Inheritance of some agronomic characters and rusts resistance in fifteen F2 wheat populations

Abstract

Six parents, i.e. Gemmeiza 9, Sids 12, Misr 1, Misr 2, Sids 1 and Sham 4, were used and evaluated with corresponding 15 F2 crosses. The parents in each cross were significantly different for most of these characters, revealing the different genetic background of the parents involved. The phenotypic variances in the F2 crosses were differed significantly from the environmental variances in the corresponding parents in most cases. The parents Gemmeiza 9, Sids 12, Misr 1, Misr 2 were resistant for leaf rust and Gemmeiza 9, Sids 12 and Sids 1 were resistant to stem rust. Among the crosses, three crosses, i.e. Misr 2 x Sids 1, Misr 1 x Sids 1 and Gemmeiza 9 x Sids 1 gave the highest grain yield. The means of F2 hybrids were higher than the means of the parents for most studied characters. The ranges of the F2 values went out the ranges of the two parents in most cases, exhibiting transgressive segregation. Most characters showed moderate to high values of broad sense heritabilities. The studied plants in the F2's crosses segregated and gave ratios fitted the ratios 9:7, 9:7, 3:1, 1:3, 13:3 and 3:13 for leaf rust and 9:7, 7: 9, 3:1, 1:3, 3:13 and 1:15 for stem rust with insignificant χ2 values, indicating that the resistant parents for leaf and stem rusts had one or two genes and were complimentary dominance, recessive or independent in their expressions. Based on the resistance to leaf and stem rusts, suitable plant height (90-110 cm) and grain yield higher than the highest parent, 8-17 plants were selected from seven crosses.