多效唑对"延香梨"生长调控及果实品质的浓度效应OA

Taking'Yanxiang'pear as the experimental material,the effects of foliar application of paclobutrazol at different concentrations on tree growth,leaf physiological characteristics,and fruit quality of'Yanxiang'pear were investigated,with the aim of providing a reference for efficient and high-quality cultivation of'Yanxiang'pear and the rational use of paclobutrazol.The results showed that paclobutrazol significantly inhibited new shoot elongation of'Yanxiang'pear,and the inhibitory effect increased with increasing concentration.Under treatments of 500 and 1 000 mg·L-1,the activities of antioxidant enzymes(SOD,POD and CAT)as well as the contents of chlorophyll and soluble sugars in leaves were significantly increased,while malondialdehyde(MDA)content was reduced.In addition,fruit quality was improved,as reflected by increased single-fruit weight,soluble solids content,and soluble sugar content,decreased titratable acidity,and prolonged storage life.However,treatments of ≥ 1 500 mg·L-1 resulted in decreased antioxidant capacity,increased MDA accumulation,and deterioration of fruit quality.Overall,paclobutrazol exhibited a regulatory pattern of'promotion at low concentrations and inhibition at high concentrations'in'Yanxiang'pear production,with 500-1 000 mg·L-1 being the appropriate application range.