Twenty one wheat hybrids and their seven parental genotypes were evaluated in the research farm of the Faculty of Agriculture, Ain shams University, Shoubra El-khema, Cairo, Egypt, in 2016/2017 growing season. The genetic analysis was conducted using Griffing (1956), Method 2, model 1).                 Significant differences among parent genotypes and their 21 crosses for all the studied traits (days to 50% heading, days to maturity, flag leaf area, plant height, number of spikes/ plant, spike length, number of spikelets/ spike, number of kernels/ spike, 1000-kernel weight and grain yield/ plant) were detected. This indicated that, variability exists among these populations may increase the chance appearance of good new combination that can be isolated in the succeeding generations. Parents versus crosses mean squares as an indication for average heterosis over all crosses were significant for all studied traits.                 Mean squares of general (GCA) and specific (SCA) combining abilities were significant for all studied traits except spike length trait for SCA which was insignificant. GCA/SCA ratios were more than unity for all studied traits, which indicating that the additive type of gene action is of great importance in the inheritance of these traits. Heterosis over the better parents showed that, the best hybrids were Gemmiza 9xGiza 168, Sakha 93x Giza, 168, Sakha 94x Jawahir-14, Sakha 94x Bob white, Giza 168xAcsad 925 and Jawahir-14x Bob white for grain yield/ plant trait and some of the other studied traits. The best general combiner parents were Sakha 94, Jawahir-14 and Bob white for grain yield/ plant trait and some of the other studied traits. The best SCA hybrids were Gemmiza 9x Sakha 93, Gemmiza 9x Giza 168, Sakha 93x Jawahir-14, Sakha 94xJawahir-14, Sakha 94x Acsad 925, Sakha 94xBob white, Giza 168x Jawahir-14, Giza 168x Acsad 925, Jawahir-14x Bob white and Acsad 925x Bob white for grain yield/ plant trait and some of the other studied traits. These result could be used in wheat breeding programs.

Data on rabbits produced from a total number of 518 parities were analyzed to evaluate crossing effects among two breeds of rabbits. The breeds tested were Gabali (GAB) and Bouscat (B). sex effects on post weaning body weight were also studied. A total number of 80 rabbits at marketing age were slaughtered to evaluate effects of mating type and sex on some carcass traits. Mating type affected significantly (P ≤ 0.001) progeny weight from weaning up to marketing age and preslaughter, carcass, slaughter weight, hot carcass weight, fore legs weight and hind legs weight at marketing age. Meanwhile, the effects were not significant on loin weight and dressing percentages . Sex insignificantly affected body weight although body weights of female rabbits were slightly heavier than those of male rabbits. Effects of sex on carcass traits were not significant. Heterosis % and superiority % of body weight estimates were positive for all post weaning weights. Positive heterosis was shown for some carcass traits.

A 7x7 half diallel cross along with their parental wheat cultivars were evaluated under two sowing dates (19th Nov. and 17th Dec.).The results revealed that mean squares due to sowing dates, genotypes and genotypes x sowing dates interaction were significant for most of the studied traits. Delaying sowing date to Dec. reduced all studied characters compared to the normal sowing date except electrolyte leakage which increased by delaying sowing date. Heterosis over better parents showed that, the best hybrids under stress condition were Misr 2 X Giza 168 and Sids 1 X Giza 168   for grain yield / plant and some of other studied traits.  General and specific combining ability mean squares indicated the importance of both additive and non-additive gene effects in the inheritance of the studied traits with few exceptions. However, the additive effect was more important than the non-additive effects in the inheritance of days to 50% heading, plant height, No. of spikes/ plant,No. of kernels / spike and 1000-kernel weight while, the non-additive effects were more important than the additive effects in the inheritance of electrolyte leakage and flag leaf area. The best general combiner parents for grain yield / plant and some of other studied traits were Gemmeiza 11 and Giza 168under stress condition. The best hybrids for SCA effects were Sakha 93 X Sids 1, Gemmeiza 11 X Giza 168, Misr 2 X Giza 168 and Sids 1 X Giza 168 under stress condition for grain yield / plant and some of other studied traits. The crosses Gemmeiza 11 X Giza 168   (HSI 0.36), Gemmeiza 7 X Giza 168   (HSI 0.58) and Sakha 93 X Giza 168   (HSI 0.60) have recorded the lowest values of heat susceptibility index (HSI), indicating their tolerance to heat stress (late sowing date).