Variation in seed dormancy and storage behavior of three liana species of derris (Fabaceae, Faboideae) in Sri Lanka and ecological implications

Non dormancy, three of the five classes of dormancy and orthodox and recalcitrant storage behavior occur in seeds of Fabaceae. The aim of the study was to characterize whole-seed dormancy and storage behavior in seeds of three tropical species of Derris (Fabaceae), which are lianas. Seed Moisture Content (MC); effects of drying and low temperature on viability; water-uptake of intact and scarified seeds; and effects of scarification, fruit coat removal and GAS on germination were determined. Seed coat anatomy was studied to check for evidence of physical dormancy. Seeds of D. parvifolia and D. scandens had low MC and those of D. trifoliata high MC. D. trifoliata seeds were sensitive to both drying and low temperature storage. Seeds of D, scandens were water-impermeable and those of D. parvifolia and D. trifoliata water-permeable. D. parvifolia seeds germinated without treatment, whereas those of D. scandens required scarification. Removal of fruit coat and application of GAS overcame dormancy in D. trifoliata seeds. A palisade layer was present only in the seed coat of D. scandens. D, trifoliata seeds are recalcitrant and those of the other two species orthodox. Seeds of D. parvifolia are nondormant and those of D. scandens and D, trifoliata have Physical (PY) and Physiological (PD) dormancy, respectively. The ecological implications of nondormancy/dormancy in relation to orthodoxy/recalcitrant seed storage behavior in tropical lianas are discussed.