Improvement of sexual destination in Atropa acuminata Royle (Solanaceae) - A critically endangered medicinal plant of northwestern Himalaya

Abstract

Good seed set is no guarantee of absolute sexual destination in plants. Seed viability and seed vigour are crucial phases in the life cycle of every sexually reproducing plant. The present study was an attempt to improve the sexual destination-the germination and seedling survival of Atropa acuminata Royle (Solanaceae), an endemic and extremely restricted sub-alpine medicinal plant of North West Himalayas under ex situ conditions at (1580 m) with an aim to develop a successful germination protocol and agrotechnique in order to revegetate disturbed areas. Among various treatments given to the seeds, GA 3, Scarification, warm water treatment and chilling at 4°C for 90 days were found to be most effective with percentage germination of 73.3±18.80, 79.95±9.40, 66.6±6.6, 45±7.07 (X±SE), respectively. The results reveal that the seeds do not germinate unless specific environmental signals or events occur which trigger the genetic and hormonal response of the seeds thereby facilitating their germination. The diversity and the extent of the dormancy mechanisms encountered here suggest that under harsh conditions, natural selection may favour seeds with a genetic system for dormancy and delayed germination. A relation was observed between seed size/weight, %age germination and subsequent seedling survival. Seedling survival is also effected by specific habitat requirement and stiff intra and inter-specific competition particularly the whimsical behaviour of Sambucus wigthiana (an alien species which grows in the vicinity of Atropa) is beyond the ken of Atropa, adding fuel to the already burning candle apart from habitat fragmentation and herbivory. © 2007 Asian Network For Scientific Information.