Effects of Potassium Fulvic Acid on Growth and Physiological and Biochemical Characteristics of Zucchini Seedlings under Combined Stress of Drought and Low Temperature
The zucchini variety'Nongyuan No.1'was used as material to explore the effects of potassi-um fulvic acid on growth and physiological and biochemical characteristics of seedlings under combined stress of drought and low temperature.Seven treatments were set as follows:control(CK,no drought and low tem-perature stresses and no potassium fulvic acid),DL(no potassium fulvic acid under combined stress of drought and low temperature),and T1,T2,T3,T4 and T5(watering potassium fulvic acid at concentrations of 0.020%,0.035%,0.050%,0.065%,0.080%under combined stress of drought and low temperature).The results showed that dry and fresh weights,proline content,activities of SOD,POD and CAT,and photosyn-thetic capacity of zucchini seedlings were all inhibited under drought-low temperature stress,and the inhibitory effects could be alleviated by different concentrations of potassium fulvic acid.Among them,treatment T3 had the best effect.Under T3 treatment,leaf area,whole plant fresh weight,whole plant dry weight,proline con-tent,activities of SOD,POD and CAT,total chlorophyll and net photosynthetic rate significantly increased by 13.89%,16.20%,17.43%,19.43%,13.48%,7.13%,16.28%,19.66%and 17.95%,respectively com-pared to DL treatment,while MDA content decreased by 14.37%;the leaf Fv/Fm,ΦPSⅡ,ETR and qP sig-nificantly increased by 4.25%,17.57%,14.85%and 14.01%,while Fo and NPQ decreased by 5.3%and 15.79%.Treatment T3 reduced the damage of drought-low temperature stress to the photosynthetic organs of leave.In conclusion,potassium fulvic acid could alleviate the inhibitory effects of drought-low temperature stress on zucchini seedlings,and better effects could be obtained at concentration of 0.05%.
万方数据
维普
