Inheritance of Powdery Mildew Resistance in Some Egyptian Wheat Cultivars

Powdery mildew diseases (PM) are widespread globally and have contributed to significant yield losses. Resistance to powdery mildew infection can be improved in wheat genotypes by detecting resistance genes to PM that are present in the wheat genotypes. Using six wheat genotypes, i.e., Misr-4, Sakha-94, Sakha-95, WEMBLEY, KAVKAZ, and PM16, in a 6×6 diallel crosses without reciprocals and their F2 generation to find out and select high yielding and resistance genotypes to PM materials. Significant heterosis in F1 generation was obtained for all traits. Heterosis of grain yield relative to the better parent varied from 6.33 to 32.47% in F1 crosses. Three crosses (P1 x P5, P2 x P4, and P5 x P6) showed significant positive heterotic effects for grain yield. Six crosses (P1 x P5, P1 X P6, P2 x P4, P4 X P5, P4 X P6, and P5 X P6) showed significant positive heterotic effects for PM resistance. General (GCA) and specific (SCA) combining ability mean squares were significant for all studied traits. The GCA/SCA ratio was greater than unity for all traits, indicating the predominance of additive gene action in the genetic system controlling for these characters. The results of wheat genotype quality showed that P4 recorded high crude protein, while P1 recorded improved seedling parameters such as seedling dry weight and seedling vigor index compared to other parents. Hereby, the previous significant crosses can be utilized in the breeding program to improve resistance of wheat to powdery mildew infection, protein content, and yield.