A New Leaf Blight Disease Caused by Alternaria jacinthicola on Banana in China

Bin Wang,Jiapeng Liu,Yongyan Zhang,Chunzhen Cheng,Guiming Deng,Peitao Lü,Fan Liu,Dongliang Qiu,Ou Sheng

doi:10.3390/horticulturae8010012

Abstract

A leaf blight disease with an incidence level of about 50% was found on Robusta banana in Guangdong province of China in September 2020. The early symptom appeared as pale gray to black brown, irregular, small, necrotic lesions mainly on the top 3–5 leaves. Severely infected leaves were withered and necrotic. Two representative fungus strains, strain L1 and strain L2, were isolated from affected banana leaves, and morphological and molecular identification analysis confirmed that the two fungi were both Alternaria jacinthicola. Many Alternaria species have been reported to cause wilting, decay, leaf blight and leaf spots on plants and lead to serious economic losses in their production, including A. alternata, causing leaf blight and leaf sport diseases on banana. The Koch’s postulates of A. jacinthicola causing the leaf blight disease was further fulfilled, which confirmed that it is the causal agent of this disease. To our knowledge, this is the first report of A. jacinthicola causing leaf blight on banana in China.

Highlights

Banana (Musa spp.), one of the most popular and widely grown fruit and a major source of food crop, is a staple for more than 400 million people and a huge commercial export [1]
AAA Group) with an incidence level of about 50% was observed in the banana germplasm evaluation orchard of the Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences located in Suixi county, Zhanjiang city, Guangdong Province
The colony characteristics and conidial morphology these two fungus strains were further observed and analyzed. Their colony mycelia were white to dark brown that gradually changes to black on the underside on PDA medium (Figure 1C,D)

Summary

Introduction

Banana (Musa spp.), one of the most popular and widely grown fruit and a major source of food crop, is a staple for more than 400 million people and a huge commercial export [1]. The banana industry has been considered as an important economic pillar for many farmers in south China. As cultivated banana cultivars are generally low in disease resistance, the development of the banana industry has been greatly constrained by many infectious diseases caused by pathogenic microorganisms. Among these diseases, banana wilt disease and several leaf diseases have caused great yield and economic losses [2,3]. The banana leaf diseases, were much less focused compared to the former disease. Many fungi have been identified as pathogenic fungi causing severe leaf diseases on banana [10,11,12,13]

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