早在达尔文时代,就已指出异花授粉植物自交的有害性和杂交的有益性,并曾作了不少的尝试来阐明这一现象的本质,这一现象特别明显地表现在这些事实上,即自交系生产力急剧的下降和具有优势的杂种生产力也往往如此急剧的提高。 As early as in the Darwinian era, the harmfulness of selfing of cross-pollination plants and the usefulness of crossbreeding have been pointed out and many attempts have been made to elucidate the nature of this phenomenon, a phenomenon that is particularly evident in these facts, That is, the sharp drop in productivity and the dominant heterosis in inbreds tend to increase so sharply.