Variation in seed morpho-physiological traits of Nauclea orientalis L. in a seedling seed orchard and the effect of seed sortation on their physiological parameters

Abstract

The aim of this study was to identify the morpho-physiological diversity of seeds in several mother trees of N. orientalis at 6-year-old in a seedling seed orchard in Parungpanjang, Bogor and to identify the effectiveness of seed sortation in improving the seed germination. A total of 17 mother trees were collected for their fruit, measured the morphology of the seeds and tested their germination. The results showed that fruit and seed dimensions and weight, germination capacity were strongly influenced by the mother tree. Germination capacity and the highest germination capacity was resulted by family no. 22-BT (90%) and 48-MJ (92%). The highest coefficient of variation was given by seed weight per fruit (83.03), followed by germination capacity (66.66) and fruit weight (65.95). Seed sortation had a significant effect on germination capacity, germination rate, and mean germination time, but had no significant effect on germination value. In general, a sieve size of 300-420 μm gave the best results for increasing germination capacity (59.5%), germination rate (1.67% day-1), and mean germination time (18 days). Other sieve sizes, i.e., 420-600 μm was also able to improve seed germination so that for seed sortation applications 300-600 μm sieve sizes can be used.