Analysis of Combining Ability and Heterosis in Partial Diallel Cross of Cotton

Abstract

Abstract Nine cultivars of American plantain cotton (Gosspium hirsutum L) were used. (1-Kafco, -2CI22, 3-Spiro, -4AK259, -5 Backcoat, -6 Montana, -7Lachata, 8- Condor, -9Dn 1047) and partial diallel cross (18 hybrid) which They were obtained according to the method proposed by Kempthorne and Curnow (1961) for the purpose of estimating the genetic parameters and genetic behavior of the traits of seed cotton yield and its components. The genotypes (parents + hybrids) were planted in the 2021/2022 agricultural season in Baiji District - Salah al-Din provainc (latitude 34.92944 and longitude 43.49389), using a completely randomized block design with three replicates. The results showed that the average variance of the genotypes was highly significant for most traits except for the traits (early flowering and number of seeds per boll). The father (Den 1047) gave highly significant and desirable effects for the general combining ability for three traits, followed by the fathers (CA22, Lachatta, and Chondro). This is evidence that These combinations have the largest number of genes with additional action, which play an important role in the inheritance of these traits. The hybrid (Kafco) – The value of the additional genetic variance was greater than the value of dominance genetic variance for the traits (plant height, early flowering, number of total boll, flower cotton yield, and total flower cotton yield). Narrow-sense heritability value was medium for the traits (number of fruiting branches, number of seeds per boll, average weight of the boll, and early yield) and high for the rest of the traits. Therefore, it recommend using the father (Den 1047) in plant breeding and improvement prog because it gives the highest productivity of seed cotton per plant as well as the highest productivity per unit area.