The objective of this study is the production of friable embryogenic callus in citrus to having the necessary material for protoplast isolation to be integrated into rootstock improvment programm using the asexual pathway. Ovules, embryos and styles explants of Citrus five genotypes: Poncirus trifoliate, Citrus reshni Hort. ex Tan, Citrus amblicarpa, Citrus volkameriana and Citrus paradisi Macf., are cultured in MT medium supplemented with 4% sucrose, 0.05% of malt extract and 1% agar was used as basal medium. Hormones (kinetin (Kn), 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP) were added to this medium at different concentrations. The rate of callus of different explants was evaluated by determining the percentage of callus induction by explant. The conducted experiments show a significant effect of genotype, explant type and hormone combination chosen. Friable callus forms were on the 3 explants with variable frequencies. Embryo explants show is most favorable to the production of friable callus; the best callogenesis is obtained with the culture media containing auxin and cytokinin combined M2 (1mg/l 2,4D+ 0.5 mg/l BAP) and M3 (1mg/l2,4D + 0.5mg/l Kn), by against the style explants and ovule have induced embryogenic calli respectively on the M4 (0.5 mg/l BAP) and M5 (1mg/l Kn) medium.

Citrus fruits have a great national social and economic importance. This work is part of an improvement and genetic diversification program of citrus, the aim of this study is to purpose and to study the variability of selection criteria related to the quality of the fruit. 107 clones of clementine were applied by gamma irradiations on Marisol clementine buds. They were grafted onto macrophylla and planted with a spacing of 3x5 m2. The evaluation was focused on the organoleptic and pomological criteria. Statistical analysis showed significant differences between the control and irradiated clones of Clementine (Marisol) for all studied variables (sugar content, number of seeds per fruit, average fruit weight and percentage of juice and maturity index) except for the acidity of the fruit. Four irradiated clones of clementine were selected because of their good quality 30M57 ; 30M67 ; 50M51 ; 50M87 ; 50M91 ; 50M89 (seedless fruits, large caliber).