Responses of radish (Raphanus sativus L.) plants at different growth phases to ozone exposure
Abstract
Three growth phases of radish (Raphanus sativus var. ‘Pusa chetki’) namely, early vegetative phase (EVP, 20 days); late vegetative phase (LVP, 35 days); and reproductive phase (RP, 50 days) were exposed to two ozone concentrations (75 and 150 ppb) in closed top dynamic chambers for 12 days. Ozone treated plants exhibited visible injuries (white spots mainly on the upper surface of leaves). Significant reductions in shoot length (4 to 35 %), shoot biomass (4 to 62 %), total number of flowers (10 to 44 %), and hypocotyl biomass (40 to 80 %) were also observed. Ozone exposure was more detrimental during EVP compared to LVP and RP. Results of this study also showed that 150 ppb of ozone exerted more harmful effects at all growth phases than 75 ppb.
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