Generic relationships and dating of lineages in Winteraceae based on nuclear (ITS) and plastid (rpS16 and psbA-trnH) sequence data

Phylogenetic analyses of representative species from the five genera of Winteraceae (Drimys, Pseudowintera, Takhtajania, Tasmannia, and Zygogynum s.l.) were performed using ITS nuclear sequences and a combined data-set of ITS + psbA-trnH + rpS16 sequences (sampling of 30 and 15 species, respectively). Indel informativity using simple gap coding or gaps as a fifth character was examined in both data-sets. Parsimony and Bayesian analyses support the monophyly of Drimys, Tasmannia, and Zygogynum s.l., but do not support the monophyly of Belliolum, Zygogynum s.s., and Bubbia. Within Drimys, the combined data-set recovers two subclades. Divergence time estimates suggest that the splitting between Drimys and its sister clade (Pseudowintera + Zygogynum s.l.) occurred around the end of the Cretaceous; in contrast, the divergence between the two subclades within Drimys is more recent (15.5-18.5 MY) and coincides in time with the Andean uplift. Estimates suggest that the earliest divergences within Winteraceae could have predated the first events of Gondwana fragmentation. (C) 2009 Elsevier Inc. All rights reserved.

Essential Oil from Leaves and Stem Bark of Southeastern Drimys brasiliensis Miers (Winteraceae)

The chemical composition of essential oils obtained from fresh leaves and stem bark of Southeastern Brazilian native Drimys brasiliensis Miers were analyzed by GC and GC/MS and 37 compounds were identified. The oils from fresh leaves showed the presence of monoterpenes (53.9%) and sesquiterpenes (38.4%), with sabinene (9.5%), myrcene (10.5%), limonene (10.6%) and cyclocolorenone (16.0%) being the most abundant. The stern bark oil was characterized by predominance of sesquiterpenoids (87.6%) and the absence of monoterpenes, the main components being cyclocolorenone (28.3%) and spathuleneol (22.9%). A small amount of phenylpropanes (6.8-6.9%) was also detected in both oil samples.

Pharmacological and toxicological studies of Drimys angustifolia Miers. (Winteraceae)

Drimys angustifolia Miers. (Winteraceae) is a Brazilian medicinal plant used as analgesic, antiulcer and anti-inflammatory without studies to assure its efficacy and safety Leaf and stem bark extracts were evaluated to determine the antiulcer, analgesic, antiinflammatory and antioxidant activities. Preliminary toxic effects and qualitative phytochemical profile were also performed. The antiulcer activity was detected in both extracts. Administration of the leaf extract at 250 mg/kg inhibited total lesion area by 76.50% (p < 0.01 in ethanol/HCl method), while carbenoxolone at 250 mg/kg reduced lesions by 69.48%. Stem bark extract (250 mg/kg) inhibited lesion by 81.42%, while carbenoxolone by 74.10%. Similar effects were observed in the ethanol-induced ulcer method, but no activity was observed in piroxican model. The effects involve nitric oxide in gastric protection, since the L-NAME treatment reversed the protection given by the extracts. Antioxidant effects suggest an involvement against oxidative stress. In the pain (writhing, tail-flick and hot-plate tests) and inflammation (carrageenan-induced paw edema) models, the extracts did not present any effect. The phytochemical studies demonstrated that both extracts contain flavonoids, saponins, glycosilated triterpenoids, fixed acids, cyanogenic glycosides, quinones, tannins, xanthone and steroidal aglycones. Toxicological studies showed that the extracts are safe at the effective antiulcer doses. (c) 2006 Elsevier B.V.. All rights reserved.

Reproductive biology in the primitive relic Angiosperm Drimys brasiliensis (Winteraceae)

From field observations on Drimys brasiliensis, principally in the Botucatu region of São Paulo State, Brazil, new data on the reproductive biology, the rhythm of growth, and the development of lateral cymose inflorescences, flowers and fruits are presented. Pollination accelerates the rate of flower-development for about 4-6 days. Pollination experiments show that D. brasiliensis is not self-sterile; because of mechanical devices the sticky pollen grains do not normally come into contact with the stigmata unless an animal pollen vector is involved. The pollinators are diurnal Coleoptera, Diptera and Thysanoptera which eat from the pollen, lick from the stigmatic exudates and (in case of the flies) probably also from the staminal glands. Fruit- and seedeaters are birds which seem to be the main dispersal agents. Establishment of new individuals normally is through seedlings, but also by vegetative propagation through plagiotropous branches which may root and separate from the mother plant. The morphological, developmental and reproductive aspects in D. brasiliensis are discussed in a wider context, compared with data from other Magnoliidae, and related to aspects of early Angiosperm evolution. © 1980 Springer-Verlag.

Stomatal plugs of Drimys winteri (Winteraceae) protect leaves from mist but not drought

Two outstanding features of the flowering plant family Winteraceae are the occlusion of their stomatal pores by cutin plugs and the absence of water-conducting xylem vessels. An adaptive relationship between these two unusual features has been suggested whereby stomatal plugs restrict gas exchange to compensate for the presumed poor conductivity of their vesselless wood. This hypothesized connection fueled evolutionary arguments that the vesselless condition is ancestral in angiosperms. Here we show that in Drimys winteri, a tree common to wet forests, these stomatal occlusions pose only a small fixed resistance to water loss. In addition, they modify the humidity response of guard cells such that under high evaporative demand, leaves with plugs lose water at a faster rate than leaves from which the plugs have been experimentally removed. Instead of being adaptations for drought, we present evidence that these cuticular structures function to maintain photosynthetic activity under conditions of excess water on the leaf surface. Stomatal plugs decrease leaf wettability by preventing the formation of a continuous water film that would impede diffusion of CO2 into the leaf. Misting of leaves had no effect on photosynthetic rate of leaves with plugs, but resulted in a marked decrease (≈40%) in leaves from which the plugs had been removed. These findings do not support a functional association between stomatal plugs and hydraulic competence and provide a new perspective on debates surrounding the evolution of vessels in angiosperms.

Dendroecology of Drimys brasiliensis Miers (Winteraceae) in two Atlantic cloud forests in Paraná State, Southern Brazil.

2016

木通科（Lardizabalaceae）系统学的初步研究

我们系统地比较研究了木通科全部七个属十三个常见种的心皮、胚珠、果实、种子、花粉和染色体等性状，并就木通科科的系统位置和科内属间亲缘关系作了初步的探讨。 研究结果认为： 1、木通科是一个单元超源的自然类群，并且对它的原始性的认识比以往更为深化。 2、整个木通科可分为四个自然类群（族）。Stauntonieae族是东亚支系的主要类群、具典型的散生胎座，包括3个属（Akebia、Holboellia和Stauntonia）。这三个属是本科中系统位置明显相近的属，其中又以Holboellia和Stauntonia最为近缘;LArdizabaleae族具减化的散生胎座包括两个属（Lardizabala和Boquila）与Stauntonieae族有亲缘关系。但族内两个属之间的分化是明显的，应为南美支系上已分化的类群;Decaisneae族（仅Decaisnea—属）以其不完全闭合的心皮而与上两族有一定的渊源，但它有很多的特殊性状。Sinofranchaotioao族（仅Sinofranchotia一属）虽具亚边缘胎座和其他性状而与Decaisneae族有联系，但它的心皮完全闭合，从而成为本科中性状比较特殊而系统位置比较孤立的类群。 3、木通科与小檗目中各科近缘还不如与木兰类中的Winteraceae和Illiciaceae等科近缘才显得更为自然些。

五味子属的花发育形态学和系统学-兼论五味子科的演化

五味子属隶属于木兰亚纲八角目五味子科，全属共15种，呈东亚一北美间断分布，东亚是其分布中心。五味子科因花部器官数目多而不定，螺旋状排列等特征，被确认为原始多心皮类的一员，与八角科、木兰科、Winteraceae等有亲缘关系。同时，因为它具有一些特化的性状，如具3沟或异极6沟型花粉、花单性，而常被视为木兰亚纲中进化水平较高的类群。然而，近年来分子系统学的研究结果显示，五味子科是被子植物最基部的分支之一。这使得该科成为解决原始被子植物起源与演化问题的重要类群之一，而倍受关注。中国是五味子属植物分布最集中的地区，有着得天独厚的资源优势。在论述了该属研究现状和存在问题的基础上，作者重点从花发育形态学和分子系统学，对该类群进行了较为深入的研究，发现了一些重要的新的性状，为该类群的系统发育分析提供了有力的证据。 1. 借助于扫描电镜，对全属成熟雄花的6种变异类型的代表种，进行了全面细致的花形态建成的观察和分析。首次发现该属雄花形态建成的式样有3类，并分别将之命名为柱托型、平托型和球托型，它们的主要特征如下：柱托型在花发育的全过程里，花托部分保持柱状，雄蕊始终螺旋状排列;平托型的花原端在分化出雄蕊原基后，向上的生长减弱而侧向的生长增强，最终形成扁平五边形的花托，雄蕊先螺旋状排列后轮状排列：球托型的雄蕊原基仍是螺旋状向顶发生，但与此同时，雄花花托部分球形膨大，并逐渐在雄蕊着生处产生浅凹和孔穴。显然，这3种式样在花形态发生的早前期相一致，而在雄蕊原基萌动后并开始分化时，它们之间发生分异，导致成熟雄花的形态显著不同。作者认为，雄花形态式样反映了五味子属系统发育的渊源，柱托型是原始类型，平托型和球托型是衍生类型，它们可能在系统发育的较早期就已分异，各自朝不同的方向演化。根据这一新的证据，将五味子属分成3亚属：大花五味子亚属、五味子亚属和团蕊五味子亚属。它们雄花的形态发生式样分别为柱托型、平托型和球托型。还发现在雄花的形态发生同为柱托型的类群中，大花五味子群和少蕊五味子群的雄蕊在成熟时，药室由初始时位于药隔两侧的位置逐渐外转至药隔的背面或侧背面，造成开裂时呈外向或外侧向纵裂：而华中五味子群的雄蕊成熟后，药室仍位于药隔的两侧面，呈侧向纵裂。 南五味子属是五味子属最近缘的类群，以南五味子为代表种，进行了雄花形态发生的研究，该种雄花的形态建成式样属于柱托型，但又不同于五味子属的柱托型，其主要的区别表现在南五味子的雄蕊在成熟时变成轮状排列，该特征使它似乎界于大花五味子群和五味子群之间，呈过渡类型。因而，对于传统分类学中，依据果实的形态将五味子科划分为五味子属和南五味子属，需要重新审视。 2. 根据对花形态发生的观察和分析，文章提出五味子属中雄花形态发生式样为柱托型的大花五味子亚属是最原始的类群，而具平托型和球托型式样的类群演化程度都相对较高。五味子属雄花的演化趋势主要表现在花托从柱状向扁平状和球状演化：雄蕊数目由多数变为少数并最终向定数演化：雄蕊群由螺旋状排列向轮状排列演化。有性生殖过程中的传粉习性可能是导致五味子属雄花形态产生变异的原因。在白垩纪，鞘翅目昆虫仍是最主要的传粉媒介，它们在起到传粉作用的同时，也对植物的花器官造成严重损害。五味子属植物的祖先类群为了适应这种传粉习性，采取了不同的策略。雄花花托柱状，雄蕊螺旋状排列的类群，以多数雄蕊保证传粉得以完成：而在雄蕊数目少的类群中，则补偿性地增大花器官的营养组织部分，达到保护花药的目的。 关于五味子属植物单性花的性质，常被认为是较进化的性状。本研究结果显示，雄花中未出现雌性部分的残存，雌花中也未出现雄性部分的痕迹。因此，在形态上，五味子属表现出完全单性的特征。作者认为，五味子属的单性花性质不同于由两性花退化所形成的单性花，它可能反映了被子植物祖先类群花的另一种演化路线。 另外，作者通过对五味子属雌花形态发生的研究，比较和分析了诸多原始被子植物类群心皮的形态及其发生过程，赞成Endress认为离生多心皮类中既有对折心皮，也有囊状心皮，它们在原始类群中并存的观点。五味子属植物雌花的形态较一致，心皮在原基腹面基部的活动不明显，成熟心皮具明显的腹缝，腹缝两侧形成柱头脊，在类型上属于对折型心皮，体现了该属的原始性。 3. 作者选取了核基因组的rrs区和叶绿体基因组的trnL-F区，对五昧子属的10个种(代表了全部雄花类型)和南五味子属的4个种(分属2个组)以及作为外类群的华中八角，首次进行了序列分析。结果表明，从代表不同基因组的两个片段得到的分支图非常一致，都显示出：a) 五味子属的类群分别聚在3个不同的支上，并且这3个支完全对应于花形态发生的3种式样：b) 南五味子属的成员与五味子群聚在一起并得到Bootstrap分析很高的支持率，说明它们可能是单系的。该结果支持基于花形态发生研究所得到的结论。作者认为过去的分类中，将五味子属和南五味子属分割成两个属可能是不妥当的，值得深入研究。 4. 通过花发育形态学和分子系统学的研究，结合其它方面的资料，作者认为传统分类依据果实形态划分成的五味子属和南五味子属，可能都不是严格的单系类群。南五味子属的类群与五味子属中雄花花托为扁平五边形的类群显示出有很强的相关性。将两个属共同处理，分为3个亚属，似较适宜。由于尚需对南五味子属扩大取样研究，目前暂不对它进行处理。本文仅对传统意义上的五味子属的系统处理如下： 五味子属Schisandra Michx． 亚属1大花五味子亚属 Subgen.1 Pleiostema (Smith)Law 组1大花五味子组 Sect.1 PleiostemaSmith 组2华中五味子组 Sec.2 Sinoschisandra(Law)Liu 组3少蕊五味子组 Secc.3 Maximowiczia(Rupr.)Nakai 亚属2五味子亚属 Subgen.2 Schismxtm 亚属3团蕊五味子亚属 Subgen.3 Sphaerostema(Bl.)Law 5. 五味子科(或包括南五味子属在内的广义五味子属)现代分布格局显示，中国华中、华东和西南至印度支那北部的地域是该类群的多样性中心，而在整个分布区的外围，则零星散布着一些演化水平较高的类群。因此，五味子科很可能是在东亚大陆起源、分化后，往四周扩散。通过白令陆桥或欧美大陆到达北美：受第四纪冰川影响，形成东亚一北美间断分布。在东喜马拉雅、印度尼西亚的分布也都是扩散的结果。