褪黑素引发对旱地小麦种子萌发期抗旱性的影响OA

In order to clarify the regulatory effect of melatonin on the drought resistance of dryland wheat(Triticum aestivum L.)dur-ing seed germination stage,the dryland wheat variety Shangmai 5226 was used as the experimental material to determine the effects of different concentrations(0,75,150 and 300 μmol/L)of melatonin priming on seed germination and seedling physiological indexes under different drought intensities[0,10％,15％,20％and 25％of polyethylene glycol(PEG-6000)].The results indicated that with the intensification of drought stress,germination potential,germination rate,seedling water content,coleoptile length,radicle length,radicle number,and chlorophyll content showed a decreasing trend,while soluble sugar and proline contents increased.Com-pared with the drought-stressed treatments that did not receive priming,melatonin priming at 75 and 150 μmol/L increased germina-tion potential and germination rate to varying degrees under 10％,15％,and 20％PEG-6000 treatments(except for germination rate under 20％PEG-6000),and melatonin priming at 75,150,and 300 μmol/L significantly enhanced soluble sugar content under 10％and 15％PEG-6000 treatments.The comprehensive evaluation using the membership function method showed that under melatonin priming at 75 and 150 μmol/L,the comprehensive evaluation values for the 10％and 15％PEG-6000 treatments were higher than those of the corresponding drought-stressed treatments without priming;similarly,under 300 μmol/L melatonin priming,the values for the 15％and 25％PEG-6000 treatments were higher than those of their respective controls without priming.In conclusion,75 and 150 μmol/L melatonin priming could effectively alleviate the drought stress of 10％and 15％PEG-6000 intensities.