Heterosis, combining ability and gene action for yield and quality traits in tomato (Solanum lycopersicum L.)

Author Name: *Ankur Agarwal, D. N. Arya, R. Ranjan, Zakwan Ahmed
Author Email: ankurdr@rediffmail.com

Abstract

Eight parental lines of diverse origin of tomato were crossed in a 8 × 8 diallel mating design excluding reciprocals. The 28 F1 hybrids along with their parents were evaluated in a randomized block design with three replications. In the present study, significant and highest general combining ability effect for fruit yield and average fruit weight was recorded in CLN 5915-206 (49.06 and 8.23 respectively), for total soluble solids in CLN 2264H (0.18) and for dry matter content in Best of All (0.32). The highest significant heterosis over better and standard parent was recorded for average fruit weight (74.69 and 117.27) followed by total soluble solids for better parent heterosis. The range of heterosis for fruit yield over better parent was 6.63-35.90% and cross between CLN 5915-206 × CLN 1314G recorded the maximum heterosis over both better (35.90) and standard parent (56.32%) for the trait. Genotype with positive and moderately high gca for dry matter (Pith Sel, DARL-1 and Best of All) and TSS (CLN 2264H and DARL-1) exhibited good specific combining ability for exploiting hybrid vigour for these traits. Genetic components H1, H2 were highly significant for all the traits exhibiting the importance of both additive and dominant gene effects in regulating these traits.

Keywords

Tomato, Heterobeltiosis, Total Soluble Solids, Dry Matter Content, Genetic Divergence.

Introduction

Exploring natural diversity as a source of novel alleles to improve the productivity, quality and nutritional value of the crop is the base line of any breeding programme (Fernie et al. 2006). Exploitation of hybrid vigour and selection of parents on the basis of combining ability and gene action have been important breeding approaches in crop improvement. The studies of combining ability is essentially useful in connection with testing procedures in which it is desired to study and compare the performance of a line in hybrid combination. Tomato (Solanum lycopersicum L.) is the second most consumed vegetable of the world after potato with a production of 123.6 million tons from 4.5 million ha area. World crop area of tomato has increased by 164% in the last 40 years with a rise in per capita consumption from 14 kg/year during 1985 to 19 kg/year during 2005 (FAO 2008). Considering this, the present investigation was undertaken to generate information on nature of gene action and combining ability in eight parental lines of tomato to assess the prepotency of parents in hybrid combination.

Conclusion

Considering higher per se performance, significant sca effects and non additive gene action for yield per plant, the crosses viz., CLN 5915-206 × CLN 1314G, and CLN5915-206 × Best of All can be further exploited.

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