Effect of Storage and Cold-Stratification on Seed Physiological Aspects of Buniumpersicum: A Threatened Medicinal Herb of Trans-Himalaya

摘要

Kalajira (Bunium persicum) is an economically and medicinally important threatened plant species of cold desert region of trans-Himalaya that needs appropriate conservation interventions. The seeds exhibit very deep dormancy which is a major restriction for its cultivation/expansion. Therefore, we have analysed the seed physiological aspects of a B. persicum population from Lahaul (Himachal Pradesh, India) with an aim to alleviate seed dormancy and/or improve germination. The freshly harvested seedsexhibited high viability (93%) as determined by tetrazolium test. The seeds, however, were completely dormant Seed storage under ambient conditions for 42 months did not alter the dormancy/germination status. But, the viability declined gradually 18 months onward leading to about one-third loss after 42 months. Of the various dormancy breaking treatments tested (H2S04-scarification, stratification at 4°C, leaching, KN03, SNP, NaN3 and GA3), only the moist-stratification at 4°C (continuous) effectivelyreleased the dormancy in freshly harvested as well as differentially stored seeds. Remarkably, the seeds germinated only at low temperature (4°C); germination ceased upon shifting the seeds from 4 to 25°C. Further, the response of seeds to this treatment declined consistently with the progression of storage period. The activity of catalase, an important antioxidative enzyme in the seeds, also declined with the progression of seed storage suggesting the involvement of oxidative stress in storage-dependent changes in seed viability and responsiveness to low temperature. Involvement of phenolics in observed changes might be excluded. The findings are of potential significance for seed-based propagation of B. persicum.