出版社：Chinese Association for Aerosol Research in Taiwan
摘要：Maize is an important C4 crop and how it will respond to elevated atmospheric carbon dioxideand ozone levels is not well documented. To understand how the growth and nutritional quality ofmaize will be affected under elevated carbon dioxide (CO2) and tropospheric ozone (O3) interaction,a field experiment was conducted under free air O3 and CO2 enrichment rings (FAOCE) growingHQPM-1 and PMH-1 maize cultivars at New Delhi, India. Each cultivar was exposed to ambientand elevated CO2 (559 ppm) alone and along with ambient and elevated O3 (71.8 ppb) throughoutthe growing period. Elevated CO2 (EC) significantly increased the leaf area index (10.8–22.5%),chlorophyll (11.2–17.3%) and photosynthetic rate (12.1–16.5%) in the two cultivars over theambient. O3 exposure of 27 ppm hr (AOT4O) under elevated O3 (EO) treatment led to a significantdecline in yield (p < 0.01) by 9.2% in HQPM-1 and 9.8% in PMH-1. Under elevated CO2 the increasein grain yield was higher under HQPM-1 (25.4%) as compared to PMH-1 (9.04%). The proteincontent increased under EO (8.1–12.5%) and decreased under EC (13.4–13.6%) in the two maizecultivars due to yield dilution effect. Lysine, phosphorus and potassium content of the grainsignificantly decreased in both the cultivars under elevated CO2. Carbohydrate and amyloseconcentrations in grains increased (9.9–15.5%) under EC and decreased (10.8–16.7%) under EO,however, no significant change in yield, protein, amylase, carbohydrate, lysine, potassium andphosphorus was observed under the interaction treatment ECO as compared to the ambient.After two years of study we could conclude that elevated CO2 (559 ppm) was able to offset thenegative effect of elevated O3 (71 ppb) on grain yield by 11.2% in PMH-1 and by 18.8% in HQPM-1without significantly affecting the grain quality in both the maize cultivars.
