Elevated atmospheric carbon–dioxide affects seed vigour of rice (Oryza sativa L.)

Abstract

Our understanding of crop response to elevated [CO2] concerning its growth and yield has improved significantly. However, little is known about the germination and vigour of seeds harvested from mother plant grown under elevated [CO2], particularly in rice. Since elevated [CO2] influences the physiological functions of crop and seed development process, it is expected that such changes will alter the quality of the seed. To test this hypothesis, rice crop (IR 36) was grown in open top chamber (OTC) with varying [CO2] [410 (ambient), 510, 610 and 720 ppm] and seed quality in terms of germination and vigour [accelerated ageing test (AAT) and electrical conductivity (EC)] was assessed. Elevated [CO2] up to 610 ppm had no effect on seed germination; but, [CO2] at 720 ppm reduced the germination of freshly harvested seeds. Elevated [CO2] at 610 and 720 ppm reduced seed vigour. An increase in abnormal seedlings and dead seeds were symptomatic of the seed physiological deterioration associated with loss of seed vigour. Elevated [CO2] at 720 ppm reduced seed nitrogen content, substrate availability, and its subsequent translocation. Thus, atmospheric [CO2] above 610 ppm reduced seed vigour of rice.