外源钙对盐胁迫下火麻生理特性及次生代谢产物的影响OA北大核心

In order to explore the effects of exogenous CaCl2 on physiological characteristics and secondary metabolites of Cannabis sativa L.under salt stress,seedlings of C.sativa were taken as test materials,and 4 treatments were set up through pot-soil culture method,including 300 mmol·L-1 NaCl(C0)stress treatment and 300 mmol·L-1 NaCl stress+5(C1),10(C2)and 20 mmol·L-1 CaCl2(C3),and no stress was used as control(CK).The photosynthetic and fluorescence parameters,physiological indexes and the contents of secondary metabolites(total flavonoids and cannabidiol)were determined under different treatments.The results showed that,with the salt stress time prolonged,the photosynthetic parameters such as net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),photosynthetic pigments,maximum photochemical efficiency(Fv/Fm)decreased significantly,soluble protein content,antioxidant enzyme activity,total flavonoids and cannabidiol content decreased,malondialdehyde,soluble sugar,proline contents increased,and membrane lipid peroxidation degree intensified.After the application of exogenous CaCl2,the Pn,Gs,Tr,photosynthetic pigment,Fv/Fm,antioxidant enzyme activities and the contents of soluble sugar,soluble protein,free proline and secondary metabolites all showed a trend of first increasing and then decreasing with the increase of CaCl2,while the malondialdehyde content showed a trend of first decreasing and then increasing.Compared with treatments of CK and C0,the variation amplitude of all indexes of C.sativa treated with exogenous CaCl2 decreased,and there was obvious dosage effect.Low dosage of exogenous calcium could alleviate salt stress to a certain extent,but high dosage could produce new damage,and the treatment with 10 mmol·L-1 CaCl2 had the best effect on enhancing salt resistance of C.sativa seedlings.Above results provided scientific and technological support for cultivation and application of C.sativa in saline soil area.