Malformation presence in mango seedling trees cultivated within infected Egyptian orchards.
Youssef S. A., Shalaby A. A., Sztejnberg A., Maymon M., Zveibil A., Klein-Gueta D., Freeman S.
Author Affiliation: Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt.
: 479-482
Abstract : Mango malformation, caused by the fungus Fusarium mangiferae, is one of the major diseases of mango, it occurs worldwide and causes significant economic loss due to the general incapacity of malformed inflorescences bearing fruits. Studies were conducted to gain an understanding of certain aspects of the epidemiology, survival and spread of the pathogen in general and specifically in seedlings, the majority of which, in Egypt, are cultivated in infected orchards. After 16 weeks, the pathogen survived in approximately 88% of infected panicles buried in the soil, whereas populations were not detected in materials placed on the soil surface. Vegetative malformed mango seedlings growing under infected mature trees and infected panicles were sampled in 2 locations in Egypt to determine the distribution of the pathogen within the plant tissue. The presence of the pathogen was detected by plating on a Fusarium-specific medium and verified by a PCR-specific primer amplification. With PCR, the pathogen was detected in 97% of the seedling apical meristems, declining gradually to 5% colonization in roots. Based on this study, it was shown that the inoculum of the pathogen originated from infected panicles and affected seedlings from the meristem, with infections descending from top to lower stem sections and roots. The results indicate the potential applicability of species-specific primers for early detection and identification of F. mangiferae in infected tissue.