荷花“重瓣化”的花器官形态发育比较观察

荷花（Nelumbo nucifera）的花型可分5种,最原始为单瓣型,然后由单瓣演化出半重瓣、重瓣、重台和千瓣型。为了揭示荷花重瓣化的分子机理,有必要从花器官的形态发育特征探究荷花花型成因及“重瓣化”的形态发育特征。实验分别选取5种荷花花型的代表品种：‘单洒锦’ （单瓣型）、‘大洒锦’ （重瓣型）、‘中山红台’ （重台型）、‘至尊千瓣’ （全重瓣型）、‘千瓣莲’ （千瓣型） 为材料,进行花芽分化过程形态的石蜡切片比较观察。结果发现：花芽分化过程中5个品种的萼片原基分化期和花瓣原基分化期相似,而雄蕊和雌蕊原基发育存在明显差异：单瓣、重瓣和重台品种均有正常的雄蕊和雌蕊原基分化;全重瓣品种发育初期有雄蕊及雌蕊原基分化,但后期全部瓣化;‘千瓣莲’品种不形成雄蕊和雌蕊原基,而是直接形成2至多个“花瓣增殖中心”,并由此不断分化出细小花瓣。研究认为重瓣型荷花品种的“重瓣化”花瓣主要来源于雄蕊的向心式瓣化,其次是雌蕊瓣化,属于雌雄蕊起源。而对于‘千瓣莲’型品种,花瓣的具体来源方式、花托是否直接参与瓣化及其在重瓣化过程中的作用有待于结合分子生物学手段开展进一步研究。     

荷花“重瓣化”的花器官形态发育比较观察

荷花（Nelumbo nucifera）的花型可分5种,最原始为单瓣型,然后由单瓣演化出半重瓣、重瓣、重台和千瓣型。为了揭示荷花重瓣化的分子机理,有必要从花器官的形态发育特征探究荷花花型成因及“重瓣化”的形态发育特征。实验分别选取5种荷花花型的代表品种：‘单洒锦’（单瓣型）、‘大洒锦’（重瓣型）、‘中山红台’（重台型）、‘至尊千瓣’（全重瓣型）、‘千瓣莲’（千瓣型）为材料,进行花芽分化过程形态的石蜡切片比较观察。结果发现：花芽分化过程中5个品种的萼片原基分化期和花瓣原基分化期相似,而雄蕊和雌蕊原基发育存在明显差异：单瓣、重瓣和重台品种均有正常的雄蕊和雌蕊原基分化;全重瓣品种发育初期有雄蕊及雌蕊原基分化,但后期全部瓣化;‘千瓣莲’品种不形成雄蕊和雌蕊原基,而是直接形成2至多个“花瓣增殖中心”,并由此不断分化出细小花瓣。研究认为重瓣型荷花品种的“重瓣化”花瓣主要来源于雄蕊的向心式瓣化,其次是雌蕊瓣化,属于雌雄蕊起源。而对于‘千瓣莲’型品种,花瓣的具体来源方式、花托是否直接参与瓣化及其在重瓣化过程中的作用有待于结合分子生物学手段开展进一步研究。     

基于SSR标记的荷花品种遗传多样性及群体结构分析

采用SSR标记技术对42个荷花品种( Nelumbo spp.)的基因组DNA进行扩增,在此基础上,对供试品种进行UPGMA聚类分析、群体结构分析和主坐标分析( PCoA)。结果表明：采用17对SSR引物从42个荷花品种的基因组DNA中扩增出77个位点,多态性位点百分率为88.31%;每对引物可扩增出1~9个多态性位点。根据Nei's遗传距离,供试的42个荷花品种可被分成Ⅰ和Ⅱ两组,分别包含3和39个品种;在Nei's遗传距离0.150处,Ⅱ组被进一步分成Ⅱa、Ⅱb和Ⅱc 3个亚组,分别包含3、16和20个品种。群体结构分析结果表明：组分概率高于等于0.80时,供试的42个荷花品种被分成Pop1、Pop2和混合群3个亚群,分别包含17、16和9个品种。 PCoA分析结果表明：在F1水平上,供试的42个荷花品种被分成2个部分;其中,Pop1亚群的品种均分布在第二和第三象限,而Pop2亚群的品种则分布在第一和第四象限。总体来看,聚类分析、群体结构分析和PCoA分析的结果基本一致。综合分析结果表明：玉组包含美洲黄莲( N. lutea Pers.)品种‘艾江南',且与传统中国莲( N. nucifera Gaertn.)品种的亲缘关系最远,故认为该组为美洲黄莲;Ⅱ组为中国莲,其中,Ⅱc亚组以传统中国莲品种为主,而Ⅱb亚组则偏重于美洲黄莲。总体上看,供试的42个荷花品种主要被分为中国莲和美洲黄莲两组,而中美杂交莲并没有独立成组,其成因有待进一步研究。     

莲科系统学和遗传多样性研究现状

分析回顾了莲科的系统位置、莲品种分类的现状与问题和莲的遗传多样性。莲科（Nelumbonaceae）植物传统上被归入睡莲科（Nymphaeaceae）。许多研究表明,莲科与睡莲科在形态、细胞、孢粉等方面差异很大,因而建立莲科,置于睡莲目（Nymphaeales）、毛茛目（Ranunculales）或莲目（Nelumbonales）中。分子系统学研究发现,睡莲科为被子植物的基部类群之一,而莲科则是真双子叶植物的基部类群之一,与山龙眼科和悬铃木科有密切关系。莲科含莲（Ndumbo nucifera）和美洲黄莲（N．lutea）两种,间断分布于太平洋的两岸。莲在我国有悠久的栽培历史和广大的栽培面积,栽培品种超过600个。由于杂交和反复回交的原因,品种之间的遗传关系非常复杂。莲的遗传资源的研究还很不充分,尤其是野生类型。对一些栽培品种的研究其实验材料又含有美洲黄莲的遗传组分,因而多高估了莲的遗传多样性。     

荷花新秀——霸王袍

1988年开始,我们试图通过莲属种间杂交,达到增加荷花品种花色之目的。经5年多的努力,我们选用“美国黄莲”(Nelumbo penta-petala)作母本,用中国莲(Nelumbo nucipera)的优良品种“玉楼台”作父本,在其杂交的后代中,筛选出了花色黄橙、重瓣的品种“霸王袍”。该品种1993年在中国荷花研究中心通过技术鉴定,1994年在全国第八届荷花展览中获优秀新品种特等奖。适宜盆植或池植,长势健壮,花色鲜丽。     

荷花品种比较试验

从始蕾、始花期、群体花期、着花密度、株型、花型等方面对41个荷花品种进行比较试验。结果表明,大株型荷花品种以祝福、西湖红莲最好;中小株型以金珠落玉盘、小精灵、绿云、小碧台、玉碗、红宝石、醉半熏、淡云、雨花、桃红小碗、红碗莲、瑶池春暖等12个品种最好,具有较高的观赏价值和商品价值。     

基于EST-SSR标记的莲属种质资源遗传多样性分析

利用EST-SSR分子标记对30个亚洲莲、6个美洲莲及14个亚美杂交莲品种(野生居群)进行遗传多样性分析,结果表明:从123对EST-SSR引物中筛选出52对(42.3%)扩增稳定、具有多态性的引物;利用这52对引物对50个不同类型代表的莲属品种进行扩增,共获得177条多态性条带,引物的等位基因数和多态性信息量(PIC)的范围分别为2~8个和0.63(NNFB-1059)-0.91(NNFB-750),平均为3.4个和0.79。利用NTSYS-pc2.11软件对扩增结果进行Jaccard相似性系数分析,50个荷花品种材料遗传相似系数为0.24~0.86;通过UPGMA法进行聚类分析,在遗传相似系数0.37处供试荷花材料可分为4大类群:亚洲莲品种均聚类在I、II类群中,III类群绝大部分为亚美杂交莲品种,IV类群为美洲莲,亚美杂交莲品种与亚洲莲品种的亲缘关系相对较近,与传统分类及前人研究结果相一致。     

不同荷花品种出泥部分与根状茎生长性状和部分生理指标的比较及相关性分析

在盆栽条件下,对不同荷花(Nelumbo nucifera Gaertn.)品种〔藕莲品种'大紫红'('Dazihong')、花莲品种'中国红·上海'('Zhongguohongshanghai')和花藕兼用莲品种'逸仙莲'('Yixianlian')〕出泥部分(叶和花)和泥下部分(根状茎)的生长性状和部分生理指标进行了比较研究,并对3个荷花品种出泥部分与根状茎间的生长性状和部分生理指标进行了相关性分析.结果表明:'大紫红'在整个生长发育期不开花;'中国红·上海'开花时间相对较早(6月上旬),花重瓣且色泽鲜艳;'逸仙莲'开花时间相对较晚(7月上中旬),花单瓣呈白色.3个荷花品种中,'大紫红'立叶数最少,立叶面积最大,根状茎膨大明显,根状茎中可溶性糖和可溶性蛋白质含量最高;'中国红·上海'立叶数最多,立叶中叶绿素含量最高,根状茎节间长度最长,但根状茎膨大不明显;'逸仙莲'立叶数居中,叶柄最长,根状茎膨大明显,根状茎中可溶性蛋白质、可溶性糖、淀粉和维生素C含量介于其他2个荷花品种之间.相关性分析结果表明:荷花立叶面积与根状茎节间长度呈显著负相关,而与根状茎中可溶性糖、可溶性蛋白质及维生素C含量呈极显著或显著正相关;叶柄长度与根状茎直径和根状茎节间质量呈显著正相关;立叶中叶绿素含量与根状茎节间长度和根状茎中淀粉含量呈显著正相关,而与根状茎中可溶性糖含量呈显著负相关.研究结果显示:根据供试3个荷花品种的立叶面积、叶柄长度、立叶中叶绿素含量可间接判断根状茎的生长发育及营养品质状况,并可进一步应用于快速选育花藕兼用莲品种.     

夏日荷花竞妖娆

正荷花常指亚洲莲(Asian lotus)、圣莲(Sacred lotus)、东方莲(Eastern lotus),但广义的荷花应该是整个莲属(Nelumbo)植物的统称。荷花为多年生水生植物,分布在亚热带和温带地区,性喜相对稳定平静的浅水湖泊、泽沼地、池塘等水生环境。现存荷花仅两种:即亚洲莲(N.nucifera)和美洲莲(N.lutea)。前者分布于亚洲和澳洲北部,有粉红色、紫红色、红色、白色、杂色等多色品种,也有单瓣、半重瓣、重瓣和花被片数可达7 000以上的极端重瓣品种‘千瓣莲’,栽培历史悠久,品种很多;后者又叫美     

不同类型莲资源的RAPD聚类分析

利用17个随机引物对32份莲属(Nelumbo)品种资源进行RA PD分析.扩增形成207条谱带,其中多态带193条,占93.23%,显示该属植物在我国具有丰富的遗传多样性.结果还表明:(1)莲属种质资源可分为3个品种群:花莲、子莲和藕莲,与传统的园艺学分类相吻合.(2)美洲黄莲与中国莲的花莲之间在DNA水平上差异不大,遗传背景与花莲更相似.(3)藕莲、子莲和花莲可能由不同遗传背景的野莲演化而来.     

Molecular Diversity in Indian Tobacco Types as Revealed by Randomly Amplified DNA Polymorphism

During the past five decades, a large number of tobacco varieties have been developed for different end uses in India through pure line selection from local land races, mutation breeding, and hybridization involving local selections and exotic introductions followed by pedigree selection. No systematic effort has been made to understand the existing diversity pattern in these varieties, which is crucial to define future breeding strategy in this important commercial crop. We characterized 46 varieties belonging to 10 different manufacturing tobacco types cultivated under different agro-climatic conditions in India along with two wild species of Nicotiana using 40 arbitrary primers in RAPID. The level of polymorphism among the varieties of N. tabacum was 59.4%, which was more than double the level observed in the other cultivated species N. rustica (25.2%). A broader range (0.64 to 0.94) of pair wise similarity measures in N. tabacum than in N. rustica (0.83 to 0.92) reflected the more diversified breeding efforts in the major cultivated species. The two wild species namely, N. glutinosa and N. gossei clustered separately from the two cultivated species. Molecular classification of the varieties corresponded largely with their manufacturing trait and parentage. RAPID markers provided sufficient resolution to distinguish among closely related tobacco types. Nine RAPID markers were found conserved across all the varieties and species. The markers found specific to the varieties can be used in correct identification of the carrier genotypes in trade and commerce. This is the first report on the molecular diversity analysis of Indian tobacco.     

中国黄杨属植物数量分类的研究

本文采用系统聚类分析方法对中国黄杨属植物20种、3亚种和2变种进行了分类学研究,研究结果表明：营养器官的32个特征性状、繁殖器官的35个特征性状和总的67个特征性状的系统聚类结果与该属植物形态分类结果相吻合,从而为该属植物新分类群的建立,种、亚种和变种的鉴定以及某些划分不合理的种群纠正提供了一种新的科学依据和手段。     

小麦品种间感染纹枯病的差异及普遍率与严重度的关系

通过人工接菌方法比较了６个小麦主栽品种间感染纹枯病的差异,结果表明,高感类型有阜阳８６１、温麦４号和皖麦１９,中感类型有扬麦１５８、豫麦１８和豫麦２１．各品种苗期病株率反映不出品种感病程度的差异,以灌浆后期的病情指数为标准比较品种间抗感染程度较为适宜．认为寄主生育阶段影响小麦纹枯病的ＩＳ关系．回归分析表明,按内茎和外茎发病程度分级可减少田间调查误差,且省时省工．     

A classification system for mosquito life cycles: life cycle types for mosquitoes of the northeastern United States.

A system for the classification of mosquito life cycle types is presented for mosquito species found in the northeastern United States. Primary subdivisions include Univoltine Aedine, Multivoltine Aedine, Multivoltine Culex/Anopheles, and Unique Life Cycle Types. A montotypic subdivision groups life cycle types restricted to single species. The classification system recognizes 11 shared life cycle types and three that are limited to single species. Criteria for assignments include: 1) where the eggs are laid, 2) typical larval habitat, 3) number of generations per year, and 4) stage of the life cycle that overwinters. The 14 types in the northeast have been named for common model species. A list of species for each life cycle type is provided to serve as a teaching aid for students of mosquito biology.     

A new look at variation in Darwin's species of acorn barnacles

Darwin's studies on barnacles, begun to satisfy his curiosity about specimens from the Beagle , but later extended to the large collections of other naturalists, lasted for 8 years and produced a set of definitive monographs. Darwin was particularly troubled over the taxonomy of two groups of acorn barnacles, Balanus tintinnabulum and B. amphitrite , which he ultimately classified as clusters of wellmarked varieties. Recent studies, based on established taxonomic methods or on statistical treatment of morphometric data, suggest these are clusters of full species and that the 'intermediate' forms are just phenotypic variants. Darwin was also troubled by the small chthamalid intertidal barnacles, which he eventually grouped as varieties of a world-wide species, Chthamalus stellatur. Gel electrophoresis and morphometrics now show this to be a heterogenous assemblage of distinct species, some very different, others closer together, all with restricted geographical range, but all showing extreme variability in the characters normally used for classification.
Darwin's difficulties with the classification of the highly varying barnacles, and his anatomical studies on these peculiar animals, must have had considerable influence on the development of his theories about natural selection, more than is usually acknowledged by writers on evolution. These 'lost years' were in fact a period of intense zoological enquiry, and Darwin's change in attitude with regard to species and variation in nature underwent a big change, as can be seen from the letters and from the differences between the early drafts written before the barnacle work and the later Natural Selection and The Origin. Whether we regard the difficult groups of Balanus as clusters of species or clusters of varieties, they still draw attention to evolutionary processes as in Darwin's day.     

甘蔗品种黑穗病抗性评价体系的建立

为了建立甘蔗品种黑穗病抗性评价体系,选用9个引进品种,设计一个包括6个对照品种在内的田间试验。首次采用混合小种进行人工浸渍接种,通过整个新植蔗生长季病害进展曲线下的面积、茎感染率和株感染率3个病情指数,以及病害流行学参数潜伏侵染期和持续发病期的分析,对其扰痛性进行评价。在分析以上参数相关程度的基础上,引进了系统聚类分析法进行进一步评价。结果显示;9个引进甘蔗品种中,ROC26属于感病品种,其余属于抗病或高抗品种;3个病情指数和持续发病期的两两相关均为显著正相关,潜伏侵染期与这些参数的相关为负相关,但未达到显著水平;在类间距离大于1．0的条件下,可将15个品种聚为6类,进一步明确了备品种抗黑穗痛性的相似程度;抗性鉴定标准对照种NC0310、F134、NC0376和Ya71—374的应用,明确了接种源为小种1和小种2,通过一次接种试验,明确了供试品种对2个小种的抗性水平,标准对照种的抗性表现,还说明了本生长季发病条件基本是适宜的。本文建立的甘蔗品种抗黑穗病评价体系是切实可行的。     

Object-based classification of land cover and tree species by integrating airborne LiDAR and high spatial resolution imagery data

We evaluated the effectiveness of integrating discrete return light detection and ranging (LiDAR) data with high spatial resolution near-infrared digital imagery for object-based classification of land cover types and dominant tree species. In particular we adopted LiDAR ratio features based on pulse attributes that have not been used in past studies. Object-based classifications were performed first on land cover types, and subsequently on dominant tree species within the area classified as trees. In each classification stage, two different data combinations were examined: LiDAR data integrated with digital imagery or digital imagery only. We created basic image objects and calculated a number of spectral, textural, and LiDAR-based features for each image object. Decision tree analysis was performed and important features were investigated in each classification. In the land cover classification, the overall accuracy was improved to 0.975 when using the object-based method and integrating LiDAR data. The mean height value derived from the LiDAR data was effective in separating “trees” and “lawn” objects having different height. As for the tree species classification, the overall accuracy was also improved by object-based classification with LiDAR data although it remained up to 0.484 because spectral and textural signatures were similar among tree species. We revealed that the LiDAR ratio features associated with laser penetration proportion were important in the object-based classification as they can distinguish tree species having different canopy density. We concluded that integrating LiDAR data was effective in the object-based classifications of land cover and dominant tree species.     

Moist lower montane rainforest classification: a case study from Bwindi Impenetrable National Park,Uganda

Moist lower montane vegetation has rarely been classified beyond broad zonational belts over large altitudinal ranges due to highly diverse species composition and structure. This study shows it is possible to further classify such forest types within Bwindi‐Impenetrable National Park (BINP), and that these assemblages can be explained by a combination of environmental conditions and past management. Botanical and environmental data were collected along some 4000 m of linear transects from the area surrounding Mubwindi Swamp, BINP. Ordination using Nonmetric Multidimensional Scaling (NMDS) and classification using Two‐way Indicator Species Analysis (TWINSPAN) successfully identified four different species assemblages. These forest types were then named on the basis of the ecological characteristics of the species within the group, and the environmental conditions influencing the distribution and past disturbance of the forest. The techniques used were in agreement for three out of the four forest types identified. Analysis using an environmental overlay showed a significant association between forest type and altitude. The results of this study indicate that a regional classification of forest types within moist lower montane forest belt using only tree species is possible, and that the forest types identified can be explained by environmental conditions and past management.     

Taxonomic analysis of volatiles emitted by ornamental crabapple flowers

To identify and classify volatile compounds in the fragrances of crabapple flowers from ornamental and original species in the peak April Tai’an, Shandong flowering season. Volatile components from flowers were identified using dynamic-headspace sampling, purge and trap and GC/MS. Eighty compounds were detected in the 17 ornamental crabapple cultivars, while sixty-eight compounds were found in the nine original species, including forty-four compounds in both the original species and cultivars. The main volatile components and common components of crabapple flower aroma include: 3-methyl-1-butanol, ocimene, benzyl alcohol, 3-methyl-4-oxo-pentanoic acid and heptane. Based on the relative volatile content the 26 taxa could be classified into seven different groups through UPGMA cluster analysis. The different volatile contents, such as myrcene and benzaldehyde, result in the extraordinary aroma of different crabapple varieties. M. ‘Dolgo’, M. ‘Eleyi’, M. ‘Hopa’, M. ‘Liset’, M. ‘Makamik’ and M. ‘Royalty’ are good breeding varieties of sweet flowering crabapples which could be used to breed additional ornamental cultivars with excellent fragrance and high value.     

芥菜16个变种的RAPD研究

利用ＲＡＰＤ技术对芥菜（ＢｒａｓｉｃａｊｕｎｃｅａＣｏｓ．）１６个变种的遗传变异进行研究。从６０个随机引物中筛选出２７个有效引物,共扩增出３３６条ＤＮＡ带,其中２７５条为多态性带,占８１８５％,平均每个引物扩增的ＤＮＡ带数为１２４４条。利用１９个有效引物扩增的２４０条ＤＮＡ带对芥菜１６个变种间的亲缘关系进行ＵＰＧＡ聚类分析,计算出１６个变种间的平均遗传距离为７３４,在此基础上建立了中国菜用芥菜１６个变种的ＤＮＡ分子系统树图。该系统将芥菜的１６个变种划归Ａ、Ｂ、Ｃ三个组,其中Ａ组７个变种,Ｂ组８个变种,Ｃ组只有１个变种,Ｂ组又可细分为两个亚组。对芥菜遗传多样性的分子基础进行了探讨。