Six parental genotypes namely "673 (P1), 3M-637-D (P2), 3M-673-EB (P3) , 86E2143
(P4), 86E2147 (P5) and WA20 (P6)" representing wide range of variability in most of the studied traits,
were employed and crossed in half diallel fashion. This investigation was carried out at the
Experimental Farm of Ismailia Agriculture Research station, Ismailia Governorate, Egypt, during the
three summer seasons of 2015, 2016 and 2017, to study the important economical traits of muskmelon
as fruit width, fruit length, flesh thickness, cavity diameter, total soluble solids, ascorbic acid content,
carotenoids content, fruit weight, total yield/vine and fruit number/vine. A greater ratio of GCA/SCA
than unity was detected for most studied traits, revealing that the inheritance of these traits was mainly
controlled by additive gene effects. On the contrary, both TSS and ascorbic acid content traits, nonadditive
type of gene action seemed to be more prevalent. The maximum significant MP heterosis in
desirable direction (112.4%) was recorded for ascorbic acid followed by total yield/vine (101.0%),
number of fruits per vine (100%), TSS (65.3%), flesh thickness (62.1%), fruit weight (59.8%) and
fruit length (53.6%). Heterobeltiasis (over the best parent better, BP) was observed and the maximum
significant manifestation was orderd as: Ascorbic acid (108%), number of fruits per vine (69.4%),
both TSS (%) and cavity diameter (58.8%) and total yield per vine (49.8%). The cross 3M-637-D (P2)
x 86E2143 (P4) was derived from low x high general combiner parents for total yield/ vine and
exhibited the highest mean yield, highest heterosis, highest SCA effects for yield. It showed also,
significant or highly significant desirable SCA effects for eight important traits.