Performance of Four Chrysanthemum [Dendrathema grandiflora (Ramat.) Kitam.] Varieties Conserved In Vitro

Four chrysanthemum varieties were conserved in vitro at low temperature conditions for 6 mo in four culture media: 1/2 Murashige and Skoog (MS) + 2.5% dimethylsulfoxide (DMSO) and in Tsuchiya media at 1/2, 1/4 and full strengths. Plantlets of all varieties conserved in MS + 2.5% DMSO had shorter internodes, lesser leaf and internode number and no root formation compared with varieties conserved in Tsuchiya media. Decreasing the nutrient concentration of the Tsuchiya medium to 1/4 strength induced more optimum plantlet growth and root development. Mortality in all varieties started at 4 mo storage period. Varieties 'Puspita Nusantara' and 'Tirta Ayuni' conserved in 1/4 strength Tsuchiya medium produced the highest number of roots at 6 mo storage. They also had the highest plantlet survival rate. The results showed that successful conservation of chrysanthemum plantlets in vitro can be achieved through modification of the nutrients in the culture medium. The findings would greatly help to reduce the maintenance costs of active plant growth in base collections under in vivo conditions.