Photosynthesis And Cold Resistant Characteristics Of Torreya Grandis

Wannan Huizhou center of the basin of Torreya under natural conditions,the net photosynthetic rate were measured in different seasons,In different seasons on chlorophyll fluorescence parameters of different ages to determine and compare Torreya different ages and Torreya chilling were determined,Photosynthetic fluorescence analysis of the different ages and cold properties Torreya main results are as follows:1?Torreya leaf net photosynthetic rate diurnal variation curve showing a single peak in the spring,12:00 peaking in the winter,but also showing a single peak,the peak occurred at about 13:00,summer and autumn,there "midday depression" phenomenon net photosynthetic rate curves are bimodal curve.During the summer,reaching a peak at 10:00 and 15:00,in the autumn,11:00 and 15:00 respectively spikes.Leaves in the findings of Torreya daily average net photosynthetic rate of the different seasons show: Spring is 5.832?mol m2s1,in the summer of 4.243?mol m2s1,in autumn 4.856?molm2s1,in winter 2.263?molm2s1,namely spring> autumn> summer> winter.2?Light measured by the seasons in different seasons-the light response curve shows that Torreya blades in the spring,summer,autumn,winter light compensation point,light saturation point,the maximum net photosynthetic rate and maximum apparent quantum efficiency were followed 20.56?mol /?m2 ? s?,1423?mol /?m2 ? s?,11.532?mol /?m2 ? s?and 0.0402;18.21?mol /?m2 ? s?,1102?mol /?m2 ? s?,8.856?mol /?m2 ? s?and 0.0236;19.15?mol /?m2 ? s?,1221?mol /?m2 ? s?,8.054?mol /?m2 ? s?and 0.0386;25.36?mol /?m2 ? s?,652?mol /?m2 ? s?,3.882?mol /?m2 ? s?and 0.0159.Description in different seasons,different leaves Torreya energy utilization.3?Diurnal variation curves of Torreya leaf transpiration rate in the spring,fall and winter presents a single peak,only summer bimodal,10: 00-11: 00 appears the first peak,At l2: 00 to l3: 00 second peak occurs,In the spring,Peaked around 12:00,In the fall,peaking at around 11 o'clock,In winter,Peak around 12:00.In the year,the transpiration rate range Torreya leaves for 1.834-4.826 mmol ? m-2 ? s-1.4?Water use efficiency of spring leaves Torreya was "single peak" shape,Reached a peak of 2.536?mol · mmol^-1 at about 11:00;Summer water use efficiency curve as "bimodal" type,first peaked at 9: 00-10: 00,for 1.752?mol · mmol1,The second peak occurs at 15: 00-16: 00,for 1.003?mol · mmol^-1,Fall of water use efficiency change is consistent with the trend of the summer,9: peak occurs around 00 to 1.352?mol · mmol1,at 15: 00-16: 00 peak occurs,the peak for 1.4?mol · mmol^-1,In winter,the diurnal variation of water utilization is more gentle curve,the maximum is 1.256?mol · mmol1,appeared in 16:00.5?Diurnal variation of different ages in different seasons Torreya leaf chlorophyll fluorescence parameters were mainly determined,The results showed that chlorophyll fluorescence parameters Torreya in spring and autumn day small changes in amplitude,In the summer 8: 00-18: 00,Fm,Fm ',Fv,Fv / Fm,Fm / F₀,Fv / F₀ fall after showing the diurnal variation of liters,the lowest value appears in 14:00;The NP,Q first and then lift the law,peaking at 12:00,Fm,Fm ',Fv,Fv / Fm,Fm / F₀,Fv / F₀ in the diurnal variation of the winter was then decreased the maximum in 14:00,The NP,Q,but in contrast,the minimum in 14:00.Spring season Fv / Fm,Fm / F₀,Fv / F₀ is significantly higher than summer and winter seasons,indicating Torreya blade PS ?reaction center electron transfer efficiency and potential activity was significantly higher than in winter and summer;Torreya leaves NP,Q was significantly higher in the winter and summer,spring and autumn,winter and summer show Torreya absorb light energy dissipation mostly used to protect the photosynthetic apparatus itself.Torreya size leaves of different ages in the same season in the same period Fm,Fm ',Fv,Fv / Fm,Fm / F₀,Fv / F₀ and so there are differences,but the size of the order is indeed consistent with the size of the arrangement order 18a> 22a> 27a> 12a> 8a> 6a> 3a.NP,Q value,but on the contrary.Torreya fluorescence above the blade in diurnal variation in different seasons proved PS ?reactivity Torreya leaves of different ages in the winter and summer were suppressed to some extent,and with different age,the extent of inhibition is not the same,and almost no inhibition occurs in spring and autumn.6?Tree with leaves of different ages in a year and a half lethal temperature in different periods,soluble sugar content and MDA molality as a basis for Torreya?Torreya grandis?Cold Leaves were studied.The results show that the measured season?1,2,3,10,11,December?,lethal temperature minimum age Torreya each blade segment appear in January?-11.44--8.95 ??,the highest values appear in October?-4.75--4.03 ??.Torreya leaves lethal temperature and tree age related to its lowest value between 17-21 a appear in the tree.In winter?1,2,11,in December?,Torreya soluble sugar content of its lethal temperature was a significant negative correlation between the quality of this and malondialdehyde were significantly higher than the molar concentration of October and March.