Metabolism mediated interaction of α-asarone and Acorus calamus with CYP3A4 and CYP2D6

The present study was aimed to investigate the possible interaction of the standardized extract of Acorus calamus (AC) with Cytochrome P450 enzyme, quantitative determination of the α-asarone in the AC rhizome was performed by RP-HPLC method. In vitro interaction of the plant extract was evaluated by CYP450-carbon monoxide complex (CYP450-CO) assay. Effect on individual isoforms such as CYP3A4 and CYP2D6 isozymes were analyzed through fluorescence product formation and respective IC₅₀ values were determined. CYP450-CO assay showed moderate interaction potential. Extract showed higher IC₅₀ values (46.84 ± 1.83-32.99 ± 2.21 μg/ml) comparing to the standard inhibitors and lower IC₅₀ value than α-asarone (65.16 ± 2.37-42.15 ± 2.45 μg/ml).     

Nitrogen uptake from 15N-enriched fertilizer by four tree crops in an Amazonian agroforest

Mixed tree cropping systems have been proposed for sustainable nutrient management in the humid tropics. Yet, the nutrient interactions between intercropped trees have not been addressed sufficiently. In the present study we compare the temporal and spatial patterns of the uptake of applied ¹⁵N by four different tree crops in a mixed tree cropping system on a Xanthic Ferralsol in central Amazônia, Brazil, during one year. Most of the N uptake occurred during the first two weeks. Very little N was recovered by peach palm (Bactris gasipaes), more by cupuassu (Theobroma grandiflorum) and annatto (Bixa orellana) and most by Brazil nut (Bertholletia excelsa). Due to tree pruning the total accumulation of applied ¹⁵N in the above-ground biomass of annatto decreased throughout the year. It remained constant in cupuassu and peach palm and increased in Brazil nut. Brazil nut showed an extensive root activity and took up more fertilizer N applied to neighboring trees than from the one applied under its own canopy in contrast to the other three tree crops. Therefore, trees with wide-spread root systems may not need to receive N fertilizer directly but can take up N applied to other trees in the mixed cropping system. This means that such trees may effectively decrease N leaching when intercropped with trees that have dormant periods or places with low N uptake, but also exert considerable resource competition.This revised version was published online in November 2005 with corrections to the Cover Date.     

《东北草本植物志》第1卷补正（V）

本节对东北蕨类植物的４科６属１０种２变种进行了补遗和订正，考证了名称及有关文献，讨论了所述分类群与其近亲分类群的区别特征。     

PGPB对红树植物木榄幼苗的接种效应

通过盆栽试验研究了植物促生菌(PGPB)对红树植物木榄幼苗的接种效应,供试菌为6种解磷菌(即B.amy,Vib,B.atr,Xan,B.Lic,P.M.)和5种固氮菌(即Au4,Phy,24S,JA4,cd),结果表明:(1)分别接种6种解磷菌株6个月后木榄幼苗的生长均得到了不同程度的促进,与对照相比,木榄苗高增加21.57%～9.54%,生物量增加27.49%～20.32%,叶片的氮含量增加33.33%～1.35%,叶片的磷含量增加24.42%～2.04%;经差异显著性检验,B.amy和Vib 2个菌种对木榄幼苗的促生效应比其它解磷菌株更明显;(2)分别接种5种固氮菌株6个月后木榄幼苗的生长均得到了促进,与对照相比,木榄幼苗的均高增加24.07%～10.22%,生物量增加32.36%～19.71%,叶片的氮含量增加23.39%～4.05%,叶片的磷含量增加32.79%～4.99%;差异显著性检验表明:Au4和Phy 2个菌种对木榄幼苗的促生效果比其它固氮菌更显著.     

Tephrosia species and provenances for improved fallows in southern Africa

Seeking an alternative to Sesbania spp. tree fallows, a Tephrosia species and provenance trial was conducted at Msekera Research Station, Chipata (Zambia) to evaluate eleven Tephrosia vogelii and three Tephrosia candida provenances. They were tested for biomass production, quality of biomass, resistance to root-knot nematodes, nitrogen release, and for their effects on soil nitrogen dynamics. At the end of 1.5 years, the T. candida provenances 02970, 02971 and 02972 from Madagascar produced two times greater amount of aboveground biomass than the T. vogelii provenances. There was little variability among the T. vogelii provenances in terms of litter and biomass production. Weed growth was significantly greater under T. vogelii than T. candida provenances. While Tephrosia vogelii provenance 98/02 from Zambia and T. candida 02972 were highly tolerant to the Meloidogyne incognita nematodes, T. vogelii provenances 02977, 98/03, 02973 from Kenya, Zambia and Malawi, respectively, were highly susceptible to the nematodes. The Tephrosia species and provenances showed a wide variability in terms of N, lignin and polyphenol concentration in their foliage. Mineralization of N in the foliage of T. candida provenances 02970 and 02971 and T. vogelii provenances 98/04 and 02974 from Malawi occurred rapidly within 14 weeks of incubation. At the end of the 2-year growth period, there was significantly greater total inorganic N under T. candida provenance 02972 (12.5 mg kg⁻¹) than T. vogelii (5 mg kg⁻¹) provenance Mungwi 98/02. Maize (Zea mays L.) yields after T. candida provenances were greater than those after T. vogelii provenances. Further testing of the most promising provenances is needed for their effects on subsequent maize yields under a range of farm conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

大黄酚对黄瓜白粉病的生物活性及内吸传导性研究

采用喷雾法研究了大黄酚对黄瓜白粉病的生物活性及其在黄瓜组织中的内吸传导性。结果表明,大黄酚对黄瓜白粉病菌具有较高毒力,感染白粉病的叶片经200 mg/L的大黄酚处理2 d后,霉状物变褐色,病斑枯死。扫描电子显微镜观察显示,黄瓜白粉病菌经大黄酚处理后,菌丝和分生孢子梗扭曲、变形,分生孢子塌陷。盆栽试验表明,利用大黄酚防治黄瓜白粉病具有较长的持效期,黄瓜子叶上喷施100 mg/L的大黄酚,20 d后接种病原菌,其防效仍达84.83%,与有效成分500 mg/L的硫磺悬浮剂防效相近。此外,大黄酚在黄瓜组织中具有一定的跨层传导性,其横向传导性较弱,几乎无向顶及向基的传导性。     

不同降水年型氮磷配施对冬小麦产量形成及水量平衡的影响

通过田间定位试验,探讨不同降水年型下氮磷配施对冬小麦产量形成及水分利用的影响,为改善麦田水分状况,建立与水分条件相适应的肥料组合模式提供依据.结果表明:(1)试验条件下,与对照处理相比,高氮高磷处理产量及水分利用效率均较高,平水年和干旱年的产量分别较对照增加68.37%和62.95%;水分利用效率分别较对照增加36.7...     

内蒙古锡林郭勒天然草原禾本科牧草根际18株固氮细菌的初步分类鉴定

采用16SrDNA测序方法对从内蒙古锡林郭勒天然草原四种主要禾本科牧草根际分离获得的18个固氮菌株进行属水平的鉴定,结果表明：其中7株属于土壤杆菌属（Agrobacterium）、3株属于产碱菌属（Alcali-genes）、1株属于固氮菌属（Azotobacter）、1株属于芽孢杆菌属（Bacillus）、3株属于假...