Infection Dynamics of Fusarium mangiferae, Causal Agent of Mango Malformation Disease

Abstract

Conditions affecting germination and growth of Fusarium mangiferae, causal agent of mango malformation disease, were studied in vitro. Both conidial germination and colony growth required temperatures >5 degrees C and reached a peak at 28 and 25 degrees C, respectively. A minimum 2-h wetness period was required for conidial germination, reaching a peak after 8 h of wetness. High incidence of fungal colonization in buds, predominantly the apical buds, was detected compared with inoculated leaves. The pathogen was detected in the roots of inoculated soil 19 weeks postinoculation but not in aboveground parts of the plants, and symptoms of the disease were not observed, either. Dry, malformed inflorescence debris serving as a source of inoculum caused significantly higher colonization (52 and 20%) of inoculated buds, compared with that (0%) of the untreated controls. Incidence of sampled leaf disks bearing propagules of F. mangiferae from an infected orchard peaked in June and July and decreased during the following months, whereas airborne infections on 1-month-old branches was the highest in May and June, corresponding with inoculum availability released from infected inflorescences. Colonization pattern, determined in naturally infected vegetative and woody branches, was significantly higher in node sections than in the internode sections. This study sheds light on infection dynamics, colonization patters, and the disease cycle of F. mangiferae in mango.

The role of eriophyoids in fungal pathogen epidemiology, mere association or true interaction?

“…At least in the case of the mango bud mite, we are convinced that this is not the case because it was demonstrated that the mite can vector the spores to the buds, the fungus's sole port of entry to the plant and enhance disease severity (Gamliel-Atinsky et al 2009b). Furthermore, the spores could benefit from the ability of the mites to travel long distances by wind (Zhao and Amrine 1997).…”

“…Results from our recent study demonstrated that the apical bud is the exclusive penetration site for the fungal pathogen (Gamliel-Atinsky et al 2009b) which also serves as the exclusive living habitat of A. mangiferae. Most conidia of F. mangiferae disseminate in the air and randomly fall on the tree canopy which takes up most of the surface area of the orchard.…”

New Insights into Mango Malformation Disease Epidemiology Lead to a New Integrated Management Strategy for Subtropical Environments

“…Malformed panicles, which can persist on the tree until the following season as dry, black masses, serve as sources of inoculum for as long as they remain on the tree (Fig. 3E) (22). MMD etiology.…”

“…The distribution of F. mangiferae in affected trees suggests that apical buds are the primary sites of infection and that systemic colonization of branch tissues does not occur (21,22,57). In Flor ida, F. mangiferae was restricted almost entirely to malformed floral and vegetative tissues (57).…”

First evidence of ethylene production byFusarium mangiferaeassociated with mango malformation

“…5 Malformation is not only well-known in India but has also been confirmed in most mango-growing countries such as Pakistan, the Middlle East, Egypt, South Africa, Brazil, Sudan, Central America, Mexico, United States, Cuba, Malaysia, Australia, Israel, UAE and Bangladesh. [6][7][8][9][10] There are several confusions in the literature to explain the nature of this malady because research efforts made up to now have not been Malformation is arguably the most crucial disease of mango (Mangifera indica L.) at present. It is receiving great attention not only because of its widespread and destructive nature but also because of its etiology and control is not absolutely understood.…”