Effects of PEG Simulated Drought Stress on Seed Germination and Physiology of Pinus yunnanensis
The seed germination and protective enzyme activity of P.yunnanensis seeds were determined under different PEG concentration(0％,0.5％,1.0％,1.5％,2.0％,2.5％,3.0％,3.5％ and 4.0％) to study the drought tolerance of P.yunnanensis at seed germination stage.Results:1) The germination rate,germination potential and germination index of P.yunnanensis seeds present the first rising and then declining trend overall with increase of drought stress.The germination rate of P.yunnanensis seeds under 0.5％ PEG is 29.50％ (maximum) prior to 15 d,which indicates that 0.5％ PEG stress can promote germination of P.yunnanensis seeds to a certain extent.2) The DNA content in P.yunnanensis seeds shows the low-high-low trend with increase of PEG concentration.The MDA content of P.yunnanensis seeds under 1.0％ and 2.5％ PEG is 0.90 time and 1.85 times that of CK respectively.The SOD activity of P.yunnanensis seeds shows a first rising and then declining trend with increase of PEG concentration and the SOD activity of P.yunnanensis seeds under 1.0％ PEG is the maximum (222.30 U/gFW) but the SOD activity of P.yunnanensis seeds under 4.0％ PEG is 0.50 time that of CK.The CAT activity of P.yunnanensis seeds reduces gradually with increase of PEG concentration and the SOD activity of P.yunnanensis seeds under 4.0％ PEG is the minimum,50.66％ lower than CK.In conclusion,Mild drought (0.5％ PEG concentration) has a certain promotion effect on germination of P.yunnanensis seeds but the drought resistance of P.yunnanensis seeds is not strong.
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NSTL
万方数据
维普
