Deviation in physical and physiological seed attributes within a seed lot of soybean [Glycine max (L.) Merril.]

Seed quality variation as influenced by seed position on the mother plant and ovule position within the pod were studied as possible with in plant components contributing to heterogeneity in quality of seeds within lots of soybean [Glycine max. (L.) Merrill] cultivar PS -1092 were grown in two successive years under North-West Himalayan Agri-system. The seed quality along with subsequent seedling growth was evaluated within the plant for different stem type and pod section. The largest seed size was obtained on main stem on the mother plant where the earliest pods were formed whereas within the pod distal position had greater seed weight. Seed germination % was greatly influenced by different stem type and seed position within the pod on the mother plant and significantly higher germination % was recorded for main stem type over primary and secondary branches while seed attached at distal end within the pod had greater germination over middle and proximal location within pod. The subsequent seed and seedling vigour in terms of seedling length, fresh and dry weight of seeding, vigour index, relative growth index (RGI) and earlier germination as indicated by lower value of mean germination time (MGT) and time to 50% germination (T50) as well as electrical conductivity of seed leachates were varied in different stem type and pod section. On the basis of these parameters the seeds obtained from main stem exhibited greater vigour over primary and secondary branches respectively. However, in pod section the seed attached at distal end with in the pod exhibited greater seedling vigour than middle and proximal end of the pod section.