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

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。

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.

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。

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。

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。

不同干燥方法对梅花品质的影响及评价

【目的】探究不同干燥方法对梅Prunus mume干花品质的影响,并对其进行综合评价,为实际干燥加工中保持梅花的品质提供参考。【方法】采用热风干燥法、微波干燥法、复合干燥法和真空冷冻干燥法对8个梅花品种‘东方朱砂’‘Dongfang Zhusha’、‘骨红朱砂’‘Guhong Zhusha’、‘晓红宫粉’‘Xiaohong Gongfen’、‘粉皮宫粉’‘Fenpi Gongfen’、‘粉台玉蝶’‘Fentai Yudie’、‘月光玉蝶’‘Yueguang Yudie’、‘久观绿萼’‘Jiuguang Lve’、‘素玉绿萼’‘Suyu Lve’的鲜花进行干燥,以色差值、抗氧化能力、总黄酮质量分数等作为评价指标,比较不同干燥方法对梅花品质的影响,运用熵权-变异系数法组合赋权计算综合评分,并用加权逼近理想解排序法验证评价模型,得到最优的干燥方法。【结果】4种干燥方法中,真空冷冻干燥处理的梅花色差值与收缩率最小,分别小于33.09、28.7%,且样品总黄酮、花青素、总绿原酸质量分数最高。真空冷冻干燥法与复合干燥法处理材料的可溶性蛋白质质量分数最高,抗氧化能力最强。挥发性成分在复合干燥后保留率最高,大于50%。综合评分排名由高到低依次为真空冷冻干燥组、复合干燥组、热风干燥组、微波干燥组。【结论】4种干燥方法中真空冷冻干燥法后有效成分质量分数最高,其次为复合干燥法。真空冷冻干燥与复合干燥后梅花品质较佳,可用于梅花精品加工与干花批量生产。

梳帽卷瓣兰花部特征对蝇类传粉者的适应性

为揭示梳帽卷瓣兰(Bulbophyllum andersonii)的繁殖特性和传粉机制,在2023年对分布于云南西双版纳的梳帽卷瓣兰野生居群开展了传粉生物学研究,包括开花物候、繁育系统、传粉昆虫、花部微观形态特征及花的挥发性成分等。结果如下:梳帽卷瓣兰的盛花期在7月中旬,单花花期为5 d;繁育系统属于异交并依赖传粉者,自然结实率为26.06%;套袋试验表明自交不亲和,不存在无融合生殖和自动自花授粉现象;唇瓣的铰链结构、传粉通道及宽大的侧萼片等花部特征在传粉过程中发挥重要作用;曲角杆蝇(Gampsocera sp.)是其唯一有效传粉者并在访花过程中表现出舔舐唇瓣的行为;通过扫描电镜观察发现,唇瓣上附着大量的特殊颗粒,可能是访花者的食物报酬;花部挥发性气味主要含有单萜类、芳香类等化合物,其中邻苯乙醚和避蚊胺可能与昆虫访花行为有关。上述研究结果表明,梳帽卷瓣兰的花形态结构与气味适应于曲角杆蝇进行传粉,属于特化传粉系统。

藏香猪流行性腹泻病毒的PCR检测及毒株分型

为明确四川省凉山彝族自治州某藏香猪规模化养殖场哺乳仔猪腹泻的病因,试验采集腹泻仔猪的粪便和肠道样品进行实验室病原学诊断,采用RT-PCR方法检测4种常见肠道病毒的感染情况。检测结果显示,猪流行性腹泻病病毒(PEDV)检测为阳性,猪delta冠状病毒、猪传染性胃肠炎病毒和猪A群轮状病毒3种病毒均为阴性。进一步采用RT-PCR扩增该毒株S1基因序列并测序。结果显示,该毒株与G2型变异毒株同源性最高,与其他基因型毒株同源性相对较低,因此判定该猪场仔猪发病是由猪流行性腹泻病毒G2型变异毒株感染所致。对病猪进行紧急免疫接种、治疗、消毒等综合防控措施,控制住了疫病的蔓延和发展。总结此次猪流行性腹泻病的治疗经验,为养猪场对该疫病的治疗和防控提供借鉴。

不同品种玫瑰花及花蕾气味的电子鼻分析

以玫瑰花及花蕾为试验材料,采用电子鼻技术,通过聚类分析、主成分分析(Principal Component Analysis,PCA)、正交偏最小二乘法判别分析(Orthogonal Partial Least-squares Discriminant Analysis,OPLS-DA)等多元统计学方法,研究了不同品种玫瑰花及花蕾的气味特征。结果表明,14个品种玫瑰花被分为三类,组间差异标志物为W1W、W5S、W2S,即无机硫化物、氮氧化合物、醇醚醛酮类,3种差异标志物的强度大小为1组>2组>3组,均具有显著差异;8个品种玫瑰的花蕾被分为三类,组间差异标志物为W5S、W1W,即氮氧化合物、无机硫化物,两种差异标志物的强度大小为1组>2组>3组,均具有显著差异;玫瑰花与花蕾的挥发性成分含量存在差异,大部分玫瑰的花蕾挥发性成分含量高于玫瑰花,少部分玫瑰花蕾挥发性成分含量低于玫瑰花或成分含量差异不大,且主要差异标志物为W1W、W5S、W2S、W2W,即无机硫化物、氮氧化合物、醇醚醛酮类和有机硫化物。通过电子鼻技术可快速有效区分不同品种玫瑰花和花蕾的挥发性成分差异,可为玫瑰香气研究和质量评价提供参考。

不同花期珠兰花及珠兰花茶香气品质分析

以5种开放状态(花苞、初开、半开、全开、凋谢)的珠兰花为材料,采用感官评价、顶空固相微萃取结合气相色谱-质谱联用、气味活性值(odor activity value,OAV)等分子感官技术分析不同花期的珠兰花香气品质,并进行主成分分析与正交偏最小二乘判别分析及置换检验。结果表明,5种不同开放状态珠兰花的感官评价和挥发性物质的种类与含量均存在差异。全开珠兰花香气纯正持久,品质最佳;其次是半开、初开状态,略带花香;凋谢状态花香与腐败气味交杂,花苞状态花香无且青气重,都不宜窨制花茶。共检测出挥发性化合物98种,各开放状态下总含量范围为77.521~200.838μg/g,其中醇类22种、醛类13种、烯烃36种、酯类14种、酮类4种、其他类9种。全开珠兰花挥发性化合物含量最高,其中OAV>1的香气化合物有28种,OAV>50的有9种。由于全开状态珠兰花在表观与香气特征及释香能力上比较突出,由此分别窨制绿茶与红茶,发现其具有玉兰花香属性的茉莉酮酸甲酯等香气成分含量较素茶坯有明显增加,对改善茶叶香气品质有正向效果。综上,全开状态珠兰花最适窨制珠兰花茶。