Response of bulb yield per plant, chlorophyll content and photosynthetic pigments concentration of onion (Allium cepa L.) genotypes to priming and seed size

In order to evaluate the response of bulb yield per plant, chlorophyll content and photosynthetic pigments concentration to priming and seed size of onion genotypesa field experiment was conducted in 2012 and 2013 cropping season at Agriculture and Natural Resources Research Center of East Azarbayjan, Iran. The experimental treatments included priming (at four levels: hydro priming, osmopriming (in %2 KNO3), priming with Folammin amino acid (in 2%) and control (without priming), seed size (at three levels: small, medium and large) and cultivars (at two levels: Red Azarshahr and Zargan). Following characteristics such as bulb yield per plant, chlorophyll content including: bulbing stage, physiological maturity stage, photosynthetic pigments concentration including: chlorophyll a, chlorophyll b, carotenoid, total chlorophyll and chlorophyll a/b ratio of onion were studied. Analysis of variance of data showed that all studied characters were significant in 1% level of probability. Results showed that seed priming and seed size improved bulb yield per plant, chlorophyll content and photosynthetic pigments concentration characteristics. The highest bulb yield per plant, chlorophyll a, chlorophyll b, chlorophyll a/b ratio were obtained from plant that primed with Folammin amino acid 195.85 (g), 33.48, 7.79 (mg/g.FW), 4.3, respectively and the lowest were achieved from control plants. Also mean comparison indicated that the higher values of bulb yield per plant, chlorophyll a, chlorophyll b, chlorophyll a/b ratio were obtained from large seed size 180.66 (g), 21.60,7.20 (mg/g. FW), 3.9, respectively and the lower of it achieved from small seed size.