Seed viability and oil content in seeds of Pongamia pinnata of five sources stored at different moisture and temperature regimes

The present research was conducted with the objective to study the variation in seed oil content among five seed sources across diverse agro-climatic conditions and storage behaviour of seeds up to two years. Seeds collected in May 2010 were stored up to May 2012 at three moisture levels (6%, 9% and normal), two temperature regimes (room temp. and-5°C) and three types of containers (cloth bags, polythene bags and air tight containers). The parameters of oil content (%), germination (%), seedling length (cm), seedling dry weight (mg) and seedling vigour (index-I & II) were measured. Seeds collected from the test trees of different agro-climatic zones were bulked zone-wise (seeds collected from all the 10 test trees from one agro-climatic zone were bulked). The seeds from each agro-climatic zone were divided into three equal parts. The maximum oil content was in RJ-7 agroclimatic zone and minimum in PB-3 agro-climatic zone. The oil content decreased with passage of time. Decline in the seed oil content was not significant up to a period of 12 months but by 24th month of storage the oil content declined significantly up to 6%. There was no germination after 12 months in the seeds stored at room temperature with normal and 9% moisture content irrespective of the type of containers used for storage. Seedling vigour declined significantly with increasing period of storage. Seeds stored in polythene bags and air tight containers had higher seedling length than cloth bag storage. Seeds with 6% moisture level stored at-5°C retained viability up to 16 months in air tight containers. The oil content was maximum (34.75%) in RJ-7 agro-climatic zone.