生物土壤结皮与种子附属物对4种荒漠植物种子萌发的交互影响   总被引：2，自引：0，他引：2  

李国栋  张元明 《中国沙漠》2014,34(3):725-731

生物土壤结皮能直接或间接地影响维管植物种子萌发与群落建成,种子本身的生物学特征（如种子附属物等）对萌发也存在一定影响。本研究选取古尔班通古特沙漠4种常见的具有不同形态附属物的藜科植物（梭梭（Haloxylon ammodendron ）、粗枝猪毛菜（Salsola subcrassa ）、心叶驼绒藜（Ceratoides ewersmanniana ）和角果藜（Ceratocarpus arenarius ））种子,设置苔藓结皮、地衣结皮和裸沙3种土壤基质,通过去除或保留种子附属物,对比研究了生物土壤结皮与种子附属物对种子萌发的影响。结果表明：粗枝猪毛菜和梭梭的苞片显著抑制了种子萌发（p <0.05）,心叶驼绒藜的柔毛和角果藜的刺状附属物对种子萌发没有显著影响（p >0.05）。与裸沙相比,苔藓结皮显著抑制了4种植物种子的萌发（p <0.05）,地衣结皮显著抑制了粗枝猪毛菜种子的萌发（p <0.01）,而对其他3种植物种子的萌发无显著影响（p >0.05）。同时,附属物与结皮对粗枝猪毛菜种子的萌发还具有交互作用,表现为显著抑制种子萌发（p <0.01）。可见,生物土壤结皮对具有不同附属物的荒漠植物种子萌发具有不同的影响,进而造成维管植物种子萌发的空间异质性,影响维管植物分布和多样性。  相似文献   

重污染底泥对苦草（Vallisneria natans）和黑藻（Hydrilla verticillata）繁殖体萌发及幼苗生长的影响     

张淑娴  李竹栖  张浩坤  李霞  彭雪  葛芳杰  张璐  吴振斌  刘碧云 《湖泊科学》2023,35(4):1247-1254

为探究重污染底泥对沉水植物繁殖体萌发和幼苗生长影响,以苦草（Vallisneria natans）种子和黑藻（Hydrilla verticillata）冬芽为研究对象,以轻污染底泥为对照组,通过室内模拟实验研究了重污染底泥对两种繁殖体萌发和幼苗生长、生理特性的影响。实验结果表明,与轻污染底泥相比,重污染底泥对苦草种子萌发和幼苗生长无显著影响。黑藻冬芽萌发和幼苗地上部生物量在两组间没有显著差异,但重污染底泥组幼苗的地下部生物量显著高于轻污染底泥组,其地上部和地下部生物量比值由7.06±0.38下降至2.97±0.08。此外,苦草和黑藻幼苗受到重污染底泥胁迫表现出不同的生理响应。苦草幼苗叶片的类胡萝卜素含量显著减少,可溶性糖和蛋白含量分别降低11.56%、24.10%,根系活力也明显受到抑制,仅为（34.93±3.28） mg/（g·h）;黑藻幼苗生理响应与苦草略有不同,其叶片的叶绿素a、b含量显著增加,根系活力降低44.29%,可溶性糖和蛋白含量在轻污染组和重污染组之间无显著差异。由此可见,重污染底泥对苦草种子和黑藻冬芽的萌发影响不显著,但会明显影响幼苗的生长发育和生理特性,研究结果为...  相似文献   

外来水生植物再力花的化感作用探析     

缪丽华  王媛 《湿地科学》2012,10(1):81-86

再力花(Thalia dealbata)是近年来在湿地造景中应用较广泛的外来水生植物。为探究该种植物是否对其他植物生长产生影响,采用种子萌发法,测定了再力花不同部位浸提液对3种敏感植物萝卜(Raphanus sativus)、白菜(Brassica chinensis)和黄瓜(Cucumis sativus)种子萌发和幼苗生长的影响。结果表明,再力花各个部位浸提液对3种植物种子的萌发率、根长、芽长、鲜质量和干质量都有不同程度的抑制作用,尤其是高浓度(50mg/mL)浸提液,对种子萌发和幼苗生长有显著的抑制作用(p<0.01)。再力花叶片浸提液浓度为50mg/mL时,对萝卜、黄瓜和白菜种子萌发的抑制率分别为39.51%、10.53%和85.19%;根状茎浸提液浓度为50mg/mL时,对萝卜、黄瓜和白菜幼根长度的抑制率分别为87.4%、71.23%和91.7%,对幼芽长度的抑制率分别为51.21%、45.71%和69.66%。再力花各个部位都有化感物质分布,根状茎浸提液的化感作用最强,其他部位依次为根、叶柄和叶片。  相似文献   

Vivipary in the cactus family: A reply to Ortega-Baes’ et al. evaluation of 25 species from northwestern Argentina     

J.H. Cota-Sánchez  Á. Reyes-OlivasD.D. Abreu 《Journal of Arid Environments》2011,75(9):878-880

This is a reply to Ortega-Baes’ et al. (2010) survey of 25 Argentinean species of cacti evaluated for vivipary. We argue that the sample size and geographic area of the species investigated is insufficient to totally exclude the putative commonness of this condition in the Cactaceae. We indicate possible reasons why they did not find viviparous fruits in their survey. Failure to detect vivipary in cacti of NW Argentina may be correlated with limited taxonomic sampling and geographic region in addition to intrinsic and extrinsic plant factors, including different stages of fruit and seed development and genetic, ecological, and edaphic aspects, which, individually or in concert, control precocious germination. We uphold that viviparity is putatively frequent in this family and list 16 new cases for a total of 53 viviparous cacti, which make up ca. 4% incidence of viviparism in the Cactaceae, a substantially higher percentage than most angiosperm families exhibiting this condition. The Cactaceae ranks fourth in frequency of viviparity after the aquatic families of mangroves and seagrasses. We suggest the re-evaluation of cactus vivipary, primarily as a reproductive adaptation to changing environments and physiological stress with a secondary role as a reproductive strategy with limited offspring dispersal/survival and fitness advantages.  相似文献   

Spatial patterns of the soil seed bank and extant vegetation across the dry Minjiang River valley in southwest China     

Y.J. Li  W.K. Bao  N. Wu 《Journal of Arid Environments》2011,75(11):1083-1089

The medium-scale spatial patterns of soil seed banks (SSBs) and extant vegetation and the roles of abiotic factors are poorly understood. We selected the dry Minjiang River valley of southwest China to investigate SSB structure and corresponding extant vegetation in a medium-scale size (200-230 km long, 3-4 km wide) at eight sites across the valley using a germination method and field surveys. We found that, there was low seed density and species number in SSB and less coverage and litter thickness for community in extant vegetation at central sites compared with transitional sites across the dry valley; Quercus spp. occurred frequently in extant vegetation at transitional sites, while Caryopteris spp., Jasminum spp., Rabdosia parvifolia, Sophora davidii, Campylotropis spp., and Bauhinia faberi var. Microphylla was present frequently at central sites; Carex spp. and Artemisia spp. occurred frequently in SSB at transitional sites, while Ajania spp., Poa spp., and Fagopyrum caudatum was present more frequently at central sites. Hierarchical cluster analysis and Kendall’s correlation showed that the spatial variation of both SSB and extant vegetation had significant correlation with rainfall and air evaporation.  相似文献   

台湾地区种子植物区系的基本特征     

方碧真  卓正大 《热带地理》1995,15(3):263-271

本文通过对有关资料的统计分析，从区系的组成成分、地理成分、古老成分及特有成分等方面论述了台湾地区种子植物区系的基本特征，并简析了其形成的原因。  相似文献   

西班牙加那利群岛种子植物的特有现象     

周跃泰勒  D 《热带地理》1995,15(4):362-368

加那利群岛位于摩洛哥以西的中大西洋东部海面。群岛种子植物的特有现象十分突出。特有区系历史久远，至今尚保留着旧有的特征。特有种属最集中的月桂林特有植物区系的发展历史可追溯到早第三纪，是当时特提斯海沿岸亚热带植物区系之一部分。许多特有成分受第三纪晚期的冰期活动和撤哈拉地区干旱的影响从古地中海周围伸延到这里来，并且自上岛后便开始了新的进化繁衍历程。特有区系可分为古特有、新特有和变异残余三个类群。  相似文献   

紫外辐射增强对菠菜种子萌发及出苗的影响   总被引：6，自引：0，他引：6  

何雨红  郑有飞  王传海  何都良 《南京气象学院学报》2001,24(2):265-268

研究了紫外辐射（UA－B）增强对圆叶和尖叶菠菜种子萌发出苗的影响，结果表明，UV－B辐射增强将显著降低圆叶菠菜种子的出牙率和出苗率，延缓发牙进程，出苗速度，影响幼长势，而对尖叶菠菜的影响较小，增强UV－B辐射还能有效抑制菠菜种子发牙时因病菌感染而发生的霉变，并减少幼苗期病虫害的蔓延和发展。  相似文献   

The distribution of rare phenolic type compounds in wild and cultivated wheats     

Raymond Cooper  David Lavie  Yitzchak Gutterman  Michael Evenari 《Journal of Arid Environments》1994,27(4)

In 14 species of Aegilops, four species of Triticum and two species of Hordeum, a complex of rare phenolic compounds was found and showed quantitative differences between the wild and domestic species. There was a dramatic reduction in the cultivars to about 5% of the amount of these phenolic constituents. In the wild species these phenolic compounds may act as important germination regulators, such as water-dissolving germination inhibitors which may act as 'rain gauges'. This is especially important for the germination at the appropriate time in species inhabiting arid regions or deserts.  相似文献   

Acacia exchanges: Wattles, thorn trees, and the study of plant movements     

Christian A. Kull  Haripriya Rangan   《Geoforum》2008,39(3):1258-1272

Plants are frequently moved around the world, creating new regional landscapes and environmental imaginaries. Building on previous work in environmental history and geography, we develop a three-part approach to analyzing plant movements and apply it to trees from the Acacia genus (sens. lat.) exchanged between Australia and the rest of the world. First, we investigate the agents, circuits, and frequencies of acacia movements, including transoceanic transfers, regional diffusion, and ecological dispersal. Second, we trace bundles of knowledge or technology that accompany the acacias, highlighting how they help shape regional biogeographies. Finally, we analyze how different societies, with distinct economies, politics, and environmental sensibilities, receive introduced plants. This approach allows us to see transferred plants as active agents in region-forming processes, and to avoid normative tropes like ‘miracle plants’ or ‘alien invasives’. The highlighted species include Acacia colei, Acacia melanoxylon, Acacia mearnsii, Acacia farnesiana, Acacia nilotica, Acacia mangium, and their close relatives.  相似文献