RESPONSES OF SEEDS OF AZADIRACHTA-INDICA (NEEM) TO SHORT-TERM STORAGEUNDER AMBIENT OR CHILLED CONDITIONS

Neem seeds show curious post-shedding behaviour and have been variousl y documented as orthodox, intermediate or recalcitrant, apparently rel ating to provenance. In addition, even in the air-dry state, hermetica lly stored seeds rapidly lose viability. In the present case, putative ly recalcitrant, hydrated neem seeds from a Kenyan coastal provenance were stored in loosely-closed polythene bags to ascertain: l. Whether or not the axes showed metabolic enhancement indicative of the onset o f germination under ambient storage conditions for 10 d; and 2. Whethe r chilling (4 +/- 2 degrees C for 10 d) had an adverse effect on the a xis cells. There was a slight germination lag relative to the control material in the ambient-stored seeds, which is ascribed to their parti al enclosure, but the totality of germination was unaffected, while ch illing had markedly adverse effects on both rate and totality. The ult rastructure of control material; sampled prior to storage. was typical of embryonic axes in the stage of late development or early stages of germination: During ambient storage, there was considerable enhanceme nt of ultrastructural features indicating that germination (even thoug h slightly delayed) was indeed underway. In contrast, a regression of subcellular development accompanied chilling, many axis cells showing degenerative changes. In terms of this behaviour, seeds of A. indica f rom this African provenance conform to the characteristics expected of tropical recalcitrant species.