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1.
蔡联炳 《植物研究》2002,22(3):278-284
生殖器官性状一直是禾本科植物分类的主要依据,但由于各个性状所附实体的形态特点、着生位置、发育程度和环境饰变的差异,其分类价值是不尽相同的。为了克服该类性状使用上的种种弊病,本文特对主要宏观性状的分类价值进行了评述,总结了它们在应用中各自适宜的等级范围。其中象花序的类型、小穗的着生、小花和果实的形状等价值较高,通常适合于族级以上类群的划分;花序的形状、小穗的排列、果实的类型等价值偏低,通常适合于属、种级类群的区分;而花序的长短与粗细、小穗轴、内稃等价值较低,通常适合于种级或种级之下类群的鉴分。  相似文献   

2.
Tobacco plants ( Nicotiana tabacum L., var. Badischer Burley) were treated with chemicals (sprays and soil drenches) known to affect sex expression in other species. Their effect was tested on sex balance, pollen sterility, embryogenic pollen grain (P-grain) formation in situ, and on pollen plant formation in anther and pollen cultures after anther preculture. Napthalene acetic acid (NAA) increased the length of pistils and stamens and shifted sex balance towards femaleness when the plants were raised in long or short days at 24 or 15°C. In parallel, pollen sterility, P-grain frequency in situ and pollen plant production from anther and pollen cultures were increased by NAA. Alar 85 redueed the length of pistils and stamens and shifted sex balance towards femaleness when the plants were raised in long days at 24°C, but shifted it towards maleness in short days and/or at 15°C. In parallel, pollen sterility, P-grain frequency in situ, and pollen plant production in vitro were increased when plants in long days at 24°C were treated with Alar 85, but decreased when plants in short days and/or at 15°C were treated. Ethrel, Cycocel, and GA3 applied in a similar manner, were ineffective. Water sprays and nitrogen starvation shifted sex balance towards femaleness in long days at 15°C and increased pollen sterility, P-grain frequency in situ and pollen plant production in vitro. At 24°C, water sprays and nitrogen starvation had no effect.  相似文献   

3.
萍乡显性雄性核不育水稻超微结构研究   总被引:7,自引:0,他引:7  
利用电镜技术对萍乡显性核不育水稻可育株和不育株花粉形成及发育过程和药壁组织的基本结构及其发育进行了研究。导致了其不育花粉败育的主要原因有:(1)绒毡层细胞表现为延迟解体,乌氏体不能与小孢子细胞壁的形成,特别是纯合不育株绒毡层细胞存在乌氏体的异位分布;(2)药隔维管束异常,导致营养物质运输缺乏,薄壁细胞液泡化,排列紊乱,杂合不育株薄壁细胞互相融合,出现核转移的独特现象。  相似文献   

4.
A comparative study is presented of the pollen emissions of Urticaceae, Plantaginaceae and Poaceae, collected during 1995 with Hirst samplers (Burkard or Lanzoni) at five sites in western Spain: two Mediterranean sites located in the south (Huelva and Seville) and three Atlantic sites in the north (Orense, Vigo and Santiago). The annual pollen of Poaceae and Plantaginaceae collected in the Atlantic cities was found to be twice that in the Mediterranean sites, and the total amount of Urticaceae was higher at sites with an urban environment and subject to sea influence (Vigo, Huelva and Seville). At all the sites, the start of the main pollination periods (MPP) took place in the following order: Urticaceae, Plantaginaceae and Poaceae. It was also observed that the MPP of these three pollen types began earlier in Huelva and Seville, where the mean temperatures necessary for the beginning of pollen emissions are recorded very early. Regarding the variation in pollen concentrations throughout the year, Urticaceae presented peaks of maximum concentration in March (Huelva, Seville, Vigo and Orense) and June (Santiago); Plantaginaceae in March (south) and June (north); and Poaceae in May (south) and June–July (north). At northern sites, pollen emissions of Urticaceae and Plantaginaceae continued throughout the summer, while in the south they decreased considerably from May onwards. From the allergenic point of view, the indices of reactivity described for Urticaceae and Poaceae were exceeded more often at northern sites, in particular at Vigo. The meteorological conditions associated with periods of highest pollen emission of these three herbaceous types are a rise in mean temperature, light or absent rainfall, and abundant sunshine. The statistical correlations between pollen emissions and meteorological factors were not well-defined, either for the stations or for all the taxa, although they were clearer for the Atlantic cities and for Urticaceae.  相似文献   

5.
Fossil grass pollen is common in Late Tertiary sediments and its rare occurrence in the Early Tertiary led to the belief that its presence is restricted to Tertiary sediments. A literature survey shows that rare occurrences of Graminidites spp. have been reported from Campanian–Maastrichtian strata worldwide. All reported Graminidites spp. have been studied by transmitted light microscopes, which are inadequate to resolve their fine exine sculpture. Graminidites sp. occurs in the Maastrichtian Scollard Formation of Alberta, Canada, and is studied here with light microscopy and scanning electron microscopy. A new species, G. ulkapites, occurs at the initiation of a temperate climate in the area. It occurs in post‐dinosaurian beds locally but in pre‐Cretaceous–Tertiary boundary strata, which implies that grasses could also be present in dinosaur inhabitations. Grass phytoliths, reported from dinosaurian coprolites from the Maastrichtian Deccan Intertrappean sediments of India, indicate that grasses were ingested by dinosaurs even if not included in the dinosaurian diet. A plot of worldwide Senonian occurrences of Graminidites spp. on a late Maastrichtian palaeogeographic map demonstrates that the data are inadequate to reveal the place of origin or migratory pattern. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167 , 235–248.  相似文献   

6.
The objective of this project was to study the pollen spectrum of the Marahué Wildlife Reserve (Central Argentina), the quantity and quality of airborne pollen grains, and to evaluate the contribution of outside sources, to protect a natural habitat with xerophytic shrub vegetation (“monte”) (the term “monte” is used for the dominant xerophytic shrub vegetation in the “partido” of Villarino) approximately 90 km south of Bahía Blanca. Sampling was performed weekly throughout a whole calendar year (January–December, 2003) using a volumetric impact sampler. Observations of flowering in the field were performed at the same time as the aerial sampling. Herbarium specimens were collected to make pollen collections of the species found in the study area, for reference purposes. The most abundant pollen types were Poaceae (31.3% total annual pollen), Amaranthus/Chenopodiaceae (25.3%), Eucalyptus (5%), Brassicaceae (3.9%), and Plantago (3.9%). This study showed the dispersion dynamics of pollen grains from characteristic species of the “partido” (the province of Buenos Aires is divided into partidos which are roughly equivalent to counties) of Villarino, the exotic flora of the surrounding area, and the pollen types from outside the region.
María Gabriela MurrayEmail:
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7.
天然药物紫杉醇的研究与开发综述   总被引:7,自引:0,他引:7  
本文对近年来紫杉醇(Taxol)的研究与开发进行了综述,其中包括:1.对紫杉醇研究的历史回顾;2.独特的药理作用机制;3.在植物界的分布;4.前药设计;5.半合成;6.全合成;7.组织培养;8.真菌发酵;9.构效关系等。  相似文献   

8.
The relative pollen productivity (RPP) of Pinus cembra, Larix, Picea, Gramineae, and Cyperaceae was estimated for the Upper Engadine area, an inner-alpine sub-continental valley in SE Switzerland lying above 1800 m a.s.l. The influx of pollen originating from lowlands was assumed constant between the investigated sites and could thus be used to establish relative pollen accumulation rates (rPAR) as a basis for further calculations. Wind above the canopy was assumed as the major mode of pollen transport and the effect of different wind speeds was tested. In order to evaluate the results pollen percentage values were simulated and compared with the empirical data. The method is sufficiently accurate for evaluation of spatially-explicit vegetation models, although the low number of sites eludes robust statistical testing.  相似文献   

9.
通过四川螺髻山(1984、2017年)表土和化石孢粉与植被的关系分析发现:孢粉组合中木本植物含量(91.0%)占绝对优势,松属、冷杉属、青冈属、常绿栎类、落叶栎类、桤木属、杜鹃花科、禾本科和蒿属为主要花粉类型;人工次生林花粉组合能很好地反映母体植被的群落特征,并可指示优势种的存在和人类活动痕迹;针阔混交林花粉组合能较好地反映群落整体特征,花粉类型能与母体植被中优势种较好地对应;常绿阔叶林、针叶林和灌丛草甸的花粉组合难以反映母体植被的群落特征。DCA表明,花粉谱的百分含量,能较好地区分人工扰动植被和天然植被,但人工次生林、常绿阔叶林和针阔混交林之间以及针叶林和灌丛草甸之间未能区分。30年前后表土孢粉组合变化明显,1984年样品以松属、青冈属和桤木属等花粉为主,而2017年采样分析中松属、桤木属花粉占绝对优势。随着人类活动的加强,部分地区松树和桤木大面积飞播或种植,表土孢粉组合对当地植被指示意义与扰动强度呈负相关关系。现生植被与表土孢粉组合的差异能为恢复古植被和古环境提供参考,但原生植被已经被破坏地区的孢粉图谱,就很难作为重建历史时期植被的根据。本研究可以为亚热带山地利用孢粉学恢复第四纪时期植被与气候,探讨人类活动与环境的关系提供理论依据和实践参考。  相似文献   

10.
Pollen monitoring with a Hirst like pollen trap for 30 years in Basel, Switzerland allows understanding of the behaviour of the different plants producing allergenic pollens. It becomes evident that in this time period the different tree pollen like Hazel and Birch increased, whereas in the control, the observed amount of a herb pollen like Artemisa did not change. Moreover, it was observed that in the different trees flowering took place earlier namely at the beginning of the year. This was especially impressive for Hazel, where flowering was shifted ofmore than one month. These aerobiological observations were supported and confirmed by some epidemiological studies, showing that tree pollen allergy has become more important in the last years compared to grass pollen allergy and herb pollen allergy. The reason for the increase of tree pollen counts and the shift in the flowering time depends on the observed increase of the annual temperature, an increased input of nutrients like CO2or NOx but probably also a real increase of certain trees, like birch for example, in parks and avenues. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

11.
荸荠营养器官的发育与解剖学研究   总被引:1,自引:0,他引:1  
荸荠同化茎起源于肉质主茎倒2或倒3叶的叶腋内。同化茎基部着生二鞘状叶,鞘状叶对早期同化茎穿出土面具保护作用。匍匐茎大多起源于同化茎基部鞘状叶的叶腋内。当植株开始抽生花茎时,地下匍匐茎顶端开始膨大。球茎的膨大是匍匐茎顶端5-6节的基本组织经细胞有丝分裂,增加细胞数目,然后由细胞体积的扩大来实现的。球茎具足够的营养物质供来年顶芽萌发的需要,故属水生植物冬芽的性质。  相似文献   

12.
近一个多世纪来,树木发育阶段理论的应用研究取得了令人瞩目的成就,在果树育种,造林,园艺等领域得到广泛应用并取得了巨大的经济效益,与此形成鲜明对比的是,树木发育阶段理论研究的核心内容如发育阶段转变的遗传基础,分子机制等方面的基础研究工作却进展缓慢,对各个阶段的发育特性和利用潜力认识不足,在一定程度上限制了该理论在生产实践中的应用和推广范围,本文就树木发育阶段理论的研究现状,存在问题及在橡胶树育种中的应用等进行了综述和探讨。  相似文献   

13.
The major allergenic pollen prevalent in the Derby air in May is Quercus pollen which has been monitored volumetrically from 1970–1997. Quercus pollen levels in Derby are increasing, showing an established long term trend, with 1995 being an exceptionally high year. There is now an earlier start date and a longer seasonal duration. The mean Quercus diurnal periodicity for 1991–1997 shows a peak at 15.00 hours.A detailed study of the 1990–1997 seasons established that a maximum temperature of 20 °C or above, at the usual time of flowering, occasions the start of the Quercus pollen season. Average May temperature and drought in the previous June and July are important factors in determining Quercus pollen totals. Predictions for the forthcoming seasons were produced which compared favourably with the actual pollen totals.  相似文献   

14.
免疫组织化学检测Ⅰ型糖尿病(IDDM)病人血清中的胰岛细胞抗体(ICA)需用“O”型血人胰腺做抗原。因为人胰腺来源困难,所以,本研究选用猪、家兔、大鼠、小鼠和豚鼠以及“O”型血正常人胰腺作抗原,对11例IDDM患者和10例正常人血清,进行ICA免疫组织化学检测,以期筛选寻找ICA免疫组织化学检测的最佳抗原替代品。选用已确诊为IDDM并用“O”型血正常人胰腺作抗原ICA检测为阳性患者的血清11份,正常人血清10份,同步用POPA免疫组织化学技术进行检测。结果发现:在11份IDDM患者血清中,用猪胰腺与用“O”型血正常人胰腺作抗原,11例均为阳性,而用家兔和大鼠胰腺作抗原各有10例为阳性。但用小鼠和豚鼠胰腺作抗原,则分别只有2例和1例呈阳性。在10例正常人血清中,人和各种动物胰腺均呈阴性反应。本研究结果表明猪胰腺是ICA免疫组织化学最佳替代品,其次是家兔和大鼠的胰腺。小鼠和豚鼠胰腺作抗原检测ICA结果差异较大  相似文献   

15.
New distributional recores of hydroxycinnamoyl spermidines (HCS), including novel trisubstituted HCSs and flavonol glycosides, in pollen of Higher Hamamelidae are presented. The 51 taxa analyzed by HPLC and TLC included members of the families Fagaceae (Castanoideae, Fagoideae, Quercoideae), Betulaceae, Juglandaceae, Myricaceae, Hamamelidaceae, Rosaceae, and Buxaceae (Simmondsia). The results support generic concepts in the Higher Hamamelidae derived from morphological and chloroplast DNA data and support a close evolutionary relationship between the Higher Hamamelidae and the Rosidae.  相似文献   

16.
Summary Trends of the atmospheric dispersion of the pollens of Urticaceae, Poaceae, Asteraceae,Plantago, Chenopodiaceae-Amaranthaceae, Polygonaceae, Oleaceae, Betulaceae-Corylaceae,Quercus, Castanea, and Cupressaceae-Taxaceae were studied from 1981 to 1989 in two localities (Genoa and Sanremo) about 120 km apart on the coast of Liguria in Italy. Statistical analysis revealed, in particular, and overall increase in pollen rain in Genoa during the period considered. The following observations were carried out on the pollens of greatest allergological interest: Urticaceae, a slightly increasing trend in Genoa; Poaceae, a moderately increasing trend in Sanremo; Oleaceae, almost parallel, uniform trendsin both centres. The values of this study lies in its ability to point out any increase which may occur over the years in the dispersal of certain allergenic pollens.  相似文献   

17.
云南丽江-大理地区现代表土花粉垂直分布特征   总被引:4,自引:0,他引:4  
文章主要研究云南丽江-大理地区不同海拔高度表土花粉。虽然松属花粉在各个植被带都占有优势,但是建群种花粉含量相对较高。降趋对应分析法(detrended correspondenc eanalysis,简称DCA)分析显示,表土花粉的分布和海拔之间具有非常密切的关系,DCA第一轴的值和海拔高度之间的线性相关系数达0.82(r^2=0.82)。此次研究表明,在云南山地,可以通过含量相对较高的花粉来重建古植被。  相似文献   

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20.
成人肾恶性横纹肌样瘤的研究:1例报告及文献复习   总被引:2,自引:0,他引:2  
应用组织化学、免疫组织化学及电镜技术对我国首例成人肾恶性横纹肌样瘤(m alingantrhabdoidtum or, MRT) 进行了研究, 与婴幼儿MRT相比本例有以下临床病理特点: (1) 以血尿为早期和唯一症状,肿块缺乏特征性CT 改变; (2) 光镜下大量PAS阳性嗜酸性球形小体多位于细胞外, 电镜下细胞外小体由微丝构成并有界膜包绕; (3) 免疫组化显示肿瘤细胞向神经外胚层、横纹肌和组织细胞多向性分化; (4) 肿瘤侵袭力较低, 高度表达nm 23-H1 蛋白, 随访18个月术后化疗效果佳, 提示其恶性度较婴幼儿MRT 低。  相似文献   

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