Changes in biochemical and enzymatic activities with ageing in seeds of different sizes of sunflower (Helianthus annuus L.) under invigoration treatments

A laboratory experiment was conducted at Department of Seed Science and Technology, Institute of Agricultural Science, University of Calcutta, West Bengal, India in 2015 to evaluate the changes in biochemical and enzymatic activities with natural ageing of various sized sunflower seeds using different invigoration treatments. Experiment comprised various size categories of seeds (composite, large, medium and small) treated with powdered ingredients (aspirin @ 50 mg, bleaching powder @ 2 g and red chilli powder @1 g per kg of seeds) along with control (dry seeds) and thereby, subjected to natural ageing for 4 months. Seed quality deteriorated with ageing of seeds. Specifically, there were increments of electrical conductivity, leaching of sugar and reduction in activity of α-amylase, dehydrogenase, catalase and peroxidase enzymes along with protein. Deterioration was less in large sized seeds treated with either red chilli powder or bleaching powder over other treatments as they checked the changes of biochemical and enzymatic activities to a large extent. Germination and seedling quality also showed less deterioration in storage under those invigoration treatments. Therefore, pre-sowing invigoration treatment of large sized sunflower seeds with either red chilli powder or bleaching powder may be recommended to check the seed quality deterioration associated with natural ageing in West Bengal condition.