低磷胁迫对麻竹幼苗叶片非结构性碳水化合物及抗氧化保护酶系统的影响OACSTPCD

[Objective]The study aimed to investigate the tolerance of Dendrocalamus latiflorus seedlings to low phosphorus(P)en-vironment by monitoring the physiological changes of leaves of D.latiflorus seedlings under different levels of P shortage.[Method]D.latiflorus seedlings were subject to low P stress by hydroponics under indoor controlled condition,with most nutrients prepared ac-cording to Hoagland formula except for P,which was set up to 5 levels of P stress(0,0.2,0.4,0.8 and 1.6 mmol·L-1)using KH2 PO4.[Result]The contents of reducing sugar and soluble sugar in leaves of D.latiflorus seedlings were increased in response to higher P supplies,while the contents of starch,cellulose and malondialdehyde(MDA),and the activities of antioxidant enzymes[catalase(CAT),peroxide(POD)and superoxide dismutase(SOD)]were decreased.Compared with severe P depletion(0 mmol·L-1),the physiological indexes of D.latiflorus seedlings under 1.6 mmol·L-1 P supply were significantly different,with 56.45%and 67.08%higher contents of reducing sugar and cellulose;while the contents of starch,soluble sugar and MDA,and the activities of CAT,POD and SOD were down by 34.86%,14.61%,73.89%,64.19%,89.99%and 65.34%,respectively.Among all the physiological indices,MDA contents varied significantly under different levels of P stress;the variation range of soluble sugar was the smallest,while that of POD was the greatest.[Conclusion]D.latiflorus seedlings demonstrated relatively high resistance to low P stress and was adaptable to low P environment at seedling stage.