Abstract
The objective of this study was to investigate the general combining ability effects of parents and specific combining ability
effects of crosses under normal and water deficit condition for various traits related to fibre quality. For this purpose, 50 F1
crosses and their 15 parents was field planted under two different moisture regimes i.e. normal and water deficit condition in
the experimental area of Department of Plant Breeding and Genetics, UAF. Analysis of variance under normal and drought
condition revealed that genotypes showed highly significant differences for all the traits under both conditions. For most of
fibre quality traits, under normal condition, among the lines, the good general combiners were IUB-212 and FH-113 and poor
general combiners were VH-295 and NS-121. Among the testers, the good general combiners were IR-3, CIM-443 and S-12
and poor general combiners were MNH-147 and FH-1000. Under the drought condition, among the lines, the good general
combiner was IUB-212 and poor general combiners were VH-295 and FH-142. Among the testers, the good general combiner
was S-12 and poor general combiners were MNH-147 and IR-3. For most of fibre quality traits the best specific combiner were
VH-144 × CIM-443 and AA-802 × S-12 under normal condition while under drought condition the best specific combiner
were VH-144 × CIM-443, VH-295 × IR-3, VH-144 × FH-1000 and VH-295 × CIM-443. The variance due to specific
combining ability was greater as compared to the general combining ability variance for all the traits indicating the dominant
role of non-additive genes under normal and drought condition. The crosses VH-144 × CIM-443 and VH-295 × IR-3 can be
used in variety development program for drought prone areas of Pakistan with high specific combining ability for fibre quality
traits under drought condition. All fibre quality traits having non-additive gene action suggested usage of this material in the
hybrid development programme in cotton.
