نوع مقاله : مقاله پژوهشی
1 دانشآموختۀ کارشناسی ارشد حشرهشناسی کشاورزی گروه گیاهپزشکی دانشگاه گیلان، گیلان
2 دانشیار، گروه گیاهپزشکی دانشگاه گیلان، گیلان
3 دانشیار، گروه بیوشیمی دانشگاه تربیت مدرس، تهران
عنوان مقاله [English]
Epilachna chrysomelina is one of major pests of cucurbitaceous plants. Biochemical properties of α- amylase were studied in melon ladybird. The optimal pH for α- amylase was found at 4. Also, high amylolytic activity was found at temperature 50 °C. The specific activity of this enzyme in digestive system of different larval instar, foregut, midgut, hindgut and female and male adults were determined. Results showed that the highest specific α- amylase activity was detected in the digestive system of 3rd instar larvae and the enzyme activity in males and females digestive system did not show any significant difference. The enzyme specific activity in midgut was 5- and 8.3-fold higher than foregut and hindgut. The Michaelis–Menten constant (Km) of α-amylase was obtained as 0.69 mg/ml. Zymogram analysis of α- amylase showed one isoform. Also, inhibitory effect of inhibitors extracted from seeds of Lathyrus sativus, Trifolium alexandrium, Zea mays, Faba vulgaris, Lentis culinaris, Vigna unguiculata, Phaseolus vulgaris and Vigna radiate were evaluated on E. chrysomelina α- amylase activity. Among these inhibitors, the inhibitors extracted P. vulgaris and V. radiate were able to inhibit E. chrysomelina amylase.