CONSTRUCTION OF SELECTION INDICES BASED ON GENETIC PARAMETERS AND CHARACTER ASSOCIATION IN TOMATO

Abstract

The field experiment was conducted in the experimental field of Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during the period from November 2012 to April 2013 to construct of selection indices based on genetic parameters and character association in tomato (Lycopersicon esculentum L.). In this research work, the varieties of seven tomatoes were used viz. Roma, Ratan, Super marmande, Roma vf}, Roma vf, Pusha robi and Champion. The experiment was laid out in the Randomized Complete Block Design (RCBD) with three replications. Mean performance, Variability, heritability, correlation coefficient, path coefficient analysis and construction of selection indices were done on yield and yield contributing characters namely, days to 50% flowering, plant height, canopy width, fruit no./ plant, fruit length, fruit diameter, fruit weight, 1000-seed weight, shelf life, yield per plant. Highest yield/plant (2.547kg) was recorded from Supermarmend and lowest Roma vf}. Phenotypic variance (0.153) was higher than genotypic variance (0.089) which was supported by moderate difference between phenotypic (19.153%) and genotypic (14.597%) coefficient of variation. Low heritability (58.079) was supported by low genetic advance over mean (0.467). Yield / plant of seven tomato varieties showed positive and highly significant with fruit weight (g) whereas non-significant and positive association with canopy width (cm), the highest direct effect was paid by fruit diameter (13.347) followed by fruit number/plant (9.922) and the lowest direct effect was paid by followed plant height (1.942). Among the characters, none had exerted always-positive indirect effect towards the yield/plant but the interactions of the characters had resulted either positive or negative net relationship with yield/plant in tomato. Among the single character functions, 1000-seed weight appeared as the most yield enhancing factor with the highest relative efficiency (77.52%) over direct selection based only on yield/plant. The function developed through integration of all eight characters may be considered to gain the maximum relative efficiency (141.61%) across the direct selection yield/plant in tomato. In a conclusion, it opined that there is an enough scope of improving yield potential in tomato through adopting different types of selection practice.