General and specific combining ability of cotton germplasm in Mozambique using circulant dialells

Abstract

The genetic diversity of species is an important way to maintain the natural capacity to respond to climate change and all stresses. This study aimed to estimate the general combining ability (GCA) and the specific combining ability (SCA) of the characteristics among 41 cotton cultivars and 9 inbred lines using circulant diallel. In 2016, 41 cultivars and 9 inbred lines and 75 hybrid combinations were evaluated at the Namialo Cotton Research and Seed and Multiplication Centre in the Meconta District, Nampula province. The experimental design was Federer's augmented blocks with four repetitions. The evaluated characteristics were: days for 50% of flowering (DAFlw), days for 50% of fruiting (DAFrut), plant height, average number of bolls (AnB), seed cotton yield in kilograms per hectare (Yield) and the mass of one hundred seeds (M100). The algorithm for establishing diallel crosses was based on Kempthorne and Curnow, where S was equal to 3. There was a predominance of non-additive effects for all characteristics analysed. The genotypes ALBAR FQ 902, IRMA 12-43 and MARICO showed greater additive effects for DAFlw, DAFrut, AnB, Yield and, M100