الفهرس 
Genotypes by environments interactionOnly 14 pages are availabe for public view
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Abstract
Objectives:
1- Genetic variabilities and genotypic by location interactions.
2- Determination of superior parents and combinations through combining ability effects.
3- Type of gene which control of some quantitative traits under studying and heritability in broad and narrow senses.
4- To determine the genetic divergence among parents and F1 Progenies as well as to investigate the importance of the evaluated traits.
Methods & Results:
In the first season (2010/2011), hybridization among the selected parental genotypes at Sakha Agricultural Research Station at Kafr El-Sheikh governorate – Cotton Research Institute. In the second season (2011/2012), all 34 genotypes ( 24 genotypes of F1 and 10 parental genotypes ) were evaluated at two locations. The first location was at Sakha Agricultural Research Station at Kafr El-Sheikh governorate – Cotton Research Institute. The second location was at Experimental Farm of Faculty of Agriculture, Mansoura University- Al-Dakahliya governorate.
The obtained results could be summarized as follows:
1- Analysis of variance revealed highly significant difference among genotypes for all studied traits over two locations and their combined. This mostly due to the genetic factors rather than environmental ones as indicated by the high genetic variances.
2- The performance of parents distinctly varied from location to another.
3- The ratio of GCA variance to SCA variance revealed predominance of non-additive gene action for all studied traits.
4- The results revealed that the magnitude of non-additive genetic variance was larger than additive genetic variance for all studied traits.
5- Principal component analysis indicated that the first five components were significant.
Conclusion:
1- it could be concluded that the performance of parents and F1 hybrids varied from location to another for yield and earliness traits and somewhat stable for fiber character.
2- The magnitude of SCA variance was greater than GCA for majority of the traits indicating that additive × non-additive and non-additive type of interactions were significantly higher among hybrids which could be exploited by heterosis breeding.
3- However, most studied traits were governed by non-additive, dominance or epistatic genetic variance. Thus, recurrent selection approach would be appropriate for improvement of such traits.
4- In the same time, multivariate methods such as principal components analysis is useful for identifying most important traits effecting for genetic variation of population.