This investigation was carried out, during three fall seasons (2015, 2016 and 2017).
Five genotypes of pepper (2 commercial cultivars and 3 inbred lines derived from Egyptian pepper)
were used in a half diallel crossing program. Data were recorded for plant height, branch number/
plant, fruit length, fruit diameter, average fruit weight, number of fruits per plant, fruits yield per plant,
total soluble solids (TSS) and content of Vitamin C. The obtained results showed significant
differences among the different genotypes for all studied traits under this study. Both additive and
non-additive gene effects are involved in the genetic mechanism for all studied traits. Both Line-16
and Line-21 were good general combiners for Vitamin C. Tropic cultivar appeared to be good general
combiner for fruit length, while, Line-6 was good for each of fruit diameter, number of fruits/plant and
fruit yield/plant traits Also, the same two parents, as well as both Tropic and Line-6 appeared to be
good general combiner for one or three important traits. Parental genotype Line-16 could be of great
value for varietal improvement program. Seven out of ten crosses exhibited significant positive
specific combining ability (SCA) effects for fruit yield/plant and two or more important yield
components, indicating the possibility of combine each of high yields and high of average fruit weight,
TSS (%) and content of Vitamin C. The intercept of regression line on the covariance axis in plant
height, number of branches/plant and Vitamin C shows a clear cut case of partial dominance and over
dominance role of genes in all other traits. The maximum significant true heterosis in desirable
direction (30.29%) was recorded for fruit length followed by fruit diameter (27.90%), number of fruits
(19.93%), fruit yield (16.19%), average fruit weight (13.55%), plant height (9.72%), and Vitamin C
(2.98%). The four cross combinations, (Line-16 x Line-21, Yellow wonder x Line-16, Tropic x Line-
21 and Line-6 x Line-21), are promising for genetic improvement either for yield or some of its
important components through heterosis and/or selection in the segregating generations to exploit a
fixable additive gene action.