COMPARISON OF VARIOUS EXPLANTS ON THE BASIS OF EFFICIENT SHOOT REGENERATION IN GLADIOLUS

Abstract

Different stages/sizes of the same explants have different regenerative capacity even cultured on the same nutrient medium. In present study different stages/sizes of various explants including nodal cultures from different stages of flower spike, whole flower buds only at sleeping stage, whole cormels of different sizes, cormel sprouts of different sizes and cormel slices of the cormel were explored and optimized for efficient shoot regeneration in three commercial grown varieties of the gladiolus. Different plant growth regulators including benzyl aminopurine (BAP), kinetin (KIN) and naphthalene acetic acid (NAA) alone or in combination with each other were used for each explant in order to explore the possibility of increasing rate of shoot induction and regeneration. Out of five explants, cormel sprouts of medium size (12 days old) was evaluated the best explant in terms of mean shoot induction (77.50%) and number of shoots (11.60) in White friendship. On the basis of interaction of varieties and plant growth regulators, the highest results for shoot induction (98.33%) and number of shoots (22.07) were observed from same cormel sprout on MS medium containing BAP 4 mg L-1. The heading stage of nodal cultures (7.67), medium size of cormels and cormel sprouts (11.60) each and top slice of cormels (3.65) were considered the best stages/sizes from each explant for efficient number of shoots.