Response of sugarcane (Saccharum sp.) varieties to embryogenic callus induction and in vitro salt stress

Response of three varieties of sugarcane (Saccharum sp.) to callus induction, embryogenic callus production and in vitro salt tolerance was studied. For callus induction and embryogenic callus production, leaf bases segments were subjected to in vitro culture on Murashige and Skoog (MS) medium supplemented with 3 mg 1-1 2,4 Dichlorophenoxyacetic acid for 4 weeks. To evaluate salt tolerance of the varieties, growing calli were exposed after two subsequent subcultures (4 weeks each) to different concentrations of NaCl (0, 17, 34, 68 and 102 mM) added to the culture medium for 4 weeks. Comparision of genotypes was based on callus induction percentage, embryogenic callus production percentage and relative fresh weight growth (RFWG). For salt tolerance, necrosis percentage and relative fresh weight growth of callus were used. The three varieties responded well to callus induction with a percentage of induction about 82, 84 and 100% for CP70-321, NCo310 and CP65-357, respectively. The high percentages of embryogenic callus obtained for the three varieties indicated that these varieties have a high capacity for embryogenic callus production. Relative fresh weight growth of callus was about 1.076, 1.282 and 0.925 for CP70-321, NCo310 and CP65-357, respectively. NaCl effect resulted in calli necrosis and a reduction of their growth. However, growing calli derived from varieties CP70-321 and NCo310 showed less necrosis percentages and less relative fresh weight growth reduction under salt stress. They appeared to be more salt tolerant in vitro than CP65-357.African Journal of Biotechnology Vol. 4 (4), pp. 350-354, 200

Development of an efficient regeneration system for bombarded calli from immature embryos of Moroccan durum wheat varieties

ArticleOne of the biggest obstacles limiting genetic transformation of durum wheat is the lack of an efficient regeneration system for bombarded tissues. Our study aims to optimize culture conditions for regenerating bombarded calli from immature embryos of four durum wheat varieties ‘Amria’, ‘Chaoui’, ‘Isly’ and ‘Marouane’, through comparing the effects of phytohormones (IAA, zeatin and their interaction) and nitrogen amount and sources on callus induction and plant regeneration. Both tested induction media induced approximately the same rate of induced calli for all the tested varieties. However, the interaction of the induction and the regeneration media showed a highly significant effect on plantlet regeneration for all tested varieties. After bombardment, IM1/RM2 combination proved to be the favourable medium with up to 200% and 120% plantlets regenerated for ‘Chaoui’ and ‘Isly’ varieties respectively. Encouraging results obtained in this study will help to promote the research in genetic transformation and its improvement

Effect of genotype on callus induction and plant regeneration from leaf explants of sugarcane (Saccharum sp.)

Nine sugarcane genotypes (CP59-73, CP63-588, CP80-314, SP71-1081, F160, L62-96, CP70-321, CP57- 614 and Clone III) were evaluated for their callus induction capacity, embryogenic callus production and plant regeneration ability. Leaf cylinders were used as explants using Murashige and Skoog (MS) based medium supplemented with 3 mg l-1 2,-4 dichlorophenoxyacetic acid. Plant regeneration was accomplished on hormone free modified MS medium supplemented with casein hydrolyzate. The genotypes tested showed high callus induction percentage (69 to 95%) and high embryogenic callus percentage (60 to 100%). These genotypes also showed excellent regeneration capacities, with regeneration percentages ranged between 88 and 100%. Significant differences were observed between genotypes for callus induction capacity, embryogenic response and plant regeneration ability indicating that these criteria are genotype dependent. Plant regeneration ability is highly correlated with embryogenic callus production. The in vitro regenerated plants were successfully rooted and well acclimatised in growth cabinet conditions

In vitro culture techniques as a tool of sugarcane bud germination study under salt stress

Germination was the first stage confronted to soil salinity and it is important to determine salt effects on this stage. In this study, we reported an in vitro procedure for studying sugarcane bud germinationand shoot growth under salt stress with different NaCl concentrations (0, 17, 34, 68 and 102 mM) using cultivar NCo310. Germination percentage of control was about 92% after 8 days. Germination of buds,plant fresh and dry mass decreased with increasing salinity. Data indicated that in vitro culture techniques could be used to evaluate salt stress effects in sugarcane at the germination stage