生物文献汇报

1、Target and non-target toxicity of botanical insecticide derived from Couroupita guianensis L. flower against generalist herbivore, Spodoptera litura Fab. and an earthworm, Eisenia foetida Savigny,XXX 2018.9,Introduction,Plants are the biochemical factories in nature able to produce a complex mixture of chemical compounds. C. guianensis, the flowers are used in medicine, the extracts have antifungal, antibiotic, antiseptic, analgesic properties and larvicidal activity. S. litura has hundred and f

2、ifty host types and settled resistance ranged from 100 to 2700 fold against pyrethroids. So it is urgent to find new ways to control S. litura. Earthworms are subtle indicators of soil quality, acting as decomposers in improving soil structure.,Content,Investigation of active compounds through gas chromatographic techniques. Assessment of the dose dependent toxicity of active compounds against S. litura. Measurement of the behavioral response of S. litura treated with active compounds of C. guia

3、nensis. Estimation of bioefficacy of active fractions on nutritional physiology of S. litura and effects of active fractions on gut histological alterations in the S. litura. Ecotoxicological evaluation of active fraction and chemical pesticides against E.fetida.,Methods and Result,Investigation of active compounds,Plant collection(fine particle size) Crude extract preparation(hexane, chloroform, ethyl acetate and methanol) Chromatographic analysis(F1, F2, F3, F4, F5 and F6 ) GCMS analysis(Fig.

4、1B. Table 1) FT-IR and HPLC analysis(Fig. 1C),GCMS FT-IR and HPLC analysis,Mortality bioassays,Bioassays were implemented on second, third and fourth larval instars of S. litura using concentrations of 100, 200, 400 and 800 ppm of fraction F6.,Developmental study,Developmental studies were executed with second instar larvae. Fresh leaves of castor treated with 50, 100, 150 and 200 ppm of fraction F6 and reared on larvae. Every 24 h, larval weight was recorded (Fig. 5). The duration of larval and

5、 pupal stages were recorded (Fig. 4). Pupae were weighed on the first day after pupation (Fig. 6). Fecundity assay was determined by the number of progeny produced (Fig. 6).The mean adult longevity of S. litura was observed from the first day of emergence from the pupae and recorded (Fig. 4).,Fig. 4,Fig. 6,Fig. 5,Developmental study,Food utilization, consumption and nutritional indices,Food utilization, consumption and nutritional indices of S. litura were measured to quantify the effect of the

6、F 6 fraction of C. guianensis on food utilization of fourth instar larvae of S. litura (Table 2).,Histology,Sectioning of larvae exposed to 50 and 100 ppm of fraction F6 was done with small pieces of mid gut tissue from fourth instar larvae (Fig. 8).,Earthworm toxicity,Percentage mortality of earthworm in filter paper test (FPT) and artificial soil test (AST) after treatment with fraction F6 and chemical pesticides.,Discussion,The fraction F6 obtain eight compounds, Octacosane was shown to have

7、toxicity to Culex quinquefasciatus; Ascorbic acid has been reported to cause slower growth and increased mortality against S. litura; Hexacosane exhibits oviposition deterrence against red spider mites; and so on. The larvae exposed to the secondary metabolites of Fraction F 6 not only developed slower, but also produced smaller pupae at each treatment concentration. As pupal duration increased in response to increasing treatment concentrations, the mean pupal weight was significantly reduced; D

8、ecreases in pupal weight often result in lower eggs.,The nutritional indices clearly recommend that the toxic chemical compounds present in fraction F6 have strong negative effects on food absorption and digestion of S. litura. The midgut of the digestive system plays a vital role in the digestion of food and in the digestive enzymes secreted . Epithelial layers was showed degraded ; Damaging to cytoplasm organelles in the midgut was increased; the epithelial layer burst and the cytoplasmic ooze of cellular components mixed with food. Earthworms are capable to survive well in both toxicological assay while treated with the fraction F6 of C. guianensis. Suggest that fraction F6 of C. guianensis had no adverse effects on the soil non-target organism.,

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