Fruit ripening is a complex, genetically programmed process that culminates in dramatic changes in colour, texture, flavour, and aroma of the fruit flesh. The following research has been done in greenhouse and the laboratory of horticul tural science of Ferdowsi University in Iran. In this research 16 tomato lines in a factorial design were crossed to study the combining ability of parental lines for yield and fruit longevity in F1 hybrids. The 16 lines were arranged in two parental groups, that 7 lines were as mother lines and 9 line where as father lines, and the genotypes were planted in a four replication completely random ized design. The main factors that were measured and studied are yield and the longevity period of fruits. Results from analysis of variants show that hybrids, general combining ability and specific combining ability have a significant differ ence in 1% level. The highest yield was obtained from the Fla × CT6 hybrid that was equal with 10.180 kg per plant. The highest fruit longevity was belonged to LA3770 × Al3012 hybrid with an amount of 151 days. The study of combining abilities of parents shows that male line, A130, with 27.7 days and female line Fla with 21.5 day storage period are better than other parental lines. The most specific combining ability was found to be related to hybrid Dns × Kalg with 73.1 day period. Also, the biggest amount of Hetrosis was shown to be the same Hybrid with 97 day period longer than its parents’ average storage period. Finally the lines Al3012, LA1793, Fla and LA3770 were known as the lines with high combining ability for producing the hybrids with long lasting fruits and also the lines 611, Al3013, Al3012 and Fla were known as lines with high combining ability for yield.

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