Enhancement of seed germination in hot pepper following presowing treatments

Rapid and uniform seedling emergence is a pre-requisite for better plant establishment. One of the major problems of hot pepper growers is difficulty in obtaining proper seedling emergence under low temperature conditions. Chilli cv. Pusa Jwala seeds were osmoprimed (-1.0 MPa PEG 6000 for 7 days), haloprimed (KNO3 30mM for 24h) and hydroprimed (soaking in water for 24h). Solid matrix priming (SMP) of the seed was performed by mixing seed with moist vermiculite followed by incubation for 48h at 25 degrees C. Solid matrix priming improved germination by 16 percent at 15 degrees C and 10 percent at 20 degrees C and 25 degrees C. Solid matrix priming followed by halopriming and osmopriming significantly improved speed of germination. Hydropriming reduced speed of germination as compared to untreated control. SMP and osmopriming significantly reduced leakage of electrolytes in seep water over control. Seed leachates of the primed seed had lower content of total free amino acids and water soluble sugars thereby suggesting that priming enhanced repair of membranes. Imbibed primed seeds exhibited greater activities of the enzymes of glyoxylate cycle involved in lipid to sugar conversion during germination. X-ray radiography of the primed seed showed reduced free space area between embryo/ endosperm and seed coat. This decline of free space suggests further development of embryo during priming. These results indicate that among the different priming treatments studied, solid matrix priming is the best and can be effectively employed to prime large amount of hot pepper seed at one time. It is also cost effective as the medium can be re-used many times.