Five watermelon cultivars and 10 F 1 hybrids as well as the reciprocal crosses
F_1r were used to study the general and specific combining ability effects (GCA and
SCA) for number of morphological, yield and fruit quality traits. The results showed that: The GCA was significant for all studied traits except branches number and
leaves number, the SCA was significant for days to female flower, fruit number,
fruit weight, TSS and rind thickness. The other traits were insignificant. The
reciprocal was insignificant for stem length, branches number, total yield and
fruit number, but was significant for other studied traits. The additive gene effects were the most important in the inheritance of all
studied traits. The parental cultivar Giza-1 was the best general combinor tor "most
morphological characters. The parent Giza-21 and Charleston Grey were best
general combinor for most yield and fruit characters. The highest desirable SCA effects resulted from the crosses "Giza-1 x
Charleston Gray", "Giza-1 x Dulzera" and "Crimson sweet x Dulzera".