干旱胁迫对沙葱光合和生理指标的影响OA

In order to clarify the photosynthetic response mechanism and physiological adaptation strategy of Allium mon-golicum,a sandy vegetable,in response to drought stress and to provide a theoretical basis for the water-saving cultivation of this species in arid and semi-arid areas,three-year-old seedlings of this species were used as test materials.Four drought treatment gradients were set up by pot culture and water control method,with soil relative water contents of 78.00％(CK),65.00％(LS),45.00％(MS)and 25.00％(SS),respectively.The results showed that compared with CK,the LS treatment significantly reduced root length by 19.78％,while plant height was slightly higher than that of CK.The activities of Rubisco,PEPC,PPDK,and NAD-ME increased by 17.00％,12.98％,11.97％,and 87.12％,respectively.Sol-uble sugar contents in leaves and roots increased by 24.17％and 78.30％,respectively.In contrast,the growth of A.mon-golicum was inhibited under MS and SS treatments.Specifically,under SS treatment,root length and plant height de-creased by 29.36％and 21.19％,respectively,compared with CK;the ETR of the photosystem II reaction center was low-er than that of CK,and the quantum yield of regulated energy dissipation at PS II(Y(NPQ))was 38.68％the highest,These results indicate that A.mongolicum is not suitable for growth under MS and SS treatments.Under LS treatment,however,the plant maintains metabolic balance by increasing leaf PEPC activity and transports soluble sugars(fructose,sucrose)to the roots,thereby enhancing the adaptability of the root system to drought stress.In summary,under LS treat-ment,A.mongolicum exhibits active adaptability,making it suitable for promotion and application in water-saving produc-tion systems.