同源四倍体(2n=4x=32)的性质。在同源四倍体中,任何一个基因位点上都可能会有多达四个的不同等位基因,这样同源四倍体中某一位点上基因间的互作就要比二倍体内的这种互作在程度和数量上要高的多。苜蓿对自交的敏感性极高,这一点在以往的文献中已有许多记载,苜蓿只所以在自交后会迅速衰退,其原因可能就是由于多基因位点内互作效应丧失的结果。正是由于在 The effectiveness of alfalfa breeding depends greatly on the nature of its autotetraploid (2n = 4x = 32). In an autotetraploid, there may be as many as four different alleles at any one locus, so that the interaction between genes at one locus in the autotetraploid is more than twice This kind of interaction in the body is much higher and more quantitative. Alfalfa has a high sensitivity to selfing, as documented in previous literature. Alfalfa only declines quickly after selfing, probably because of the loss of interactional effects at multiple loci. It is because of