With a warming climate and the usage of monocultures in food production it is possible we may face more issues concerning food insecurity in the future as pollinators struggle to find food in agricultural landscapes. Therefore, it is of value to know whether common agricultural weeds are important sources of food for pollinators. Pollinators are vital in the growing of food-crops and may depend on different agricultural weeds during their flying season. This study is based on observational citizen science data on the flowering of 24 agricultural weeds classified as useful to pollinators in the years 2008-2022. Data on first flowering and length of flowering was compared between life history classifications based on life span and time of germination. The results showed that while there is variation both between groups and within groups among the selected species, summer annuals are among the last to start flowering. Species classed as “summer and winter annuals”, i.e that can germinate either in spring or autumn, had a longer flowering period than the other classes. Winter annuals were first to flower while the perennials and “summer and winter annuals” differed more among each other. Weather dependency was also addressed by comparison over years. Overall, the selected species were not significantly affected by mean winter temperature, mean summer temperature or mean summer precipitation.

No description available.

Abstract Plant reproductive success is affected by a number of factors, such as climatic conditions and plant resource status during flowering and fruiting, and pollen origin in fertilization. In the present thesis project, different aspects of plant reproductive ecology were investigated in order to identify constraints on sexual reproduction and seed set in two clonal dwarf shrubs (Vaccinium myrtillus and V. vitis-idaea) and one long-lived perennial herb (Campanula rotundifolia). The work comprised phenological observations and experiments with the clonal shrubs at natural boreal forest sites in the Oulanka National Park in northern Finland. The impact of mycorrhiza on C. rotundifolia fitness traits was tested in hand pollinations in a greenhouse experiment. Pollen origin had some effect on fruit set, and had strong effects on the number of matured seeds in all three species. Seed yield reductions upon hand self-pollination as compared with hand cross-pollination were attributed to inbreeding depression in V. myrtillus, and presumably to partial self-incompatibility in C. rotundifolia. V. myrtillus and V. vitis-idaea showed a population structure where the number of matured seeds per fruit increased with increasing distance between pollen donor and pollen recipient. Clonal growth in concert with the foraging behaviour of bumblebee pollinators is thought to cause the possibility of either uniparental or biparental inbreeding, with a strong effect on the number of matured seeds per berry. In a flower-removal experiment lasting three years, costs of fruiting to future fecundity and vegetative traits were observed, but not to future survival in V. vitis-idaea and V. myrtillus. The response was more pronounced in the evergreen than in the deciduous species. In Campanula rotundifolia, mycorrhiza was associated with a cost to the plants' reproductive effort, as plant biomass and the number of flowers produced per plant were decreased in mycorrhizal plants in comparison with non-mycorrhizal plants. There was no difference in seed number, seed weight or germination between the seeds of mycorrhizal and non-mycorrhizal plants. However, the offspring of mycorrhizal plants had a higher relative growth rate, while also having a higher seed phosphorus concentration. In summary, sexual reproduction was variably constrained by previous reproduction in Vaccinium, and contrary to expectations, by mycorrhiza in Campanula. However, mycorrhiza had positive effects on some measures of offspring fitness. In all three species, self-pollination limited seed production.

How come the same species of plants can naturally occur under various conditions in different parts of the world? A plant's ability to adapt in response to a changing climate hinges on the presence of genetic variation in traits, such as flowering phenology. In this study, I examine whether flowering start varies genetically within populations and compare this variation to differences between populations. This study quantifies genetic variation in flowering time in two Italian populations of Arabidopsis thaliana whilst using two Swedish populations as a reference. This was done using a randomized block design where plants were grown in a controlled climate. To characterize and measure flowering phenology, time of bolting and flowering were recorded. The experiment included four populations, a total of 150 maternal lines, and 2980 plants. One-way ANOVAs conducted separately by population indicated significant among-line variation in the two Italian populations. Flowering time differed between the Italian and Swedish populations, but not between the two Italian populations. More data would be needed to draw conclusions about the among-line variation in the Swedish populations. The results indicate that the Italian populations have the potential to respond to selection on flowering time, which is a likely consequence of a changing climate.

Repeated polyploidization events are thought to be among the most important causes of sympatric speciation throughout evolutionary time. Changes in phenology and trait expressions that arise in polyploids have been shown to affect plant interactions with insect herbivores and pollinators. If these interactions are changed, selection subsequent to the polyploidization event could contribute to further divergence, or increased similarity, of cytotypes. This study was conducted to investigate plant interactions with insect herbivores and pollinators and patterns of selection in tetraploid and octoploid Cardamine pratensis L. (Brassicaceae), and to answer the following questions: i) Is there phenotypic selection on flowering phenology and number of flowers? ii) Is pollen limitation or herbivory most important for variation in reproductive output? iii) During what stages of ovary and ovule development do variation in fitness mainly arise? iv) Can the intensity of interactions be linked to phenology and number of flowers, suggesting that selection is mediated by pollen limitation or herbivory? v) Do intensity of interactions, and of interaction-mediated selection, differ between ploidy levels? From a combination of an observational study of herbivory and a hand pollination experiment, selection was found for earlier flowering in both subspecies. Intensity of herbivory was an important determinant of plant reproductive success, while hand pollination had little effect. Positive effects of flowering time on intensity of herbivory suggest that selection for earlier flowering was mediated by herbivores. Tetraploids initiated flowering later and suffered from more intense herbivory than did octoploids. The direction of selection was similar in both subspecies. However, differences strength of selection and intensity of herbivory suggest that there is a possibility of selection for their further divergence. / Polyploidisering anses vara en av de viktigaste orsakerna till artbildning inom populationer. Skillnader i blomningskaraktärer, såsom fenologi och blomantal, som uppstår i och med polyploidiseringen har visat sig påverka växters interaktioner med såväl pollinatörer som herbivorer. Förändringar i växt-insektsinteraktioner till följd av polyploidiseringen kan leda till selektion för ökade skillnader, eller likheter, mellan cytotyper. Studiens syfte var att undersöka växters interaktioner med insekter i form av pollinatörer och herbivorer, samt att undersöka selektionsmönster hos tetraploida och oktoploida Cardamine pratensis L. (Brassicaceae). Jag ville även besvara följande frågor: i) Sker selektion på blomningstid och blomantal? ii) Vilken växt-insektsinteraktion är viktigast för variation i reproduktionsframgång? iii) Under vilka utvecklingsstadier uppstår den största variationen i fitness? iv) Kan intensiteten av interaktionerna kopplas till blomningsfenologi och blomantal, vilket skulle indikera att selektion förmedlas genom pollenbegränsning eller herbivori? v) Skiljer sig styrkan av interaktionerna, och av interaktionsförmedlad selektion, mellan ploidinivåer? Studien utformades som en kombination av en observationsstudie av herbivori och ett handpollineringsexperiment, och jag fann selektion för tidigare blomning hos de två underarterna. Reproduktionsframgång styrdes av herbivori snarare än pollenbegränsing. Förlust av potentiell fitness genom att fröämnen inte utvecklades till frön var den faktor som starkast påverkade variation i fitness, och detta var också den fas i utvecklingen som bidrog i störst utsträckning till kvantitativ förlust av fitness. Ett positivt samband mellan blomningsfenologi och herbivoriintensitet indikerar att selektion för blomningstid var förmedlad av herbivorer. Tetraploider blommade senare och utsattes för mer intensiva herbivorattacker än oktoploider. Detta, samt skillnader i selektionsstyrka, indikerar att selektion skulle kunna leda till ökad divergens av underarterna.

Understanding the relationships between solitary bees’ flight phenology and flowering phenology is important in the context of global warming. Using Swedish citizen science data, observations of oligolectic solitary bees and flowering phenology were used together with temperature data. All five bees studied had flight period that overlapped with the flowering period their corresponding host plant. None of the species were affected by the temperature, although there was a correlation between earliest observations of flowering phenology and flight phenology. The later the flowering observation was made, the later the flight observation was made. No correlation was found between the length of flight period and length of the flowering period. Increasing temperature is not the only factor that effects flight phenology and flowering phenology.

Terrestrial plants exist in almost every habitat on the earth, ranging from warm and moist tropical rainforests, hot and dry deserts, and to cold and barren tundras. Furthermore, a single species may encounter different climatic conditionshabitats within its range distribution which climatic conditions differs from one to another. In this study, I examine the flowering phenology and fitness of two locally adapted genotypes of Arabidopsis thaliana, one from the southern range limit (Italy) and one from the northern range limit (Sweden) in Europe, in an outdoor common-garden experiment in Uppsala. Flowering start was recorded to characterize flowering phenology, whilst survival and fecundity was recorded to characterize fitness. Flowering start differed significantly between the two genotypes as with the Swedish genotype startinged flowering 24 days later than the Italian genotype. The Italian genotype had higher fitness (number of fruits per seedling planted), which was due to a slightly higher survival and fecundity. The relative fitness of the two genotypes was thus intermediate to that observed in reciprocal transplants between the native sites of origin of the two populations.

Species' floral traits and flowering times are known to be the major drivers of pollinator-mediated plant–plant interactions in diverse co-flowering communities. However, their simultaneous role in mediating plant community assembly and plant–pollinator interactions is still poorly understood. Since not all species flower at the same time, inference of facilitative and competitive interactions based on floral trait distribution patterns should account for fine phenological structure (intensity of flowering overlap) within co-flowering communities. Such an approach may also help reveal the simultaneous action of competitive and facilitative interactions in structuring co-flowering communities. Here we used modularity within a co-flowering network context, as a novel approach to detect convergent and/or over-dispersed patterns in floral trait distribution and pollinator sharing. Specifically, we evaluate differences in floral trait and pollinator distribution patterns within (high temporal flowering overlap) and among co-flowering modules (low temporal flowering overlap). We further evaluate the consistency of observed floral trait and pollinator sharing distribution patterns across space (three geographical regions) and time (dry and rainy seasons). We found that floral trait similarity was significantly higher in plant species within co-flowering modules than in species among them. This suggests pollinator facilitation may lead to floral trait convergence, but only within co-flowering modules. However, our results also revealed seasonal and spatial shifts in the underlying interactions (facilitation or competition) driving co-flowering assembly, suggesting that the prevalent dominant interactions are not static. Synthesis. Overall, we provide strong evidence showing that the use of flowering time and floral trait distribution alone may be insufficient to fully uncover the role of pollinator-mediated interactions in community assembly. Integrating this information along with patterns of pollinator sharing will greatly help reveal the simultaneous action of facilitative and competitive pollinator-mediated interactions in co-flowering communities. The spatial and temporal variation in flowering and trait distribution patterns observed further emphasize the importance of adopting a more dynamic view of community assembly processes.

This study investigates the hybridization of two species of cattails, Typha latifolia (Common Cattail) and T. angustifolia (Narrow-leaved Cattail) in the Czech Republic. The aim of this study was to determine, how often T. latifolia and T. angustifolia hybridize, whether hybridization is allowed by overlapping flowering time of these species and whether it is possible these species controlled cross in a culture. For detection of hybrid individuals were used microsatellite DNA markers, which allow to detect hybridization events and differentiate hybrids from the parental species. Molecular analysis revealed that hybridization of T. latifolia and T. angustifolia occurs in the Czech Republic, but it is not frequent. Of the 267 analyzed individuals, 130 individuals were pure species T. latifolia, 108 individuals pure species T. angustifolia and 29 individuals were hybrids. Of the hybrids, 23 were advanced hybrids, 5 were backcrosses and only one individual was F1 hybrid. Flowering time of T. latifolia and T. angustifolia overlaps, which allows hybridization, and flowering time to not act as a prezygotic reproductive isolation barrier and gametes T. latifolia and T. angustifolia can blend together. In controlled crosses the female spikes T. latifolia and T. angustifolia created seeds, but these were...

Made available in DSpace on 2014-08-20T14:22:07Z (GMT). No. of bitstreams: 1 Dissertacao_ Zeni_Fonseca_Pinto_Tomaz.pdf: 537146 bytes, checksum: 4410efffebf745b503737ec2db7a1acb (MD5) Previous issue date: 2009-03-31 / In Brazil, most peach production is concentrated in the state of Rio Grande do Sul. This sector involves working on small families farms. The increase in the product demand brings out the critical level of the consumers regarding to product quality. Therefore, the market requires new attributes accomplished to the product; considering aspects such as organoleptic characteristics, food security and environmental protection. This work aimed to reduce peach tree vigor of the cultivar Jubileu by using different interstocks length of Granada . It was carried evaluations to indicate the better length of interstock to promote tree vigor reduction without significatively altering phenological and productivity characteristics, and fruit quality. And also, it was measured the effect of different interstock lengths on flowering and harvesting time, yield and qualitative characteristics of the fruits. The experiment was carried out at the Centro Agropecuário da Palma belonging to the Faculdade de Agronomia Eliseu Maciel of the Universidade Federal de Pelotas. Important part of the vegetative growth and production of peach cv. Jubileu is directly related to interstock length. The increase in interstock length anticipates the beginning of flowering and full bloom. The vigor reduction induced by the longer interstocks promotes an increase in floral differentiation. The twenty cm length interstock promotes an increase in plant mortality; therefore, it is indicated Granada interstocks with 10 and 15cm length. The use of intergrafting, independently interstock length, has little effect on physic-chemical characteristics of the fruits. Ten and fifteen cm length interstock were most efficient for yield without altering peach quality of Jubileu . / No Brasil, a maior produção persícola concentra-se no Rio Grande do Sul. Esse pólo envolve famílias que exploram a atividade em pequenas áreas. Aliado ao aumento da demanda, cresce também o grau de exigência dos consumidores quanto à qualidade do produto, ou seja, o mercado passou a exigir novos atributos, contemplando aspectos ligados às características organolépticas, à segurança alimentar e a proteção do ambiente. Com o presente trabalho objetivou-se avaliar a interenxertia para reduzir o vigor das plantas de pessegueiro da cultivar Jubileu através do emprego de diferentes comprimentos de interenxertos da cv. Granada. O trabalho constou de um experimento, no qual foram realizadas avaliações para indicar o comprimento de interenxerto que promova a redução do vigor das plantas e avaliar o efeito dos diferentes comprimentos de interenxerto na floração, colheita, na produção e nas características qualitativas das frutas. O experimento foi desenvolvido no Centro Agropecuário da Palma da Faculdade de Agronomia Eliseu Maciel da Universidade Federal de Pelotas. Os principais resultados obtidos permitem concluir que o crescimento vegetativo e a produção do pessegueiro Jubileu está diretamente relacionada com o comprimento do interenxerto. O aumento do comprimento do filtro antecipa o início da floração e a plena floração. A redução do vigor induzida pelos interenxertos de maior comprimento promove aumento na diferenciação floral. O interenxerto de 20cm promove aumento da mortalidade das plantas e, portanto, para o adensamento de pomares, indica-se o emprego de filtros da cv. Granada com comprimento entre 10 e 15cm. O emprego da interenxertia, independentemente do comprimento do interenxerto, afeta as características físico-químicas dos pêssegos Jubileu . Os interenxertos de 10 e 15cm de comprimento foram mais eficientes na produção, sem alterar a qualidade dos pêssegos Jubileu .