Photosynthesis And Fluorescence Characteristics Of Different Rootstocks Of The Vitis Vinifera Response To Drought Stress

This experiment studied the change of photosynthetic characteristics,chlorophyll content and chlorophyll fluorescence characteristics for grafting grape and grape seedlings under drought stress.Results are as follows:1.The photosynthesis rate,stomatal conductance and transpiration rate of the grape grafted on different rootstocks decreased with the increase of drought stress,the results were:Cabernet-Beta>Cabernet-5BB>Cabernet-SO₄>Cabernet,Merlot-Beta>Merlot-5BB>Merlot-SO₄>Merlot,Syrah-Beta>Syrah-5BB>Syrah-SO₄>Syrah.However,the substomatal CO2 concentration of the grape grafted on different rootstocks increase with the increase of drought stress,the results were:Cabernet-Beta<Cabernet-5BB<Cabernet-SO₄<Cabernet,Merlot-Beta<Merlot-5BB<Merlot-SO₄<Merlot,Syrah-Beta<Syrah-5BB<Syrah-SO₄<Syrah.2.The diurnal variation photosynthetic rate of all grape were obviously double peaks with the increase of drought stress.The midday rest phenomenon of photosynthetic rate of the grape grafted on different rootstocks was obvious at 14:00,however,the rootstocks can obviously improve photosynthetic rate of all grape.So,the midday rest phenomenon of photosynthetic rate of the grape grafted on fifferent rootstocks has eased off.3.The total chlorophyll content and carotenoid of the grape grafted on different rootstocks decreased with the increase of drought stress,the results were:Cabernet-Beta>Cabernet-5BB>Cabernet-SO₄>Cabernet,Merlot-Beta>Merlot-5BB>Merlot-SO₄>Merlot,Syrah-Beta>Syrah-5BB>Syrah-SO₄>Syrah.4.The Fv/Fm,qP and Yield of the grape grafted on different rootstocks decreased with the increase of drought stress,the results were:Cabernet-Beta>Cabernet-5BB>Cabernet-SO₄>Cabernet,Merlot-Beta>Merlot-5BB>Merlot-SO₄>Merlot,Syrah-Beta>Syrah-5BB>Syrah-SO₄>Syrah.