Estrutura genética de isolados do fungos causador da Sigatoka-amarela em bananeira

Abstract

Among the major diseases affecting banana is yellow Sigatoka, caused by Mycosphaerella musicola Leach. The objective was to study the genetic diversity and population structure of the fungus M. musicola, the main banana-producing regions. Additionally, we investigated the population structure is correlated with geographic origin. For this, we evaluated 83 isolates collected in the states of Bahia (BA), Rio Grande do Norte (RN) and Minas Gerais (MG) through SSR, ISSR and the combination of the two (SSR / ISSR). According to AMOVA analysis for the three most genetic variation occurred among haplotypes within municipalities, in which only the use of ISSR was not significant. High variability was detected among isolates, with primers combined observed distinct haplotypes 100%, with 98.79% of SSR haplotypes with unique and ISSR were 83.13% different haplotypes. Regarding the genetic composition based on Bayesian clustering was noted the presence of 21 probable ancestral groups for study sites with primers combinations, different from what occurred with the use of SSR and ISSR were found in which the presence of 14 probable ancestral groups. The highest Gst was 0.11 between RN and MG for SSR, already Nm indicating gene flow was high among all states. Compared to IA and rd, the hypothesis was accepted for sexual recombination in some micro study. However, it was not detected any structuring of the population according to the sampling sites, and the knowledge about the distribution of genetic variability of M. musicola will assist in strategies to control the disease.