This study was conducted in three different locations in Egypt, i.e., Ismailia, Nobaria and
Gemmeiza Research Stations. Fis of 15 wheat crosses produced from 6 half-dialleles in
addition to their six parents were statistically and graphically analysed to detect the genetic
effects governing 5 quantitative characters. Results for gca, sea and heterosis differed from
one location to another according to the parental genotypes and the environmental
conditions in these locations. The parents Agent and Sakha 69 showed the best gca in Fi
for plant height, spike length and 100-grain weight, while for number of grains/spike and
grain yield/plant Sakha 92, Baart and Sakha 69 were the best. The best combinations for sea
were the cross 7 for plant height at Ismailia and Nobaria cross 11 for spike length and grain
yield/plant in all locations and in combined analysis. Cross 5 for grains/spike at Ismailia, {
cross 1 for 100-grain weight at all locations and in pooled analysis. The MP and BP heterotic I
effects were high for some crosses and differed from location to another and in combined
analysis. All characters were controlled by both additive and nonadditive gene effects in
all three locations in Fi with unequal allele frequency of the parents. Asymmetrical i
distribution of positive and negative alleles among the parents and Fi at all locations were j
detected for all traits. Overdominance or partial dominance were exhibited for some traits i
at different locations with the excess of dominant genes. One, two or more pairs of genes j
controlled the inheritance of these traits. Narrow sense heritability was relatively high or I
moderate for some trait at different locations. The rvalue was positive and significant only f
for 100-grain weight at Ismailia (0.93) and negative for plant height at Gemmeiza (- 0.89). J
In the Wr-Vrgraphs, the parents showed variation in the dominant and recessive positions
for all trails at all locations. Grain yield/plant in Fi was phenotypically and genotypically
correlated with plant height and the 100-grain weight at Gemmeiza, phenotypically only
with spike length at Ismailia and Gemmeiza, and with number of grains/spike at
Gemmeiza. Also there was a genotypical correlation only with the 100-grain weight at
Ismailia.
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