Abstract:
This study was undertaken to estimate the combining ability and heterosis in six diverse
genotypes of roselle using a half diallel mating design. The 6 parents and the 15 F1s were
evaluated in a randomized complete block design with three replications in three different
locations, Maiduguri, Yola and Biu, Nigeria. Data were recorded of calyx yield and its
contributing traits. Analysis of variance showed there were significant differences among the
parents and their hybrids which shows both additive and non-additive gene action were in
operation. The estimates of variance components showed GCA variances were lower than the
SCA variances with all showing ratios of less than one. This indicates that the non-additive gene
action played greater part in the inheritance of all traits than the additive gene action. The
parents, Fy, Ft and Nh84 were considered good general combiners for most of the traits studied.
While for calyx yield, Fy, Ft and Qr were identified as good combiners and they can be used for
calyx yield improvement breeding programme. The best cross combinations which exhibited
desirable SCA effects for calyx yield and other important yield components were, Nh84 x Nh75,
Fy x Nh75, Qr x Na147 and Fy x Nh84. There were no positive significant heterotic values
recorded for all traits. The cross combination Ft x Na147 showed significant negative heterosis
for fruit yield, while crosses, Ft x Nh75, Fy x Nh84 and Na147 x Qr also exhibited significant
negative heterosis for number of flowers. These crosses can be used for developing early
flowering and early fruiting varieties in roselle. |
