目前引起棉花病害的细菌有 30多种 ,传统鉴定法需逐步分离提取病菌 ,费工费时 ,而现在的分子生物学鉴定法用 PCR技术 ,放大任一微生物任一部位的特定 DNA,以此确定其碱基序列 ,由于特定生物有固定的 DNA顺序 ,就可以与已建立的DNA序列库进行比较 ,从而了解致病菌所属类型 ,而且 At present, there are more than 30 kinds of bacteria that cause cotton diseases. The traditional identification method needs to be gradually separated and extracted from bacteria, which takes a long time. However, the current molecular biology method uses PCR to amplify specific DNA in any part of any microorganism to determine Its base sequence, due to a specific organism has a fixed DNA sequence, can be established with the DNA sequence library to compare to understand the type of pathogens, and