Response of sugarcane (Saccharum species hybrid) genotypes to embryogenic callus induction and in vitro salt stress

Abstract

The present research work has been carried out to study the response of three genotypes of sugarcane (Saccharum species hybrids) for callus induction, embryogenic callus production and their in vitro salt tolerance.For callus induction and embryogenic callus production, leaf base segments were subjected to in vitro culture on Murashige and Skoog (MS) medium supplemented with 3 mg l−1 2,4 Dichlorophenoxyacetic acid for 4 weeks. To evaluate salt tolerance of the varieties, cultured 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. Comparison of genotypes was based on callus induction percentage, embryogenic callus production percentage and relative fresh weight growth. For salt tolerance, necrosis percentage and relative fresh weight growth of callus were used. The three genotypes responded well to callus induction with about 82, 84 and 100 percentage of induction for GT 54-9(C9), NCo310 and Co 413, respectively. The high per cent of embryogenic callus obtained for the three varieties indicated that these genotypes have a high capacity for embryogenic callus production. Relative fresh weight growth of callus was about 1.076, 1.282 and 0.925 for GT 54-9, NCo310 and Co413, respectively. The effects of NaCl resulted in calli necrosis and a reduction of their growth. Growing calli derived from genotypes GT 54-9 and NCo310 showed less necrosis percentage and less relative fresh weight growth reduction under salt stress. They appeared to be more salt tolerant in vitro than Co 413.The finding of superior genotypes GT 54-9 and NCo 310 and inferior one Co 413 for salt tolerance together with their high potential for embryogenic callus induction may be a model varities to study physiological mechanisms associated with in vitro salt tolerance and in vitro selection for salt tolerance in sugarcane.