First Record of Melanospora chionea as a Possible Cause of Pink Root Rot Disease on Tomato Plants in Egypt

Abstract

Tomato is one of the most important vegetable crops in the world. It is infected with several disease through the growth season, but new disease appeared as a new challenge to tomato productivity, causing pink root rot. Symptoms of pink root rot were observed on tomato (Lycopersicon esculentum Mill.) grown in Beni Sweif Governorate (Nasser, Sumosta, Beba and El-Wasta Counties) in summer 2013 as poor growth, chlorosis and then necrosis of the tip branches, by maturity. Typical symptoms on the infected root especially, epidermis were picked areas and both of cortex and vascular bundles were colored with pink along the infected tissues consistent with both those that were observed in the field. Based on morphological characteristics of the isolated fungus, disease symptoms and a pathogenicity test, Melanospora chionea was identified as the causal agent of pink root rot of tomato. Identification of this species was confirmed by sequencing of internal transcribed space (ITS region) of ribosomal RNA gene. M. chionea has not previously been reported on tomato. The host range of this disease was defined between numerous hosts belonging to Fabaceae, Malvaceae, Cucurbitaceae and Solanaceae. The aim of this work to determine and description of the disease and identification of the pathogen morphologicaly and genetically. More work is required to find appropriate methods for controlling this new disease.