تقدير بعض المعالم الوراثية في الجيل الثاني لتراكيب ورائية من القطن

Abstract EN

Cotton varieties, Iranian, Bulgarian Gord 26, Lachata, French CA22, Syrian line 106, Pima, Bulgarian Chripam539 and Coker310, and all their F2 half diallel crosses were grown at Al-Hawija, Kirkuk Governorate in mid-April, 2011 using randomized complete block design with three replications to study general and specific combining abilities for parent and crosses respectively and estimation of phenotypic variance components and some genetic parameters for characters: plant height, number of fruiting branches per plant, number of bolls per plant, boll weight, earliness, lint index and seed cotton yield per plant.

Analysis of variance results showed that mean square of genotypes, general and specific combining ability was significant for all characters.

The variety Bulgarian Chripam539 appeared as a good general combiner for all characters, and (Bulgarian Gord 26 x Lachata), cross as good specific combiner for all characters except plant height.

The variances (additive, dominance and environmental) appeared significant from zero for all characters, and the dominance variance was higher than additive one for all characters except plant height.

Both additive and dominances variances was high as compared with environmental one for all characters.

The average degree of dominance was higher than one for all characters indicating the presence of over dominance control its inheritance with the exception of plant height, as the partial dominance present.

Narrow sense heritability ranged from 6.23 % for boll number to 66.13 % for plant height, as was high for plant height and low for other characters, while broad sense heritability was high for all characters and ranged from 89.41 % for boll weight and 98.99 % for plant height, while genetic advance from selection in the third generation as percent from character mean was high for plant height where valued 18.023 %, while it was low for other characters.