Pectic zymogram analysis for characterizing genetic diversity of the mango anthracnose pathogen.
Gantotti B. V., Davis M. J.
Author Affiliation: University of Florida, Institute of Food and Agricultural Sciences, Tropical Research and Education Center, Homestead, FL 33031, USA.
: 353-359
Abstract : Sixty-three isolates of the mango anthracnose pathogen Colletotrichum gloeosporioides [Glomerella cingulata], from naturally infected leaves, panicles, flowers, and immature and mature fruits in Florida, USA, were subjected to pectic zymogram analysis. The fungi were cultured in a minimal medium containing pectin to induce production of pectinase [polygalacturonase]. Culture filtrates containing extracellular polygalacturonases were subjected to pectin-polyacrylamide gel electrophoresis and comparative analysis of the resultant zymograms lead to identification of 10 representative pectic zymogram groups (PZG). Two of the 4 PZGs produced by isolates from mature fruits were most prevalent, and one of these PZGs associated with mature fruits was also found to occur on immature fruits. The other prevalent PZG on mature fruits was also prevalent among leaf isolates. Pectic zymogram analysis not only revealed genetic diversity within the population of the mango anthracnose pathogen, but also indicated that isolates of various PZGs were differentially distributed on different tissues of mango trees. The technique is simple, rapid, and amenable to analysis of a large number of strains.