Distribution and prevalence of Fusarium subglutinans in mango trees affected by malformation.
Ploetz R. C.
Author Affiliation: University of Florida, Institute of Food and Agricultural Sciences, Tropical Research and Education Center, 18905 SW 280th St. Homestead, FL 33031, USA.
Canadian Journal of Botany 72 : 7-9
Abstract : Infection of malformed and non-malformed mango trees by F. [Gibberella fujikuroi var.] subglutinans was assessed in Florida, USA. All malformed floral panicles, but only 50% of the non-malformed panicles, were infected by the fungus. When within-panicle infection was evaluated, an av. of 84.5% of the small pedicel and peduncle tissue pieces from malformed panicles were infected. When malformed and non-malformed panicles were both assessed, 68.3% of the tissues from malformed panicles, but only 11.7% from non-malformed panicles, were infected. Slight infection (2.2%) was observed in branch tissue that supported malformed panicles, and the fungus was never isolated from branches that supported non-malformed panicles, In nutritional complementation tests with nitrate non-utilizing (nit) mutants, 55 of 64 isolates of G.f. var. subglutinans from malformed mango panicles were in the same vegetative compatibility group. It is concluded that mango malformation in the study area was significantly correlated (P0.0001) with infection by genetically related populations of G. f.var. subglutinans. It is also suggested that the greater prevalence of G. f. var. subglutinans in malformed than in asymptomatic panicles indicates that malformation symptoms develop in floral tissues only after they are extensively colonized by this fungus.