梨小食心虫滞育过程中几种代谢酶活力的相关变化

梨小食心虫Grapholita molesta是一种重要的蛀果害虫,以老熟幼虫滞育越冬。为明确梨小食心虫滞育幼虫对低温的生理适应性,用3,5-二硝基水杨酸比色法、双试剂法及代谢酶活力测试盒分别测定了梨小食心虫幼虫体内海藻糖酶（trehalase,TRE）、山梨醇脱氢酶（sorbitol dehydrogen-ase,SDH）及己糖激酶（hexokinase,HK）、丙酮酸激酶（pyruvate kinase,PK）和碱性磷酸酶（alkalinephosphatase,ALP）的活力变化。在低温条件下,滞育幼虫体内各酶活力明显不同,TRE活力在滞育初期显著提高,而后随滞育时间的延长而逐渐降低;SDH活力总体变化较为平缓,变化量较小;HK、PK和ALP活力在滞育前期均显著降低,且随后一直保持在较低水平。滞育期间,5种代谢酶的活力均与滞育发育及温度有关;通过相关代谢酶的调节,梨小食心虫的代谢速率维持在较低水平,提高了虫体的耐寒能力,从而顺利完成滞育。

Related Changes of activities of several metabolic enzymes in larvae of Oriental fruit moth, Grapholita molesta, during diapause period

Oriental fruit moth, Grapholita molesta, is a major pest of tree fruits, overwinters in mature diapause larva stage. In order to clear the physiological adaptation of diapause larvae of this pest in low temperature, the activities of several metabolic enzymes including trehalase (TRE), sorbitol dehydrogenase (SDH), hexokinase (HK), pyruvate kinase (PK) and alkaline phosphatase (ALP) in diapause larvae were measured using 3,5-dinitrosalicylic acid colorimetry, dual reagent method and testing kits. The activities of these metabolic enzymes were significantly different during diapause period at low temperatures. Initially TRE activity significantly increased, then gradually decreased with the prolongation of the time of diapause. SDH activity changed gentler and was no larger fluctuation. HK, PK and ALP activities significantly reduced during the early phase, and then fluctuated at a lower level during the late phase. During diapause period, diapause intensity and environmental temperature have significantly affected on five metabolic enzymes. The metabolic rate remained at low level through the regulation of metabolic enzymes could improve the ability of cold hardiness of Oriental fruit moth, and successfully complated the diapause.