一、品种混杂退化的概念品种混杂退化是指优良品种在生产过程中,由于机械混杂和生物学混杂等原因,生活力逐渐衰退,以致产量降低,品质变劣。如棉花衣分降低,纤维长度变短,铃重减轻,短绒率增加,产量下降,植株各部分形态发生各种变异等。二、品种混杂退化的原因 1.机械混杂 First, the concept of mixed species degradation of mixed species degradation is the degradation of hybrid varieties in the production process, due to mechanical hybrids and biological mixed reasons, the gradual decline of viability, resulting in reduced yield, poor quality. Such as cotton clothing points to reduce fiber length shorter, boll weight reduction, increased short fiber rate, yield decline, the various parts of the plant morphogenesis and other variations. Second, the reasons for the variety of mixed degeneration 1. Mechanical mixed