Effects of EBR and MT on the Photosynthetic Physiology of Lily Seedlings Under Salt Alkali Stress
Taking lily bulbs from'Siberia'as the test materials,an indoor potted experiment was conducted to investigate the effects of foliar application of 2,4-epibrassinolide(EBR),melatonin(MT),and their complex treatments on the growth,photosynthesis,chlorophyll fluorescence parameters,ion transport,and antioxidant system of lily seedlings under moderate salt alkali stress,in order to provide reference for both parties to alleviate lily salt alkali stress.The results showed that under salt alkali stress,the height,leaf surface area,and biomass of lilies significantly decreased.The application of EBR and/or MT could alleviate the growth inhibition of lilies.Under 150 mmol·L-1 saline alkali stress,compared with the control(CK)treated with water spray,the SPAD value of EBR+MT treatment increased by 37.2％,and the N content in the aboveground and underground parts of lilies increased by 83.6％and 40.7％,respectively.Among the chlorophyll fluorescence parameters,the maximum photochemical efficiency(Fv/Fm),potential activity(Fv/Fo),and photochemical quenching coefficient(qP)of PS Ⅱ increased by 14.6％,42.9％,and 50.0％,respectively,while the non photochemical quenching coefficient(NPQ)decreased by 9.2％,and the net photosynthetic rate(Pn)increased by 14.6％,42.9％,and 50.0％,respectively The transpiration rate(Tr)and stomatal conductance(Gs)increased by 56.3％,29.7％,and 42.7％,respectively,while intercellular carbon dioxide(Ci)decreased by 19.3％.Under 150 mmol·L-1 saline alkali stress,the Na+content in the aboveground and underground parts of lilies increased,while the K+content decreased.After EBR+MT treatment,the K+/Na+values in the aboveground and underground parts of lilies increased by 110.9％and 98.8％,respectively.The simultaneous application of EBR and/or MT treatment could promote the expression of Cu/Zn SOD,POD,and CAT genes in lilies,and activate the activities of antioxidant enzymes SOD,POD,and CAT.In conclusion,the application of EBR and/or MT treatments can increase the SPAD value of lilies to varying degrees,slow down the inhibition of salt alkali stress on the PSⅡ photosystem,maintain the balance of Na+and K+in the plant,activate the expression of antioxidant enzyme genes such as SOD,POD,and CAT,and increase enzyme activity,promoting the increase of lily plant height and biomass.Among them,the salt alkali resistance of lily seedlings was better under the combined application of EBR+MT treatment.
2,4-epibrassinolidemelatonincomplex salt alkali stresslilyion balance
万方数据
维普
