| During the last several decades, the increased ground surface O3concentration and weakened solar radiation duing to aerosol radiation effect had aroused the attention of the Governments.Both Increased O3and weakened solar radiation had strongly negative influence on crops of physiological ecology as well as yield, which will directly threaten to the safety of food crops. Therefore, open top chambers (OTCs) and shade shed were utilized to carrying out experiments.Settings CK(OTC without O3and shading), O1(100nL/L O3), S1(shading20%), S2(shading40%) and O1+S1(100nL/L O3and shading20%), O1+S2(100nL/L O3and shading40%)6different treatments, via the plant height of winter wheat,flag leaf, second leaf and non-leaf organ photosynthetic capacity, grain filling to analyzing the impact of shading and ozone stress on winter wheat, Which will provide basic data for accurate assessment of winter wheat growth and yield loss under O3concentration increase and surface solar radiation weakened context. The main conclusions were as follows:(1) Shading and O3stress changed plant morphology.plant height-. relative growth rate and leaf area increased, the length and width of flag leaf and second leaf increased Significantly, Leaf width was more sensitive to the stress and had highly significant positive correlation on yield. Shading was the leading factor.(2)Carbon metabolism was major supersession of plant under O3stress; Nitrogen metabolism was major supersession of plant under shading stress; The accumulation of winter wheat assimilates into Nitrogen metabolism mainly dominated by Carbon under shading and O3stress, and shading was the leading factor.(3)Chlorophyll content of flag leafN Second leaf and non-leaf organ and transfer rate of leaf soluble sugar increased under shading and O3stress. Photosynthesis of second leaf and non-leaf organs could compensation the damage of flag leaf.While stress reduce source dry matter cumulative and coordination capacity of the sink to source.Ultimately panicle dry matter accumulation decreased significantly. Dry matter allocated to the hull and cob grain more, grain proportion declined relevantly.(4)Leaf area decreased under O3stress. Shading can offset the negative effects of O3on leaf area, the impact of leaf area was greater of shading than O3, and shading was the leading factor. Both shading and O3could decline dry matter accumulation, composite treatment cut down more than single treatment. Logistic curve can well simulate dynamic cumulative process of dry matter based on the relative dry matter and the relative accumulated temperature.(5) Both O3and shading declined yield by diminishing panicles, grains per ear, grain weight and1000-grain weight. Compared with single factor, composite two factors declined significantly, the two factors had a certain synergy. |
