脱毒红薯及应用前景生产上应用的红薯品种经过若干年种植后会发生退化，产生退化的原因主要有三个方面：（１）无性变异引起的退化。红薯品种多为遗传杂合体，虽采用无性繁殖也会发生变异，当劣变体混杂在良种内繁殖并占优势时，必然降低良种的应用价值，引进良种退化。（... Detoxification sweet potato and the application prospects of sweet potato varieties used in production after years of planting will degenerate, there are three main reasons for the degeneration: (1) degeneration caused by asexual mutation. Most varieties of sweet potato genetic heterozygosity, although the use of asexual reproduction will also occur when the mutagen mixed breeding and dominant in the elite, will inevitably reduce the value of the elite, the introduction of improved degeneration. (...