Inheritance of important quality attributes of tomato under low temperature field conditions

• Published in: Advances in horticultural science 2005-01, Vol.19 (3), p.158-162
• Main Authors: Dhaliwal, M.S., Chahal, D.S.
• Format: Article
• Language: English
• Subjects: Agriculture; Epistasis; Fruits; Genetic inheritance; Genetic variation; Low temperature; Plants; Tomatoes; Vegetable crops; Vegetables
• ISSN: 0394-6169; 1592-1573

Tomato fruit yield and quality are considerably impaired under both low and high temperature conditions. Though efforts have been made to improve yield by improving fruit setting ability of the genotypes, information is still lacking concerning the genetic control of fruit quality attributes under low temperature conditions. The present investigation was therefore undertaken at the Vegetable Research Farm and Biochemistry Laboratory of the Department of Vegetable Crops, Punjab Agricultural University, Ludhiana, India to study inheritance of fruit pH, total soluble solids (TSS%) and lycopene content under sub-optimal temperature conditions. Generations mean analysis that provides a valid estimate of gene effects and an unambiguous test for presence or absence of epistasis was used for genetic analysis of the characters. Parents L-3841 possessing the cold setting ability and PNR-7 and San Pedro lacking the cold setting ability were involved in crosses to generate two sets of P₁, P₂, F₁, F₂, BC₁ and BC₂ generations. Estimates of scales A, B and C and c² test indicated that the additive-dominance model was inadequate to account for total genetic variability exhibited by all the three characters in both the crosses. Estimates of gene effects based on the best-fit digenic interaction model indicated the importance of both additive and dominance gene effects in both the crosses for all the three characters. However, the dominance effects were negative for pH in Cross-I and for lycopene content in both the crosses. Additive × additive interaction effects were important only for pH and TSS% in Cross-II. Dominance × Dominance digenic interaction effects were significant and positive for pH and lycopene in Cross-I but negative and significant for pH and TSS% in Cross-II. Based upon the magnitude and direction of gene effects and considering self-pollinated nature of the crop, pure line breeding is recommended for genetic improvement of tomato with respect to the three quality attributes studied.