Preliminary Study On Leaf Structure And Physiological And Biochemical Characteristics Of Photinia Frasery During Leaf Color Change

Photinia fraser which has leaves red,shaped compact and a wide range of uses and other characteristics,is an important landscape color plants.The experiment used ThisPhotinia fraserto green spaces planted two years for materialsas materials and aimed to study the leaf morphological,anatomical characteristics,photosynthetic characteristics,leaf pigment content,soluble sugar content and pH value during green process of leaf discoloration and discussthe leaf structure and physiology during leaves turn from red to green so that provide a basis for better use of information.The main results are as follows:(1)the Photinia fraser with leaf color changes,wet/dry ratio increases gradually,increasing from 24.7%to 51.9%,and the biggest percentage change between March to April is 44%.Relative water content decreases,decreasing from 75.3%to 48%,and change from red to green to yellow-green leaves the biggest.Leaf was positively correlated with wet/dry ratio(p<0.05),with wet/dry ratio,leaf color is green.Description in Photinia fraser dark green leaves during water content decreases,and as the leaves turning green variation becomes smaller.(2)Photinia fraser when leaves turn from red to green over time,leaf thickness showed an increasing trend from 203.37 ±8.91?m increase to 249.56 ± 2.80 ?m,an increase of 22.7%.Increasing trend in the palisade and spongy tissue thickness,Palisade from 56.46 ± 5.51?m increases to 81.79 ± 2.26 ?m,an increase of 44.9%.Spongy tissue increases from 105.40 ± 5.22 ?m to 142.31 ± 21.02 ?m,an increase of 35%.Leaf blade thickness-related,but was positively correlated with palisade and spongy tissue thickness(p<0.05),palisade and spongy tissue becomes thicker,dark greenish leaves.Photinia fraser upper and lower epidermis cuticle thickness decreased epidermal thickness increased from 19.09 ± 0.89 ?m to 24.44 ± 0.40 ?m,an increase of 28%.The thickness of the lower epidermis increased from 10.51 ± 0.18?m to 14.19 ± 0.67?m,an increase of 35.0%..The upper and lower epidermis was negatively correlated with leaf color(p<0.05),epidermal thickness,but the lower epidermis thickness,leaf color is green.Description of Photinia fraser leaves turning green in the process,gradually thinning,skin on,palisade and spongy tissue thickness increases,thickening of the blade thickness.(3)Photinia fraser when leaves turn from red to green over time,anthocyanin content decreased from 8.78 to 2.36,decreased by 6.42,or 73.1%.And in leaf color changes from red to red-green was the highest in leaf color changes from red to green to dark green by much.Leaf was positively correlated with relative content of anthocyanins(p<0.05),with less content,leaf color is green.As a photosynthetic pigment chlorophyll and carotenoid contents are changing over time,gradually increasing.Chlorophyll content increased from 0.38 mg/g to 1.61mg/g increase 1.21mg/g,323.7%per cent.Carotenoid content increased from 0.23 mg/g to 0.95 mg/g,increased 0.72 mg/g,by 13%.Leaf color and pigment content was significantly and negatively correlated with light(p<0.05),the photosynthetic pigments(chlorophyll a + b,chlorophyll a,chlorophyll b,and carotenoids)content,leaf color is green.In the anthocyanin content in Photinia fraser dark green leaves gradually reduce,and changes from red to green leaves most obvious 3-4 month the biggest percentage change.Photosynthetic pigments increased and leaf color changes gradually decreased after turning green.(4)Photinia fraser when leaves turn from red to green over time,leaf color is red,concentration of soluble sugars and soluble sugar content,namely 5.129 ?mol/L and 2.05 ?mol/g.Leaf color is light green and soluble sugar concentrations of soluble sugar content,2.224 ?mol/L and 0.89?mol/g,respectively.Leaf was negatively correlated with sugar(p<0.05),that is,high sugar content,leaf color is green.Photinia fraser pH value of seasonal increase,from 3.68 to 4.99 per cent,increased 1.31,35.6%percent,an increase is unlikely,leaf color and pH values are not related,but the pH value was negatively correlated with anthocyanin contents(p<0.05),that is,high pH value,low content of anthocyanins.Description of Photinia fraser leaves turning green in the process of soluble sugar concentrations and soluble sugar content decreases pH value increases.(5)in Photinia fraser when leaves turn from red to green over time,net photosynthetic rate of Photinia fraser in leaf color is red to minimum,for 4.20 ±0.513 ?mol·m-2 · S-1,Max in the leaf color to green,to 11.31 ± 0.450?mol · m-2 · S-1.In color from red to green in net photosynthetic rate during the period has been increased,to slightly reduce the leaf color is dark green.NET photosynthetic rate of leaf color and has a significant negative correlation(p<0.05),the leaf color is green,photosynthetic rates high.Description of Photinia fraser NET photosynthetic rates of leaves turning green in the process increases,and as the leaves turning green variation becomes smaller.In General,Photinia fraser leaf color changesfrom red to green gradually with the seasons and the green deepened after the color turns green totally.The leaves turn from red to green with leaf water content reduction,leaf thickness increasement,photosynthetic pigments and photosynthetic capacity increasement and stabilizition of green leaf structure and physiological and biochemical characteristics.