Two field experiments were carried out at the Experimental Station, Fac of
Agric Mansoura Univ during the growing seasons of 1997/98 and 1998/99.The
objectives of thl mvesuqatron was aimed to evaluate combining ability of some
canota inbred lines and their hybnds .mder different plan population density. The
Ijenetic Weltel inls were the four line 0' Drakkar, Frdo. Serw 4 and Serw 6 as ell as
all possible combinations among them according to a comple e diaitel matting design.
A. split plot design wrth thre replicates W s used. Test of 19 lficance of the mean squares for general combining ability (GCA)
and specrnc cornbuunq ability (SCA) cleared that GCA and SCA were highly
. ign,ficant for most of studied trails III addition, the magnitudes of SCA were larger
,han thE' rrespondmq values of GCA In most studied traits and this finding
suggested th t mese traits were mainly controlled by dominance genes, indicating
:h I the non-additive genetic variance played a major role in the inheritance of these
traits On the olher hand, the mean squares of reciprocal effects were significant of
most of cases but Ihelr values were Ie s than the correspo ding values of GCA and
,)CA. "his rrdicates that maternal effect played a minor role In the expression of these
'-alts. For lCA ffp.c:ts, ttle pa-ents S 30 and S 32 could be utilized in a breeding
')rogram to: rnprov no most of studied traits to pass favorable genes for irnprovinq
h"bnds_ For SeA effects. the two c mbinauons of P, . - p) and P2 X P. showed the
'"llghest pos.tive and Significant values for most of studiea traits