Incidence and Molecular Identification of Cochliobolus carbonum as Causal Organism of Rice Seedling Blight

Publication date: Available online 26 July 2018Source: Beni-Suef University Journal of Basic and Applied SciencesAuthor(s): Rabie A.S. El-Shafey, Kotb A. Attia, Fatma A. Mostafa, Rabab M. ElamawiAbstractDuring last few years, seedling blight and black lesions along culm of rice seedlings have been appearing frequently in nurseries. Identification of the causal organism was the objective of this research. The identification was done based on morpho-pathological characteristics and Internal Transcribed Spacer (ITS) region sequencing analysis. The pathogen effects on germination and development of rice seedlings were studied under laboratory and greenhouse conditions. Based on the morphological examination, 10 isolates were identified as Cochliobolus carbonum fungus. This organism recorded different levels of pathogenicity, and most of the isolates showed high virulence, up to 56% as seedling infection with isolate ECC-5. The germination percentage was reduced to 73% for cultivar Sakha 101. Sakha 101 recorded highest infected seedlings percentage (44%) under artificial inoculation. The isolates’ reaction was more variable on seedlings than on leaves of Egyptian rice cultivars. Infection severity on leaves of isolate ECC-5 recorded highest average for infection, while isolate ECC-3 did not exhibit any infection. Most of C. carbonum isolates were induced severe infection on rice seedlings. Therefore, the identified isolates were recorded as a novel pathogen causing seedling blig...
Source: Beni Suef University Journal of Basic and Applied Sciences - Category: Science Source Type: research