SURVIVAL RATE AND GROWTH PERFORMANCE OF IN VITRO RAISED PLANTLETS OF ORCHID (DENDROBIUM SP.) IN DIFFERENT HARDENING SUBSTRATES

Abstract

Orchids are the most beautiful flowers and they are valued for cut flower production. They
are known for their long lasting beautiful flowers which occupy a very high price in the
market. Micropropagation plays an important role to meet growing market demand. The
present study was carried out to standardize potting media for hardening of the in vitro
raised plantlets of Dendrobium sp. under net house conditions. The potting media used for
acclimatization contained coconut husk, brick pieces, charcoal and chip stones in different
ratios. The observations were recorded on survival percentage, shoot length, number of
leaves per plant, leaf width, number of root per plant, length of longest root after
transplanting to ex vitro conditions. In this experiment, the treatment contained coconut
husk: brick pieces: charcoal: chip stones at ratio 1:1:1:1 proved the best potting medium for
higher survival rate (90%) at four weeks after transplanting to ex vitro conditions and for the
subsequent development of plantlets under ex vitro conditions during acclimatization.