The chromosome-level genome of double-petal phenotype jasmine provides insights into the biosynthesis of floral scent

Jasmine(Jasminum sambac Aiton)is a well-known cultivated plant species for its fragrant flowers used in the perfume industry and cosmetics.However,the genetic basis of its floral scent is largely unknown.In this study,using PacBio,Illumina,10×Genomics and highthroughput chromosome conformation capture(Hi-C)sequencing technologies,a high-quality chromosome-level reference genome for J.sambac was obtained,exploiting a double-petal phenotype cultivar‘Shuangbanmoli’(JSSB).The results showed that the final assembled genome of JSSB is 580.33 Mb in size(contig N50=1.05 Mb;scaffold N50=45.07 Mb)with a total of 39618 predicted protein-coding genes.Our analyses revealed that the JSSB genome has undergone an ancient whole-genome duplication(WGD)event at 91.68 million years ago(Mya).It was estimated that J.sambac diverged from the lineage leading to Olea europaea and Osmanthus fragrans about 28.8 Mya.On the basis of a combination of genomic,transcriptomic and metabolomic analyses,a range of floral scent volatiles and genes were identified involved in the benzenoid/phenylpropanoid and terpenoid biosynthesis pathways.The results provide new insights into the molecular mechanism of its fragrance biosynthesis in jasmine.

Diversity Analysis in Selected Non-basmati Scented Rice Collection

Diversity analysis among 23 rice varieties including 16 non-basmati scented accessions, 5 basmati accessions and 2 non-scented accessions was performed by random amplified polymorphic DNA （RAPD） and inter-simple sequence repeat （ISSR） marker systems. The varieties analyzed by 11 RAPD and 8 ISSR primers yielded an average of 65% and 80% polymorphism, respectively. The average number of polymorphic bands generated per RAPD primer was 6 and per ISSR primer was 5.87. RAPD and ISSR data analysis individually could not segregate basmati and non-basmati scented rice accessions. However, the analysis using a combined data could group basmati and non-basmati scented rice accessions separately. The bands present specifically among three accessions of non-basmati scented rice were also identified. The study revealed a high genetic diversity among non-basmati scented rice accessions.

Endocrine status and scent attractiveness in male dwarf hamsters Phodopus sungorus injected with thymus-dependent and thymus-independent antigens

We studied the influences of immune activation by thymus-dependent(sheep red blood cells,SRBC)and independent(bacterial lipopolysaccharide,LPS)antigens on odor signals and endocrine status in dwarf hamsters.Administration of SRBS to mature males resulted in a drop of sexual scent attractiveness of soiled bedding collected during 5 days after injection.This effect was accompanied with a decline of fecal testosterone.Reduction of the male scent attractiveness after SRBC treatment had maximum manifestation in males of dwarf hamsters with low humoral immune response to this challenge.Contrary to the effects of SRBC,males injected with LPS showed an increase of scent attractiveness.Differences in the time that mature females spent sniffing olfactory stimuli(LPS vs control),correlated positively with differences in concentration of testosterone in feces collected from LPS and saline treated males.We discuss the adaptive meaning of the opposite olfactory effects,which induced by activation of the nonspecific innate immunity with LPS and by activation of specific acquired immunity with SRBC.

Composition and Development Prospects of Scented Rice

Containing higher aromatic composition,scented rice is better than ordinary rice varieties in taste and nutrition. Major composition of scented rice is 2-acetyl-1-pyrroline( 2-AP). Different scented rice varieties have different content of 2-AP. The content of 2-AP is not only influenced by genetic factors,but also closely connected with types and content of nutrition elements in soil,soil moisture management,environmental temperature,and storage. 2-AP synthesis and regulation are possibly connected with Proline and enzyme.

Zhe9248—a new scented rice line cames out in Zhejiang

This novel rice line is developed recently’by a research team led by Associate Prof QIU Baiqin, Crop Breeding and Cultivation Institute, Zhejiang Academy of Agricultural Sciences. Zhe 9248 is of high resistance to blast, early mature and of higher yield. Being soft, smooth, and glossy, the cooked rice of "Zhe 9248" has excellent eating quality. The kernels of "Zhe 9248" are hardened to such a degree that they could be capa-

Analysis of inheritance of scented rice variety Shenxiangjing 4

We analyzed the inheritance of fragrance bysoaking rice grains or leafblades in 17g/l KOHsolution, using scented rice (Shengxiangjing 4)and non-scented rice (Huxuan 19 and Lao-laiqing) as materials. The Fplants of various crosses did notpresent fragrance. In the Fthe segregating ra-tio of fragrance and non-fragrance plants and

Smelling fit： scent marking exposes parasitic infection status in the banded mongoose

Preference for uninfected mates is presumed beneficial as it minimizes one＇s risk of contracting an infection and infecting one＇s offspring. In avian systems, visual ornaments are often used to indi- cate parasite burdens and facilitate mate choice. However, in mammals, olfactory cues have been proposed to act as a mechanism allowing potential mates to be discriminated by infection status. The effect of infection upon mammalian mate choice is mainly studied in captive rodents where ex- perimental trials support preference for the odors of uninfected mates and some data suggest scent marking is reduced in individuals with high infection burdens. Nevertheless, whether such effects occur in nonmodel and wild systems remains poorly understood. Here, we investigate the interplay between parasite load （estimated using fecal egg counts） and scent marking behavior in a wild population of banded mongooses Mungos mungo. Focusing on a costly protozoan parasite of the genus Isospora and the nematode worm Toxocara, we first show that banded mongooses that engage in frequent, intensive scent marking have lower Isospora loads, suggesting marking behavior may be an indicator trait regarding infection status. We then use odor presentations to demonstrate that banded mongooses mark less in response to odors of opposite sexed individuals with high Isospora and Toxocara loads. As both of these parasites are known to have detrimental effects upon the health of preweaned young in other species, they would appear key targets to avoid during mate choice. Results provide support for scent as an important ornament and mechanism for advertising parasitic infection within wild mammals.

Male and female meadow voles Microtus pennsylvanicus respond differently to scent marks from the top- middle-, and bottom-scent donors of an over-mark

Previous studies have shown that individuals responded preferentially to the mark of the top-scent donor relative to that of the bottom-scent donor of an over-mark. However, terrestrial mammals are likely to encounter over-marks consisting of the scent marks of more than two same-sex conspecifics in the intersections of runways, near the nests of sexually receptive female conspecifics, and inside and along the borders of the territories of conspecifics. We determined how meadow voles, Microtus pennsylvanicus, respond to the marks of the top-, middle-, and bottom-scent donors of an over-mark. We tested the hypothesis that voles exposed to an over-mark will respond preferentially to the scent marks that were deposited more recently, the scent marks that were on top or near the top of the over-mark, compared to the scent marks that were deposited earlier or near the bot- tom of the over-mark. Voles spent more time investigating the mark of the top-scent donor than that of the either the middle- or bottom-scent donor. However, males but not female voles spent more time investigating the middle-scent mark than the bot- tom-scent mark. We also tested the hypothesis that voles evaluate and respond to over-marks differently from single scent marks. Voles spent more time investigating the marks of the top-, middle-, and bottom-scent donors compared to scent marks that were not part of the over-mark. Voles can distinguish among the overlapping scent marks of three scent donors and sex differences exist in the values they appear to attach to each of these scent marks [Current Zoology 57 （4）： 441-448, 2011 ].

Coat color and its effect on preference for the scent marks of opposite-sex conspecifics in the meadow vole Microtus pennsylvanicus

Many mammal species can distinguish between opposite-sex conspecifics that differ in a certain trait. In that coat coloration is associated with differences in physiological and behavioral traits, coat color may affect the attractiveness of odor cues produced by conspecifics. Individuals may be able to respond preferentially to conspecifics with a particular coat color. In the present study, we test the hypothesis that scent marks of brown and blond voles differ in their attractiveness to male and fe- male conspecifics. Male voles and brown females did not discriminate between blond- and brown-coated opposite-sex con- specifics suggesting that they are neither selecting potential mates dissociatively nor associatively. However, blond females be- haved as if the scent marks of blond males were more attractive than were the scent marks of brown males. Our data suggest that blond females who are already conspicuous to predators, may select blond males as mates because they do not appreciably in- crease the risk of detection to predators, particularly avian predators. Moreover, because these conspicuous males have survived to mate they may have good genes that reflect their relatively higher quality

Female scent mobilizes leukocytes to airways in BALB/c male mice

The scent of receptive females as a signal to reproduction stimulates male mice to olfactory search of a potential breeding partner.This searching behavior is coupled with infection risk due to bacterial contamination of the fecal and urine scent marks.We hypothesized that sniffing of female soiled bedding induced the migration of immuno-competent cells into airways as a possible adaptation to breeding-related infection.Using bronchoalveolar lavage in a study on mice,we found the number of leukocytes to be significantly higher in male mice that were provided new portions of soiled bedding daily from female cages,in comparison with male mice that were kept in isolation from female scent.The number of leukocytes in blood was equal in both groups.However,monocytes were fewer in number in male mice exposed to female scent than in male mice isolated from female mice.Scent-induced migration of leukocytes was accompanied by typical behavioral(increased sniffing activity and aggressiveness)and morpho-logical(increase preputial glands and seminal vesicles)responses to olfactory sexual stimulus.

Folowing the Scent of Jasmine

Tea has been linked with China for centuries, but I grew up knowing little about China＇s tea or even China. Before coming to Beijing, I was familiar with green tea and black tea, but not much else. As an American with southern roots, black tea was usually served over ice in the summer, with sugar （which counteracted the bitter taste produced by over-brewing the tea）. I discovered green tea after college, and learned to love it hot, with no sugar.

Making Sense of Scents

Could a whiff of wintergreen revive drowsy drivers? A research project at Dowling College on New York’s Long Island aims to answer that question.Clifford Bragdon,the professor heading the project,says that previous re-

室温贮藏对花果香红茶风味品质的影响

为探明室温贮藏对花果香红茶风味品质和生化组成的影响,本研究比较了4种不同年份(0、1、2、3a)花果香红茶风味感官品质,并采用顶空固相微萃取-气相色谱-质谱联用技术和超高效液相色谱-静电场轨道阱高分辨质谱对花果香红茶中挥发性化合物和非挥发性化合物进行检测。结果表明,室温贮藏对花果香红茶的感官品质影响显著,室温贮藏3 a茶叶失去花果香品质特征,以陈酸等品质特征为主。基于主成分分析和系统聚类分析均可将供试茶样划分成不同年份的4个类群,基于偏最小二乘判别分析和单因素方差分析可从不同贮藏年份花果香红茶中筛选出芳樟醇、顺式-β-罗勒烯、己酸等15种挥发性差异化合物(变量投影重要性(variable importance in project,VIP)>1和P<0.05),茶氨酸、表儿茶素、葡萄糖酸等154种非挥发性差异化合物(VIP>2和P<0.05)。挥发性化合物中芳樟醇、己醛、顺式-β-罗勒烯、2-戊基呋喃等的含量随贮藏年份增加而减少,而己酸、二氢猕猴桃内酯、1-乙基-2-甲酰基吡咯、反式-β-紫罗兰酮等的含量随贮藏年份增加而增加。非挥发性化合物中大部分氨基酸类、核苷酸类、糖类、茶多酚等的含量随贮藏时间延长而减少,而有机酸和脂类化合物等的含量多呈增加趋势。研究结果可为阐明花果香红茶贮藏过程的风味品质变化提供科学依据,也有利于引导市场理性存茶和科学消费。

先锋的突围——论麦家《人生海海》的叙事策略

《人生海海》是麦家蛰伏多年的又一部长篇力作,相比于以往的“特情”题材小说,麦家将目光更多地投向了童年与故乡幽微深处的记忆,围绕“上校”身上的谜团,以限知视角和“纯文学”叙事语言进行着“英雄传奇”的突围式写作。麦家让平凡小人物和传奇大英雄于宏阔的历史背景下进行着人心与人性的交锋,于乡村叙事之中展现传奇之处,又以人性之本超越经典传奇。这部作品彰显了麦家独到的叙事能力,体现了麦家从类型化的桎梏转向“纯文学”叙事的努力,同时也传达出其对“人生海海”生命哲学的体悟。

基于HS-SPME-GC-MS分析三种茶坯窨制桂花茶的香气成分

为探究3种茶坯窨制桂花后的香气差异,采用顶空固相微萃取-气相色谱-质谱联用技术(Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry,HS-SPME-GC-MS)、感官审评和香气活性值(Odor Activity Value,OAV)对桂花红茶、桂花美人茶和桂花乌龙茶的香气成分进行分析。结果显示,窨制后3种桂花茶中共检测出726种共有香气成分,324种差异香气成分(P<0.05)。桂花茶以杂环化合物、萜类、酯类、烃类及酮类为主,占比78.73%。桂花茶中的关键呈香成分(OAV>10)为呋喃酮、α-紫罗兰酮、芳樟醇、柠檬醛、脱氢芳樟醇、月桂醇等。其中桂花红茶主要香气成分为芳樟醇、月桂烯、α-紫罗兰酮、β-紫罗兰酮、乙酸芳樟酯、苯甲醇、月桂醇等;桂花美人茶中主要香气成分为苯乙醛、柠檬醛、脱氢芳樟醇、芳樟醇、萜品油烯、α-紫罗兰酮、β-紫罗兰酮等;桂花乌龙茶主要香气成分为α-紫罗兰酮、吲哚、β-紫罗兰酮、月桂醇等。研究表明,桂花窨制能明显改善不同茶坯香气,赋予茶坯较浓郁持久的桂花香,其中以桂花红茶的品质最优。

基于全基因组的栀子花香成分合成TPS基因系统分析

栀子(Gardenia jasminoides J.Ellis)花色洁白且香气怡人,不仅具有极高的观赏价值,还是重要天然香料来源。萜类是栀子花独特香气的主要组成成分,但合成该类挥发性产物的关键萜类合酶(TPS)尚未鉴定。本研究基于栀子高质量基因组,通过转录组数据、系统发育树和保守结构域分析等,全面挖掘栀子萜类花香成分合成相关的TPS基因。结果显示,栀子基因组共注释到44个GjTPS基因,不均匀分布于11条染色体,其中9个GjTPS参与串联复制事件。所有GjTPS被划分为5个亚家族,其中27个属于被子植物特有的TPS-a、TPS-b和TPS-g分支。结合栀子5个器官的转录组数据及实时荧光定量PCR分析,筛选出5个候选GjTPS基因,其在盛开期的花器官中特异高表达,且含有DDXXD和NSE/DTE活性基序。其中,GjTPS1、GjTPS2、GjTPS3和GjTPS27为TPS-b分支酶,推测为芳樟醇或罗勒烯等栀子主要花香成分合成酶,而TPS-a分支的GjTPS18可能是金合欢烯合酶。

石斛属花香物质的合成及相关基因调控研究进展

大部分兰科石斛属植物都具有极高的药用和观赏价值。全球大约有1200~1500种石斛属植物,在我国分布的有76种,主要分布在西南、华南和台湾等地,其中云南最多,有62个种。花香是观赏植物重要的品质性状,随着分子生物学发展,在花香物质的生物合成途径、相关基因调节机制和基因工程方面等取得了较大进展,对近年来报道的石斛属26种植物中17种主要赋香成分和植物花香的生物合成途径、相关酶与基因调节机制的研究成果进行了综述,并对今后的研究和发展方向等进行了展望,旨在为今后植物花香性状的改良提供参考。

窨制方式对玫瑰红茶品质的影响

传统花茶的窨制主要是以鲜花与茶叶结合,为探究不同的窨制方法对玫瑰红茶的滋味和品质的影响,通过4种窨制方法(鲜花赋香、玫瑰细胞液喷洒赋香、玫瑰细胞液蒸气赋香、花瓣与细胞液蒸气结合赋香)对红茶进行赋香,完成玫瑰红茶的窨制。以色差、茶多酚总量、游离氨基酸含量、儿茶素等指标为依据,结合HS-SPME-GC-MS对不同窨制工艺制得的玫瑰红茶香气成分进行分析。结果表明,4种赋香方式所得玫瑰红茶的理化成分具有显著性差异(P<0.05)。用鲜花赋香和细胞液喷洒赋香的两种红茶茶汤偏红、偏黄,明亮度不及其它2种赋香方式。以喷洒玫瑰细胞液的窨制方式得到的玫瑰红茶氨基酸含量较高(112.66 mg/L);以玫瑰鲜花窨制得到的玫瑰红茶茶多酚含量较低(680.38 mg/L)。玫瑰红茶的主要呈香化合物为苯乙醛、芳樟醇、(E,E)-2,4-庚二烯醛、水杨酸甲酯、乙酸苯乙酯、β-紫罗酮、香叶醇、2-正戊基呋喃和正己醛这9种,玫瑰鲜花细胞液窨制的玫瑰红茶中含有的9种主要呈香化合物显著高于其它3种。本研究有助于创新玫瑰红茶的窨制方式,为高品质玫瑰红茶的窨制提供参考。

不同梅花品种花香成分鉴定与分析

【目的】比较梅花Prunus mume不同品种间的花香成分差异,了解梅花花香成分组成,为梅花花香代谢途径关键酶基因挖掘和分子育种提供参考。【方法】以不同品种群为材料,采用顶空固相微萃取法和气相色谱质谱联用技术(HS-SPME-GC-MS)测定了20个梅花品种的花香成分,明确梅花花香的特征香气物质,分析梅花不同品种群的花香成分及相对含量差异,并按照花香成分组成对梅花品种进行聚类分析。【结果】在20个梅花品种中共鉴定出43种挥发物,其中苯环/苯丙烷类化合物种类最多且相对含量最高,在梅花各品种中的相对含量均高于85%。乙酸苯甲酯、苯甲醇、丁子香酚、甲基丁香酚、苯甲醛和肉桂醇是梅花花香的主要成分,朱砂和宫粉品种群花香化合物数量最多,其次是跳枝和绿萼品种群,玉蝶和垂枝品种群花香化合物数量较少。聚类分析表明:根据花香成分的种类及相对含量,20个梅花品种可分为5类。【结论】梅花不同品种群的香气成分及其相对含量均有差异,不同花香成分对不同品种梅花香气的贡献也有差异。