一、多系品种的概念及其防病机制“多系品种”亦称“综合品种”,由一系列稳定一致的品系组成。这些品系的主要农艺性状大体相同,而在抗病基因上存在着差异。所以多系品种实际上是一个复合群体。组成多系品种的品系也叫“等基因系”,一般有几个到十几个。等基因系通过多次回交或包括轮迴亲本在内的复交得到。 First, the concept of multi-line species and its disease prevention mechanism “Multi-line variety” also known as “comprehensive variety”, composed of a series of consistent lines. The main agronomic traits of these lines are roughly the same, but there are differences in disease resistance genes. So multi-line species is actually a composite group. Lines composed of more lines of variety also called “isogenic lines”, usually a few to a dozen. Isogenic lines are obtained by multiple backcrosses or compounding, including the recurrent parent.