Germination Responses of Some Forage Species of Eastern Terai, Nepal
Keywords:Seed attributes, storage, viability, acid scarification, light, imbibition, potassium nirate.
AbstractFreshly harvested seeds of the species (legumes: Alysicarpus vaginalis and Desmodium triflorum; grasses. Axonopus compressus and Chrysopogon aciculatus) failed to germinate even after acid scarification and incubation under different light qualities, whereas seven-nine-month old seeds exhibited germination in the order: D. triflorum (23%) > A. compresses (17%) > A. vaginalis (13%) > C. aciculatus (4%) without acid scarification or nutrient treatment. The legumes contained yellowish brown (Yb) and brick-red (Br) seeds in their pods in the ratio of 4:1. The Yb seeds had hard seed covering very slowly permeable to water. Storage of seeds under room conditions in sealed polythene pouches up to three years profoundly inhibited germination in Br seeds but had little effect on Yb seeds. The nine-month-old Br seeds had maximum germination (24 and 38%, respectively in A. vaginalis and D. triflorum) when submerged in water for 24 h before sowing, whereas germination in submerged in water for three days as a pretreatment. Germination in Yb seeds of the same age was 72 and 77%, respectively in A. vaginalis and 84% in D. triflorum when seven-eight-month old seeds were scarified with mixed (Yb and Br) seed lot was 71% in A. vaginalis and 84% in D. triforum when seven-eight-month old seeds were scarified with sulphuric acid for 10 min and incubated under red light for a week. The fresh seeds of A. compressus had 79% in viability (TTC test) which declined to 5% after storage for three years, and nine-month-old caryopses when treated with nitric acid for ten minute and incubated under red light for 18 days had maximum (45%) germination. In C. aciculatus. Seeds had only 37% viability when fresh, and they completely lost viability after storage for two years, and nine-month old caryopses had maximum (17%) germination when treated with 0.5% solution of potassium nitrate and incubated under ordinary condition for 25 days.
Key words: Seed attributes; storage; viability; acid scarification; light; imbibition; potassium nirate
Ecoprint (An international Journal of Ecology) Vol.13, 2006 page 49-60