记笔记

Carbon dioxide enrichment ameliorates negative effects of elevated ozone in tropical wheat（Triticum aestivum L.） cultivars:An insight into metabolism,yield and grain quality

Amit Kumar MishraS.B.AgrawalMadhoolika Agrawal

Laboratory of Air Pollution and Global Climate Change,Department of Botany,Banaras Hindu University

摘要：Carbon dioxide（CO₂） and ground-level ozone（O₃）,two important components of global climate change,are rising continuously in the atmosphere and impart their significant impacts on growth and yield of various crop plants.The present study was performed to assess the growth,physiological,yield and grain quality responses of two cultivars（Malviya-37 and K-9107） of tropical wheat（Triticum aestivum L.） against elevated levels of CO₂ and O₃,individually and in combination under near-natural conditions.Plants were continuously exposed to elevated levels of CO₂（700 ppm） and O₃（ambient + 10 ppb;nearly 25%of ambient） for four hours（11.00 to 15.00h） in specially designed open top chambers（OTCs） from germination to the seed maturity.Growth and yield of the plants significantly increased under elevated CO₂（EC） and combination of EC with elevated O₃（ECO） as compared to the plants grown in ambient air（control）.Under elevated O₃（EO）,significant reductions were observed in all the growth and yield attributes and the extent was higher in Malviya-37 as compared to K-9107.Elevated CO₂ stimulated the net photosynthetic rate（P_s）,photochemical efficiency（F/F_m） and reduced the stomatal conductance（g_s）.Reactive oxygen species（-.O₂ production rate and H₂O₂ content）,lipid peroxidation,activities of antioxidative enzymes,ascorbic acid and total phenolics were higher,whereas P_s′ g_s′ F_v/F_m,soluble protein and photosynthetic pigments were reduced under elevated O₃ exposure.Under combined treatment,EC modified the plant performance against O₃ in both the cultivars.Soluble protein and total free amino-acids decreased in grains of EC,ECO and EO in both the test cultivars.Total soluble sugars and starch contents in grains increased due to EC and ECO and reduced under EO,however reducing sugars showed an opposite trend in both the cultivars.Results of the present study clearly suggested that（i） response was differential as Malviya-37 proved to be more sensitive against elevated O₃ as compared to K-9107,and（ii） elevated CO₂ provided significant protection to wheat cultivars against negative impact of elevated O₃.The study concludes that elevated CO₂ has the potential to modify seed yield and its quality in wheat by improving stress tolerance traits against O₃.

关键词：

CO₂; O₃; Wheat; Growth; Yield; Grain quality;

会议名称：

第七届国际作物科学大会

会议时间：

2016-08-14

会议地点：

中国北京