Cryopreservation of sugarcane by V cryoplate

Sugarcane accounts for 80% of sugar production. It is difficult to conserve in the field or in vitro because of biotic and abiotic stresses, so cryopreservation of the sugarcane is important for conserving its genetic diversity. This study was carried out to develop a cryopreservation protocol for sugarcane with high post cryopreservation recovery and for practical use at genebank. Factors affecting the survival rate after cryopreservation by using the V cryoplate method such as preculture medium, sucrose concentration in the loading solution (LS), exposure time to Plant Vitrification Solution 2 (PVS2), size of shoot tips, recovery medium composition, recovery with or without dark condition and alginated gel were calculated. After optimization of the protocol with one sugarcane variety, several others were also tested by using the optimal condition for cryopreservation. Shoot tips of size 1.5 to 2 mm long, pre cultured on MS medium with 0.5 M sucrose for 1 day, treated with LS having 1.6 M sucrose for 30 min and exposed to PVS2 for 30 minutes showed maximum (100%) recovery after cryopreserved in Liquid Nitrogen (LN). It was also observed that removal of alginate gel and keeping the culture in the dark for 7 days after cryopreservation significantly affects the survival of shoot tips. After optimizing the cryopreservation conditions by using sugarcane variety Ni-1, ten different varieties of sugarcane were tested with optimal condition with a regrowth percentage ranging from 58 to 100%. V cryoplate is an efficient and practical method for the cryopreservation of sugarcane shoot tips at genebank.