Manifestation of heterosis for different fruit characters in F1 hybrids of tomato

Abstract

The study was conducted employing 14 parental lines showing divergences in different characters were crossed to produce 23 F1 hybrids. Manifestation of heterosis for fruit characters namely, fruit weight, equatorial diameter, polar diameter, pericarp thickness, and locule no. /fruit are also correlated with the qualitative characters. Fruit weight of the 23 hybrids only 9 hybrids manifested significantly positive heterosis ranging between 8.82 – 48.30 % over the mid parent (H1) and of them; only 6 hybrids surpassed their respective better parent for fruit weight. In 13 hybrids out of 23 manifested significant heterosis over the mid parent ranging between 3.08-24.46% and out of them 9 hybrids had fruits with higher equatorial diameter than the respective better parent. Only 4 hybrids registered significantly higher polar diameter ranging between 0.63 to 4.66% over the mid parental value. From the study of fruit shape in the hybrids high propensity of round or flattish-round fruit in hybrid was also recorded.Pericarp thickness in 15 hybrids manifested significant positive heterosis over mid parental value and 12 of them even surpassed their respective better parent for pericarp thickness. This result suggested that high fruit weight in the hybrid was basically realized through high pericarp thickness in the hybrids. Locule no. fruit-1 as expected, 13 out of 23 F1 hybrids registered significant heterosis over the mid parental values which ranged between 4.68-35.45%. Extent of manifestation of heterosis in the hybrids for different fruit characters was analysed with reference to of genetic divergence and per se performances of the parents. The situation has been examined with reference to 4 top ranking hybrids in this investigation viz., BCT-109xBCT-115, BCT-82xBCT-110, BCT-90 x BCT-110, BCT-90 x BCT-109 which manifested high heterosis for most of the fruit characters. Per se performance of the parents the high performing hybrids in terms of manifestation of heterosis for all the five characters have been emanated either from Medium x Low or Medium x High cross combination with respect to per se performance of the parents.