With avian sperm cryopreservation protocols, the most widely used cryoprotectants (CPAs) are the glycerol (GLY; in gradual freezing: in-straw freezing method), and the dimethylacetamide (DMA; in pellets by plunging into liquid nitrogen: in-pellet rapid freezing method). Use of both methods results in a small portion of thawed live sperm with lesser fertilizing ability compared with the semen samples immediately after collection. This study was conducted to assess the pre-freezing damage occurring to the sperm due to the interaction with the cryoprotectants (CPAs) GLY (8%) and DMA (5%), as well as the post-freezing damage resulting from both freezing methods Data for each treatment, in fresh and frozen-thawed samples, were compared for sperm motility, fertilizing capacity and sperm-egg penetration holes/germinal disc (SP holes/GD). Hens (n = 50) were artificially inseminated (10 hens/treatment) six times with 3 day intervals be-tween inseminations. The treatment of fresh sperm with DMA led to a reduction (P 0.05) in the count of SP holes/GD (21.4) and the fertility rate (66.7%). The addition and elimination of GLY in fresh samples resulted in a lesser (P 0.05) number of SP holes/GD (11.8) and the fertility rate (i.e., 50.0%). The number of SP-holes/GD was least in frozen-thawed samples using both DMA and GLY (14.2 and 9.2, respectively). The fertility rate when using semen frozen with DMA in- pellets was greater (P 0.05) than with use of semen that had been frozen using GLY in straws (46.4% compared with 31.3%). The reduction in fertility compared with the control when semen was cryopreserved using GLY was 64.1%; the GLY addition and elimination was responsible for two thirds of this reduction. The reduction in fertility when using semen cryo-preserved with DMA was 46.7%; half of the reduction was attributed to the treatment with DMA. In conclusion, the mechanical damage attributed to the process for reducing GLY concentrations was more harmful to sperm fertilizing capacity than the toxicity of DMA and freeze/thaw process. For both freezing methods, the amount of sperm cryo-damage was similar, when the damage attributed to the CPA addition and elimination process was excluded.

Three field experiments were conducted at El-Wady El-Assiuty Experimental Farm, Agriculture Faculty, Assiut University, Assiut Governorate during 2013/2014 and 2014/2015 seasons to study the effect of foliar spray by antioxidant (salicylic and ascorbic acids) on the productivity of two bread wheat cultivars. Each experiment was subjected to one of three levels of evapotranspiration (100% or 75% or 50% of ET i.e. 4800, 3600 and 2400 m3, respectively) including two factors i.e wheat cultivars (Masr1 and Shandaweel 1) and three treatments of antioxidant (100 ppm salicylic, 100 ppm ascorbic and 100 ppm salicylic + 100 ppm ascorbic) using randomized complete block design in split plot arrangement with three replications. The obtained results showed that all studied factors and their involved interactions had significant effects on most of studied traits in the two growing seasons. Thus, the highest mean values of grain yield (3.24 and 3.27-ton ha-1 in the first and second seasons, respectively) were obtained from Masr 1 cultivar under 75% ET with 100 ppm Salicylic acid as foliar spray, while, the highest mean values of WUE (1.24 and 1.17 kg m-3 in the first and second seasons, respectively) were obtained from Masr 1 cultivar irrigated by 50% ET and sprayed by 100 ppm ascorbic acid.

NULL

NULL

NULL

NULL

NULL

NULL

NULL

NULL