תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםLeena Taha-Salaime - Department of Evolutionary and Environmental Biology, The Faculty of Natural Science, University of Haifa, Haifa 3498838, Israel; Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Galina Lebedev - Department of Entomology, Agricultural Research Organization, The Volcani Center, Rishon LeTsiyon 7528809, Israel.
Jackline Abo-Nassar - Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Sally Marzouk - Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Moshe Inbar - Department of Evolutionary and Environmental Biology, The Faculty of Natural Science, University of Haifa, Haifa 3498838, Israel.
Murad Ghanim - Department of Entomology, Agricultural Research Organization, The Volcani Center, Rishon LeTsiyon 7528809, Israel.
Radi Aly - Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Control of the crop pest African cotton leafworm, Spodoptera littoralis (Boisduval), by chemical insecticides has led to serious resistance problems. Ajuga plants contain phytoecdysteroids (arthropod steroid hormone analogs regulating metamorphosis) and clerodanes (diterpenoids exhibiting antifeedant activity). We analyzed these compounds in leaf extracts of the Israeli Ajuga iva L. by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) and thin-layer chromatography (TLC), and their efficiency at reducing S.littoralis fitness. First and third instars of S. littoralis were fed castor bean leaves (Ricinus communis) smeared with an aqueous suspension of dried methanolic crude extract of A. iva phytoecdysteroids and clerodanes. Mortality, larval weight gain, relative growth rate and survival were compared to feeding on control leaves. We used '4',6-diamidino-2-phenylindole (DAPI, a fluorescent stain) and phalloidin staining to localize A. iva crude leaf extract activity in the insect gut. Ajuga iva crude leaf extract (50, 100 and 250 µg/µL) significantly increased mortality of first-instar S. littoralis (36%, 70%, and 87%, respectively) compared to controls (6%). Third-instar larval weight gain decreased significantly (by 52%, 44% and 30%, respectively), as did relative growth rate (-0.05 g/g per day compared to the relevant controls), ultimately resulting in few survivors. Crude leaf extract (250 µg/µL) reduced gut size, with relocation of nuclei and abnormal actin-filament organization. Ajug iva extract has potential for alternative, environmentally safe insect-pest control.
Leena Taha-Salaime - Department of Evolutionary and Environmental Biology, The Faculty of Natural Science, University of Haifa, Haifa 3498838, Israel; Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Galina Lebedev - Department of Entomology, Agricultural Research Organization, The Volcani Center, Rishon LeTsiyon 7528809, Israel.
Jackline Abo-Nassar - Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Sally Marzouk - Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Moshe Inbar - Department of Evolutionary and Environmental Biology, The Faculty of Natural Science, University of Haifa, Haifa 3498838, Israel.
Murad Ghanim - Department of Entomology, Agricultural Research Organization, The Volcani Center, Rishon LeTsiyon 7528809, Israel.
Radi Aly - Department of Plant Pathology and Weeds Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel.
Control of the crop pest African cotton leafworm, Spodoptera littoralis (Boisduval), by chemical insecticides has led to serious resistance problems. Ajuga plants contain phytoecdysteroids (arthropod steroid hormone analogs regulating metamorphosis) and clerodanes (diterpenoids exhibiting antifeedant activity). We analyzed these compounds in leaf extracts of the Israeli Ajuga iva L. by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) and thin-layer chromatography (TLC), and their efficiency at reducing S.littoralis fitness. First and third instars of S. littoralis were fed castor bean leaves (Ricinus communis) smeared with an aqueous suspension of dried methanolic crude extract of A. iva phytoecdysteroids and clerodanes. Mortality, larval weight gain, relative growth rate and survival were compared to feeding on control leaves. We used '4',6-diamidino-2-phenylindole (DAPI, a fluorescent stain) and phalloidin staining to localize A. iva crude leaf extract activity in the insect gut. Ajuga iva crude leaf extract (50, 100 and 250 µg/µL) significantly increased mortality of first-instar S. littoralis (36%, 70%, and 87%, respectively) compared to controls (6%). Third-instar larval weight gain decreased significantly (by 52%, 44% and 30%, respectively), as did relative growth rate (-0.05 g/g per day compared to the relevant controls), ultimately resulting in few survivors. Crude leaf extract (250 µg/µL) reduced gut size, with relocation of nuclei and abnormal actin-filament organization. Ajug iva extract has potential for alternative, environmentally safe insect-pest control.
