Genetic diversity of Fusarium mangiferae isolated from mango malformation disease China

Mango malformation disease, caused by Fusarium mangiferae, is one of the most important diseases affecting mango production. Thirty-eight isolates from MM-affected mango tissues were collected from two cities and assessed for genetic diversity using vegetative compatibility groups (VCGs) and inter simple sequence repeats (ISSRs). VCGs were determined among all isolates, using nitrate non-using (nit) mutants. Out of the 455 nit mutants generated, 78.02% used both nitrite and hypoxanthine (nit1), 13.63% used hypoxanthine but not nitrite (nit3) and 7.91% used nitrite but not hypoxanthine (NitM). Five different VCGs were identified by pairing the mutants on nitrate medium. Seventy-two bands were amplified by 14 ISSR primers, with an average of 5.14 bands per primer. The size of the amplified products ranged from 300 to 2000 bp. At a genetic similarity of 0.76, the unweighted pair-group method with arithmetic mean analysis separated the isolates into five distinct clusters, comprising 33, 2, 1, 1 and 1 isolates. The VCG and ISSR data support the conclusion that the isolates of F. mangiferae are not necessarily related by geographic origin, type of host tissue, or the mango cultivar from which they were isolated. (C) 2013 Elsevier B.V. All rights reserved.