Gene action and heritability in bi-parental crosses of sunflower

Abstract

A field experiment was conducted in the contrasting locations of Kafr-El-Hamam/Sharkia and Al-Arish/North Sinai agricultural research stations of the Agricultural Research Center in Egypt. We estimated the additive and dominance genetic variances, as well as heritability in the broad and narrow senses for sunflower yield and its attributes in the cross L350 x L355 using North Carolina Design-III. The magnitude of the additive variances for all studied traits at both locations in proportion to the phenotypic variances was larger than the dominance variances. The average degree of dominance was greater than the unit, as also confirmed by the high narrow-sense heritability for most of the studied traits. The genetic improvement may be achieved through the selection of genotypes with larger head diameter and heavier seed weight which also showed moderate to high values of narrow-sense heritability. Thirty-two sunflower backcrosses were grouped into eight distinct clusters/groups by canonical analysis.

Keywords

• North Carolina Design-III
• average degree of dominance
• selection criteria
• cluster