Abstract

Field experiment was conducted during 2005 to 2008 at Indian Agricultural Research Institute (IARI), New  Delhi to study genetics of fibre strength in Gossypium hirsutum L cotton. Genotypes ‘P 56-4’ and ‘RS 2013’ were used to develop 6 generations. Additive × dominance epistasis was found significant. The F₂ of this contrasting cross showed wide range of variation from 18.1 to 33.1 g/tex for fibre strength. Distribution of F₂population also indicated transgressive segregation for fibre strength. This F₂ population was also used to identify quantitative trait loci (QTLs) linked to fibre strength using Amplified fragment length polymorphism and single sequence repeats (SSR) markers. Linkage map was constructed covering a total of 932.9 cM. The average distance between adjacent markers was 10.11 cM. Six QTLs designated as QTFS-2A.1 to QTFS-2A.6 were detected which explained 9.24 to 36.03% of the phenotypic variation.

Key words: Gossypium hirsutum, generation mean, fibre strength, quantitative trait loci (QTLs), amplified fragment length polymorphism (AFLP), single sequence repeats (SSR).