PJB-2025-1523
Evaluating rice blast resistance in Egyptian genotypes: a combined phenotypic and molecular approach
Asmaa S. Nofal, Said S. Soliman, Tarik A. Ismail, Hany Wafa, Areej S. Jalal, Salha Mesfer Alshamrani, Diaa Abd El-Moneim, Wael F. Shehata, Wessam F. Felemban, Rahma Alshamrani and Abdallah A. Hassanin
DOI:10.30848/PJB2025-3(14)
Abstract
Rice blast disease caused by the pathogen Magnaporthe oryzae is a destructive fungal disease of rice, causing significant yield losses and economic damage. Molecular screening and phenotypic assessment of blast resistance genes were conducted in five Egyptian rice genotypes: Sakha101, Sakha104, Orabi 4, Sakha101×Orabi 4, and Sakha104×Orabi 4. The severity and incidence of neck and leaf blast diseases were estimated using specific molecular markers. The highest neck and leaf blast incidence (54.44%) and (77.78%) were observed in Sakha 104 and Sakha101, respectively. Conversely, the lowest leaf and neck blast incidence (18.89% and 0%, respectively) was observed in Orabi 4. Leaf blast severity ranged from 48.09 % in Sakha104 to 10% in Orabi 4. The highest severity was recorded in Sakha 101 (38%), while neck blast severity was 0% at orabi4 and Sakha101×Orabi4. Five major rice blast resistance genes (Pi-d2, Pi-z, Pi-9, Pi-37, and Pi-b) were screened using molecular markers in the five studied genotypes. The results revealed that all genotypes were positive for the Pi-d2, Pi-z, and Pi-b markers except the absence of Pi-b marker in Sakha 104 genotype. All genotypes were negative for the Pi-9 and Pi-37 markers. The frequency of resistance genes (R genes) was 0% for Pi-9 and Pi-37 markers, 80% for Pi-b, and 100% for Pi-d2 and Pi-z. The current study concludes that rice leaf and neck blast diseases are more prevalent in the Sakha101 and Sakha104 genotypes compared to the Orabi4, Sakha101×Orabi4, and Sakha104×Orabi4 genotypes. These genotype's resistance genes hold promise as sources for breeding programs aiming to develop blast-resistant rice cultivars in Egypt.
To Cite this article:
Nofal, A.S., S.S. Soliman, T.A. Ismail, H. Wafa, A.S. Jalal, S.M. Alshamrani, D.A. El-Moneim, W.F. Shehata, W.F. Felemban, R. Alshamrani and A.A. Hassanin. 2025. Evaluating rice blast resistance in Egyptian genotypes: a combined phenotypic and molecular approach. Pak. J. Bot., 57(3): DOI: http://dx.doi.org/10.30848/PJB2025-3(14)
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