茶互利素和蚜性信息素及其组合调控大草蛉行为的效应

茶蚜群聚于茶梢上刺吸,而茶梢是加工名优茶的原料,不便施药治蚜。大草蛉虽是茶蚜主要天敌之一,但在自然情况下不足以控制茶蚜。遂探讨以茶梢互利素、蚜虫性信息素及其组合引诱大草蛉制约茶蚜的技术。使用顶空吸附法采集蚜害茶梢和健康茶梢挥发物,经GC-MS分析发现蚜害茶梢(E)-2-戊烯醛、苯甲醛和α-法尼烯的含量丰富。将蚜害茶梢挥发物中16种主要成分、蚜虫性信息素荆芥内酯和荆芥醇、以及α-法尼烯、苯甲醛和荆芥醇的2∶2∶6比例混合物分别制成味源,这19种味源的剂量都是200!g。经检测发现荆芥醇、荆芥内酯、α-法尼烯、(E)-2-戊烯醛和苯甲醛引起大草蛉的EAG值明显大于其它13种单组分引起的EAG值,而小于α-法尼烯、苯甲醛和荆芥醇混合物引起的EAG值。再将荆芥内酯和荆芥醇分别按7种比例配成7种味源,还把α-法尼烯、苯甲醛和荆芥醇的2∶2∶6比例混合物、以及(Z)-3-己烯-1-醇、(E)-2-戊烯醛、(E)-2-己烯醛、苯甲醛和α-法尼烯分别作为味源,用这13种味源分别制成的诱芯于秋季茶园中诱集大草蛉,每个诱芯含有信息物质总量是10 mg,结果表明:α-法尼烯、苯甲醛和荆芥醇混合物的诱效最强,称为大草蛉诱集剂;荆芥内酯和荆芥醇1∶9或0∶10比例的混合物诱效次之。深秋置大草蛉诱集剂诱芯于蚜群中,可诱来许多大草蛉成虫捕食茶蚜,并产卵于茶园中而增加大草蛉幼虫越冬基数,翌年春季就近捕食越冬蚜卵孵化的茶蚜。该诱集剂及其使用技术可作为一种治理茶蚜手段。     

茶尺蠖绒茧蜂对茶梢挥发物的EAG和行为反应

为筛选有效诱集茶尺蠖绒茧蜂Apanteles sp. 的信息化合物及其组合, 选用了源于健康和虫害茶梢的27种典型挥发物的10-2 g / mL石蜡溶液、混合物1（含等量反-2-己烯醛、顺-3-己烯-1-醇和芳樟醇石蜡溶液）和混合物2（含等量反-2-己烯醛、顺-3-己烯-1-醇、2-戊烯-1-醇、反-2-戊烯醛、顺-3-己烯乙酸酯、正戊醇、正己醇和1-戊烯-3-醇石蜡溶液）, 用1~2日龄雌蜂为试虫, 测试其EAG反应, 并采用Y形嗅觉仪测定其行为反应; 另外, 选择5个茶园进行了野外生测试验。 EAG结果表明: 各味源的EAG值之间差异显著; 脂肪酸衍生物引起较强EAG反应, 其次为芳香化合物和异硫氰酸酯, 再次为倍半萜类和单萜类; 单组分中, 顺-3-己烯乙酸酯、反-2-己烯醛、水杨酸甲酯、反-2-戊烯醛、苯乙酮、苯乙醇、苯甲醇、苯甲醛和茉莉酸甲酯引起的EAG值较大, 1-戊烯-3-醇、2-戊烯-1-醇、顺-3-己烯-1-醇、香叶醇、罗勒烯、α-萜品烯、(+)-雪松醇、(+)-3-蒈烯、α-忽布烯和β-紫罗酮引起的值较小, Z-茉莉酮引起的最小; 混合物1引起的EAG值最大, 混合物2引起的较小. 使用EAG值较大的水杨酸甲酯、反-2-戊烯醛和混合物1等8种味源, 以Y形嗅觉仪进行的行为测定结果与EAG反应基本一致. 以正己烷为溶剂的10^-3, 10^-2和10^-1 g / mL水杨酸甲酯、10^-2 g / mL水杨酸甲酯和反-2-己烯醛混合溶液分别制成诱集剂, 载于橡皮头诱芯, 在浙滇闽粤茶园强烈地诱集茶尺蠖绒茧蜂、单白绵绒茧蜂和其他茧蜂, 并表现梯度效应。据此认为虫害诱发的茶梢互利素引起该蜂强烈EAG反应和趋向性, 互利素与互利素或普通植物挥发物的恰当组合可于茶园中有效诱集该蜂。     

瓢虫和草蛉对小麦挥发物组分的行为及电生理反应

利用触角电位（electroantennogram, EAG）和嗅觉测定技术,比较分析了4种捕食性天敌昆虫七星瓢虫Coccinella septempunctata、龟纹瓢虫Propylaea japonica、中华通草蛉Chrysoperla sinica和大草蛉Chrysopa septempunctata对麦蚜取食诱导小麦挥发物的行为和电生理反应,揭示了瓢虫及草蛉类天敌昆虫的嗅觉反应特点。4种捕食性天敌昆虫对麦蚜取食诱导挥发物都有较高的EAG反应值,七星瓢虫和龟纹瓢虫对6-甲基-5_庚烯-2-酮、6-甲基-5-庚烯-2-醇的反应值较大;中华通草蛉和大草蛉对6-甲基-5-庚烯-2-醇和水杨酸甲酯的反应值较大,七星瓢虫对6-甲基-5-庚烯-2-醇的反应值最大,为0.96±0.18 mV;4种天敌昆虫对苯甲醛的EAG反应值较低,对反-2-己烯醛无反应。“Y”型管嗅觉测定结果表明,4种天敌昆虫对2-莰烯、6-甲基-5-庚烯-2-酮、6-甲基-5-庚烯-2-醇和水杨酸甲酯具有正趋性。说明4种多食性的捕食性天敌昆虫对麦蚜取食诱导挥发物各组分的嗅觉与行为反应各具特点;寄主麦蚜生境中的嗅觉线索在这4种捕食性天敌昆虫的寄主定位和生境选择中起重要作用。     

无翅茶蚜对茶树挥发物的触角电生理和行为反应

分别使用昆虫触角电位仪(EAG)和四臂嗅觉仪,测定了无翅茶蚜Toxopteraaurantii Boyer对14种茶树挥发性化合物、14种挥发物中"绿叶气味"组成的混合物(GLV)、14种挥发物的混合物(ACB)、以及新鲜嫩叶、芽、嫩茎、成叶和茶蚜为害嫩叶(ADYL)的EAG反应和行为反应。ACB引出最大的EAG反应值,茶树挥发物主要组分Z-3-己烯-1-醇、E-2-己烯醛、n-己醇、水杨酸甲酯和苯甲醇也引起较大的EAG反应值。4种正常茶梢的器官也引出较大的EAG反应,以嫩叶最强、依次为芽、嫩茎和成叶。有趣的是ADYL引出弱的负的EAG值。用嗅觉仪进行的生物测定表明,嫩叶以及主要的茶梢挥发性成分乙酸-Z-3-己烯酯、水杨酸甲酯、E-2-己烯-1-醇和Z-3-己烯-1-醇等也具有较强引诱活性。研究显示无翅茶蚜可能利用茶梢挥发物作为利它素而寻觅适宜的取食场所,如茶树嫩梢。     

麦长管蚜和禾谷缢管蚜对小麦挥发物的触角电位反应

采用活体蚜虫测定法,利用EAG技术比较分析了麦长管蚜Sitobion avenae和禾谷缢管蚜Rhopalosiphum padi有翅及无翅成蚜对小麦挥发物及麦蚜取食诱导挥发物组分的嗅觉反应,揭示了两种麦蚜的嗅觉变异特点。结果表明：麦长管蚜对水杨酸甲酯、反-2-己烯醛、反-2-己烯醇、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2醇的反应较强,禾谷缢管蚜对水杨酸甲酯、反-3-己烯乙酸酯、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2-醇的反应较强,并得到了剂量反应曲线。麦长管蚜的有翅和无翅成蚜对6-甲基-5-庚烯-2-酮、反-2-己烯醇和水杨酸甲酯的反应差异显著;禾谷缢管蚜的有翅和无翅成蚜对反-2-己烯醇、辛醛、里那醇、水杨酸甲酯和反-3-己烯乙酸酯的EAG反应差异显著,其原因与禾谷缢管蚜迁移及转主为害的生物学特性有关。     

绿豆象成虫对绿豆豆荚挥发物的触角电位和行为反应

【目的】探究对绿豆象Callosobruchus chinensi有引诱作用的植物挥发性物质。【方法】采用触角电位(EAG)仪和Y型嗅觉仪分别测定了绿豆象成虫对绿豆Vigna radiata豆荚挥发物的触角电位和选择行为反应。【结果】EAG测定结果表明,已交配的绿豆象雌虫对23种绿豆豆荚挥发物的EAG反应值存在显著差异,对苯甲醛、2-己烯醛、己醛、辛醛和水杨醛5种醛类化合物的EAG反应值相对较高,其中对2-己烯醛的反应值最大,达20.68;且绿豆象成虫EAG反应值在1~100μg/μL浓度下,均随挥发物浓度的提高而增强,但已交配和未交配绿豆象雌雄成虫的EAG反应值无显著差异。行为试验发现,当5种醛类物质浓度达100μg/μL时,已交配绿豆象雌、雄成虫均对苯甲醛和2-己烯醛有显著正趋性,对己醛有显著负趋性,对辛醛和水杨醛无显著趋性。【结论】绿豆豆荚挥发物中2-己烯醛和苯甲醛与绿豆象偏爱选择密切相关。     

茶梢信息物引诱叶蝉三棒缨小蜂效应的检测

为确定引诱假眼小绿叶蝉卵寄生蜂叶蝉三棒缨小蜂的茶梢信息物并检测其活性,遂于室内用Y管嗅觉仪进行行为测定,结果表明:1假眼小绿叶蝉口针刺吸和产卵管刺伤茶梢嫩茎、口针刺吸的茶树芽叶、以及口针刺吸芽叶近邻的健康茶叶的气味皆强烈引诱该蜂;2以健康茶梢、叶蝉为害茶梢挥发物中27种主要成分的3个剂量即10~(-6)、10~(-4)g/m L和10~(-2)g/m L正己烷溶液为味源,进行嗅觉反应测定,发现顺-茉莉酮、芳樟醇、橙花醇、正戊醇、正己醇、1-戊烯-3-醇、α-松油烯、α-松油醇和蒈烯的1或2个剂量显著引诱该蜂。茶园中:110~(-4)g/m L顺-茉莉酮、10~(-4)g/m L芳樟醇和10~(-4)g/m L 1-戊烯-3-醇三组分的等量混合物显著诱集叶蝉三棒缨小蜂;10-2g/m L橙花醇、10-2g/m L正戊醇、10-2g/m Lα-松油烯、10~(-6)g/m L正己醇、10~(-6)g/m Lα-松油醇和10~(-6)g/m L蒈烯六组分等量混合物的诱效更强;2加入液体石蜡作为缓释剂,可将该6组分诱集剂的半衰期延长0.7d;36:00—10:00缨小蜂比较活跃,这一时段诱捕的缨小蜂数占总诱捕数!50%。认为:假眼小绿叶蝉为害的茶梢上受害和未受害芽叶含有的顺-茉莉酮等部分挥发性化合物强烈地引诱叶蝉三棒缨小蜂,当它们按恰当比例组成诱集剂之后,则诱效显著增强,再与素馨黄色彩组合,诱效更强。     

茶蚜体表漂洗物对天敌的引诱活性及组分分析

行为生测和触角电位反应都证明茶蚜Toxoptera aurantii体表的正己烷或乙醚漂洗物对茶蚜重要天敌中华草蛉Chysopa sinica、蚜茧蜂Aphidius sp.和七星瓢虫Coccinella septempunctata具有显著的引诱效应,正己烷漂洗物的活性稍强。GC、GC-MS分析表明正己烷漂洗物中主要组分是苯甲醛、十一烷、2, 5-己二酮、2,5-二氢噻吩、芳樟醇、萘、4-甲基-辛烷、1, 2-苯甲酸-双-（二丁基-邻苯二甲酸甲酯）、二丁基-邻苯二甲酸甲酯和二十烷,其中苯甲醛、2, 5-己二酮和芳樟醇含量稍大。乙醚漂洗物中主要组分为反-2-己烯酸、正十七烷、2,6,10,14-四甲基十五烷、二十烷、四甲基四十烷、二丁基-邻苯二甲酸酯和十九烷,前2种组分含量较大。     

光肩星天牛对4种不同槭树科寄主植物的选择机制

用动态顶空采集法、TCT-GC-MS分析鉴定了复叶槭、五角枫、华北五角枫、挪威槭等4种槭树科植物挥发物的种类和相对含量,测定结果显示：4种植物的化学指纹图谱明显不同。“Y”型嗅觉行为测定结果表明,不同植物的挥发物对光肩星天牛的引诱效果不同：复叶槭对光肩星天牛的引诱效果最好,其次为五角枫,均达到了差异显著的程度,华北五角枫对光肩星天牛有引诱作用,但未达到显著程度,挪威槭对光肩星天牛既无引诱作用又无驱避作用。数据分析发现,五角枫、华北五角枫和挪威槭较复叶槭引诱作用差的原因可能与五角枫、华北五角枫中含有对光肩星天牛的驱避组分罗勒烯和反-2-己烯醇、挪威槭中含有对光肩星天牛的驱避组分（E）-1-戊烯-3-醇、反-2-己烯醇和trans-香叶基丙酮有关;在4种植物中醇类化合物、酮类和醛类化合物相对含量的排列顺序与植物的抗性顺序相同,而烷烃类和酯类化合物含量的排列顺序与植物的抗性顺序相反;复叶槭咬食程度轻的原因可能与其叶表面具有较少的表皮毛有关。     

假眼小绿叶蝉对茶梢挥发物的行为反应

【目的】研究假眼小绿叶蝉Empoasca vitis G?the对健康茶梢和蝉害茶梢挥发物的行为反应,筛选出可引诱假眼小绿叶蝉的茶梢挥发物。【方法】以动态吸附法收集健康茶梢和蝉害茶梢挥发物,用气相色谱–质谱联用仪(GC-MS)进行定性定量分析,借助于Y形嗅觉仪检测多种挥发物引诱假眼小绿叶蝉成虫的活性。【结果】从健康茶梢和蝉害茶梢中共鉴定出30种挥发物组分,其中烯烃类含量较大。健康茶梢和蝉害茶梢挥发物中共有组分有13种,蝉害之后其含量皆上升,其中Z-b-罗勒烯和乙酸叶醇酯的含量分别是健康茶梢中的142.27倍、12.90倍。蝉害茶梢中新出现的组分有12种,其中紫苏烯含量较高。在10-2、10~(-4)、10-6 g/mL浓度下,乙酸叶醇酯表现出极显著的引诱水平(P<0.01);紫苏烯在10~(-2)和10~(-4) g/mL浓度下表现出极显著引诱水平(P<0.01);10~(-4) g/mL浓度下,Z-b-罗勒烯和D-柠檬烯极显著引诱假眼小绿叶蝉(P<0.01);10~(-4) g/mL芳樟醇、10~(-6) g/mL乙酸正丁酯和10~(-6) g/mL D-柠檬烯呈现出显著引诱水平(P<0.05);混合物组分Blend1和Blend2分别表现出极显著和显著引诱水平;而10~(-6) g/mLa-法尼烯显著排斥假眼小绿叶蝉(P<0.05)。【结论】假眼小绿叶蝉成虫对健康茶梢和蝉害茶梢挥发物多种组分具有不同的行为反应,引诱效果较强的单组分或混合组分的选定可为田间引诱效果试验提供参考。     

Composition of the volatiles from intact and tea aphid-damaged tea shoots and their allurement to several natural enemies of the tea aphid

Abstract: The comparison between the composition of the volatiles from intact tea shoots (ITS) and that from tea aphid-damaged tea shoots (TADTS) was accomplished, and the difference of both volatiles in attraction to natural enemies of the tea aphid, Toxoptera aurantii , i.e the ladybug, Leis axyridis (Pallas), the aphid parasite, Aphidius sp., and the lacewing, Chrysopa septempunctata Wesmeal, was investigated in the current paper. Volatile components from ITS, obtained by air entrainment, were identified by their mass spectra and retention times and comfirmed by comparison with authentic samples. They are E-2-hexenal, ocimene, Z-3-hexenyl acetate, Z-3-hexen-1-ol, butanoic acid-3-hexenyl ester, linalool, 1-octanol, geraniol and indole. Volatiles from TADTS have been identified as E-2-hexenal, ocimene, Z-3-hexenyl acetate, Z-3-hexen-1-ol, linalool, geraniol, indole, benzaldehyde and E-2-hexenoic acid. Z-3-hexen-1-ol is the main component in the two kinds of volatiles, whilst benzaldehyde is the another main component in TADTS volatiles. The air entrainment extracts of TADTS and benzaldehyde elicit the stronger electroantennogram (EAG) responses, and the stronger upwind flight and arresting behaviour from each natural enemy in wind tunnel. EAG responses from Leis axyridis and Chrysopa septempunctata were bigger than those from Aphidius sp., whereas Leis axyridis responds to these odours slightly less than Aphidius sp. and Chrysopa septempunctata in wind tunnel bioassay. So TADTS emits volatile synomones, in which the amount of benzaldehyde is ample and its allurement is the strongest.     

EAG and behavioral responses of the wingless tea aphid Toxoptera aurantii (Homoptera: Aphididae) to tea plant volatiles

Electrophysiological and behavioral responses of the wingless tea aphid, Toxoptera aurantii (Boyer), to 14 synthetic volatiles identified from tea shoots, their partial (GLV mixture) and full (ACB mixture) blends, and fresh young tea leaves, buds, tender stems, adult tea leaves and tea aphid-damaged young leaves (ADYL) were studied by using an electroantennography (EAG) and a four-arm olfactometer. ACB elicited the largest EAG responses. Major volatile components, Z-3-hexen-1-ol, E-2-hexenal, n-hexanol, methyl salicylate and benzylalcohol, from the tea shoots were strongly EAG active. All the 4 tested tea shoot tissues also elicited significant EAG responses, with the young tea leaves being the strongest, followed by buds, tender stems and adult tea leaves. Surprisingly, ADYL elicited a weakly negative EAG response. In the olfactory assays, the fresh and tender tea leaves, as well as the individual major volatile components, e.g. Z-3-hexenyl acetate, methyl salicylate, E-2-hexen-1-ol and Z-3-hexen-1-ol, from the tender shoots (EAG-active) were all attractive. This result might indicate that the wingless tea aphids may use tea shoot volatiles as kairomone to find their optimal feeding sites, e.g. fresh tender tea shoots.     

Flavor of Black Tea

The neutral fraction of the essential oils from three kinds of black tea (same samples as described in the previous paper,¹⁾ i.e., Assam, Shan and Benihomare) was separated into carbonyl and carbonyl-free fractions and analysed by gas chromatography. On the basis of relative retentions and aroma of effluents with the references of the chromatographic data obtained by the previous works,^2–4) the major alcohols were found to be cis-2-pentenol, n-hexanol, cis-3-hexen-1-ol, three isomers of linalooloxide, linalool, nerol, geraniol, benzylalcohol, and phenylethylalcohol. In the carbonyl fraction, phenylacetaldehyde was newly identified, and besides it, the presence of iso- and n-butyr-, iso- and n-valer- aldehyde, methylethylketone, trans-2-hexenal, benzaldehyde were recognized. There were no differences in the components among three kinds of black tea, but the relative quantity of each component in the essential oil was different among three varieties.     

茶树花挥发物对叶蝉三棒缨小蜂的引诱增强效应

茶树(Camellia sinensis)是我国重要的经济作物。小贯小绿叶蝉(Empoasca onukii)是为害茶树的主要害虫之一。叶蝉三棒缨小蜂(Stethynium empoascae)是小贯小绿叶蝉的主要卵寄生蜂, 但茶树花对叶蝉三棒缨小蜂的引诱机制尚不明确。基于析因设计的方差分析结果显示, 茶树花可引诱天敌叶蝉三棒缨小蜂, 显著缩短其寄生行为的搜寻时间。茶树花可显著增强叶蝉为害茶梢对缨小蜂的吸引作用, 而对健康茶梢的增强效应不显著。基于气相色谱-质谱(GC-MS)的结果显示, 健康茶梢中的挥发物种类和相对含量较少, 而叶蝉为害茶梢和茶树花中挥发物种类和相对含量显著增多。偏最小二乘法判别分析(PLS-DA)结果显示, 茶树花挥发物具有明显的聚类特征。变量重要性投影结果表明, 17种茶树花挥发物在判别分析中可能起重要作用。行为测定结果显示, α-水芹烯、顺式氧化芳樟醇、反式氧化芳樟醇、苯甲醛和苯乙酮对叶蝉三棒缨小蜂具有显著的引诱效果。研究初步阐明了茶树花通过释放挥发物引诱叶蝉三棒缨小蜂的机制, 为制定叶蝉的生物防治策略提供了理论依据。     

Response of female Cydia molesta (Lepidoptera: Tortricidae) to plant derived volatiles

Peach shoot volatiles were attractive to mated female oriental fruit moth, Cydia molesta (Busck), in a dual choice arena. No preference was observed between leaf odours from the principle host plant, peach, and the secondary host plant, apple. Twenty-two compounds were identified in headspace volatiles of peach shoots using gas chromatography-mass spectrometry. Green leaf volatiles accounted for more than 50% of the total emitted volatiles. A bioassay-assisted fractionation using different sorbent polymers indicated an attractant effect of compounds with a chain length of 6-8 carbon atoms. The major compounds of this fraction were tested either singly or in combinations for behavioural response of females. Significant bioactivity was found for a three-component mixture of (Z)-3-hexen-1-yl acetate, (Z)-3-hexen-1-ol and benzaldehyde in a 4:1:1 ratio. This synthetic mixture elicited a similar attractant effect as the full natural blend from peach shoots as well as the bioactive fraction.     

Electroantennogram responses of Douglas-fir seed chalcids to plant volatiles

Douglas fir seed chalcids females oviposit specifically into Douglas cones which they locate using olfactory and visual cues. We have tested whether this specialization was correlated with a specialized sensitivity towards cone volatiles. Field collected adults were presented a series of pure volatile chemicals. Electroantennogram responses (EAG) were recorded to generally occurring terpenoids and straight chain alcohols and aldehydes found in flowers and plant leaves. Monoterpenes identified in Douglas cone headspaces (alpha-pinene, beta-pinene, 3-thujene, alpha- and beta-phellandrene, gamma-terpinene and myrcene) elicited lower EAG responses than fatty acid derivatives corresponding to green odours. The EAG response profile of females differed significantly from that of males. Females were very sensitive to hexanol-1, heptanal, (Z)-3 hexenol-1, terpineol and terpinen-4-ol. Male responses were significantly higher to humid air, nerolidol, thujan-4-ol, hexanal, carvacrol, piperitone and farnesol. Several compounds (Z- verbenol, carvone, jasminol, geraniol, nerol and eugenol) elicited long lasting electrophysiological responses (over 5 s) in both sexes.     

我国西南元江大理茶的挥发性成分及其抗氧化活性(英文)

大理茶 ( Camellia taliensis) 为山茶科山茶属茶组植物,主要分布于云南横断山脉澜沧江至伊洛瓦底江流域,即从云南的西部及西南部至缅甸北部。在其分布区,大理茶亦被称为野生大茶树,常用于加工制作茶叶。采用水蒸气蒸馏法、GC 及 GC/MS 联用技术,首次对大理茶的鲜幼叶和鲜幼叶及老叶分别制成的绿茶中的挥发性成分进行提取和分析,共鉴定出 91 个化合物。研究结果表明,大理茶鲜幼叶的主要香气成分为棕榈酸 ( 30. 52%) ,亚油酸 ( 19. 82%) ,植醇 ( 8. 75%) 和亚麻酸乙酯 ( 2. 54%) 等有机酸及其酯和二萜类,而制成绿茶后,其主要香气成分则为芳樟醇 ( 28. 43%) ,脱氢芳樟醇 ( 1. 13%) ,α-松油醇( 11. 68%) ,橙花醇 ( 4. 92%) 和香叶醇 ( 12. 34%) 等单萜醇类成分。从大理茶鲜叶到由其制成的绿茶,香气成分发生了较大变化,形成了 28 种原鲜叶中未检测到的香气成分,其中,( Z,Z,Z) -9,12,15-十八烷三烯-1-醇的含量分别达到 1. 21% ( 幼叶绿茶) 和 11. 2% ( 老叶绿茶) ,是大理茶制作的绿茶的特征香气成分。DPPH 和 ABTS+自由基清除实验结果显示大理茶鲜叶及其制成的绿茶的挥发性成分均具有一定的抗氧化活性,但均弱于茶多酚的抗氧化活性。     

Fragrance volatiles of developing and senescing carnation flowers

Thirteen major volatiles of the carnation flower fragrance signature have been identified by GC/MS. Of these, ten, hexanal, (2E)-hexenal, 1-hexanol, 2-hexanol, 3-hexen-1-ol, nonanal, benzaldehyde, benzyl alcohol, benzyl benzoate and caryophyllene, were quantified. The steady-state levels of these ten volatiles change independently as the flowers develop and senesce, suggesting that their synthesis is developmentally regulated. In addition, the chemical composition of the fragrance signature in naturally senesced flowers proved to be very different from that for flowers that had been induced to senesce prematurely by treatment with ethylene. Thus, senescence-related changes in carnation floral scent appear not to be directly regulated by ethylene. From cellular fractionation studies, it is evident that all of the volatiles, except 2-hexanol, are present in both membranous and cytosolic compartments, suggesting that their synthesis is membrane-associated and that they subsequently partition into the cytosol in accordance with partition coefficients.