Effect of desiccation damage on the seed viability of Hydnocarpus alpina Wight. of Western Ghats

Abstract

Hydnocarpus alpina Wight is an evergreen endangered medicinal tree species of Western Ghats. Several local names are available based on the distribution among the state in India that is Torathi (Kannada), Maravetti/Marotti (Malayalam), Attuchankalai (Tamil), Kastel (Hindi). Hydnocarpus alpina has very appreciated value in various medicinal properties like anti-larvicidal, anti-feedant, antimicrobial etc. due to the presence of significant chemical constituents. The seeds of this tree species are characterized with high moisture content and are intolerant to desiccation. They are under recalcitrant type seeds.Fully mature H. alpina seeds have 20% moisture content on harvest and recorded 80% germination. After 2 weeks of desiccation at open laboratory conditions (28±2 °C and 65% RH) their moisture content and percentage of germination decreased to 10.2% and 20 % respectively. Complete loss of viability occurred at 10% moisture level. This clearly indicates the recalcitrant nature of seeds. Different biochemical parameters such as lipid peroxidation, leachate conductivity, assay of free radical scavenging enzymes, analysis of primary metabolites like total soluble sugars, starch, total proteins, amino acids, lipids, phenols etc. were recorded for finding the biochemical basis of desiccation induced damage on seed viability. The results of the study reveals the metabolic disturbances associated with the desiccation of seeds and such parameters can be considered as markers for assessing the seed viability. Hence, safest low moisture content for the long term storage of seeds can be identified for the conservation of this endangered species of Western Ghats.