GENE ACTION AND HETEROSIS FOR YIELD AND QUANTITATIVE TRAITS IN FCV TOBACCO
Loading...
Date
2009-08-15
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Sciences, Bangalore
Abstract
An investigation was carried out at Zonal Agricultural Research Station, Navile,
Shimoga, during 2007 kharif to assess general combining ability (gca) effects and their
variances of seven lines and four testers, specific combining ability (sca) effects and their
variances and standard and mid-parent heterosis of line × tester crosses and to understand
the relationship of parental gca effects with specific combining ability effects and midparent
heterosis of their crosses in FCV tobacco. Analysis of variance for combining
ability indicated the significant variability among lines, testers and their crosses providing
statistical validity for estimating parental gca effects and sca effects and heterosis of their
crosses for all the traits under study. While significant mean squares due to parents’ vs
crosses indicated the presence of average heterosis, those due to line × tester interaction
component indicated the involvement of dominance and/or dominance-based epistatic
gene interaction in the inheritance of all the traits under the study. Epistatic gene action is
a clear indication of unpredictability of performance of crosses based on gca effects of
their parents alone. The crosses such as KST-29 × FCH-197, KST-27 × FCH-197 and
LV-2 × A-3 were significant specific combinations with high heterosis for several traits.
The conditional probability of crosses with higher mid-parent heterosis and specific
combining ability is higher when at least one of their parents has higher general
combining ability. The superiority of H × L and/or H × H crosses to those of L × L
crosses is of practical utility to a breeder, when he has to attempt successful hybridization
economically in terms of time, cost and the number of crosses. The choosing parents
based on their combining ability is therefore highly rewarding for recombining desired
traits spread across several parents.
Description
Keywords
null