Yadav Achchhelal, Bhatia Arti, Yadav Sudesh, Kumar Vinod, Singh Bhupinder
School of Environmental Scienecs, Jawahralal Nehru Univeristy, New Delhi, 110067, India.
Centre for Environmental Science and Climate Resilient Agriculture, Indian Agriculture Research Institute, New Delhi, 110012, India.
Heliyon. 2019 Aug 20;5(8):e02317. doi: 10.1016/j.heliyon.2019.e02317. eCollection 2019 Aug.
Global food security is challenged by increasing levels of CO, O and temperature trough their impacts on production and grain quality of wheat, one of the major C crops and staple food across the world. The present study was conducted to assess the effects of elevated levels of CO (EC; 550 ppm) and tropospheric O (EO; 70 ppb) as well as of combined interactive treatment [EC X EO; ECO] on plant growth, yield and grain quality of two wheat cultivars (HD-2967 and C-306) grown during 2016-17 and 2017-18 using free air ozone and carbon dioxide enrichment (FAOCE) facility under field conditions. Individually, EC, increased leaf area index (LAI; 15.9-28.2%), photosynthetic rate (Pn; 11.4-20.3%) and yield (8.2-20.9%) whereas EO declined LAI (5.1-12.5%), Pn (2.8-11.8%) and yield (2.2-14.2%) over ambient conditions (Amb: 405.2 ppm CO and 30.7 ppb O). Under ECO condition, EC increased LAI (2.2-17.1%), Pn (2.8-17.6%) and grain yield parameters (4.4-24.3%) across the cultivars in both years, but reduced the positive effects of EO on quality as compared to Amb. Dilution effect of increased yield under EC condition have reduced total protein, micro- and macro-nutrient concentrations whereas EO increased them notably compared to Amb. Starch in grains increased under EC but reduced under EO as compared to Amb. AOT40, the sum of averaged difference of O h concentration beyond 40 ppb for 7 hours (31233 ppb h) in FAOCEs rings during the crop growth period led to reduction in average grain yield of HD-2967 and C-306 by 11.6 and 8.5% or by 1.6 and 1.3% yield loss per ppb increase of O, respectively. The growth, yield and quality parameters of both wheat cultivars responded similarly but to different extent to all treatments. EC was able to offset the negative effects of EO on yield and yield components only, but not those concerning the quality of grains. To stabilize global food security, precursor gases forming tropospheric ozone must be constrained.
全球粮食安全受到二氧化碳、臭氧和温度升高的挑战，因为它们会影响小麦的产量和品质，小麦是全球主要的谷类作物和主食之一。本研究旨在评估在田间条件下，利用自由空气臭氧和二氧化碳富集（FAOCE）设施，在2016 - 17年和2017 - 18年期间，两种小麦品种（HD - 2967和C - 306）在二氧化碳浓度升高（EC；550 ppm）、对流层臭氧浓度升高（EO；70 ppb）以及组合交互处理[EC×EO；ECO]条件下对植株生长、产量和籽粒品质的影响。单独来看，与环境条件（Amb：405.2 ppm二氧化碳和30.7 ppb臭氧）相比，EC增加了叶面积指数（LAI；15.9 - 28.2%）、光合速率（Pn；11.4 - 20.3%）和产量（8.2 - 20.9%），而EO降低了LAI（5.1 - 12.5%）、Pn（2.8 - 11.8%）和产量（2.2 - 14.2%）。在ECO条件下，两年中各品种的EC均增加了LAI（2.2 - 17.1%）、Pn（2.8 - 17.6%）和籽粒产量参数（4.4 - 24.3%），但与Amb相比，降低了EO对品质的积极影响。EC条件下产量增加的稀释效应降低了总蛋白、微量和大量营养素浓度，而与Amb相比，EO显著增加了这些浓度。与Amb相比，EC条件下籽粒中的淀粉增加，而EO条件下淀粉减少。作物生长期间，FAOCEs环中7小时内臭氧浓度超过40 ppb的平均差值之和（AOT40，31233 ppb·h）导致HD - 2967和C - 306的平均籽粒产量分别降低11.6%和8.5%，或臭氧每增加1 ppb分别导致产量损失1.6%和1.3%。两个小麦品种的生长、产量和品质参数对所有处理的反应相似，但程度不同。EC仅能抵消EO对产量及产量构成因素的负面影响，而不能抵消其对籽粒品质的负面影响。为稳定全球粮食安全，必须限制形成对流层臭氧的前体气体。
