Neofusicoccum batangarum Causing Dieback of Mango (Mangifera indica) in Florida

Alina S Puig,Mike C Winterstein

doi:10.3390/agriculture11090853

Abstract

Mango (Mangifera indica) is an economically significant crop, and is affected by dieback in nearly all commercial production areas. Due to the wide range of organisms previously associated with these disease symptoms in Florida, isolations and pathogenicity tests were carried out to determine the causal organism. The pathogen was identified as Neofusicoccum batangarum based on genetic sequences from three loci (internal transcribed spacer of the rDNA (ITS), β-tubulin (BT), and translation elongation factor 1-α (EF)), recommended for members of the Botryosphaeriaceae family. Possible infection routes were determined by inoculating wounded and unwounded stems with N. batangarum. Trees wounded prior to pathogen inoculation developed larger lesions (5.85 cm ± 1.51) than unwounded trees (0.51 cm ± 0.48), p < 0.0003. In addition, lesions only developed at a small number of inoculation sites in the absence of wounds (14.3%), compared to 93% when stems were wounded. No necrosis was observed in the negative controls. This study provides molecular data on N. batangarum, and evidence of its role causing mango dieback in Florida.

Highlights

Dieback and decline affect mango (Mangifera indica) trees around the world, leading to significant yield losses in Brazil, Ghana, Oman, Pakistan, Australia, and Mexico [1,2,3,4,5,6]
The characteristic defoliation and branch necrosis can affect plants of all ages, occasionally causing death [7]. This disease has been associated with numerous fungi, Lasiodiplodia species are most frequently reported as the cause of mango dieback/decline [2,7,8]
It has been attributed to several members of the Botryosphaeriaceae such as Neofusicoccum ribis, Diplodia sp., Dothiorella dominicana, and Lasiodiplodia theobromae, based on morphological identifications [11,12]

Summary

Introduction

Dieback and decline affect mango (Mangifera indica) trees around the world, leading to significant yield losses in Brazil, Ghana, Oman, Pakistan, Australia, and Mexico [1,2,3,4,5,6]. The characteristic defoliation and branch necrosis can affect plants of all ages, occasionally causing death [7]. This disease has been associated with numerous fungi, Lasiodiplodia species are most frequently reported as the cause of mango dieback/decline [2,7,8]. Dieback of mango trees has been reported in the state since the 1970s, decreasing yield by up to 50%. It has been attributed to several members of the Botryosphaeriaceae such as Neofusicoccum ribis, Diplodia sp., Dothiorella dominicana, and Lasiodiplodia theobromae, based on morphological identifications [11,12]

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