GERMINATION RESPONSE OF SERIALLY HARVESTED GBOMA' (Solanum macrocarpon L.) SEED TO HYDR0-, OSMO- AND HALO-PRIMING

Abstract

Seeds extracted from 'Gboma ' fruits harvested at 42 to 66 day after anthesis (DAA) were primed in distilled water, polyethelene glycol (PEG 6000) at -0.1 MPa, -0.2 MPa and -0.3 MPa and NaCl at 50 mM and 100 Mm for 24 and 48 hours; unprimed seeds served as the control. PEG and NaCl-primed seeds were subsequently thoroughly washed with water and then air-dried for 24 hours. Samples of seeds of all the treatments were incubated at 30 oC over a period of 16 days to determine germination percentage (GP), germination rate index (GRI) and germination index (Gl). Across priming treatments, significantly higher (p=0.05) GP (18-19%) GRI (ca 1%-1) and GI (56-75) were recorded in seeds harvested at 58 to 66 DA4 than those from earlier harvests. Hydropriming resulted in significantly higher (p=0.05) GP GRI and GI than in the control and other priming treatments. Response to hydropriming was more pronounced in seeds harvested at 54 to 66 DAA. Response to osmo- and halopriming was poor as only a maximum of about 266 and 286 germination were recorded in the former and the latter respectively compared to 66% and 61% in 24 h and 48 h hydropriming respectively. The poor response of seeds to osmo and halopriming may not be unconnected with inappropriate duration of treatment and or inappropriate concentrations. The significantly poorer germination of unprimed seeds compared to hydroprimed lots at 58 to 66 DAA confirms the presence of dormancy