Effects Of The Cold Acclimatization On The Physiological Of Eggplant Seedlings To Low Temperature Stress

The experoment was conducted to study the effect of cold acclimation on physiology and photosynthesis in eggplant(Solanum melongena.) seedling, which used the eggplant as test material. The artificial climate box was used to simulate the low temperature condition. We recorded the changes in photosynthesis and fluorescence characteristics, membrane lipid peroxidation and antioxidant enzyme activity and osmotic regulation substances of leaf under the 3d 12℃ cold acclimatization under low temperature of 5℃ 5d and 3d stress after 25℃ during stress, again a room temperature of 5℃ after a recovery period and recovery during the 1d stress. There were three treatments, CK : 25℃(day/night) at room temperature; T1: without cold acclimation; T2: 12℃ 3d cold acclimatization. The results showed the following:(1)The treatment under 12℃-3d cold acclimation and 5℃-5d, the pigment content, net photosynthetic rate(Pn), stomatal conductance(Gs), photochemical quenching(qP), maximum photochemical efficiency(Fv/Fm) and actual photochemical efficiency of photosystem II(ФPSII) was significantly decreased, while leaf area, intercellular CO2 concentration(C i) and non-photochemical quenching(NPQ) was increased compared with the CK(25℃), and the trend was more marked during the chilling stress. During the period of cold acclimation, photosynthetic parameters were not significant difference compared with the CK. In process of low temperature stress(12℃), the pigment content, Pn, Gs, qP, Fv/Fm and ФPSII was markedly higher, but Ci and NPQ was significantly lower than that without the cold acclimation. After recovered in 3d at 25℃, the photosynthetic parameters in leaf after cold acclimation was significantly higher than that without cold acclimation in the recovery process, and the recovery rate was significantly higher than that without cold acclimation. Exposed to chilling stress for1 d again, the pigment content, Pn, Gs, qP, Fv/Fm and ФPSII was reduced, while Ci and NPQ was increased further compared to CK; those under cold acclimation had less than changes compared with that without cold acclimation. In conclusion, cold acclimation can increase the chilling tolerance of eggplant via enhancing photosynthetic capacity and PSII photochemical efficiency under chil ing stress.(2)The SOD, POD, CAT activities, MAD and relative electrolytic leakage increased under 3d12℃,its were not significant difference compared with the CK. under 5d5℃, All indicator increased significantly and have significant difference compared with the CK.The SOD, POD, CAT activities were greater under cold domestication than without cold domestication, but MAD and relative electrolytic leakage were on the contrary. The recovery rate which after cold acclimation, of seedling physiological parameters is significantly higher than without cold acclimation under 25℃ to restore 3 d; Recovery 3 d transferred to low temperature stress eggplant seedlings relative conductivity, the(MDA)and activity of antioxidant enzymes rise further. After cold acclimation of seedling activities of SOD, POD and C AT was significantly higher than that of without cold acclimation treatment of seedlings, and the increase of relative conductivity and MAD content was significantly lower than without cold domestication.(3)The proline, soluble sugar, soluble protein increased under 3d12℃,and Pro content was significantly greater than control. All indicator increased significantly under 5d5℃. The Pro, solute carbohydrate content were greater under cold domestication than without cold domestication. The recovery rate which after cold acclimation, of seedling physiological parameters is significantly higher than without cold acclimation under 25℃ to restore 3 d; Recovery 3 d transferred to low temperature stress eggplant seedlings proline, soluble sugar, soluble protein rise further. After cold acclimation of seedling proline, soluble sugar, soluble protein content was significantly higher than that of without cold acclimation treatment of seedlings.To sum up, The seedlings become more tolerant to low temperatures and survive such condition afferwards.