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.
