Study On Physiological Effects And Thermotolerance Induction Of Rosa Chinensis Var Floribunda Under High Temperature Stress

The effect of high temperature on the electrolytic leakage of membrance, thecontent of malondialdehyde (MDA), the activities of antioxidant enzymes, and thecontent of antioxidants of Rosa chinensis var floribunda were studied and thetreatments with Ca²⁺and Salicylic acid(SA) were taken to induce the thermotoleranceof Rosa chinensis var floribunda under high temperature stress. The physiology andbiochemical mechanism of high temperature on Rosa chinensis var floribunda and thetreatment of Ca²⁺,and Salicylic acid(SA) on Rosa chinensis var floribunda under hightemperature stress were also discussed. All aboved provided the base theory forcultivation and breeding of Rosa chinensis var floribunda.The results showed that the electrolytic leakage of membrane was amplified, andthe content of MDA were accumulated in Rosa chinensis var floribunda under hightemperature stress. The activities of superoxide dimutase(SOD), catalase(CAT),peroxidease(POD) and ascorbic peroxidase(APX) were decreased during the firstperiod of high temperature stress and then were activated, lately the activities weredecreased gradually with long time stress of high temperature. Ascorbic acid(ASA)content was increased during the first period of high temperature stress and then wasdecreased. The content of glutathione(GSH) was increased during all the stress period.When treated with Ca²⁺and SA, the electrolytic leakage of membrane and MDAcontent was lower than those in control under high temperature stress, the antioxidantenzymes and ASA content of Rosa chinensis var floribunda were higher than those inthe control, but the GSH content was decreased. Compared to the control, the Rosachinensis var floribunda treated with CaZ+and SA maintain higher levels of antioxidantenzyme activeties, inhibited the electrolytic leakage of membrane, and diminished thecontent of MDA in Rosa chinensis var floribunda under high temperature stress.