Effect of planting dates, mulching and application of ga3 on seed yield and quality of marigold (Tagetes Erecta L.) cv. ‘Pusa Narangi Gainda’

Abstract

Commiphora wightii (Arnott) is an important medicinal plant, belongs to Burseraceae family. This plant is considered as an endangered plant in India and listed as “Data Deficient” in the IUCN Red Data List because of excessive exploitation for taping of gum causes mortality of plants, lack of knowledge for its conservation, poor germination capacity of seed, lack of proper vegetative propagation method and unscientific cultivation. Therefore, there is an urgent need to conserve this species ex situ through in vitro methods. However, under in vitro medium browning is a major problem in Commiphora wightii due to the exudation of high amount of phenols, especially in mature explants (nodal segment and shoot apex). In present study an attempt has been made to demonstrate the effect of antioxidants on in vitro degree of browning and culture establishment of guggul. Different antioxidants viz; activated charcoal, PVP, ascorbic acid and citric acid have been tried to eliminate medium browning problem through incorporation on the responsive culture medium for shoot proliferation (nodal segment, 1.5 mg/l BAP and shoot apex, 2.0 mg/l Kn) and callus induction (leaf explants, 2.0 mg/l 2,4-D). Among the different antioxidants, activated charcoal (150-200 mg/l) was found better in reducing browning of medium, establishment of culture and promoted shoot proliferation and callus differentiation because it controls the accumulation of inhibitory substances and it immediately absorbs plant growth regulators and vitamins from the medium and gradually releases them again in the medium. Maximum callus differentiation in leaf explants was observed at 250 mg/l activated charcoal followed by 200 mg/l. Among all the antioxidants polyvinyl pyrroli done was least effective to proliferate shoot bud and callus induction.