Ascertaining of Ug99-race specific genes in wheat genotypes assigned to stem rust resistance based on phenotypic and genotypic reaction

Ibrahim Sobhy Draz

Abstract


Five wheat genotypes including two commercial cultivars (Mist1 and Misr2) and three Ug99-race specific genes (Sr24, Sr25, and Sr31) were screened for stem rust resistance based on phenotypic and genotypic reaction. Based on phenotypic reaction, Sr24 (LcSr24Ag) and Sr31 (Seri-82) exhibited seeding and adult plant resistance while the wheat cultivars, Misr1 and Misr2 were susceptible. Sr25 Agatha (CI 14048)/9*LMPG-6 DK16 exhibited seedling resistance while showed susceptibility at adult plant stage. Based on genotypic reaction, DNA markers showed that gene Sr25 was only found to be present in Misr1 and Misr2 while Sr24 and Sr31 were absent in both cultivars. Although, virulence to Sr25 was detected. However, avirulence to Sr24 remains this gene as a suitable resistance gene to be incorporated into wheat genotypes for disease resistance to local Pgt population.


Keywords


Wheat, Stem rust, Ug99-race, Race specific genes, Phenotyping, DNA markers

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