Establishment of ISSR reaction system of Fusarium and its analysis of genetic diversity.

【Objective】 To establish the ISSR reaction system of Fusarium and analyze the genetic diversity of its isolates. 【Method】 Utilization of ISSR-PCR enlargement reaction technique, the PCR ingredients was optimized and the ISSR premier was chosen. Analysis of the genetic diversity of Fusarium isolates through the established cluster map. 【Result】 The optimum conditions for ISSR-PCR were 2.0 mmol·L-1 Mg2+, 0.5 U Taq DNA polymerase, 0.2 mmol·L-1 dNTPs, 0.4 μmol·L-1 primers, 30 ng templates DNA in 20 μl reaction system and UBC885 as premier, the annealing temperature was 52 ℃. ISSR technique was used to analyze the diversity of 27 Fusarium isolates with 11 primers, and the results showed that 79 fragments were amplified; polymorphic loci were 65 which accounted for 82.3% in the total amplified fragments. The genetic diversity was analyzed according to the amplified results and a molecular dendrogram was constructed and the genetic similarities among Fusarium isolates were analyzed. The similarity coefficient of 27 Fusarium isolates was at 0.672-0.950 and at the level of 0.670 they were divided into 3 groups and 2 subgroups. 【Conclusion】 In this paper, the author has established the befitting ISSR-PCR reaction system for Fusarium and found there are manifest interspecific and intraspecific genetic diversity of Fusarium isolates. This technique can be used to analyze the interspecific and intraspecific genetic diversity of Fusarium in the future study.