American Journal of Plant Sciences, 2011, 2, 276-281 doi:10.4236/ajps.2011.22030 Published Online June 2011 (http://www.SciRP.org/journal/ajps) Copyright © 2011 SciRes. AJPS Mango Malformation: I. Toxin Production Associated with Fusarium Pathogens Wafaa Haggag M. 1 , Hazza M. 2 , Sehab A. 1 , Abd El-Wahab M. 1 1 Department of Plant Pathology National Research Center, Dokki, Cairo, Egypt; 2 Science Faculty, Botany Department, Banha Uni- versity, Banha, Egypt. Email: wafaa_haggag@yahoo.com Received April 2 nd , 2011; revised May 4 th , 2011; accepted May 18 th , 2011. ABSTRACT Eight Fusarium species i.e. F. subglutinans, F. solani, F. oxyspoum, F. sterilihyphosum, F. proliferatum, F. monili- forme, F. avena and F. chlamydspore isolated from mango malformed disease were tested for their ability to cause mango malformation disease and their production of moniliformin and total fumonisins (FB1 + FB2) using HPLC. A evaluated for moniliformin production, seven isolates were toxin producers, the production levels ranging from 0.51 to 8.90 µg/ml. The higher levels were produced by Fusarium subglutinans (8.51 µg/ml). Moderate concentrations of moniliformin was produced by F.moniliforme (6.90 µg/ml), F. oxysporum (6.30 µg/ml), F. proliferatum (4.10 μg/ml) and F. sterilihyphosum (1.10 μg/ml). Separation and identification of Fumonisin that was isolated from the pathogen- causing disease are made by (HPLC). A evaluated for total fumonisin production (FB1 + FB2), seven isolates were toxin producers, the production levels ranging from 0.10 to 8.30 µg/ml. The higher levels were produced by F. monili- forme (8.30 µg/ml. Moderate concentrations of fumonisin was produced by F .proliferatum (0.64 µg/ml) and F. subglu- tinans (0.50 µg/ml). Strong positive correlations between moniliformin and total fumonisins (FB1 + FB2) activities and malformation disease incidence by F. subglutinans, F. solani, F. oxyspoum, F. sterilihyphosum, F. proliferatum was observed. Keywords: Fusarium, Mango Malformation, Moniliformin and Fumonisins 1. Introduction Mango (Mangifera indica L.) is the most important fruit grown in tropical and subtropical region of the world. Mango (Mangifera indica L.) is the most important fruit crop in Egypt. Mango Malformation is one of the most destructive mango diseases [1,2]. Losses due to malfor- mation have not been accurately assessed because yield loss is not a linear function of disease severity [3]. Dur- ing a survey of mango plantations in Sindh for investi- gating the association of fungi with mango malformation disease (MMD), six fungal species viz., Fusarium nivale (Fr.) Ces, F. oxysporium, F. moniliforme, F. semitectum, Alternari alternata and Aspergillus niger were isolated and identified on the basis of their colony characteristics and conidial morphology [4]. F. sterilihyphosum and F. proliferatum are first report association with mango malformation in [5]. As noted by [6] mango malforma- tion probably involves two principles;1) the malforma- tion inducing principle (MIP) which works through im- balance in growth substance and in conditioning of cells; 2)The toxic principle (TP) which causes growth retardation and toxicity symptoms. Fuarium species, particularly F. moniliforme var subglutinans, are likely source of MIP and TP, and the causal agent of disease. Singh and Dhillon [7] proposed that ethylene might play role in mango malformation by suppression of apical dominance, causing more isodiametric growth of rachi- des and shortening and thickening of secondary branches of malformed panicles. Ram [8] stated that the most probable role of malformin in the causation of mango malformation might be mediated through alteration of membrane permeability leading to efflux of IAA or its metabolite. He indicates the possibility that malformin antagonizes IAA action through efflux action of auxins of the malformed cells causing loss of apical dominance at a very early stage of panicle development. Malformed mango panicles have been shown to contain reduced lev- els of auxin [7,9,10]. Strains of Fusarium proliferatum, F. subglutinans, F. anthophilum, F. annulatum, F. succisae, F. beomiforme, F. dlamini, F. napiforme, and F. nygamai from a variety of substrates and geographic areas were