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GENETIC CONTROL OF
LATE BLIGHT, YIELD AND SOME YIELD RELATED TRAITS IN TOMATO (LYCOPERSICON
ESCULENTUM MILL.)
MUHAMMAD YUSSOUF
SALEEM1, KHALID PERVAIZ AKHTAR1, MUHAMMAD ASGHAR1, QUMER IQBAL1
AND ABDUL REHMAN KHAN1
Abstract: Genetic control
of late blight (LB) and some economic traits was assessed to identify
genotypes suitable for the development of late blight resistant hybrids
in tomato. 10 F1 hybrids were derived from crossing of 2 male
sterile lines viz., TMS1 and TMS2 with 5 elite lines viz., Nagina,
Riogrande, Roma, 88572 and Picdenato according to line x tester
technique. Disease resistance was measured using detached leaf and whole
plant assay techniques. Data were also recorded for days to maturity,
number of fruit per plant, single fruit weight and yield per plant. The
analysis of variance showed significant differences among crosses,
lines, testers and line x tester interaction for almost all parameters.
Estimate of genetic components indicated preponderance of additive type
of gene action for detached leaf assay, whole plant assay, number of
fruit per plant and yield per plant whereas non-additive type of gene
action for days to maturity and single fruit weight. Among parents,
TMS2, Nagina, Roma and Picdenato showed significant favorable general
combing ability (GCA) effects for disease rating traits while TMS1 and
Riogrande indicated desirable GCA effects for yield and some yield
related traits. Among hybrids, TMS2 x Roma and TMS1 x Riogrande had
significant specific combing ability (SCA) effects for detached and
whole plant assays. However, hybrid TMS2 x Roma appeared as good
combination of LB resistance as it had both parents with desirable GCA
effects. All hybrids showed average type of SCA effects for yield and
yield components. Genetic control of LB revealed that a multiple
crossing program involving genotypes with high GCA effects would be
rewarding to identify LB resistant genotypes in early generations.
1Nuclear
Institute for Agriculture and Biology (NIAB), P.O. Box 128, Faisalabad,
Pakistan
*Corresponding
author:
mysaleem1966@gmail.com
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