Seed dormancy, germination and seed storage in henna (Lawsonia inermis)

Abstract

Henna (Lawsonia inermis L.) is an important commercial plant of India grown mainly for its leaves used for dying hair, skin etc. The seeds of henna are small typically pyramidal, endospermic with a linear embryo. The freshly harvested seeds show endogenous non-deep physiological dormancy and pre-treatment of seeds, viz. leaching, chilling, priming, GA3 and KNO3 co-application reduced dormancy. The physiological dormancy was transitory and disappeared during storage due to after-ripening. Seed storage studies revealed that seeds with 5 and 7 % moisture content did not show significant reduction in seed longevity up to 24 months in ambient storage in comparison to seeds with higher moisture content. Seed deterioration was slow at 15 and -20°C storage temperatures. The seeds are desiccation as well as chilling tolerant, therefore, exhibit orthodox seed storage behaviour which makes them ideal for ex-situ conservation in seed banks for long term storage.