多花水仙花色基因与遗传转化研究进展

综述近年来多花水仙在花色基因研究与遗传转化研究方面的进展,包括多花水仙花色成分、花色基因的克隆及其表达调控、花色基因的遗传转化等方面,分析该领域存在的问题,并对其应用前景进行展望。     

红肉脐橙落花落果规律的观察研究

2008年对红肉脐橙生理落果进行观察研究,以揭示其落花落果规律,为制定保花保果技术措施提供依据。结果表明：红肉脐橙落蕾落花时间集中在4月上中旬,4月12日出现明显的落蕾落花高峰,4月21日开始第1次生理落果,持续35d,于5月26日结束,其中5月4日和5月9日分别出现2次落果高峰;落花后18d,即5月11日开始第2次生理落果,至6月27日结束,持续47d,其中5月17～18日和6月9日分别出现2次落果高峰;红肉脐橙落花、第1次、第2次生理落果分别占总落花落果数的80．7％、16．8％和2．5％,坐果率为0．89％。生理落果以第1次生理落果为主,建议在谢花期、第10：生理落果高峰前的4月底或5月初,各喷施1次50×10^-6 GA3溶液保果,5月中旬第2次生理落果高峰前再喷施1次;红肉脐橙脐黄率为8．8％、裂果率为15．2％,裂果率偏高乃久旱骤雨所致。     

英国皇家园艺学会比色卡颜色特征及其在盆栽香石竹花色测定上的应用

为明确植物常用颜色测定工具英国皇家园艺学会比色卡（Royal Horticultural Society Color Chart,RHSCC）的颜色特征及其在花色测定应用上的科学性,以884个RHSCC色号和150个盆栽香石竹品种花色为研究对象,采用色差仪测定法和色卡目测比对法进行颜色测定,利用统计学方法和色差公式进行颜色分析。结果表明：RHSCC 884个色号在高明度、红色及黄色分量区分布密集;在a*b*二维分布上集中于第I和第Ⅱ象限;60个色号两两间最小色差值为0.50～1.50,其中4个色号处于不同UPOV（国际植物新品种保护联盟）色组。RHSCC目测法结果显示,150个盆栽香石竹品种中,47个品种花色难以比对到准确的RHSCC色号（花色及其近似色卡色差值>6.00）;部分品种花色可比对到2个RHSCC色号（色卡间色差值<3.00）。RHSCC目测法对品种分组的结果表明,粉色系颜色区间过大,白色和深紫色系区间过小;黄绿色、黄色和绿色3个色系难以在颜色阈值上区分;多数色系含有游离颜色等问题。综上,RHSCC在花色测定时需要考虑其局限性,包括部分色号间色差值过小,人眼分辨...     

中国水仙花色相关基因的克隆与分析

[目的]克隆并初步分析与中国水仙花色发育相关的八氧番茄红素合成酶(PSY)、八氢番茄红素脱氢酶(PDS)和番茄红素β-环化酶(LycB)等3个酶基因序列及结构,了解其花色形成的分子机制,为进一步研究中国水仙类胡萝卜素代谢基因工程奠定基础.[方法]以中国水仙花瓣的mRNA为模板,采用RT-PCR技术扩增PSY、PDS和LycB等3个关键酶基因的保守序列,并进行序列结构分析.[结果]分离得到的中国水仙PSY、PDS和LycB的保守序列长度分别为343、500和486 bp,分别编码112、166、161个氨基酸.基因比对结果表明,推导氨基酸序列与已知其他不同植物均具有较高同源性,分别为76.5%~96.1% 、69.8%~98.3%和77.3%~95.5%,且包含PSY、PDS和LycB酶的相关功能结构域,初步证明为目标基因,不同物种间的PSY、PDS和LycB基因具有相当高的保守性.编码蛋白预测结果发现,PSY、PDS和LycB虽然有部分疏水区域,但是不存在明显的跨膜结构域.[结论]研究结果为进一步了解中国水仙花色相关酶基因的调控功能及花瓣着色机理奠定分子基础.     

Aureusidin synthase: a polyphenol oxidase homolog responsible for flower coloration

Aurones are plant flavonoids that provide yellow color to the flowers of some popular ornamental plants, such as snapdragon and cosmos. In this study, we have identified an enzyme responsible for the synthesis of aurone from chalcones in the yellow snapdragon flower. The enzyme (aureusidin synthase) is a 39-kilodalton, copper-containing glycoprotein catalyzing the hydroxylation and/or oxidative cyclization of the precursor chalcones, 2',4',6',4-tetrahydroxychalcone and 2',4',6',3,4-pentahydroxychalcone. The complementary DNA encoding aureusidin synthase is expressed in the petals of aurone-containing varieties. DNA sequence analysis revealed that aureusidin synthase belongs to the plant polyphenol oxidase family, providing an unequivocal example of the function of the polyphenol oxidase homolog in plants, i.e., flower coloration.     

不同花色甘草种质的质量分析及其HMGR基因特征研究

在甘草群体中发现了不同花色的甘草种质,将其定义为白花类型和紫花萼类型。利用HPLC方法对不同花色种质进行了药用活性成分含量测定,发现白花和紫花萼类型的甘草酸、甘草苷和异甘草素含量均高于普通花色类型。对白花类型和紫花萼类型的两个甘草酸含量不同植株的HMGR基因特征分析结果表明,两者在HMGR部分DNA水平上存在碱基差异。     

Chemical trail-following by flying insects: a mechanism for orientation to a distant odor source

An aerial trail of odorous pheromone molecules extends downwind from a female pink bollworm moth that is receptive for mating. Males apparently sense the boundaries of the trail during their characteristic zigzag flights across it. Contrary to previous beliefs, the mechanism by which the males steer toward the odor source does not require a sensing of wind direction.     

Action spectra for phase shifts of a circadian rhythm in Drosophila

Action spectra were determined for lightinduced phase shifts of the circadian rhythm of adult emergence in Drosophila pseudoobscura. The action spectra for advance and delay phase shifts are similar; the most effective wavelengths are in the blue region, with a sharp cutoff above 500 nanometers. This similarity suggests that the same photoreceptive pigment mediates both advance and delay phase shifts.     

基于SLAF-BSA技术的蝴蝶兰花底色关联SNP分子标记开发与验证

为筛选与蝴蝶兰花黄白底色相关的单核苷酸多态性(Single-nucleotide polymorphism,SNP)位点,以'黄金豹'蝴蝶兰(♀)和'白天使'蝴蝶兰(♂)及其杂交后代为实验材料,选择33个分布在5个不同颜色分布类型组群中的黄色底色杂交后代和仅有的2个纯黄色个体作为黄色底色群体,35个分布在对应5个颜色分布类型组群中的白色底色杂交后代作为白色底色群体,分别提取DNA并等量混合后构建2个不同底色DNA混池,采用特异位点扩增片段测序(SLAF-seq)结合BSA技术,对与花底色密切相关的候选标记进行鉴定。结果表明:共获得164 874个SLAF标签,其中含21 031个多态性SLAF标签,多态率为12.76%。SLAF标记在亲本中的平均序列深度为42×,在子代中的平均序列深度为46×。关联分析表明,在阈值0.745 5时,筛选得到15个与花底色相关的SLAF候选标记,具27个SNP位点。采用SNaPshot测序技术在2个亲本、11个子代和4个不同的种质资源中验证SNP位点,筛选发现,Marker35886和Marker70907的2个SNP位点与相关SLAF序列中的SNP位点一致,对花底色的鉴定准确率分别为66.67%和73.33%,组合准确率达93.33%。本研究筛选到的2个SNP位点可作为有效的分子标记位点在蝴蝶兰育种早期进行辅助选择。     

Mapping and predicting a candidate gene for flesh color in watermelon

The color of watermelon flesh is an important trait determined by a series of carotenoids. Herein, we used Cream of Saskatchewan(pale yellow flesh) and PI 186490(white flesh) as parental materials for an F2 segregation and initial mapping using the bulked segregant analysis sequencing(BSA-seq) strategy. The BSA results revealed a flesh colorrelated QTL that spans approximately 2.45 Mb on chromosome 6. This region was preliminarily positioned in a 382-kb segment, and then narrowed down into a 66.8-kb segment with 1 260 F2 individuals. A total of nine candidate genes were in the fine mapping interval, but only Cla007528(encoding chlorophyllase) had non-synonymous mutations and was significantly expressed between the parental materials throughout flesh development. We also checked the expression patterns of the carotenoid metabolic pathway genes based on RNA-seq data and qRT-PCR validation. Three genes in the xanthophyll cycle(ClCHYB, ClNCED-1 and ClNCED-7) exhibited differential expression patterns between the two parental lines at different flesh color formation stages. ClPSY1, ClPDS, ClZDS, ClCHXE, ClCRTISO and ClLCYB also exhibited clearly different expression patterns accompanied by carotenoid accumulation.     

人口总量与结构变化影响植被覆盖的实证研究

人口变化对我国自然环境所产生的影响越来越大,其中,植被作为陆地生态系统的主要组成部分,为人类社会经济活动提供最重要的资源,其受到的影响尤其显著.基于我国31个省市的人口和植被归一化植被指数(NDVI)数据进行实证分析,结果表明,我国人口总量增长对植被覆盖变化产生了较大的负面影响,其中,工业就业人口的增长加剧了这种影响,而人口城镇化发展、年龄结构和文化素质的改善则相对减缓了这种影响.相应地,我国需要采取的措施包括加快入口城镇化、建立绿化保障制度、推广绿化新技术、优化人口就业结构、培育公民绿化环保意识等.     

Mobility gaps: a mechanism for band gaps in melanins

The semiconductor behavior of melanins is reviewed and compared with quantum mechanical models of conduction in amorphous solids. The available data are consistent with extensions of Mott's basic model for amorphous semiconductors, whereas they are inconsistent with crystalline semiconductor models. An investigation of the specific conduction mechanisms operative in melanins in terms of the amorphous model should reveal important aspects of the band structure.     

Baring high-albedo soils by overgrazing: a hypothesized desertification mechanism

Observations are reported of high-albedo soils denuded by overgrazing which appear bright, in high contrast to regions covered by natural vegetation. Measurements and modeling show that the denuded surfaces are cooler, when compared under sunlit conditions. This observed "thermal depression" eflect should, on theoretical grounds, result in a decreased lifting of air necessary for cloud formation and precipitation, and thus lead to regional climatic desertification.     

Langmuir supercells: a mechanism for sediment resuspension and transport in shallow seas

Recent measurements at a cabled sea-floor node in 15 meters of water off the coast of New Jersey suggest that Langmuir supercells, Langmuir circulations that achieve vertical scales equal to the water depth under extended storms, are an important mechanism for major sediment resuspension events on the extensive shallow shelves off the eastern U.S. coast. Because sediment resuspension is a prelude to transport, supercell events are a necessary condition for major sediment transport. Such events may also contribute to shelf-sea exchange and to offshore gradation of benthic community structure in shallow seas.     

Gravitational inconsistency in the lunar theory: confirmation by radio tracking

When range and Doppler observations of space probes near or on Moon are reduced by use of a lunar ephemeris calculated from the Brown lunar theory, residuals as large as 440 meters in position and 1.5 millimeters per second in velocity are observed. When the calculations are repeated with use of LE 5, the integrated lunar ephemeris described (1), the residuals are greatly reduced.     

Allelopathy between zooplankton: a mechanism for interference competition

The filtering rate of the copepod Diaptomus tyrrelli is reduced in the presence of its potential competitor and predator, Epischura nevadensis, by as much as 60 percent. This effect is caused by a chemical released into the water by Epischura. The chemical does not pass through dialysis tubing with a pore size of 10(4) angstroms, indicating that it is a large molecular weight compound. The reduction in filtering rate is the result of interference competition between two species and may be linked to the evolution of a mechanism for avoiding predation.     

瓯江彩鲤形态特征的两性异形和雌性个体生育力

研究了瓯江彩鲤(Cyprinus carpio var.color)体重和形态特征等19个参数的两性异形及雌性个体生育力.结果表明:除特定体长1龄雌性个体的体高和体重显著小于雄性个体外,其它17个性状不存在显著的雌雄两性异型.在2龄鱼中,雌性个体的头长、头宽、头高、眼后头长、眼间距、尾鳍长、体重和躯干重显著大于雄性个体,而体高却显著小于雄性个体,其它性状也不存在显著的雌雄两性异型;对这9个差异显著的形态特征变量进行主成分分析发现,第一和第二主成分共解释67.6%的变异,体高、体重和躯干重在第一主成分有较高的正负载系数(解释42.9%变异),头宽和眼间距在第二主成分有较高的正负载系数(解释24.7%变异).以年龄、性别为固定效应的两因素方差分析(Two-way ANOVA)显示,1龄鱼第一主成分的分值显著小于2龄鱼,雌性第二主成分的分值显著大于雄性,其它主成分的年龄、性别间无显著差异,两因素交互作片{对第一、第二主成分的分值亦无显著影响.雌性个体的生育力结果表明,瓯江彩鲤的怀卵数量与体长和体重回归关系显著.偏相关分析表明,雌性怀卵数量与体重呈显著的正相关(P<0.004),而与体长的相关不显著(P=0.502).生育力选择是瓯江彩鲤个体大小和局部特征两性异形的主要原因之一.