SURVEY ON INCIDENCE OF DAMPING- OFF AND ROOT ROT/WILT DISEASES OF CORIANDER (Coriandrun sativum L.) IN MINIA GOVERNORATE

Abstract

Coriander seedling damping-off and root rot/wilt diseases considers as the most destructive diseases causes serious economic loss on coriander production worldwide, particularly in tropical and subtropical regions. Fusarium solani, Fusarium oxysporum f.sp . c umini, Rhizoctonia solani, Phoma sp Alternaria sp. and Sclerotinia sclerotiorum were reported as the most fungi associated with these diseases. In this study, a survey has been conducted to report the incidence of coriander root rot/ wilt diseases in five different districts belongs to Minia Governorate. The survey was performed when plants were at physiological maturity stage of the growth, indicated that this diseases are prevalent in all areas under this study. Our results show that the disease incidence ranged between 7 and 45%, and disease severity was 5-32%. Twenty-nine isolates of fungi, belong to nine different species were isolated from naturally infected plants. All isolated fungi were able to infect coriander (Balady cv.) plants, with different degrees of incidence and severity. Among the 29 isolates, three isolates, which caused the highest DI,% and DS,%, were identified as Fusarium oxysporum, Rhizoctonia solani and Macrophomina phaseolina based on their morphological, cultural characters, and molecular analysis of the internal transcribed spacer (ITS) regions. In addition, the identified pathogens were able to cause seedling damping - off and root rot/wilt on caraway, cumin, dill, fennel and parsley, whereas carrot showed more resistant. Furthermore, physiological studies demonstrated that PDA, corn meal dextrose, malt dextrose agar, coriander dextrose agar and Nutrient dextrose agar were the most favorable media for these fungal isolates. The fungi can grow in a wide temperature and relative humidity ranged between 15-35 o C and 50-100% RH, with optimum temperature of 20-30 o C, and 84 to 100% RH, depending on the fungus under study.