选育甘薯优良品种，一直是实现甘薯增产增收的关键。但是近年来甘薯品种的严重退化已成为进一步提高甘薯产量的重大障碍。据调查：一般造成甘薯品种退化的原因，有以下几点： 一、人为混杂 主要是不注意选留神，特别是在补过苗以后的地块剪蔓繁种更容易造成人为品种混杂。 二、 Breeding sweet potato varieties, has been the key to increasing sweet potato yield. However, serious degradation of sweet potato varieties in recent years has become a major obstacle to further increase sweet potato production. According to the survey: The causes of the general degradation of sweet potato varieties, the following: First, the mixed people are mainly not pay attention to choose to stay God, especially after the replacement seedlings cut vine manure more likely to cause artificial species mixed. two,