植物病理学および微生物学ジャーナル

概要

Histo-pathological evaluation of the Fusarium species causing malformation disease of Mangifera indica

Wafaa Haggag M, Amin Zakaria, Hazza M, Sehab F. S and Abd El-Wahab M

Mango malformation is a serious disease in tropical and subtropical areas of the world and has been attributed to various Fusarium spp. The results of pathogenicity test under greenhouse conditions for 7 different isolates of the fungus Fusarium i.e. F. subglutinans, F. solani, F. oxysporum, sterilihyphosum, F. proliferatum, F. moniliforme, F. avenaceum and F. chlamydosporum have recorded that the F. subglutinans is the main cause of the mango malformation disease followed by F. oxysporum, F. sterilihyphosum and F. proliferatum while the other isolates appeared the symptoms of root rot when used as inoculated soil with spores suspension. Histological studies of the apical buds in mango cv. Sedekia revealed the presence of disorganised cells, degradative, hyperplasia areas and fungal mycelial infection at the base of the malformed bud during bud-inception stages. Also, large and small degenerated zones were observed in different tissues of cross-section, i.e. cortex, vascular tissues and pith zone. The infection resulted on seriously damaged and degenerated tissues which show, vast and large protolysis areas. Among other possible reasons, tissue damage caused by the fungi may lead to the abnormal development of the malformed tissues. According to the pathological and histological studies, F. subglutinans, F. proliferatum, F. oxysporum and F. sterilihyphosum were identified as the causal organisms of mango malformation. F. subglutinans is the main pathogen.