Combining Ability Analysis of Half Diallel Crosses in Durum Wheat

The parent seeds of Six durum wheat (Triticum durum Desf), (1-Azul-5, 2-Yousef-1, 3-Omgenil-3, 4-Syrian-4, 5-Mrb3/mna-1 and 6-Um-Rabee) and their half diallel crosses were planted in the field of College of Agricultural and Forestry at Hammam AL-Alil during the season 2001 2002 using randomized complete block design (R.C.B.D.) with three replications to study the effects of general and specific combining abilities for number of days to 50 % flowering, plant hight, number of grains/spike, number of spikes/plant, Biological yield, grain yield, harvest index, 1000-grain weight and protein percentage. The genotype mean variance (parents and F1) was significant at probability level of 1% for all the traits. General combining ability variance was significant at 1% probability level for all the traits except for 1000-grain weight where as specific combining ability variance was significant at 1% of probability level for all the traits except for number of days to 50% flowering which was significant at 5% of probability level. The ratio of the general combining ability to specific combining ability components was more than one for all the traits except for number of spikes / plant, 1000-grain weight and protein percentage. General combining ability effects for Syrian-4 and Um-Rabee parents were in desirable direction for most traits. The cross Azil-5 Um-Rabee exhibited desirable effects for general and specific combining ability for all the traits except for the harvest index and protein percentage.