بررسي تركيب پذيري و عمل ژن در صفات كيفي چند هيبريد بين گونه اي پنبه

Studies on combining ability and gene action for qualitative traits in some interspecific hybrids of cotton

In order to study the combining ability and gene action for qualitative traits in cotton, six selected genotypes of G.hirsutum and G.harhadense species were crossed in unidirectional diallel design. 15 hybrids with six parents (totally 21 genotypes) were studied in randomized complete block design (RCBD) with three replication at Karkandeh cotton research station (Kordkouy). Some qualitative traits (lint yield, lint percentage,2.5% lint length, lint homogenity, micronair index, fiber strength and lint elongation) were investigated. The results showed significant difference among genotypes (except for fiber strength). Mean square of GCA was significant for all traits (except for lint homogeneity) and mean square of SCA was significant for lint percentage, 2.5% fiber length, fiber strength and fiber elongation. Combining ability study and genetic analysis showed that additive gene action is effective on micronair index and lint homogeneity percent, both additive and non-additive gene actions are effective on other traits. Average degree of dominance at each locus and graphical analysis indicated partial dominance for lint yield, 2.5% fiber length and micronair index and also over dominance effect for lint percentage and fiber strength. On the base of results, the interspecific hybridization is a suitable technique for new hybrid creation, particularly to combine the lint yield of G.hirsutum with the lint qualities of G.harbadense.