Development and release of some new tomato hybrids. II. fruit physical characteristics and their heterosis

摘要

This study was conducted at Barrage Horticulture Research Station, El-Kanater, Kalubia during 1995-1997 to evaluate some recently produced tomato hybrids. Based on former evaluation studies on potential true-breeding parental lines and improved varieties, seeds of 21 hybrids were produced and evaluated for physical fruit characteristics in 1996 summer season along with their parents. Consequently, 14 of them were re-evaluated in the 1997 summer season. The heaviest fruits were produced by cv. Oxheart (182.9g) and hybrid Castleking X Castlerock (164.7g) in 1996 and by hybrids Castleking X Giza 80, Castlehy 105 X Giza 80, and cvs. Castlehy 105 and Castleking in 1997. Only 8 out of 21 hybrids evaluated in 1996 showed positive heterosis for fruit weight, with hybrid Castleking X Castlerock exhibiting the highest value of heterosis (51.1 percent). In 1997, only 3 out of 14 hybrids evaluated showed positive heterosis. They were Castlehy 105 X Giza 80, Castleking X Giza 80 and Moneymaker X Romitel and their heterosis valued 2.9, 10.9 and 12.0 percent, respectively.