ESTIMATION OF STABILITY AND GENETIC PARAMETERS FOR SOME CHARACTERS OF EGYPTIAN EXTRA-LONG STABLE GENOTYPES.

The main objectives of the present study were to evaluate the degree of
stability for several genotypes. estimation of genetic parameters and phenotypic
correlation. Twenty-four genotypes were evaluated over seven locations in 1999
season. Four traits, including seed cotton yield. lint cotton yield, boll weight and
earliness index were studied. The variance for environments (E), genotypes (G) and
GE interaction were highly significant for all traits. Most of genotypes did not vary for
parameter (0=0) while parameter }o. did not differ from "one" for all traits. There were
average stability level for seven genotypes in seed cotton yield, two genotypes in lint
cotton yield, nine genotypes in boll weight and eight genotypes in earliness index.
One genotype (Fa 1292/97) exhibited above average stability at 90 and 95
probabilities for seed cotton yield and lint yield. The genotypes (Fe 1292/97 and F,o
1363/97) exhibited complete stability for lint yield. The genotypes (F7 1298/97 and F9
1359/97) exhibited above average stability for fifty boll weight. Giza 70 showed
average stability for seed cotton yield and lint yield. Giza 80 was more productive and
showed average level of stability for seed cotton yield and earliness index. Genotypes
F,o 1363197 had high yield and showed complete stability for lint yield and average
stability for seed cotton yield and earliness.
The genetic estimates indicated the presence of substional amount of genetiC
variance (1)2g) for bali weight and earliness while the component of interaction (1)2go)
and the environment component (1)2.) were more than the genetic variance
component for seed cotton yield and lint yield. The heritability values were moderate
for boll weight and earliness and low for seed cotton yield and lint yield. Genetic gains
at 5% intensity of selection were high for boll weight and earliness index and low for
seed cotton yield and lint yield. There were significant and positive phenotypic
correlation coefficient between seed cotton yield find earliness and highly significant
positive phenotypic correlation between seed cotton and lint yield.