The Effect Of Soil Drought Stress On Physiological Character Of Prunus Sibirica

In this research , The response of photosynthetic character of prunus sibirica to soil drought stress were studied .The results show that net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance(Cs)decreased with the increases in drought stress . Compared with control(Ck), Decreases of intercellular CO2 concentration (Ci) under mild and moderate stress and increase under severe stress were found .The test of respone of photosynthesis to temperature exhibited the decline of Pn and increase of Tr under higher temperature , and water use efficiency (WUE)decreased .The stress effects of drought were aggravated under higher temperature on photosynthesis . The peak values of the diurnal variation of Tr decreased and the time of the peak moved up with the increases in drought stress.The diurnal variation curves of Pn , Cs and WUE were double-peak types under different water stress , but the curves of Pn and Cs were changed to single-peak types under severe stress .Soluble sugar content ,proline (pro) content and SOD activitiesincreased,increased order was sever>moderate>milddrought stress .Proline (pro) content increased drastically during the early period, decreased after increased .The conclusion is that Prunus sibiricaexhibits a certain adaptability to drought stess...