Germination studies on three critically endangered endemic angiosperm species of the Kashmir Himalaya, India

摘要

The critically endangered and perennial alpine endemic angiosperms, namely, Aquilegia nivalis, Lagotis cashmeriana and Meconopsis latifolia inhabit such habitats in the Kashmir Himalaya that are characterised by short growing season and heavy snow cover for about 3–4 months during winter season. The seeds of these species under natural conditions experience a long period of pre-chilling during winter prior to their germination in following spring season. Taking cue from such a requirement, present study investigated the effect of chilling and exogenous application of growth hormones, NO3 ? and NH4 + on total percent germination of otherwise deep-dormant seeds of these species, under alternate light/dark and continuous dark light regimes. Prolonged pre-chilling followed by treatment of seeds with different doses of GA3 had a pronounced stimulatory effect on the total germination percentage in all the three species. In fact, highest germination percentage in A. nivalis was recorded only when pre-chilled seeds were treated with 1.5 mM GA3 under alternate light/dark conditions. Likewise, germination of pre-chilled seeds of L. cashmeriana with ruptured seed coats was improved when treated with various concentrations of GA3. Seed germination in M. latifolia was also favourably influenced by treatment of pre-chilled seeds with GA3 or nitrogen applied either as NO3 ? or as NH4 + under alternate light/dark conditions. Treatment of seeds with kinetin (6-furfuryl-aminopurine) had no significant influence on germination percentage in any of the three species. Thus, prolonged chilling of seeds followed by their treatment with GA3 under alternate light/dark conditions are the requirements necessary for seed germination in these species.