Somaclonal variation in micropropagated dormant axillary buds of pineapple (Ananas comosus L., Merr.)

Dormant axillary buds excised from crowns of pineapple (Ananas comosus L., Merr.) cultured on growth regulator free Nitsch medium sprouted after 8-10 d. Sprouted buds produced multiple shoots (7-10 shoots per bud) upon transfer to solidified Murashige and Skoog medium supplemented with 9.67 muM NAA, 9.84 muM IBA and 9.29 muM KIN. Each isolated shoot upon subculture to liquid medium of the same composition further proliferated to form more multiple shoots (60-65 shoots) and were maintained on a gyratory shaker (90 100 rpm). In vitro grown shoots were rooted on White medium supplemented with 0.54 muM NAA and 1.97 muM IBA. In vitro plantlets were established in cups with soilrite and hardened for four weeks. Phenotypic variants such as albinos, white streaked shoots and shoots with elongated internodes were observed in in vitro cultures. Approximately 520 in vitro produced plantlets were established in the field and these plants exhibit somaclonal variation. Thirty-eight plants were found to be yellowish, spineless with anthocyanin streaks and three were anthocyanin rich, spined plants.