毛冠菊属的系统学研究

　　毛冠菊属是菊科21个“有问题”属中的一个，主要分布于青藏高原地区。按照林镕、陈艺林的概念，它包含了Nannoglottis、．Stereosanthus、Vierhapperia、Senecio和Doronicum5个属的成员。它曾先后被放入旋覆花族、千里光族和紫菀族，在上述三族中的亚族位置也不确定。它的许多重要性状，如舌片颜色、染色体数目等等，人们所知甚少。由于缺乏野外工作以及看不到大多数名字的模式，林镕、陈艺林对该属的修订有待深入的研究。本文研究了该属的外部形态学、微形态学、解剖学、孢粉学、细胞学、生态学以及ITS序列，确定了毛冠菊属的分类位置，并建立了一个新的属下分类系统。 1．外部形态 在检查大量标本（包括大多数模式）和野外居群考察的基础上，分析了主要外部形态学性状的变异式样及其对划定物种范围的价值。共确认以下9个种：青海毛冠菊、厚毛毛冠菊、狭舌毛冠菊、虎克毛冠菊、宽苞毛冠菊、大果毛冠菊、毛冠菊、玉龙毛冠菊和云南毛冠菊。川西毛冠菊被处理成狭舌毛冠菊的异名。 2．微形态学 在光镜下检查了毛冠菊属9种和紫菀族2个代表属的花柱的形状、花药顶端不育附属物、花药基部、花药基部、花盘、花丝领、药室内壁细胞等微形态性状。除了花柱基外，其他的微形态学在属内一致。管状花的花柱形态支持将毛冠菊属放在紫菀族，但其药室内壁细胞两极加厚式样表明它和广义的旋覆花有某些联系。 3．叶表皮研究 在光镜和电镜下检查了毛冠菊属8个种的叶表皮特征。．所有种的气孔器都为不规则型。青海毛冠菊表皮细胞的为多边形，而其他种都为不规则型。青海毛冠菊表皮角质层的加厚方式也与其他种明显不同。 4．扫描电镜下的舌片和花柱分枝特征 在扫描电镜下观察毛冠菊属8种和紫菀族7个代表种的舌片近轴面表皮细胞。发现毛冠菊属的舌片近轴面表皮细胞都为板状，并且沿细胞中央特征性加厚，这与紫菀族类型的表皮细胞一致，但毛冠菊属表皮细胞的角质层主要是纵向条纹或皱纹，而紫菀族总是横向的条纹或皱纹，明显不同。 在扫描电镜下又检查了毛冠菊属8种和紫菀族8个代表种的管状花花柱分枝近轴面的结构，结果在毛冠菊属管状花花柱分枝的近轴面都发现了柱头毛状的突起，而在紫菀族8种中没有发现。从突起的形状和位置判断，它可能是残存的、未充分发育的柱头毛。这表明雌性不育管状花可能刚刚从两性管状花演化而来。 也在扫描电镜下观察了毛冠菊属6种和紫菀族8个代表种的舌状花和丝状花的花柱分枝的远轴面，结果在毛冠菊属4种中发现了类似扫集毛状的突起。从这种突起的位置和形状判断，它可能是残余的扫集毛。这种突起在除雏菊以外的其他紫菀族代表种中缺失。 5．细胞学 检查了毛冠菊属8种的细胞学性状。结果发现毛冠菊属所有种的染色体基数都为x -9。染色体长度大约4um-lOum。核型公式：毛冠菊、厚毛毛冠菊、狭舌毛冠菊、宽苞毛冠菊和云南毛冠菊都为2n=14m+2sm+2st;玉龙毛冠菊、大果毛冠菊和青海毛冠菊都为2n=12m+4sm+2st。A1、A2值在属内没有明显差异。所有种的核型都是2A型。这表明在物种形成的过程中没有多倍化参与，毛冠菊属宜放在紫菀族而不是千里光族。细胞学证据支持毛冠菊属为一单系类群。 6．分子生物学 测定了毛冠菊属7种的ITS序列，并从基因库里下载了46个ITS序列，涵盖紫菀族14个亚属和旋覆花族、春黄菊族、金盏菊族。以旋覆花族、春黄菊族、金盏菊族为外类群。简约性分析显示，毛冠菊属在紫菀族中，并有较高的bootstrap值，在紫菀族中处于基部位置。Olearia和Chiliotrichum两个Hinterhuberinae亚族的代表属与毛冠菊属密切相关。在属下系统发育分析中，Olearia和Chiliotrichum被选做外类群。652个性状中，共有7】个信息位点（31个在ITSI，33个在ITS2，7个在5.8S）。简约性分析时只获得一棵最简约树。树上有两个明显的进化支，一支仅有青海毛冠菊一种，另一支包含其他种类。这种分支方式也得到形态学和生态学证据的支持。 7．毛冠菊属的系统学 从上述结果可以看出，毛冠菊属宜放入紫菀族中，在紫菀族中处于基部位置，与Hinterhuberinae亚族关系密切。综合上述研究结果，提出一个新的属下 分类系统： 毛冠菊属的新系统 组I单头组Sect. Monocephala T.G.Gao et YL.Chen Sect nov. 青海毛冠菊Nannoglottis ravida (C.Winkl.)Y.L.Chen 组II毛冠菊组Sect. Nannoglottis 系1．长舌系Ser. Delavayanae Ling et YL.Chen 厚毛毛冠菊Nannoglottis delavayi(Franch.)Ling et Y.L.Chen 狭舌毛冠菊Nannoglottis gynura(C.Winkl.) Ling et YL.Chen 虎克毛冠菊Nannoglottis hookeri (C.B.Clarke ex Hook.f.)Kitam. 宽苞毛冠菊Nannoglottis latisquama Ling et Y.L.Chen 大果毛冠菊Nannoglottis macrocarpa Ling et YL.Chen 系2．短舌系Ser. Nannoglottis 毛冠菊Nannoglottis carpesioides Maxim. 玉龙毛冠菊Nannoglottis hieraciphylla (Hand.-Mzt.)Ling et YL.Chen 云南毛冠菊Nannoglottis yuennanensis (Hand.-Mzt.) Hand.-Mzt.

毛冠菊属系统位置的核形态证据(英文)

首次记载了毛冠菊属 2种 4居群的核形态资料。两种植物的染色体间期和前期染色体为复杂型和中间型。狭舌毛冠菊两居群的染色体数目与核型公式为 2n =1 8=1 4m + 2sm + 2st( 2SAT) ;毛冠菊两居群的染色体数目与核型公式为 2n =1 8=1 4m + 2sm( 2SAT) + 2st。它们分别代表了整个毛冠菊属的两组植物 ,并包含了形态学上最原始的种类 ,因此 ,该属的染色体基数可能为x =9。核形态证据表明毛冠菊属放在紫菀族比放在旋覆花族和千里光族中更为合理。

Foraging behaviours of Diachasmimorpha kraussii (Fullaway) (Hymenoptera: Braconidae) and its host Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) in a nectarine (Prunus persica (L.) Batsch var. nectarina (Aiton) Maxim) orchard

Diachasmimorpha kraussii is a larval parasitoid of dacine fruit flies. Host utilisation behaviour, including field foraging behaviour, is poorly known in this species. The diurnal foraging behaviour of D. kraussii and one of its common hosts, Bactrocera tryoni, in a nectarine orchard was concurrently recorded. Observations of mating, resting, feeding and oviposition were taken two-hourly on 42 trees, commencing at 07:00 h and terminating at 17:30 h, for 17 days. Resting and oviposition were common events within the orchard for both species, while mating behaviours were not recorded in the orchard for either species. Feeding was not observed for D. kraussii and was rare for B. tryoni. At the level of the individual tree there was a very weak, but significant correlation between parasitoid and fly abundance over a day, but when broken down to the individual observation periods the correlations were absent, or were weakly significant in an inconsistent manner (i.e. sometimes positively correlated, sometimes negatively correlated). At the orchard level, abundance of the parasitoid was not correlated with adult fly abundance. Results suggest that D. kraussii forage independently to adult B. tryoni, a result consistent with a prediction that their foraging is largely driven by larval or plant damage cues.

Przewalskin A: A new C-23 terpenoid with a 6/6/7 carbon ring skeleton from Salvia przewalskii maxim

Przewalskin A (1), a novel C-23 terpenoid with a 6/6/7 carbon ring skeleton, was isolated from Salvia przewalskii. Its structure was determined by comprehensive 1D NMR, 2D NMR, and MS spectroscopic analysis and subsequently confirmed by a single-crystal X

Przewalskin B, a novel diterpenoid with an unprecedented skeleton from Salvia przewalskii maxim

[GRAPHIC] Przewalskin B (1), a novel diterpenoid possessing a unique skeleton, was isolated from a Chinese medicinal plant Salvia przewalskii. Its structure and relative stereochemistry were elucidated by extensive NMR analysis and a single-crystal X-ray

Identification of herb Acanthopanax senticosus (Rupr. Et Maxim.) harms by capillary electrophoresis with electrochemical detection

In this paper, a rapid, high efficient, sensitive and inexpensive approach based on a combination of simple ultrasonic extract and capillary electrophoresis (CE) separation with electrochemical detection (ED), is described to identify herbs by comparing their CE-ED profiles (namely, CE-ED electropherograms). The proposed method takes advantage of ultrasmall sample volume, low consumption of organic solvent, simple sample pretreatment and easy cleanup procedure. It was applied to analyze the CE-ED profiles of stems of herb Acanthopanax senticosus (Rupr. Et Maxim.) Harms from different sources and different parts (roots, rhizomes, stems and leaves) of this herb. By comparing peak number, peak height and peak height ratio, we found that the CE-ED profiles showed big differences for the herbs from the different sources and the different parts of this herb. In addition, the distribution of bioactive compounds (isofraxidin, rutin and chlorogenic acid) in the different parts of this herb and their content variations affected by the source were studied with the CE-ED method. Based on their own unique CE-ED profiles, these herbs from the different sources and the different parts of this herb could be easily distinguished. Therefore, the proposed approach could be used as a rapid, high efficient and sensitive method for the identification of herbal medicines.

Examination of Antioxidative System's Responses in the Different Phases of Drought Stress and During Recovery in Desert Plant Reaumuria soongorica (Pall.) Maxim

The aim of this study was to test the protective roles of superoxide dismutases (SODs), guaiacol peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) against oxidative damage and their activities in different phases of the dry down process in Reaumuria soongorica (Pall.) Maxim. leaves. Drought stress was imposed during 100 consecutive days and rewatering after 16, 72, and 100 days. The concentration of hydrogen peroxide (H2O2), malondialdehyde, and SODs activities were elevated significantly with progressing drought stress. POD and CAT activities increased markedly in the early phase of drought and decreased significantly with further drought stress continuation, and POD activity was unable to recover after rewatering. Ascorbate, reduced glutathione, APX, and GR activities declined in the initial stages of drought process, elevated significantly with further increasing water deficit progression and recovered after rewatering. These results indicate that: (1) iron SODs-removing superoxide anion is very effective during the whole drought stress; (2) CAT scavenges H2O2 in the early phase of drought and enzymes of ascorbate-glutathione cycle scavenge H2O2 in further increasing drought stress; and (3) POD does not contribute to protect against oxidative damage caused by H2O2 under drought stress.

Interannual fluctuations in floral longevity, pollinator visitation and pollination limitation of an alpine plant (Gentiana straminea Maxim., Gentianaceae) at two altitudes in the Qinghai-Tibetan Plateau

Prolonged floral longevity and bumblebees as dominate pollinators in alpine ecosystem have been suggested to overcome pollination limitation of alpine plants arising from the decrease of pollinator activity with increasing altitude. However, this conclusion has never been examined in the Qinghai-Tibetan Plateau (QTP), the highest and largest plateau in the world. In this study, we intended to test year-to-year correlations between floral longevity, visiting frequency and pollen limitation of this species between two populations (at 3200 m and 4000 m) of Gentiana straminea in this plateau. Pollinator exclusion elongated both male and female phases greatly at both sites, and durations of both male and female phases in natural condition varied greatly over three years. The visiting frequency of bumblebees varied greatly at the higher altitude, but seemed to be stable at the lower altitude. Seed production was pollination limited in both populations in most studied years. The floral durations, pollinator frequency and pollination limitation showed no significant and consistent variations with the increase of altitude. The previous hypothesis that the prolonged floral longevity of alpine plants can compensate for low levels of pollinator visitation therefore could not be confirmed, and our results further suggested that in the QTP platform, the altitude shows no consistent effect on the reproductive performance of this species, despite that the fluctuation of visit frequency intensified at the higher altitude.

Floral closure in response to temperature and pollination in Gentiana straminea Maxim. (Gentianaceae), an alpine perennial in the Qinghai-Tibetan Plateau

Floral closure may be induced by pollination and various other factors, but is rarely studied comprehensively. Different kinds of floral closure should have various effects on reproductive fitness of plants. Two contrasting types of floral closure were observed in the flowers of Gentiana straminea Maxim. in the eastern Qinghai-Tibetan Plateau. The first type occurred prior to pollination during both gender phases, in response mainly to decreasing air temperatures. Flowers closed when decreasing temperatures approached 20 degrees C and subsequently began to reopen the following day during mid-morning when air temperatures warmed to approximately 13-15 degrees C. This kind of floral closure can protect pollen grains on either stamens or stigmas, increasing fitness of both male and female. Following pollination, permanent floral closure occurred, although there was a delay between the dates of pollination and permanent closure, during which flowers continued to show temporary closure in response to low temperature episodes. The time required for permanent, pollination-induced closure varied according to the age of the gender phase, including a prolonged time before closure if pollination occurred early in the female phase. The retaining of permanent closed flowers increased both approaching (to inflorescences) and visiting (to unpollinated flowers) frequencies of individual plants when with fewer open flowers and the persisting corolla is further beneficial for seed sets of these pollinated flowers. Thus, two separate types of floral closure, one in response to environmental cues and the other in response to the age of each gender stage, appeared to have a strong influence on reproductive fitness in this species. These results revealed a different adaptive strategy of alpine plants in the sexual reproduction assurance in addition to the well-known elevated floral longevity, dominant role of more effective pollinators and increased reproduction allocation in the arid habitats.

Molecular phylogeny and biogeography of the Qinghai-Tibet Plateau endemic Nannoglottis (Asteraceae)

All taxa endemic to the Qinghai-Tibet Plateau are hypothesized to have originated in situ or from immediately adjacent areas because of the relatively recent formation of the plateau since the Pliocene, followed by the large-scaled biota extinction and recession caused by the Quaternary ice sheet. However, identification of specific progenitors remains difficult for some endemics, especially some endemic genera. Nannoglottis, with about eight species endemic to this region, is one such genus. Past taxonomic treatments have suggested its relationships with four different tribes of Asteraceae. We intend to identify the closest relatives of Nannoglottis by evaluating the level of monophyly, tribal delimitation, and systematic position of the genus by using molecular data from ndhF gene, trnL-F, and ITS region sequences. We find that all sampled species of Nannoglottis are a well-defined monophyly. This supports all recent taxonomic treatments of Nannoglottis, in which all sampled species were placed in one broadly re-circumscribed genus. Nannoglottis is most closely related to the Astereae, but stands as an isolated genus as the first diverging lineage of the tribe, without close relatives. A tentative relationship was suggested for Nannoglottis and the next lineage of the tribe was based on the ITS topology, the "basal group," which consists of seven genera from the Southern Hemisphere. Such a relationship is supported by some commonly shared plesiomorphic morphological characters. Despite the very early divergence of Nannoglottis in the Astereae, the tribe must be regarded to have its origin in Southern Hemisphere rather than in Asia, because based on all morphological, molecular, biogeographical, and fossil data, the Asteraceae and its major lineages (tribes) are supposed to have originated in the former area. Long-distance dispersal using Southeast Asia as a steppingstone from Southern Hemisphere to the Qinghai-Tibet Plateau is the most likely explanation for this unusual biogeographic link of Nannoglottis. The 23-32-million-year divergence time between Nannoglottis and the other Astereae estimated by DNA sequences predated the formation of the plateau. This estimation is further favored by the fossil record of the Asteraceae and the possible time of origin of the Astereae. Nannoglottis seems to have reached the Qinghai-Tibet area in the Oligocene-Eocene and then re-diversified with the uplift of the plateau. The molecular infragenetic phylogeny of the genus identifies two distinct clades, which reject the earlier infrageneric classification based on the arrangement of the involucral bracts and the length of the ligules, but agree well with the habits and ecological preferences of its current species. The "alpine shrub" vs. "coniferous forest" divergence within Nannoglottis was estimated at about 3.4 million years ago when the plateau began its first large-scale uplifting and the coniferous vegetation began to appear. Most of the current species at the "coniferous forest" clade of the genus are estimated to have originated from 1.02 to 1.94 million years ago, when the second and third uprisings of the plateau occurred, the climate oscillated and the habitats were strongly changed. The assumed evolution, speciation diversity, and radiation of Nannoglottis based on molecular phylogeny and divergence times agree well with the known geological and paleobotanical histories of the Qinghai-Tibet Plateau. (C) 2002 Elsevier Science (USA). All rights reserved.