Photosynthetic Characteristics Of Four Kinds Of Bamboo Of Indosasa

The photosynthesis of the plant is an important eco-physiology characteristics.The crucial and basic work of scientific cultivation,introduction and domestication is the research of the photosynthesis of the plant.The photosynthesis of four Indosasa bamboo leaves as Indosasa shibataeoides,Indosasa longispicata,Indosasa sinica and Indosasa hispida McClure introduced in Anhui Taiping Bamboo&Rattan Base were studied in the paper by using position-finding,field sampling and indoor quantitative analysis method and means.The main results are as below:Through analyzing the daily changing curve of net photosynthetic rate,it is found that the daily change curves in spring and winter appear single peak curve,while they appear double peak curve during the summer and autumn.Through analyzing the net photosynthetic rate level comprehensively,the sequence is ranked as 1.sinica(3.31±0.11?mol/m2·s)>I.shibataeoides(3.07±0.23?mol/m2·s)>I.longispicata(2.87±0.15?mol/m2·s)>.hispida McClure(2.41±0.22?mol/m2·s).The analysis result of photoresponse curve of four bamboos indicate that the light compensation points of Indosasa shibataeoides(15.35?mol/m2·s)and I.hispida McClure(14.76?mol/m2·s)are relatively low and it shows that their ability of utilizing low light is strong;while I.longispicata has higher compensation point(17.5?mol/m2·s)and light saturation point(975?mol/m2·s)and it shows that I.longispicata is photophilous bamboo.Multiple regression analysis result indicates that main factors affecting the net photosynthetic rate of four bamboos are photosynthetically active radiation(PAR),temperature(Ta),stomatal conductance(Cond)and transpiration rate(Tr).Moreover,the influencing factors affecting net photosynthetic rate in different reasons are not identical,wherein main factors affecting net photosynthetic rate in spring are atmospheric temperature,stomatal conductance and transpiration rate;the main factors affecting net photosynthetic rate in Summer are stomatal conductance and transpiration rate;main factors affecting net photosynthetic rate in Autumn are relatively atmospheric humidity,stomatal conductance,transpiration rate and intercellular carbon dioxide concentration and main factors affecting net photosynthetic rate in Winter are concentration of carbon dioxide and transpiration rate.The daily change of Fv/Fm,chlorophyll fluorescence parameter of four bamboo leaves in Spring is small,the measured value keeps about 0.82 and the fluorescence parameter fv/fm is not significantly related to the meteorological factor.The daily change of fv/fm of four bamaboo in Summer decreases followed by increasing and the minimum(<0.75)occurs at 2:00 p.m.Chlorophyll fluorescence fv/fm values of I.longispicata,I.shibataeoides and L sinica has significantly negative relation with the atmospheric temperature and has significantly positive relation with the relatively atmospheric humidity.Chlorophyll fluorescence fv/fm value of I.hispida has extremely significant negative relation with the atmospheric temperature and extremely significant positive relation with the relatively atmospheric humidity and the measured value of Fv/Fm is in the range of 0.62-0.70(<0.75).From the measured value and daily change trend of fv/fm,it is seen that I.shibataeoides and I.longispicata are affected by the reversible force at 2:00 p.m.in Summer,and I.hispida McClure is also affected by the reversible force in the experimental area.The daily change of chlorophyll fluorescence fv/fm values of I.shibataeoides,I.longispicata and I.sinica in winter is not big,which is not significantly related to the atmospheric temperature,relatively atmospheric humidity and illumination.The daily fv/fm change of I.hispida McClure appears decreasing followed by increasing and it reaches minimum(<0.75)at 2:00 pm.It indicates that it is insignificantly related to atmospheric temperature and illumination,but significantly positive related torelatively atmospheric humidity.Chlorophyll fluorescence fv/fm values of four bamboos in winter have insignificant relation with relatively atmospheric humidity and illumination,but significantly positive relation with atmospheric temperature.