三种植物提取物对菟丝子及大豆生长发育和宿主保护酶活性的影响

利用不同浓度的苦楝树皮和叶、隆缘桉叶和乌桕叶的乙醇提取物对菟丝子及其宿主大豆幼苗进行处理,15d后评价三种提取物对菟丝子和大豆幼苗的影响。结果表明:三种提取物在低浓度时对菟丝子及其宿主大豆幼苗生长发育均无显著影响,在高浓度(0.25g/mL)下,桉树叶提取物对大豆和菟丝子的损伤程度分别达到了64%和70%,苦楝树皮提取物对菟丝子损伤程度为78%,但对大豆幼苗仅为7%。桉树叶和苦楝树皮提取物处理均导致大豆叶片超氧化物歧化酶(SOD)活性升高,最高值分别为相应对照组的2.37倍和2.0倍;但对过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响不同,桉树叶提取物使大豆幼苗POD活性最大值为对照组的2.28倍,而苦楝树皮提取物处理则是CAT活性升高,最大值为对照组的1.58倍,提示桉树叶提取物对大豆较强的伤害作用与其较低的CAT活性有关。     

Efficacy of extracts of Melia azedarach L. callus, leaves and fruits against adults of the sweetpotato whitefly Bemisia tabaci (Hom., Aleyrodidae)

Bioassays with extracts of callus, fruit and leaves of the Chinaberry tree, Melia azedarach L., were performed against adults of Bemisia tabaci (Gennadius). Tissue culture of M. azedarach was carried out in Murashige and Skoog (MS) medium supplemented with indole butyric acid and benzyl adenine. Fresh and frozen leaves or fruits and the callus product were extracted in water or methanol at a ratio of 1 : 5 (w/v) for 48 h. The aqueous and methanol extracts were applied on tomato plants to determine their effect on B. tabaci adults and their corresponding oviposition and consequent adult emergence in comparison with the control, distilled water. Results have shown that extracts of callus and different age classes of M. azedarach leaves and fruits have shown significant repellent activity of 58.9–67.7% and have significantly decreased the oviposition rate of the insect without affecting the adult whitefly emergence in comparison with the control. Aqueous and methanol extracts have shown comparable effects against adult whiteflies indicating a similar efficacy of the two solvents in extracting the bioactive components of Melia . Extracts of frozen samples were found to be as effective against the pest as fresh samples, thus allowing storage of Melia parts to be used in case of shortage. This is the first report of the use of M. azedarach callus against B. tabaci; the M. azedarach callus, leaf and fruit extracts seem to present a potential source for management of B. tabaci .     

In vitro efficacy of extracts of Melia azedarach against the tick Boophilus microplus

The efficacy of ripe fruit extracts of Melia azedarach L. (Rutales: Meliaceae) was evaluated against the tick, Boophilus microplus (Canestrini) (Acari: Ixodidae). Ripe fruits of M. azedarach dried and powdered were extracted by Soxhlet apparatus successively using hexane, CHCl3 and 96% aqueous ethanol. Larvae and engorged females were immersed in decreasing concentrations from 0.25% to 0.015% of each extract. The mortality of larvae was evaluated 24, 72 and 168 h after treatment. The effectiveness of treatment against engorged females was assessed by measuring egg production. All tested extracts caused mortality of B. microplus larvae, with higher mortality rates observed in CHCl3 (100%) and hexanic extract (98%) than in ethanolic extract (50%) 168 h after treatment. The mortality was dependent on concentration and on time after treatment. Similarly hexanic and CHCl3 extracts showed higher effectiveness (varying from 14% to 100%) against B. microplus engorged females than ethanolic extract (varying from 0% to 46%). Melia azedarach extracts did not kill the adult females, but inhibited partially or totally egg production and embryogenesis. These results show that the less polar the extract of M. azedarach ripe fruits the more its effectiveness against larvae and engorged females of B. microplus. This plant may therefore be useful in the control of resistant B. microplus populations.     

植物粗提物对褐稻虱成虫取食的影响

分别用31科47种非嗜食植物乙醇提取物处理的稻株饲养褐稻虱Nilaparvata lugensStal成虫,研究对褐稻虱成虫的拒取食作用。结果表明,大多数供试植物提取物对褐稻虱有一定程度的拒取食效果。大蒜、苦楝油、白花非洲山毛豆的提取物对褐稻虱成虫拒食效果最好,24h后的拒取食率分别达89.19%、75.63%与63.74%。薇甘菊、蟛蜞菊、荚竹桃、含羞草、鱼尾葵、艾蒿、人心果和走马箭8种植物提取物拒取食率均达50%以上。相反,莎草、鸡矢藤、甘草、飞机草、地肤、水葫芦、华南毛蕨、假连翘、鼬瓣草、尾叶桉和白花丹11种植物提取物对褐稻虱成虫取食具有一定的刺激作用。     

Larvicide and oviposition deterrent effects of fruit and leaf extracts from Melia azedarach L. on Aedes aegypti (L.) (Diptera: Culicidae)

Aedes aegypti (L.) (Diptera: Culicidae), the main urban vector of dengue, has developed resistance to various insecticides, making its control increasingly difficult. We explored the effects of Argentine Melia azedarach L. (Meliaceae) fruit and senescent leaf extracts on Ae. aegypti larval development and survival, by rearing cohorts of first instar mosquitoes in water with different extract concentrations. We also analysed oviposition deterrent activity in choice tests with extract-treated ovitraps. The leaf extract showed a strong larvicide activity, with all larvae dying before pupation, and significantly delayed development time. It strongly inhibited oviposition by Ae. aegypti females. The fruit extract showed much weaker effects. This first report of highly effective larvicidal, growth regulating and oviposition deterrent activity of a senescent leaf extract of M. azedarach against Ae. aegypti, suggests that such extract could represent a promising tool in the management of this mosquito pest.     

Effects of tomato genotypes and aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5'--Solanum lycopersicum (=Lycopersicon esculentum Mill), and LA444-1--S. peruvianum (=L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1% concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.     

In vitro anthelmintic effect of Melia azedarach L. and Trichilia claussenii C. against sheep gastrointestinal nematodes

The control of parasitic diseases in small ruminants is mainly done with the use of synthetic anthelmintics. However, incorrect and indiscriminate use of these products has caused the emergence of parasite resistance. Plants with anthelmintic activity are used in folk veterinary medicine, but it is necessary to investigate and scientifically validate low-cost phytotherapeutic alternatives for future use to control gastrointestinal nematodes in small ruminants by family farmers. Thus, the aim of this study was to evaluate the in vitro anthelmintic effect of plant extracts from Melia azedarach and Trichilia claussenii by the egg hatch test (EHT) and larval development test (LDT) against sheep gastrointestinal nematodes. The hexane extract of M. azedarach fruits was extracted through cold percolation and the methanol extract of T. claussenii leaves was obtained by extraction at room temperature in solvents in order of increasing polarity. The efficacy results were analyzed using the Probit program of SAS. The M. azedarach extract showed a LC(50) of 572.2 μg/mL and LC(99) of 1137.8 μg/mL in the EHT, and LC(50) of 0.7 μg/mL and LC(99) of 60.8 μg/mL in the LDT. In turn, the T. claussenii extract presented a LC(50) of 263.8 μg/mL and LC(99) of 522.5 μg/mL in the EHT and LC(50) of 1.1 μg/mL and LC(99) of 26.4 μg/mL in the LDT. Comparing the extracts of the species from the Meliaceae family, T. claussenii showed greater anti-parasite potential in vitro than M. azedarach. However, studies on the isolated compounds, toxicity and administration forms to animals are also needed to validate low-cost alternative herbal remedies for use to control gastrointestinal nematodes by family farmers.     

Effects of Melia azedarach, (Meliaceae) fruit extracts on the leafminer Liriomyza huidobrensis, (Diptera, Agromyzidae): Assessment in laboratory and field experiments

Control of the widely distributed pest Liriomyza huidobrensis, is complicated due to the protected habit of the leafmining larvae, and their resistance to insecticides. The effects of Melia azedarach, (Meliaceae) fruit extracts against adults and larvae of L. huidobrensis, were investigated. In the laboratory, leaves of Cucurbita, sp. infested with first and third instar larvae were treated with different extract solutions. Larval and pupal survival, as well as wing‐spread of adults, were ssessed. Female adult behaviour towards the extract was also analysed in terms of number of feeding punctures and number of offspring left on treated/untreated leaves. In the field, an infested Vicia faba, crop was sprayed four times at weekly intervals with plant extract, water, and a blank solution. The number of adult leafminers and parasitoids emerging from sampled leaves from each treatment were compared. The laboratory tests showed translaminar action of the extracts, which negatively affected leafminer pupal survival, while body size was not affected. The extracts also deterred feeding by adult females and may also have caused reduction in oviposition rates. All solutions and concentrations tested had similar effects. In the field, extract effects were consistent with those from laboratory trials, number of pupae and pupal survival being lower on treated plants. Percentage parasitism was not affected by plant extract treatment, suggesting a selective activity.     

Efficacy of Melia azedarach L. extract on the malarial vector Anopheles stephensi Liston (Diptera: Culicidae)

Methanolic extracts of leaves and seeds from the chinaberry tree, Melia azedarach L. (Meliaceae) was tested against mature and immature mosquito vector Anopheles stephensi Liston (Diptera) under laboratory condition. The extract showed strong larvicidal, pupicidal, adulticidal, antiovipositional activity, repellency and biting deterency. The M. azedarach seed and leaf extracts were used to determine their effect on A. stephensi adults and their corresponding oviposition and consequent adult emergence in comparison with the control. The seed extracts showed high bioactivity at all doses, while the leaf extracts proved to be active, only in the higher dose. Results obtained from the laboratory experiment showed that the seed extracts suppressed the pupal and adult activity of A. stephensi even at low dose. In general, first and second instar larvae were more susceptible to both leaves and seed extracts. Clear dose-response relationships were established with the highest dose of 2% plant extract evoking 96% mortality. Entire development of A. stephensi was inhibited by M. azedarach treatment. Less expensive (less than 0.50 US dollars per 1 kg seed), naturally accruing bio-pesticide could be an alternative for chemical pesticides.     

Response of Eucalyptus camaldulensis Dehnh., E. globulus Labill. ssp. globulus and E. grandis W.Hill to excess boron and sodium chloride

In a sand culture experiment we investigated the effects of boron (0.01, 0.19, 0.46 and 0.93 mol m⁻³ B, as H₃BO₃), sodium chloride (0, 100 and 200 mol m⁻³ NaCl) and combined B and NaCl, over 36 days, on growth, water use and foliar ion concentrations of nine week-old seedlings of three fast-growing, commercial eucalypts ( Eucalyptus camaldulensis Dehnh. , E. globulus Labill. ssp. globulus and E. grandis W.Hill.). Shoot dry weight was significantly reduced by high concentrations of NaCl (p < 0.001) and by B and NaCl in combination (p ≤ 0.05) but not by B alone. Root dry weight was significantly reduced by both NaCl (p < 0.001) and B (p < 0.001), but not by combined B and NaCl. Foliar B concentrations increased with higher concentrations of applied B and decreased with higher NaCl concentrations. Foliar Na concentrations were greater with higher NaCl concentrations, whereas B application had no significant effect on foliar Na concentrations. All three species accumulated relatively high B concentrations in leaves. Severe boron toxicity symptoms (BTS) were apparent only when leaf B concentrations exceeded 50 mol x 10⁻⁶ g⁻¹, but even at these high concentrations plant growth was only slightly reduced. E. camaldulensis showed least development of BTS, the lowest leaf B concentrations and least reduction in height growth due to B and NaCl. The results suggest that there was a correlation between both B tolerance and B accumulation in leaves and between tolerance to B and NaCl. This revised version was published online in June 2006 with corrections to the Cover Date.     

苦楝果多糖的分离纯化及组成分析

利用水提醇沉法提取苦楝果实中的多糖,经DEAE-52柱层析分离,得到MP1、MP2和MP3三个多糖组分,用Sephadex G-100凝胶色谱柱对MP1进行纯化鉴定,结果显示为单一峰。借助气质联用仪,对苦楝粗多糖和组分MP1进行了成分分析。红外光谱分析表明苦楝多糖的单糖残基以吡喃环和呋喃环的形式存在。     

苦楝果实活性物质研究

本文报道苦楝果实中的生物活性物质。发现果实的抽提物和单体化合物不仅具有防治作物害虫的作用,而且,还对植物有生长调节作用。通过生物活性鉴定结果表明:果实种仁的水抽提物对水稻早期萌动、发芽与秧苗的生长均有促进作用。其中,处理稻种第2天(48h),其发芽率比对照高出24.67％～42.86％;第4天秧苗的根长在1cm以上占56.5％～65.0％,而对照组只有15.5％。尤其是抽提液浓度在6000ppm时处理的稻种,测得生长10d的秧苗总长为对照的120.27％,胚根长为对照的121.54％;以及叶片中的叶绿素总含量比对照高8.5％。还证明了从果实中提取分离的几种三萜类化合物和在果实中发现的一种新化合物对苯二甲酸二甲酯,均对菜青虫有拒食和胃毒活性。     

Potent limonoid insect antifeedant from Melia azedarach

Systematic fractionation of a fruit extract from Argentine Melia azedarach L., which was monitored by an insect antifeedant bioassay, led to the isolation of meliartenin, a limonoid antifeedant, which existed as a mixture of two interchangeable isomers. At 4 microg/cm2 and 1 microg/cm2, the isomeric mixture was as active as azadirachtin in strongly inhibiting the larval feeding of Epilachna paenulata Germ. (Coleoptera: Coccinellidae) and the polyphagous pest, Spodoptera eridania (Lepidoptera: Noctuidae), respectively.     

Effection of Ocneridia volxemi Bolivar (Pamphaginae, Orthoptera) hoppers and adults by Beauveria bassiana (Deuteromycotina, hyphomycetes) conidia in an oil formulation

Ocneridia volxemi Bolivar (Pamphaginae, Orthoptera) is one of the important insects pest in the heigh plains of north east of Algeria. Larval and adult stages caused severe damage to the leaves of cereals and an other various crops. Laboratory studies were conducted to the determine the potential of the fungus Beauveria bassiana for the control of the pest of larval and adults. Positive results were obtaved when larvae and adults were sprayed with different concentration of fungus conidia (D1: 2 x 10(6) conidia/ml, D2: 5 x 10(5) conidia/ml, D3: 8 x 10(4) conidia/ml, D4: 10(2) conidia/ml). Concentration at D1 and D2 in an oil formulation showed respectively 100% and 90 % larval mortality at the first day of treatment and 100%-9% adults mortality at the five day of treatement. The results revealed that the rates of infection and mortality were significantly related to the concentration of conidia in the corresponding samples. Beauveria bassiana can be considerd as a promising biocontrol agents of Ocneridia volxemi may be an other locuts, but field experimentation is necessary to subtantiate these finding.     

Effect of methanolic extracts of neem (Azadirachta indica A. Juss) and bakain (Melia azedarach L) seeds on oviposition and egg hatching of Earias vittella (Fab.) (Lep., Noctuidae)

Abstract: The effects of methanolic extracts of neem ( Azadirachta indica ) and bakain ( Melia azedarach ) seeds on the oviposition behaviour and hatchability of eggs of Earias vittella were investigated under laboratory conditions. Treatments included 2, 4, 6, 8 and 10% concentrations of both extracts to compare with nimbecidine and untreated control. When able to choose, the adults preferred to lay a greater number of eggs on the untreated portion of the oviposition substrate (muslin) compared with the extract-treated portion. However, under no-choice conditions, higher concentrations of extracts caused proportionate reductions in the number of eggs laid. The extracts also manifested repellent activity by reducing the number of eggs laid even when the ovipositing females were not in direct contact with the extracts. Eggs laid on extract-treated oviposition substrate exhibited reduced hatching and marked adverse effects on hatching were noticed when the eggs were dipped in different concentrations of extracts. Adults fed on an extract-containing sucrose diet laid significantly fewer eggs with poor hatching. There was no egg laying when the moths were fed on a sucrose diet containing 6, 8 and 10% neem and 10% bakain extracts.     

The effect of cypermethrin on the feeding of mustard beetles Phaedon cochleariae (F.)

Cypermethrin deposits on sprayed (3, 6, 9, 12 and 15 g ha^-1) radish leaves caused a significant antifeedant effect on third instar larvae and adults of mustard beetles.
There was a significant inverse relationship between feeding and dose for both stages. In the case of adults on deposits of 1, 3 and 6 g hafeeding was reduced by 60–75% but no mortality was recorded. Much less uniform feeding was associated with higher application rates (9, 12 and 15 g ha-^I) with low mortality at the two highest doses. The mean areas of the individual holes eaten by larvae or adults in either control or treated leaves, did not differ significantly. The number of holes eaten was negatively related to application rate. The antifeedant effect was observed with low concentration of both technical and formulated cypermethrin.     

Responses of the sweetpotato whitefly, Bemisia tabaci, to the chinaberry tree (Melia azedarach L.) and its extracts

Host preference bioassays for adults of the sweetpotato whitefly were performed with leaves of the chinaberry tree Melia azedarach L., tomato, cucumber and bean. Fruit and leaf extracts of the chinaberry tree were tested against adults of the sweetpotato whitefly. Fruit extracts were tested against eggs, first and second instar nymphs, and pupae of the insect. Treatments included aqueous, methanol, and acetone fruit extracts of 200 mg ml^?1 and serial dilutions of 20.0 and 2.00 mg ml^?1, ether extract, the botanical insecticides Azatin® and Margosan® ‐O and the control, water or water with Triton®. Mortality data was collected at 6, 7, and 8 days after treatment of the eggs, nymphs and pupae, respectively. Results of the host preference bioassays indicated a significantly lower number of live insects on leaves of the chinaberry tree vs leaves of bean, cucumber, and tomato after 24 h. This indicates that M. azedarach is not a good host for the sweetpotato whitefly. Adults of the insect were significantly more repelled from tomato plants treated with the undiluted extracts when compared to the control after 72 h. There were significant differences in percent mortality of nymphal instars when exposed to the undiluted extracts compared to other extracts and the control. However, there was no significant effect of the fruit extracts on the egg and pupa instars. Thus M. azedarach extracts were found to be repellent to the whitefly adults, while the fruit extracts have shown a significant detrimental effect against early nymphal instars. In general, the methanol extracts were more active against B. tabaci than extracts with other solvents.     

Behavioural responses of diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) to extracts derived from Melia azedarach and Azadirachta indica

The impact of three different doses of botanical insecticide derived from the syringa tree, Melia azedarach and the neem tree, Azadirachta indica was tested on the behaviour of the diamondback moth, Plutella xylostella (Linnaeus). Both botanical insecticides had a significant impact on larval behaviour. At higher doses the extracts showed feeding deterrent activity, with larvae preferring the untreated sides of cabbage leaves and consuming less of the treated half of cabbage leaves. The botanical insecticides had less of an effect on the oviposition behaviour of P. xylostella moths. In laboratory and glasshouse trials, significantly fewer eggs were oviposited on the plants that had been treated with syringa extracts. Therefore, the syringa extracts appear to have a repellent effect. In contrast, when exposed to the neem extracts the moths did not discriminate between control plants and treated plants. Behavioural observation indicated that, despite the lower number of eggs oviposited on cabbage treated with syringa extracts, the moths chose cabbage treated with the highest dose of syringa more often than they chose control cabbage plants. Similar observations were found in cabbage plants treated with neem, moths chose the medium dose more often than they chose the control. Oviposition and feeding deterrent properties are important factors in pest control, and results from this study indicate that botanical insecticides have the potential to be incorporated into control programmes for P. xylostella in South Africa.     

Insecticidal effect of plant extracts on common pistachio psylla,Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae)

The common pistachio psylla, Agonoscena pistaciae (Hemiptera: Aphalaridae) is one of the most detrimental pests to pistachio trees. Nowadays various pesticides are used to control the common pistachio psylla, but extensive pesticide spraying against this pest over a period of several years has overpowered its natural enemies. The plant’s byproducts come as an alternative ecologically more compatible in substitution to the synthetic insecticides. This work aims to evaluate the insecticidal potential of herbal extracts of fruit peels of Citrus sinensis and Citrus reticulata, seeds of C. sinensis and Rubia tinctorum, and leaves of Lawsonia inermis against common pistachio psylla. Five concentration 40, 47, 56, 67 and 80 µl/ml, of these plant extracts were sprayed on the fifth instar nymphs of common pistachio psylla by Potter Spray Tower under laboratory conditions (26?±?2?°C, 60–70% RH and a photoperiod of 16L: 8D h). Results showed significant differences among the treatments of the plant extracts and between the concentrations. The LC₅₀ values of C. sinensis peels, C. reticulata peels, C. sinensis seeds, R. tinctorum seeds and L. inermis leaves were 62.04, 38.84, 43.60, 59.01 and 33.99 µl/ml, respectively. Also, all extracts showed the greatest mortality effect in 80 µl/ml concentration. According to these results, these plant extracts may use as herbal pesticides chemical control programme of common pistachio psylla.     

Antimicrobial activities of eucalyptus leaf extracts and flavonoids from Eucalyptus maculata

AIMS: We investigated the antimicrobial activities of eucalyptus leaf extracts to find effective antibacterial agents. METHODS AND RESULTS: The antimicrobial activities of leaf extracts from 26 species of eucalyptus were measured. Extracts of Eucalyptus globulus, E. maculata and E. viminalis significantly inhibited the growth of six Gram-positive bacteria (Staphylococcus aureus, MRSA, Bacillus cereus, Enterococcus faecalis, Alicyclobacillus acidoterrestris, Propionibacterium acnes), and of a fungus (Trichophyton mentagrophytes), but they did not show strong antibacterial activity against Gram-negative bacteria (Escherichia coli, Pseudomonas putida). 2',6'-dihydroxy-3'-methyl-4'-methoxy-dihydrochalcone, eucalyptin and 8-desmethyl-eucalyptin, isolated from E. maculata extracts, exhibited potent antimicrobial activities against seven micro-organisms with minimum inhibitory concentrations (MIC) ranging from 1.0 to 31 mg l(-1). CONCLUSIONS: The eucalyptus extracts and three compounds from E. maculata were found to be effective against micro-organisms that cause food poisoning, acne and athlete's foot. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows potential uses of extracts from E. globulus, E. maculata and E. viminalis, and antimicrobial compounds isolated from E. maculata.