Response of rice (Oryza sativa L.) cultivars to elevated ozone stress

Abstract The current study aimed to evaluate the cultivar specific variation in rice exposed to elevated ozone. Fifteen short duration rice cultivars were exposed to 50 ppb ozone for 30 days at reproductive stage. The physiological, biochemical, growth and yield traits of all test cultivars were significantly affected in response to elevated ozone. On average, ozone stress decreased tiller number by 22.52%, number of effective tillers by 30.43%, 1000 grain weight by 0.62 % and straw weight by 23.83% over control. Spikelet sterility increased by 19.26% and linear multiregression 3D model significantly fits the spikelet sterility and photosynthetic traits with the R 2 of 0.74 under elevated ozone. Principal Component Analysis with total variance of 57.5% by first two principle components categorized 15 rice cultivars into four major groups, ie., ozone sensitive (MDU6, TRY(R)2 and ASD16), moderately ozone sensitive (ASD18, ADT43 and MDU5), moderately ozone tolerant (ADT37, ADT(R)45, TPS5, Anna(R)4, PMK(R)3 and ADT(R)48) and ozone tolerant (CO51, CO47 and ADT36).