Development of micropropagation systems and new in vitro strategies for some import ornamental plants

Abstract

The present Investigations were conducted at the IIHR, Hessaraghatta, Bangalore to develop in vitro systems for some important ornamental plants. In Saintpaulia ionantha, leaf discs were found to be a superior source of explants than petiole section with respect to morphogenic responds. However, the axenic leaf explants responded at a faster rate during recurrent cultures. MS medium supplemented with NAA and BA at 0.5 mg l-1 was found to be optimum for callusing and differentiation of explants during initiation of cultures. Combination of IBA and BA at 1 mg l-1 resulted in maximum number of plantlets during both axenic cultures and subsequent subcultures. Higher intensity of rooting and better growth of plantlet was observed on MS medium without growth regulators. A potting mixture of soilrite + sand + compost (2:1:1 V/V) and hardening of plantlets using polythene covers for 3 weeks was found to be optimum for better establishment of plantlets. Begonia ‘Lucerna’ Petiole segments cultured on MS medium supplemented with NAA 1 mg 1-1 + BA 2 mg l-1 resulted in higher intensity of callusing and differentiation. Cymbidium aloifolium protocorms cultured on liquid Vacin and Went medium supplemented with 0.4 mg l-1 BA resulted in maximum proliferation of PLB’s and multiple shoots. Similarly, the nodal segments also induced maximum number of shoots on the same medium. Anthurium scherzerianum leaf sections initiated callus from the veins when cultured on Vacin and Went medium supplemented with 2, 4-D and BA at 1 mg l-1. The protocorms of Cymbidium aloifolium; callus, petiole sections and shoot buds of Saintpaulia ionantha were encapsulated using 2.5% sodium alginate and it was found that these encapsulated plant material could be stored at 4°C temperature. This suggested the suitability of encapsulated material for efficient delivery system, storage and effective transport under limited refrigerated condition. Anothers of Saintpaulia ionantha culture Saintpaulia ionantha on MS + IBA 1mgI-1 + BA 1 mg-1 resulted in higher callusing and differentiation of haploid plantlets. Leaf mesophyll protoplasts of Dendrobium ‘Jaquelyn Thomas’ were isolated using 5 ml enzyme solution having 0.75% cellulose and 0.4% onozuka R-10 macerozyme and an incubation period of 16 hours.