Análisis de la diversidad genética de poblaciones naturales de especies vegetales amenazadas (Silene nocteolens (Caryophyllaceae) y Sorbus aria (Rosaceae)

[ES]La riqueza genética que nos ofrecen las poblaciones naturales de la flora en Canarias puede estar bajo riesgo. Con esto en mente, se desarrollaron marcadores moleculares (SSR) específicos para el análisis genético de Silene nocteolens, una planta herbácea que solo crece en el Teide; y Sorbus aria, 50 árboles que en Canarias están restringidos a Tenerife y La Palma. En S. nocteolens se encontró una gran variabilidad genética, poca diferenciación genética entre sus dos poblaciones y un bajo porcentaje autofecundación. En S. aria se reporta un carácter triploide, menor variabilidad genética en las muestras canarias que en las peninsulares y una diferenciación genética considerablemente alta.

Análisis de la diversidad genética en poblaciones naturales de especies vegetales amenzadas: Ilex Perado SSP. Lopezilloi (Aquifoliaceae), Silene Nocteolens (Caryophyllaceae) y Sorbus Aria (Rosaceae)

Se han elminado páginas en blanco

Isolation and characterization of microsatellite loci in Sorbus aria (Rosaceae)

[EN] Sorbus aria (L) Crantz (Common Whitebeam) is native to Europe, east of the Balkans and in North Africa; it is also present in the Canary Islands. To evaluate the genetic diversity in natural populations of this vulnerable species, nine novel polymorphic microsatellite markers were isolated from enriched libraries. Microsatellite loci were screened in 97 individuals from La Palma (Canary Islands) and Sierra Nevada (Granada, Spain). Examination of the microsatellite profiles shows that S. aria individuals have up to three alleles per locus. The cloned sequences in microsatellite loci confirmed the polyploidy status of the plants. The number of alleles ranged from 5 to 14 per locus. The phenotype diversities across loci (H0 T) ranging from 0.653 to 0.847

Kann das Fusicladium von Crataegus und von Sorbus-Arten auf den Apfelbaum übergehn?

Von Dr. Rud. Aderhold

Genetic effects of chronic habitat fragmentation on tree species: the case of Sorbus aucuparia in a deforested Scottish landscape

Sustainable forest restoration and management practices require a thorough understanding of the influence that habitat fragmentation has on the processes shaping genetic variation and its distribution in tree populations. We quantified genetic variation at isozyme markers and chloroplast DNA (cpDNA), analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in severely fragmented populations of Sorbus aucuparia (Rosaceae) in a single catchment (Moffat) in southern Scotland. Remnants maintain surprisingly high levels of gene diversity (H-E) for isozymes (H-E = 0.195) and cpDNA markers (H-E = 0.490). Estimates are very similar to those from non-fragmented populations in continental Europe, even though the latter were sampled over a much larger spatial scale. Overall, no genetic bottleneck or departures from random mating were detected in the Moffat fragments. However, genetic differentiation among remnants was detected for both types of marker (isozymes Theta(n) = 0.043, cpDNA Theta(c) = 0.131; G-test, P-value < 0.001). In this self-incompatible, insect-pollinated, bird-dispersed tree species, the estimated ratio of pollen flow to seed flow between fragments is close to 1 (r = 1.36). Reduced pollen-mediated gene flow is a likely consequence of habitat fragmentation, but effective seed dispersal by birds is probably helping to maintain high levels of genetic diversity within remnants and reduce genetic differentiation between them.

Effect of phenolic-rich plant materials on protein and lipid oxidation reactions

The antioxidant activity of natural plant materials rich in phenolic compounds is being widely investigated for protection of food products sensitive to oxidative reactions. In this thesis plant materials rich in phenolic compounds were studied as possible antioxidants to prevent protein and lipid oxidation reactions in different food matrixes such as pork meat patties and corn oil-in water emulsions. Loss of anthocyanins was also measured during oxidation in corn oil-in-water emulsions. In addition, the impact of plant phenolics on amino acid level was studied using tryptophan as a model compound to elucidate their role in preventing the formation of tryptophan oxidation products. A high-performance liquid chromatography (HPLC) method with ultraviolet and fluorescence detection (UV-FL) was developed that enabled fast investigation of formation of tryptophan derived oxidation products. Byproducts of oilseed processes such as rapeseed (Brassica rapa L.), camelina (Camelina sativa) and soy meal (Glycine max L.) as well as Scots pine bark (Pinus sylvestris) and several reference compounds were shown to act as antioxidants toward both protein and lipid oxidation in cooked pork meat patties. In meat, the antioxidant activity of camelina, rapeseed and soy meal were more pronounced when used in combination with a commercial rosemary extract (Rosmarinus officinalis). Berry phenolics such as black currant (Ribes nigrum) anthocyanins and raspberry (Rubus idaeus) ellagitannins showed potent antioxidant activity in corn oil-in-water emulsions toward lipid oxidation with and without β-lactoglobulin. The antioxidant effect was more pronounced in the presence of β-lactoglobulin. The berry phenolics also inhibited the oxidation of tryptophan and cysteine side chains of β-lactoglobulin. The results show that the amino acid side chains were oxidized prior the propagation of lipid oxidation, thereby inhibiting fatty acid scission. In addition, the concentration and color of black currant anthocyanins decreased during the oxidation. Oxidation of tryptophan was investigated in two different oxidation models with hydrogen peroxide (H2O2) and hexanal/FeCl2. Oxidation of tryptophan in both models resulted in oxidation products such as 3a-hydroxypyrroloindole-2-carboxylic acid, dioxindolylalanine, 5-hydroxy-tryptophan, kynurenine, N-formylkynurenine and β-oxindolylalanine. However, formation of tryptamine was only observed in tryptophan oxidized in the presence of H2O2. Pine bark phenolics, black currant anthocyanins, camelina meal phenolics as well as cranberry proanthocyanidins (Vaccinium oxycoccus) provided the best antioxidant effect toward tryptophan and its oxidation products when oxidized with H2O2. The tryptophan modifications formed upon hexanal/FeCl2 treatment were efficiently inhibited by camelina meal followed by rapeseed and soy meal. In contrast, phenolics from raspberry, black currant, and rowanberry (Sorbus aucuparia) acted as weak prooxidants. This thesis contributes to elucidating the effects of natural phenolic compounds as potential antioxidants in order to control and prevent protein and lipid oxidation reactions. Understanding the relationship between phenolic compounds and proteins as well as lipids could lead to the development of new, effective, and multifunctional antioxidant strategies that could be used in food, cosmetic and pharmaceutical applications.

Effects of recreational use and fragmentation on the understorey vegetation and soil microbial communities of urban forests in southern Finland

The impacts of fragmentation and recreational use on the hemiboreal urban forest understorey vegetation and the microbial community of the humus layer (the phospholipid fatty acid (PLFA) pattern, microbial biomass and microbial activity, measured as basal respiration) were examined in the greater Helsinki area, southern Finland. Trampling tolerance of 1) herb-rich OMT, 2) mesic MT, and 3) sub-xeric VT forests (in decreasing order of fertility) was studied by comparing relative understorey vegetation cover (urban/untrampled reference ratio) of the three forest types. The trampling tolerance of forest vegetation increased with the productivity of the site (sub-xeric < mesic < herb-rich). Wear of understorey vegetation correlated positively with the number of residents (i.e., recreational pressure) around the forest patch. An increase of 15000 residents within a radius of 1 km around a forest patch was associated with ca. 30% decrease in the relative understorey vegetation cover. The cover of dwarf shrub Vaccinium myrtillus in particular decreased with increasing levels of wear. The cover of mosses in urban forests was less than half of that in untrampled reference areas. Cover of tree saplings, mainly Sorbus aucuparia, and some resilient herbs was higher than in the reference areas. In small urban forest fragments, broad-leaved trees, grasses and herbs were more abundant and mosses were scarcer than in larger urban forest areas. Thus, due to trampling and edge effects, resilient herb and grass species are replacing sensitive dwarf shrubs, mosses and lichens in urban forests. Differences in the soil microbial community structure were found between paths and untrampled areas and the effects of paths extended more than one meter from the paths. Paths supported approximately 25-30% higher microbial biomass with a transition zone of at least 1 m from the path edge. However, microbial activity per unit of biomass was lower on paths than in untrampled areas. Furthermore, microbial biomass and activity were 30-45% lower at the first 20 m into the forest fragments, due to low moisture content of humus near the edge. The decreased microbial activity detected at forest edges and paths implies decreased litter decomposition rates, and thus, a change in nutrient cycling. Changes in the decomposition and nutrient supply may in turn affect the diversity and function of plant communities in urban forests. Keywords: boreal forest vegetation, edge effects, phospholipid fatty acids, trampling, urban woodlands, wear

The effects of habitat edges and trampling intensity on vegetation in urban forests

Although changes in urban forest vegetation have been documented in previous Finnish studies, the reasons for these changes have not been studied explicitly. Especially, the consequences of forest fragmentation, i.e. the fact that forest edges receive more solar radiation, wind and air-borne nutrients than interiors have been ignored. In order to limit the change in urban forest vegetation we need to know why it occurs. Therefore, the effects of edges and recreational use of urban forests on vegetation were investigated together in this thesis to reveal the relative strengths of these effects and to provide recommendations for forest management. Data were collected in the greater Helsinki area (in the cities of Helsinki, Vantaa and Espoo, and in the municipalities of Sipoo and Tuusula) and in the Lahti region (in the city of Lahti and in the municipality of Hollola) by means of systematic and randomized vegetation and soil sampling and tree measurements. Sample plots were placed from the forest edges to the interiors to investigate the effects of forest edges, and on paths of different levels of wear and off these paths to investigate the effects of trampling. The natural vegetation of mesic and sub-xeric forest site types studied was sensitive both to the effects of the edge and to trampling. The abundances of dwarf shrubs and bryophytes decreased, while light- and nitrogen-demanding herbs and grasses - and especially Sorbus aucuparia – were favoured at the edges and next to the paths. Results indicated that typical forest site types at the edges are changing toward more nitrophilic vegetation communities. Covers of the most abundant forest species decreased considerably – even tens of percentages – from interiors to the edges indicating strong edge effects. These effects penetrated at least up to 50 m from the forest edges into the interiors, especially at south to west facing open edges. The effects of trampling were pronounced on paths and even low levels of trampling decreased the abundances of certain species considerably. The effects of trampling extended up to 8 m from path edges. Results showed that the fragmentation of urban forest remnants into small and narrow patches should be avoided in order to maintain natural forest understorey vegetation in the urban setting. Thus, urban forest fragments left within urban development should be at least 3 ha in size, and as circular as possible. Where the preservation of representative original forest interior vegetation is a management aim, closed edges with conifers can act as an effective barrier against solar radiation, wind and urban load, thereby restricting the effects of the edge. Tree volume at the edge should be at least 225-250 m3 ha-1 and the proportion of conifers (especially spruce) 80% or more of the tree species composition. Closed, spruce-dominated edges may also prevent the excessive growth of S. aucuparia saplings at urban forest edges. In addition, closed edges may guide people’s movements to the maintained paths, thus preventing the spontaneous creation of dense path networks. In urban areas the effects of edges and trampling on biodiversity may be considerable, and are important to consider when the aim of management is to prevent the development of homogeneous herb-grass dominated vegetation communities, as was observed at the investigated edges.

Berry phenolics: isolation, analysis, identification, and antioxidant properties

The main objectives in this thesis were to isolate and identify the phenolic compounds in wild (Sorbus aucuparia) and cultivated rowanberries, European cranberries (Vaccinium microcarpon), lingonberries (Vaccinium vitis-idaea), and cloudberries (Rubus chamaemorus), as well as to investigate the antioxidant activity of phenolics occurring in berries in food oxidation models. In addition, the storage stability of cloudberry ellagitannin isolate was studied. In wild and cultivated rowanberries, the main phenolic compounds were chlorogenic acids and neochlorogenic acids with increasing anthocyanin content depending on the crossing partners. The proanthocyanidin contents of cranberries and lingonberries were investigated, revealing that the lingonberry contained more rare A-type dimers than the European cranberry. The liquid chromatography mass spectrometry (LC-MS) analysis of cloudberry ellagitannins showed that trimeric lambertianin C and sanguiin H-10 were the main ellagitannins. The berries, rich in different types of phenolic compounds including hydroxycinnamic acids, proanthocyanidins, and ellagitannins, showed antioxidant activity toward lipid oxidation in liposome and emulsion oxidation models. All the different rowanberry cultivars prevented lipid oxidation in the same way, in spite of the differences in their phenolic composition. In terms of liposomes, rowanberries were slightly more effective antioxidants than cranberry and lingonberry phenolics. Greater differences were found when comparing proanthocyanidin fractions. Proanthocyanidin dimers and trimers of both cranberries and lingonberries were most potent in inhibiting lipid oxidation. Antioxidant activities and antiradical capacities were also studied with hydroxycinnamic acid glycosides. The sinapic acid derivatives of the hydroxycinnamic acid glycosides were the most effective at preventing lipid oxidation in emulsions and liposomes and scavenging radicals in DPPH assay. In liposomes and emulsions, the formation of the secondary oxidation product, hexanal, was inhibited more than that of the primary oxidation product, conjugated diene hydroperoxides, by hydroxycinnamic acid derivatives. This indicates that they are principally chain-breaking antioxidants rather than metal chelators, although they possess chelating activity as well. The storage stability test of cloudberry ellagitannins was performed by storing ellagitannin isolate and ellagitannins encapsulated with maltodextrin at different relative vapor pressures. The storage stability was enhanced by the encapsulation when higher molecular weight maltodextrin was used. The best preservation was achieved when the capsules were stored at 0 or 33% relative vapor pressures. In addition, the antioxidant activities of encapsulated cloudberry extracts were followed during the storage period. Different storage conditions did not alter the antioxidant activity, even though changes in the ellagitannin contents were seen. The current results may be of use in improving the oxidative stability of food products by using berries as natural antioxidants.

Paleobotánica del epipaleolítico y mesolítico vascos

Homenaje a Ignacio Barandiarán Maestu / coord. por Javier Fernández Eraso, Juan Santos Yanguas

石楠属（Photinia Lindl.）与邻近诸属的亲缘关系

本文研究的范围包括蔷薇科（Rosaceae）苹果亚科（Maloideae）的石楠属（Photinia Lindl.）、红果树属（Stranvaesia Lindl.）、楷杷属（Eriobotrya Lindl.）、石斑木属（Raphiolepis Lindl.）和花楸属（Sorbus L.)。 通过对这5个属的形态、解剖、孢粉和染色体数目等的研究，得到以下三个初步结论。 1、Eriobotrya、Raphiolepis和Sorbus三属的界限明确，Stranvaesia和广义的Photinia两属之间的界限较模糊，但此两属与上述三属的分属界限是明确的。 2、从外部形态、叶表皮结构、叶片和叶柄横切面的研究所获资料，有力地证明Photinia属内常绿组和落叶组，Sorbus属内的冠萼组和复叶组之间的区别很明显，本人赞同某些前辈植物学家所采取的小属概念，可把它们分别成为属。 3、Stranvaesia是最原始的属，它有两个演化方向，一是朝落叶方向发展演化形成Sorbus。Stranvaesia演化的另一方向是继续保持常绿习性，Photinia是这一演化支系上的中间过渡环节，而Eriobotrya和Raphiolepis处于较高地位。

花楸属的系统学初步研究

花楸属隶属于蔷薇科苹果亚科，全世界约有100种左右，主要分布在北半球的亚洲、欧洲和北美洲。广义的花楸属包括下述六个亚属，即Subg. Aria, Subg. Chamaemespilus, Subg. Micromeles, Subg. Torminalis, Subg. Cormus, Subg. Sorbus。由于缺乏野外工作和标本不够丰富等原因，部分亚属的分类处理尚不能令人满意。同时，该属的范围及其属下部分类群的系统位置存在一定的争议。本文对广义花楸属的属下类群进行了研究，通过分支分析和表征分析以及分子系统学两方面的研究，对该属的属下类群的系统位置进行了探讨。 1、分支分析和表征分析 选取了广义花楸属（Sorbus L.）属下6个亚属的34种植物作为研究对象，并以Pyrus, Crataegus, Photinia, Malus和Cotoneaster作为外类群来研究花楸属属下类群的分类关系，对该属典型的30个形态性状数据进行编码，进行了分支分析和表征分析。结果表明，广义花楸属是一个非单系类群，外类群完全镶嵌于其中。广义花楸属属下的6个亚属各自也不能形成单系，只有花楸亚属（Subg. Sorbus）形成不严格的单系。因此，我们初步认为，花楸属应该仅包含复叶类群（Subg. Sorbus），或者还会有Subg. Cormus。由于其余的4个亚属尚不能形成规则的单系或聚类，因此进一步的研究宜采用分类群的更多性状或运用分子系统学的途径。 2、分子系统学 通过对花楸属23个种类的两个DNA片段：核nrDNA的ITS和叶绿体cpDNA的trnL-F进行简约分析，构建了广义花楸属5个亚属及其与近缘属的系统发育树。结果显示，由于外类群大多镶嵌于广义花楸属中，故花楸属不能形成一个单系。其中单叶类群Subg. Aria聚类较明显，并且得到了很高的支持率，而且该亚属与外类群Crataegus和Cotoneaster的关系要比它与其它亚属的关系更近，至于其是否是独立的属还有待进一步的研究。该属中的复叶类群Subg. Sorbus在图中并不能形成严格的单系，其分类位置值得重新考虑。