番茄抗性砧木对土壤根结线虫二龄幼虫和自由生活线虫的影响

研究了引自意大利的3种番茄抗性砧木对温室土壤根结线虫二龄幼虫的控制作用以及对土壤自由生活线虫的影响。供试温室土壤共鉴定12科26属自由生活线虫,分属食细菌性线虫、食真菌性线虫、植食性线虫和杂食性线虫4种营养种群。试验结果表明,3种抗性砧木均显著地降低了嫁接苗植株根际土壤中根结线虫工龄幼虫（J2）的密度,从而控制了根结线虫病的发生;与不种植番茄的空白对照相比,种植番茄促进了根际自由生活线虫的繁殖,但抗性砧木根际自由生活线虫的密度小于感病对照“FA189”。所有处理根际自由生活线虫优势种群为食细菌性线虫。     

黄瓜砧木对南方根结线虫生长发育的影响及其与根系分泌物的关系

黄瓜是设施主栽蔬菜,长期连作导致根结线虫病发生和危害加重;嫁接是提高黄瓜对根结线虫抗性的有效手段,但不同砧木品种间存在差异。为探明嫁接提高黄瓜抗根结线虫能力的机制,试验选用不同抗性的砧木品种‘云南黑籽南瓜’(低感)和‘甜砧南瓜’(高感),以‘新泰密刺’自根黄瓜为对照,采用人工接种,研究了黄瓜砧木对南方根结线虫生长和繁殖的影响,并探讨了根系分泌物与线虫卵孵化的关系。结果表明:线虫侵染初期,3个品种根内的二龄幼虫(J2)数差异显著,‘云南黑籽南瓜’最少,‘甜砧南瓜’次之,‘新泰密刺’最多;侵入根内的J2均能正常发育为成虫,根内线虫总数以‘云南黑籽南瓜’最少,‘新泰密刺’最多;根际J2数量以‘新泰密刺’最多,‘云南黑籽南瓜’最少;发生二次侵染前,根际卵粒数呈现出相同的特点。黄瓜及其砧木根系分泌物明显影响根结线虫卵的孵化,孵化率以‘云南黑籽南瓜’最低,‘甜砧南瓜’次之,‘新泰密刺’最高;接种根结线虫后,根系分泌物影响下的卵孵化率较未接种时明显增加,‘新泰密刺’增幅最大,‘云南黑籽南瓜’增幅最小;随着生育时间延长,三者根系分泌物对卵孵化的促进作用逐渐增强。低感砧木根系分泌物对南方根结线虫卵孵化具有明显的抑制作用,可显著降低线虫在其根内及根际的发育,可能是抗线虫的机制之一。     

与辣椒抗根结线虫基因Me1紧密连锁的EST-SSR标记开发

以含抗根结线虫病基因Me1的PM217与感线虫品种茄门,及其F1、F2作为试验材料,采用南方根结线虫（Meloidogyne spp.）人工接种鉴定,根据鉴定结果,利用分离群体分组分析法（bulked segregantanalysis,BSA）建立抗感池,共筛选到3对（118、141及211）多态性EST-SSR引物...     

生物有机肥对甜瓜根结线虫病的田间防治效果研究

为研究生物有机肥对根结线虫的田间防治效果,在根结线虫发病严重的甜瓜田进行了田间试验。结果表明: 1）在仅施用无机肥的田块,根结线虫病发生严重,而在施用生物有机肥的田块,发病率降低,最高防治率达81.1%; 2）与对照相比,施用加入根结线虫拮抗菌X5的生物有机肥料使地上部鲜重增加,根系鲜重（根结量）减少; 3）施用生物有机肥可显著减少土壤中根结线虫二龄幼虫的密度和根中卵块的数量; 4）生物有机肥处理与常规肥料处理的土壤线虫DGGE图谱明显不同,分别归于两个聚簇,表明土壤线虫群落结构受到施用含根结线虫拮抗菌的生物有机肥影响。综上所述,施用生物有机肥能有效防治田间条件下根结线虫对甜瓜的危害。     

昆虫病原线虫共生细菌对南方根结线虫卵孵化的影响

为探讨不同种(品系)昆虫病原线虫共生细菌的不同稀释倍数对南方根结线虫Meloidogyne incognita卵孵化的影响,采用培养皿法进行室内生测,定期调查根结线虫卵孵化情况。结果表明,4种(品系)昆虫病原线虫(斯氏属两个种和嗜菌异小杆两个品系)共生细菌的10×稀释液,6 d时Hb-NJ共生菌使M.incognita的卵孵化率最低,为8.6%,以TSY培养液为对照,其孵化率为29.1%,Hb-NJ共生菌对M.incognita卵孵化的抑制作用最强,相对抑制率为70.6%,其它3种昆虫病原线虫Hb-IGA、Sc-All和Sf-IGA共生细菌的孵化率为分别为24%、22.6%和25.2%,其相对抑制率是17.2%、22.3%和13.4%;8 d时线虫Hb-NJ、Hb-IGA和Sc-All共生菌的相对抑制率分别为67.1%、39.3%和41.7%,10 d时4种(品系)昆虫病原线虫共生菌对M.incognita的孵化率和抑制率均无显著性差异(p0.05)。4种(品系)昆虫病原线虫共生菌的20×和50×稀释液对M.incognita卵孵化没有明显的抑制作用。基于以上结果,Hb-NJ的共生细菌可以通过抑制南方根结线虫的卵孵化导致线虫群体下降而达到防治线虫的目的,因此是一种潜在的生物杀线虫剂。     

定殖烟草根结线虫卵和雌虫机会真菌的多样性

机会真菌对根结线虫的生物防治具有巨大潜力。本研究于2010—2011年针对来源于中国7个省份的156份烟草根结线虫样本,分别分离根结线虫游离卵、卵块和雌虫上定殖的机会真菌。应用18S rDNA-ITS片段测序结果结合菌株的形态学观察和培养性状鉴定定殖游离卵、卵块和雌虫上的真菌。根据分离到菌株的培养性状、形态学和rDNA-ITS序列分析,对定殖于南方根结线虫或北方根结线虫的9 839个游离卵、408个卵块和284个雌虫的真菌菌株,明确鉴定出9属13个种,其中定殖根结线虫新记录种5个,即长梗木霉、芬芳镰刀菌、渐狭蜡蚧菌、虫草棒束孢和交枝顶孢。淡紫紫孢菌Purpureocillium lilacinum(原名:淡紫拟青霉)为优势种,分布广泛,在云南、安徽、湖北、贵州和山东省均被分离到。该菌在南方根结线虫和北方根结线虫的游离卵、卵块和雌虫平均分离率分别为0.49%、24.00%和16.90%,说明其地理和生态适应性广泛。不同地区来源的烟草根结线虫卵和雌虫上定殖的机会真菌种类存在明显差异。目前尚无渐狭蜡蚧菌和虫草棒束孢作为线虫病原物的报道,有待于进一步深入研究其对根结线虫的致病性。     

连作番茄根区病土对番茄生长及土壤线虫与微生物的影响

探索连作番茄根区病土对番茄根结线虫病的诱导效果及引起连作障碍的微生态机制,可为深入了解番茄连作障碍发生机理及探究番茄连作障碍防治方法提供科学依据。本研究利用盆栽试验,测定了番茄在健康土壤及接种病土土壤中生物学特性变化及根结线虫侵染状况,并分析鉴定了土壤中微生物及线虫的种类与数量。结果表明,接种连作番茄根结线虫病株根区病土会对番茄生长及根结线虫侵染产生影响:1)番茄苗期根系根结数达9个?株~(-1),健康土壤无根结;土壤线虫数量较健康土壤增加390.4%;收获期番茄根结线虫侵染率达62.7%,病情指数为80.0%。2)番茄生长受到抑制,叶片防御酶活性降低,收获期茎叶及根系鲜质量较健康土壤分别减少50.2%及33.1%,苗期番茄叶片PPO活性较健康土壤降低15.8%,POD活性较健康土壤增加24.0%,差异均达显著水平(P0.05)。3)番茄根系更易感染有害菌,根系内病原菌甘蓝假单胞菌数量较健康土壤增加463倍,根区土壤细菌、真菌及放线菌总数分别增加46.3%、94.5%及134.0%。4)食细菌线虫、食真菌线虫及植物寄生性线虫数量分别为健康根区土壤的3.3倍、1.6倍及7.3倍,其中的植物寄生线虫95.6%为根结线虫。综上所述,接入连作番茄根结线虫病株根区病土不仅导致番茄遭受根结线虫侵染,而且会导致土壤线虫总量及植物寄生线虫所占比例大幅增加,并使番茄根系内有害细菌数量显著增加,对番茄生长造成显著抑制作用,同时影响番茄的生理生化特性,受线虫侵染番茄防御性酶活性降低,使其更易被根结线虫及病原菌侵染,番茄根区土壤线虫、微生物及根系内优势细菌的种类与数量及其之间的作用发生改变。     

黄秋葵对南方根结线虫抗性的转录组分析

为了解黄秋葵抗南方根结线虫相关基因组学,利用Illumina Hi-seq TM2500高通量测序技术研究受南方根结线虫侵染后黄秋葵种质12C2转录组基因的差异表达。结果表明,接种南方根结线虫18 h后,从接种和未接种的黄秋葵种质12C2根尖中共获得71.49 Gb有效数据,Q30碱基百分比均达到94.0%以上。共获得2 318个差异表达基因(DEGs),包括1 156个上调基因,1 162个下调基因,其中功能注释基因2 202个。根据unigene库序列进行GO、KOG和KEGG注释,细胞壁代谢相关基因——内切葡聚糖酶基因家族、聚半乳糖醛酸酶基因家族、葡聚糖内-1,3-β葡糖苷酶基因家族和果胶裂解酶基因家族下调表达,植物激素代谢相关基因——生长素响应蛋白基因、生长素流入运输载体基因下调表达,茉莉酸合成酶基因上调表达,调控相关基因表达的WRKY和MYB转录因子基因家族上调表达,参与植物细胞的膜联蛋白基因家族上调表达,植物细胞周期蛋白基因家族下调表达。本研究结果为开展黄秋葵抗南方根结线虫基因组学和分子生物学研究奠定了基础。     

黄瓜连作土壤高温处理对根结线虫和枯萎病的影响

[目的]设施黄瓜连作导致根结线虫和枯萎病发生普遍且严重,利用夏季温室休闲期高温闷棚是解决上述土传病害安全而有效的途径之一。本试验模拟高温闷棚,研究不同温度处理连作土壤根结线虫和枯萎病的变化,旨在为利用太阳光进行温室高温消毒提供理论支撑。[方法]本试验以连作1~19茬‘津优30’黄瓜品种的土壤为试材,首先探明不同连作茬次黄瓜的根结线虫和枯萎病发生程度以及土壤中二者病原物种群数量的动态变化,然后对发病较重的第17茬连作土壤分别进行45℃、50℃、55℃和60℃的高温处理,最后测定比较不同温度处理后的土壤中病原物数量变化,并对高温处理后的土壤进行栽培试验,测量和比较两种病害的发生程度及植株各项生长指标。[结果]随着黄瓜连作茬次的增加,土壤中根结线虫和枯萎病菌的种群数量均增加,两种病害也逐茬加重,至第17茬两种病害的发病程度及其对应病原物的数量均达最高(或次高)水平;对第17茬黄瓜连作土壤进行45℃~60℃的高温处理,随着温度的升高,土壤中的根结线虫和枯萎病菌的数量均减少,当处理温度达55℃时可完全杀灭土壤中根结线虫,达60℃时可同时杀灭枯萎病菌;用高温处理的连作土壤栽培黄瓜秧苗,其根结线虫病和枯萎病的发生程度均随着处理温度的升高而减轻,当处理土壤的温度达到50℃和60℃以上时,根结线虫病和枯萎病分别被完全控制;另外,用60℃处理的连作土壤定植黄瓜,其后期植株生长指标和壮苗指数也显著优于对照。[结论]土传病害随连作茬次增加而加重主要是缘于土壤中病原物积累,定植前对土壤55℃以上的高温处理,可有效减少乃至完全杀灭土壤中根结线虫和枯萎病菌,从而减轻或杜绝两种病害的发生。     

黑龙江省安达地区大豆孢囊线虫生理小种遗传分化现象

大豆孢囊线虫病是严重制约大豆生产的重要世界性病害,黑龙江省是我国大豆的主产区域之一,田间种植抗线3号生理小种的品种抗性已减弱甚至丧失,但线虫具体发生怎样的变异还不清楚。目前,Riggs和Schmit的鉴别标准已不能满足当前小种的鉴定,通过线虫的卵量来比较鉴别寄主的抗性差异可能将是更进一步分析小种变异的重要指标之一。本研究在田间鉴别寄主初步鉴定变异的地块,采取了安达地区两个地点的土样进行单孢囊分离培养和温室生理小种鉴定,同时也采取了山东泰安4号生理小种的田间土样作为对照。每个土样进行单孢囊繁殖,然后扩繁接种鉴别寄主,35 d~40 d后调查植株根表和土壤里的雌虫总数,再研磨雌虫收集卵量。利用孢囊的雌虫指数温室盆栽结果鉴定出安达的两个土样和山东的样品都是4号生理小种,但是通过线虫卵量和对照感病品种Lee比较,却发现安达的两个样品和山东的4号样品有很大的差异。田间初步实验和温室盆栽鉴定结果表明安达地区3号生理小种已经发生变异,温室试验表明该地区存在4号小种,且小种的毒性有明显的分化。图2,表2,参15。     

Genetic diversity for root-knot nematode resistance in white clover and related species

A total of 237 Plant Introduction in eleven Trifolium species were evaluated for resistance to Meloidogyne arenaria (Neal) Chitwood race 1, M. hapla Chitwood, M. incognita (Kofoid & White) Chitwood race 3, and M. javanica (Treub) Chitwood. Plants were infected with 1500 nematode eggs collected from 'Rutgers' tomato (Lycoperiscon esculentum Mill.) roots with 0.5% NaOCl. Ratings of galling severity and egg mass production were assigned to each plant 8 wk after inoculation. Host plant reaction was classified as immune, highly resistant, resistant, moderately resistant, intermediate, moderately susceptible, susceptible, and highly susceptible according to the resistance index . More than 95% of 171 white clover accessions were moderately to highly susceptible to all four nematodes species. The best white clover accessions were only moderately resistant to either M. arenaria (PI 291843 and PI 306286) or M. hapla (PI 100250 and PI 204930). Accessions with moderate resistance or resistance to root-knot nematodes were found among relatives of white clover, with T. ambiguum M. Bieb. exhibiting the greatest resistance level. Among the other Trifolium species evaluated, T. carolinianum Michx. PI 516273 was immune or highly resistant to all four nematode species while accessions of T. hirtum All. showed a wide range of reaction to root-knot nematodes. Identified germplasm of white clover relatives with resistance to root knot nematodes should be useful for the selection of parents in white clover breeding programs.     

镉胁迫对黄麻光合作用及隔积累的影响

为揭示镉(Cd)胁迫下黄麻的光合耐性及其对Cd的富集特征,通过土壤盆栽试验分析了Cd胁迫下黄麻的生长、光合色素、气体交换参数及对Cd富集能力的变化.结果表明,当Cd浓度≤10 mg· kg-1时,黄麻根长、株高和各器官生物量降幅较小;而当Cd浓度≥20 mg· kg-1时,根长、株高和各器官生物量降幅进一步增大.随着Cd浓度的升高,黄麻叶片光合色素含量显著降低,但却能维持较高的Chla/b值,这可能有助于黄麻对Cd的耐性.Cd胁迫使净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)显著降低,但胞间二氧化碳浓度(Ci)随Cd浓度的升高而逐渐增大,表明黄麻光合速率的下降是由非气孔限制因素引起的.随着Cd浓度的升高,黄麻各器官Cd含量和累积量逐渐增大,在浓为100 mg· kg-1Cd处理下,地上部和地下部Cd含量均达到最大值,分别为232.46 mg· kg-1和186.98 mg· kg-1.Cd胁迫下,黄麻地上部和地下部富集系数均大于1,各处理迁移系数在0.85～1.65之间,表明黄麻对Cd有较强的富集和转运能力.Cd浓度为5～ 10 mg·kg-1时,Cd提取率超过1.9％.因此,黄麻是一种潜在的修复轻、中度土壤Cd污染的植物材料.本研究结果为挖掘新的植物修复材料提供了理论依据.     

Response to root-knot nematodes of a germplasm collection of red clover and related species

A germplasm collection of red clover (Trifolium pratense L.) and seven related species was evaluated in greenhouse tests for resistance to Meloidogyne arenaria (Neal) Chitwood, M. hapla Chitwood, M. incognita (Kofoid & White) Chitwood, and M. Javanica (Treub) Chitwood. Plants were rated for root galling severity and nematode egg production at eight weeks after inoculation with 1500 nematode eggs. A resistance index, RI = (gall₂; + egg₂;), was generated to assess the plants' reaction to nematode infection as immune, highly resistant, resistant, moderately resistant, intermediate, moderately susceptible, susceptible, or highly susceptible. More than 98% of red clover accessions were intermediately to highly susceptible to all four root-knot nematode species. Only one accession, PI 271627 introduced from India, had a moderate resistance level to the four nematodes tested. About one third of the T. medium accessions were resistant or highly resistant to M. arenaria, M. incognita, and M. javanica whereas more than 50% of the T. alpestre accessions were highly resistant or immune to all four nematodes species. Genetic factors for resistance to root-knot nematode could be introduced into T. pratense through interspecific hybridization with T. medium and/or T. alpestre     

Biocontrol efficiency of Fusarium wilt diseases by a root-colonizing fungus Penicillium sp.

Soil-inhabiting fungal pathogen Fusarium oxysporum often causes severe yield losses in many crops. We investigated the effect of a plant growth-promoting fungus, Penicillium sp. EU0013 on Fusarium wilt disease. In dual culture experiments, EU0013 inhibited the growth of Fusarium wilt pathogens by producing an inhibition zone. In experiments using sterile potting medium under controlled conditions, EU0013 significantly reduced the severity of Fusarium wilt on tomato (Solanum lycopersicum L.) and cabbage (Brassica oleracea L. var. capitata). In non-sterile soil, benomyl-resistant mutants of EU0013 were selected by exposing the conidial solution of EU0013 to ultraviolet light. The selected mutant EU0013_90S isolate did not show any distinct differences from EU0013 in colony characteristics, growth rate or antifungal activity against Fusarium wilt pathogens in dual culture. The effect of EU0013_90S on tomato wilt was studied under greenhouse conditions using non-sterile soil. Two-weeks old tomato seedlings were dipped in four different concentrations of EU0013_90S conidial suspension (1?×?10³, 1?×?10⁴, 1?×?10⁵, and 1?×?10⁶ conidia mL^–1). Seedlings were then planted in soil inoculated with either F. oxysporum f. sp. lycopersici race 1 CU1 or race 2 JCM 12575 (1?×?10⁶ bud-cells g^–1). We found the greatest disease suppression occurred when seedlings were dipped in the highest concentration of EU0013_90S conidia. This same inoculum concentration of EU0013_90S also resulted in the highest disease reduction in soil infested with JCM 12575. Higher root colonization with EU0013_90S showed a significant reduction in Fusarium wilt disease, suggesting that colonization by Penicillium sp. EU0013_90S is important for efficient biocontrol of these diseases.     

Anti-inflammatory activities of mogrosides from Momordica grosvenori in murine macrophages and a murine ear edema model

Momordica grosvenori (Luo Han Guo), grown primarily in Guangxi province in China, has been traditionally used for thousands of years by the Chinese to make hot drinks for the treatment of sore throat and the removal of phlegm. The natural noncaloric sweetening triterpenoid glycosides (mogrosides) contained in the M. grosvenori fruits are also antioxidative, anticarcinogenic, and helpful in preventing diabetic complications. The aim of this study was to assess the anti-inflammatory properties of mogrosides in both murine macrophage RAW 264.7 cells and a murine ear edema model. The results indicate that mogrosides can inhibit inflammation induced by lipopolysaccharides (LPS) in RAW 264.7 cells by down-regulating the expression of key inflammatory genes iNOS, COX-2, and IL-6 and up-regulating some inflammation protective genes such as PARP1, BCL2l1, TRP53, and MAPK9. Similarly, in the murine ear edema model, 12-O-tetradecanoylphorbol-13-acetate-induced inflammation was inhibited by mogrosides by down-regulating COX-2 and IL-6 and up-regulating PARP1, BCL2l1, TRP53, MAPK9, and PPARδ gene expression. This study shows that the anticancer and antidiabetic effects of M. grosvenori may result in part from its anti-inflammatory activity.     

Aliphatic ketones from Ruta chalepensis (Rutaceae) induce paralysis on root knot nematodes

This paper reports on the use of Ruta chalepensis L. extracts as a potential nematicide against root knot nematodes Meloidogyne incognita and Meloidogyne javanica . The essential oil (REO) and methanol extract (RME) of R. chalepensis were tested against second-stage juveniles, with REO inducing paralysis in both species (EC(50/1d) = 77.5 and 107.3 mg/L) and RME being selective for M. incognita (EC(50/1d) = 1001 mg/L). Chemical characterization of extracts was done by means of GC-MS and LC-MS, revealing mainly aliphatic ketones and coumarins, respectively. The first-ranking volatile nematicidal component in terms of individual activity against both species was 2-undecanone (EC(50) = 20.6 and 22.5 mg/L for M. incognita and M. javanica, respectively). This fact together with its high concentration in the most active extract found in this study, namely, REO (2926 mg/kg), categorizes 2-undecanone among the nematicidal principles of R. chalepensis. On the contrary, coumarins rutin and 8-methoxypsoralen were not found to be nematicidal at concentrations of ≤500 mg/L. Interestingly, M. incognita was found more sensitive than M. javanica.     

Effects of interaction of Meloidogyne incognita,Alternaria dauci and Rhizoctonia solani on the growth,chlorophyll, carotenoid and proline contents of carrot in three types of soil

Disease complex of carrot (Daucus carota L.) involving root knot nematode Meloidogyne incognita and two fungi Alternaria dauci and Rhizoctonia solani were studied in three soil types. More plant growth, chlorophyll, carotenoid and proline contents were found in carrot grown in fly ash mix soil than plants grown in sand mix soil and loamy soil. Inoculation of M. incognita, R. solani, and A. dauci reduced plant growth, chlorophyll and carotenoid but increased proline contents. Inoculation of M. incognita 20 days prior to a fungal pathogen caused a greater reduction in plant growth, chlorophyll and carotenoid than fungal pathogen was inoculated prior. Inoculation of A. dauci prior to R. solani or vice versa had a similar effect on plant growth, chlorophyll, and carotenoid. Nematode multiplication and galling was higher in plants grown in sand mix soil followed by loamy soil and fly ash mix soil. Both fungi had adverse effects on galling and nematode multiplication. Blight disease index caused by A. dauci was 3 and crown rot index by R. solani was also recorded 3. These disease indices were 5 when pathogens were inoculated in combinations.     

The Fate of Plant Pathogens and Seeds During Anaerobic Digestion and Aerobic Composting of Source Separated Household Wastes

Anaerobic digestion is becoming a more common method for treatment of organic wastes. Little is known, however, about the effects of this process on the fate of plant pathogens and seeds. Therefore, the fates of the plant pathogens Plasmodiophora brassicae, Heterodera schachtii, Meloidogyne incognita, Ralstonia solanacearum, tobacco mosaic virus (TMV) and tomato seeds were followed during anaerobic digestion of source separated household wastes. With the exception of TMV, all test organisms were destroyed to below detectable limits within one day of anaerobic digestion at 52°C. Two days of anaerobic digestion did not reduce the concentration of TMV. However, two days of anaerobic digestion followed by 19 days of high temperature composting at 58°C reduced the concentration of infectious TMV particles by a factor of almost three orders. Anaerobic digestion followed by 12 days of composting at 68°C was even more effective. Although TMV concentrations were not eliminated entirely, we conclude that short-term high temperature anaerobic digestion followed by high temperature composting is a highly efficient process for the eradication of detrimental agents from solid wastes.     

Inhibitory effects of cucurbitane glycosides and other triterpenoids from the fruit of Momordica grosvenori on epstein-barr virus early antigen induced by tumor promoter 12-O-tetradecanoylphorbol-13-acetate

Two new triterpene benzoates, 5-dehydrokarounidiol dibenzoate (1) and karounidiol dibenzoate (2), and two new triterpene glycosides, 5alpha,6alpha-epoxymogroside IE(1) (8) and 11-oxomogroside A(1) (9), along with 15 known triterpenoids (one triterpene benzoate, 3; three triterpene mono-ols, 4-6; one triterpene aglycon, 7; and 10 triterpene glycosides, 10-19), were isolated from the ethanol extract of the fruit of Momordica grosvenori. The structures of 1, 2, 8, and 9 were determined on the basis of spectroscopic and chemical methods. Among the known triterpene glycosides, mogroside I E(1) (12) was a new naturally occurring compound. Eighteen triterpenoids (2-19) and 11-oxomogrol (20), a hydrolysis product of 9, were evaluated with respect to their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, which is known to be a primary screening test for antitumor promoters. All of the compounds tested showed potent inhibitory effects on EBV-EA induction (70-100% inhibition at 1 x 10(3) mol ratio/TPA).     

狼尾草等6种植物对十溴联苯醚污染土壤的生理响应及其修复效果

考察了狼尾草、龙葵、空心菜、苣菜、芥菜和鱼腥草6种植物对土壤中十溴联苯醚（BDE-209）的生理响应及其修复效果。结果表明,在BDE-209污染条件下,供试植物体内丙二醛（MDA）含量升高,表明植物受到一定的毒害作用,而在植物抗逆境机制作用下,植物体内可溶性蛋白质含量升高,超氧化物歧化酶（SOD）活性下降;在供试植物生物量方面,BDE-209对龙葵、空心菜和狼尾草地上部有促进作用,而对苣菜、芥菜具有一定的抑制作用;6种修复植物体内均检测出BDE-209,且地上部与根部BDE-209含量具有显著差异,其中狼尾草根部干重含量高达16.93mg·kg-1;修复60d后,土壤中BDE-209含量均有一定程度的下降,最高去除率可达40.44%,且根际土与非根际土BDE-209去除率有显著差异。修复效果依优劣次序为狼尾草〉龙葵、空心菜〉鱼腥草〉芥菜〉苣菜。