干旱低温复合胁迫下黄腐酸钾对西葫芦幼苗生长和生理生化特性的影响

Effects of Potassium Fulvic Acid on Growth and Physiological and Biochemical Characteristics of Zucchini Seedlings under Combined Stress of Drought and Low Temperature

本试验以西葫芦‘农园1号’为材料,设置7个处理,分别是对照(CK,无干旱低温胁迫且不浇灌黄腐酸钾)、DL(干旱低温胁迫下不浇灌黄腐酸钾)和T1、T2、T3、T4、T5(干旱低温胁迫下黄腐酸钾浇灌浓度分别为0.020%、0.035%、0.05%、0.065%、0.08%),研究干旱低温胁迫下黄腐酸钾对西葫芦幼苗生长和生理生化特性的影响。结果表明:干旱低温胁迫下西葫芦幼苗的干鲜重、脯氨酸含量和SOD、POD、CAT活性以及光合能力均受到抑制,不同浓度黄腐酸钾处理均可缓解干旱低温对西葫芦幼苗生长和生理生化指标的抑制作用。其中T3处理效果最佳,其幼苗叶面积、全株鲜重、全株干重、脯氨酸含量和SOD、POD、CAT活性与DL相比分别显著增加13.89%、16.20%、17.43%、19.43%和13.48%、7.13%、16.28%,MDA含量降低14.37%,叶绿素总量、净光合速率显著增加19.66%和17.95%,叶片的Fv/Fm、ΦPSⅡ、ETR、qP显著升高4.25%、17.57%、14.85%和14.01%,Fo、NPQ分别降低5.30%、15.79%,即减轻了干旱低温胁迫对叶片光合器官的损伤。综上看出,黄腐酸钾可以在一定程度上缓解干旱低温胁迫对西葫芦幼苗生长和生理生化指标的抑制作用,以0.05%黄腐酸钾处理(T3)效果较为显著。

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%.