Line X Tester Analysis for Combining Ability and Heterosis in Okra [abelmoschus Esculentus (L.) Moench]

Abstract

The present investigation, "line x tester analysis for combining ability and heterosis in okra [Abelmoschus esculentus (L.) Moench]. was conduct 45 F 1s and F2 population developing through line x tester along with 18 parents ( 15 line and 3 testers) viz, lines 7216, KS-312, P-7, 7219, KS-321, KS-341, KS-305 (Red), KS- 427, KS-437, KS-423, KS-442, K-Bonia, 7109, AB-1 and VR0-3 testers PK, AB-2 and B0-2 in Randomized Block Design (RBD) with three replications at the Hmticulture Research Centre of Sardar Vallabh Bhai Patel University of Agriculture and Technology, Meerut during Kharif2007-08. The observation were recorded on 10 randomly selected plants for 10 characters namely, days to flowering, plant height, number of branches per plant, number of first fruiting node, length of first fruiting node, length of internodes, length of fruit, width of fruit, number of fruits per plant and edible fruit per plant. Analysis of variance indicated highly significant difference among the parents (lines and testers), lines vs testers, F2s, parents vs F,s and F2 population and parents vs F2 population. Jt 6stract ... 1 Study on gca effect testers PK exhibited maximum general combining ability for the character, days to flowering, plant height, number of first fruiting node and length of first fruiting node and tester AB-2 exhibited for length of internodes, width of fruit, number of fruits per plant and edible fruit yield per plant, while line KS-442 exhibited the maximum general combining ability for all characters except number of first fruiting node, length of first fruiting node, length of internodes and length of fruit. Based on sea effect the best cross combinations for yield and yield contributing characters are KS-442 x PK and KS-423 x AB-2 for days to flowering, KS-423 x AB-2 for plant height, KS-423 x AB-2 for length of first fruiting node, KS-442 x AB-2 for length of internodes, KS-437 x PK for length of fruit, AB-1 x AB-2 for edible fruit yield per plant. The high magnitude of heterosis and per se performance hybrid K-Bonia x B0-2 over better parent and KS-442 x PK for edible fruit yield per plant indicated that this cross can be exploited commercially for producing hybrids fruit yield per plant cross KS-312 x B0-2 showed maximum inbreeding depression. The correlation coefficients were consistently significant and positive in all three populations between edible fruit yield per plant and number of fruit per plant and plant height at both genotypic and phenotypic levels. On the basis of path coefficient analysis the genotypic correlation coefficient for days to flowering, width of fruit and length of first fruiting node was negative and significant due to direct effect and edible fruit yield and plant height was positive and significant due to positive direct effect in parents. }l6stract ... 2 The height coefficient of variability was found for number of braches per plant in three generations at phenotypic coefficient of variability level and ·width of fruit in F 1 and number of branches per plant in F2 population at genotypic coefficient of variability level. Heritability estimates in broad sense were high with low and medium genetic advance for all characters in both F 1 and F2 population. Only one characters number of branches per plant in both F 1 and F2 population showed moderate heritability line x tester mating as well as among select plant in early segregating generations would also help in developing population having optimum homozygous and heterozygous balance Key words:- ANOVA, gca and sea variance and their effects, heterosis and inbreeding depression, heritability, variability and genetic advance correlation and path coefficient.