In Vitro Rapid Plantlet Regeneration of Orchid HybridCattleya Summer Song

摘要

Orchids are the most valued cut flowers because of their long shelf life, diverse varieties and unrivalled beauty. One serious hurdle in the application of regeneration protocols of orchids is the low as well as slow rate of conversion of protocorm-like bodies (PLBs) to shoots. Cattleya Summer Song {Cattleya Summer Ski Slope x Cattleya Fleecy Clouds; registered by Lenette in 1974) is an ornamentally important orchid hybrid. In the current work, we have attempted to study the effect of plant growth regulators (BAP, kinetin, AdS04, GA3 and NAA) and the polyamine, putrescine on multiplication and development of PLBs to shoots and plantlets. A cluster of 4 or 5 shoots of Cattleya when treated with the cytokinin BAP yielded 34 PLBs per culture after eight weeks of culture. Clumps of 25-30 PLBs were administered with the plant growth regulators (PGRs). 5uM BAP was the most effective for multiplication of PLBs. Putrescine (50uM) promoted the rapid development of these PLBs to shoots. Of the various concentrations of the two auxins (NAA and IB A) assessed, 5uM IB A led to the formation of long healthy roots in these shoots. The plantlets were transferred to the green house after eight weeks of pre-hardening on MS basal medium where these showed a survivalrate of ninety nine per cent.