Study On The Photosynthetic Physiological Characteristics And Drought-tolerance Of Five Species Of Salvia

Five species of Salvia L.,which belong to Family Labiatae,were annual or perennial herbaceous plant. In this article,one-year old of five species of Salvia (Salvia coccinea 'Lady Red', Salvia surpreba 'mainacht',Salvia leucantba,Salvia guaranitica,Salvia uliginose) were used as materials to study its photosynthetic physiological characteristics and drought tolerance in natural,The results indicated that:(1) The photosynthetic capacity of five species of Salvia is different,the order was as follows: Salvia guaranitica>Salvia leucantba>Salvia coccinea 'Lady Red'≈Salvia uliginose>Salvia surpreba 'mainacht';Photosynthetic characteristic parameters of five species of Salvia were different, they all had different abilities of using strong light and different light adaptation range,the order was as follows: Salvia leucantba>Salvia coccinea 'Lady Red'>Salvia uliginose >Salvia guaranitica>Salvia surpreba 'mainacht';by comparison of the apparent quantum yield,the light percent conversion register as Salvia guaranitica >Salvia uliginose >Salvia coccinea 'Lady Red'≈Salvia surpreba 'mainacht'>Salvia leucantba.The curves diurnal variation of net photosynthetic rate of five different Salvia presented two peaks, there was obvious photosynthetic depression.The curves diurnal variation of transpiration rate of five species of Salvia presented single peak,The curves diurnal variation of water use efficiency presented two peaks.The interrelation between the net photosynthetic rate of five different Salvia and the affecting factors is not same,and the main factors was as follows:photosynthetically active radiation,air relative humidity,stomatal conductance.(2) Compared ability of drought tolerance according to the changes of physiological and biochemical parameters and chlorophyll fluorescence parameters during the drought stress on five different Salvia,The results indicated that: the content of chlorophyll kept decreasing,and the relative electric conductivity persistently increased,the MDA content,Soluble protein content and antioxidant enzymes activity showed"first and decreased afterwards"with deeper drought stress,the changes of physiological and biochemical indexes during drought stress of five different salvia were different. chlorophyll fluorescence parameters were affected by drought stress,while the change range was ditterent,Initial fluorescence(Fo),Variable fluorescence(Fv),Maximal PSⅡefficiency(Fv/Fm),chemical quenching coefficient(qP),non-chemical quenching coefficien(tqN)and others could be used to compare the drought-tolerance ability of different Salvia.According to the parameter changes,the drought-tolerance ability of different Salvia in drought stress condition by the comprehensive appraisal index as follows:Salvia coccinea 'Lady Red'>Salvia leucantba>Salvia uliginose >Salvia guaranitica>Salvia surpreba "mainacht".