Download or read book Evolution of Wind pollination in Fraxinus Oleaceae written by Eva Wallander and published by . This book was released on 2001 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ecology and Evolution of Wind Pollination written by Jannice Friedman and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The evolution of wind pollination (anemophily) has occurred at least 65 times in the flowering plants and over 10% of angiosperm species are wind pollinated. However the pollination and mating of anemophily species is poorly understood, particularly in comparison with animal-pollinated species. My thesis employs a range of approaches and tools to examine the evolution and ecology of wind pollination. These include comparative analyses, theoretical modeling, field and glasshouse experiments, the use of genetic markers and quantitative genetics. Experimental studies on diverse taxa were used to address questions concerned with the efficacy of outcrossing mechanisms, the ecological and demographic context of pollination and mating, and the plasticity of sex allocation.Comparative analyses indicated that wind pollination is correlated with unisexual flowers, reduced ovule number, small unshowy flowers, an absence of nectar, and open habitats. These analyses also demonstrated that anemophily originates more often in lineages with unisexual flowers. This suggests that wind pollination evolves in diclinous taxa as a mechanism of reproductive assurance because autonomous selfing is mechanically precluded. Empirical data on stigmatic pollen loads in 19 anemophilous species challenge the widespread assumption that anemophilous plants commonly have uniovulate flowers because they capture few pollen grains. Further, a model based on floral costs and the aerodynamics of pollen capture demonstrated that when flowers are inexpensive it is optimal to produce many flowers each with few ovules, because this allows more efficient sampling of the airstream. Manipulative field experiments on seven Carex species indicated that neither monoecy nor protogyny, two putative outcrossing mechanisms, are effective at limiting selfing. Based on these results I suggest that geitonogamy can provide reproductive assurance in anemophilous species with unisexual flowers. Field experiments and the application of sex-specific markers in Rumex nivalis revealed that the local neighbourhood of maternal plants affects pollination intensity and progeny sex ratios. Finally, I demonstrated that plant density in Ambrosia artemisiifolia affects stigmatic pollen loads but not outcrossing rates. Through a quantitative genetics experiment in A. artemisiifolia, I detected significant genetic variation for plasticity in sex allocation, potentially enabling adaptive adjustment of sex allocation to local environmental conditions.
Download or read book Ash written by Edward Parker and published by Reaktion Books. This book was released on 2021-05-19 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ash is a beautifully illustrated account of the botanical and cultural faces of the ash tree. The book maps the tree’s evolution and geographical spread across the entire Northern Hemisphere over the last 44 million years, and describes the 43 species that grace the planet today. Edward Parker also explores the botany, cultural history, and medicinal uses of the tree, from its significance in ancient Indo-European cultures, to its remarkable properties in treating Alzheimer’s disease. In addition he looks at topical issues, such as the devastating effects that the spread of the emerald ash borer beetle and the ash dieback fungal infection are having on Northern Hemisphere forests.
Download or read book The Ecology and Evolution of Wind Pollination written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: PhD.
Download or read book Plant Pollinator Interactions written by Nickolas Merritt Waser and published by University of Chicago Press. This book was released on 2006-01-15 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher description
Download or read book Plant Biodiversity and Genetic Resources written by Andreas W. Ebert and published by MDPI. This book was released on 2021-06-18 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers included in this Special Issue address a variety of important aspects of plant biodiversity and genetic resources, including definitions, descriptions, and illustrations of different components and their value for food and nutrition security, breeding, and environmental services. Furthermore, comprehensive information is provided regarding conservation approaches and techniques for plant genetic resources, policy aspects, and results of biological, genetic, morphological, economic, social, and breeding-related research activities. The complexity and vulnerability of (plant) biodiversity and its inherent genetic resources, as an integral part of the contextual ecosystem and the human web of life, are clearly demonstrated in this Special Issue, and for several encountered problems and constraints, possible approaches or solutions are presented to overcome these.
Download or read book The Himalayan Soap Pod Tree Gymnocladus assamicus written by Baharul I. Choudhury and published by CABI. This book was released on 2019-10-17 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biology, distribution and population status of G. assamicus -- Phylogeny and phylogeography of the genus Gymnocladus and its close relatives -- Reproductive ecology of Gymnocladus assamicus -- Seed biology and modes of regeneration -- Seedling dynamics and ecology of G. assamicus -- Conservation and management of plant biodiversity in the Eastern Himalayan regions with emphasis on soap pod tree (G. assamicus).
Download or read book American Journal of Botany written by and published by . This book was released on 2003 with total page 1004 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolution of Wind Pollination in Leucadendron Proteaceae written by Megan Rae Welsford and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biomechanical and Ecological Insights on Evolutionary Transitions from Animal to Wind Pollination in Flowering Plants written by David Timerman and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind pollination (anemophily) has evolved from animal pollination (zoophily) at least 65 times among angiosperm lineages and is associated with a characteristic syndrome of floral traits, probably reflecting convergent adaptation to aerodynamically driven processes. In this thesis, I investigated the floral trait modifications promoting wind pollination, their fitness effects in contrasting environments, and the evolutionary significance of ambophily, in which both wind and insect pollination occur. I focused on traits promoting pollen release in air because it is the critical first stage of wind pollination and is constrained in most zoophilous taxa. I begin by reviewing the aerodynamic principles governing pollen release to identify likely targets of selection for anemophily. I then performed a comparative biomechanical analysis of pollen release using Thalictrum (Ranunculaceae), an herbaceous genus with multiple independent transitions between pollen vectors. I demonstrated that turbulence-induced vibration of stamens is the primary mechanism of pollen release, and is more likely to occur in species with lower natural frequencies, an intrinsic property of materials in which length and mass vary inversely. I also investigated intraspecific variation in natural frequency and its effects on fitness in dioecious ambophilous T. pubescens. I detected heritable population differences in natural frequency and thus pollen release, and demonstrated using field experiments that selection favours lower natural frequencies when pollinators limit seed set. I then investigated the evolutionary stability of ambophily in T. pubescens by evaluating how variation in density and sex ratio affects pollination success through animal versus wind pollination. I demonstrated that fitness losses resulting from declining pollinator service are offset by wind pollination suggesting that the reproductive flexibility provided by ambophily may be adaptive in populations facing demographic uncertainty. Finally, I examined factors causing male-biased sex ratios in T. pubescens. Several lines of evidence indicated that the bias is likely established early in the life cycle, perhaps at the seed stage, perhaps reflecting an adaptive bias of the primary sex ratio. My thesis provides novel results and insights on the biomechanics of wind pollination and the microevolutionary processes operating during the early stages in the transition from animal to wind pollination.
Download or read book Comparative Flowering Ecology of Fraxinus Excelsior Acer Platanoides Acer Pseudoplatanus and Tilia Cordata in the Canopy of Leipzig s Floodplain Forest written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: How do gender separation and the transition to wind pollination happen in temperate trees? What does the reproductive ecology in the crowns of temperate forest trees look like? These connected questions intrigued researchers before and since Darwin but it is only in the last years that a direct study of the latter question has been enabled. A research crane was used to study the flowering ecology of Fraxinus excelsior, Acer platanoides, Acer pseudoplatanus and Tilia cordata in Leipzig's floodplain forest. These species originate from hermaphrodite insect pollinated plant families and exhibit different grades of gender separation and different stages between insect and wind pollination. As they are typical elements of temperate deciduous forests, an ecological comparison of their flowering ecology may shed new light on the evolution of gender separation and wind pollination in this habitat. Using the crane, gender distribution, flowering phenology in relation to microclimate, pollination levels (including pollen tubes in the styles) and fruit set were studied in ca. 200 trees over 2-4 years. Main results are a new appreciation of the sexual system of Fraxinus excelsior as dioecy, of Tilia cordata as andromonoecy and a detailed description of the intricacies of the heterodichogamous sexual system of Acer pseudoplatanus. Several flowering phenological patterns are described in Fraxinus excelsior and Acer platanoides in relation to microclimate in early spring. The role of small arthropods is underlined as gall mites may play a role in gender specialisation in Fraxinus excelsior, gall midges are related to maleness in T. cordata and thrips are probably the pollinators of Acer pseudoplatanus in the stand. Thrips pollination is suggested to be a possible stepping-stone between insect pollination and wind pollination, which may drive the transition in Acer pseudoplatanus and possibly in intensively flowering dominant species in other habitats. The study presents the comple.
Download or read book Floral Diagrams written by Louis P. Ronse De Craene and published by Cambridge University Press. This book was released on 2022-04-07 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floral morphology is key for understanding floral evolution and plant identification. Floral diagrams are two-dimensional representations of flowers that replace extensive descriptions or elaborate drawings to convey information in a clear and unbiased way. Following the same outline as the first edition, this comprehensive guide includes updated and relevant literature, represents the latest phylogeny, and features 28 new diagrams. Diagrams are presented in the context of the most recent classifications, covering a variety of families and illustrating the floral diversity of major groups of plants. A strong didactic tool for observing and understanding floral structures, these diagrams are the obvious counterpart to any genetic study in flowering plants and to the discussion of major adaptations and evolutionary trends of flowers. This book is invaluable for researchers and students working on plant structure, development and systematics, as well as being an important resource for plant ecologists, evolutionary botanists and horticulturists.
Download or read book Proceedings written by and published by . This book was released on 2004 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plants of the World written by Robert W. Minor and published by . This book was released on 2003 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Embryology of Flowering Plants Terminology and Concepts Vol 3 written by T B Batygina and published by CRC Press. This book was released on 2019-04-23 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant embryology, dealing with the regularities of initiation and the first stages of development of an organism, is now flourishing because of the overall progress being made in natural sciences. Such discoveries of the 20th century as production of plants from a single somatic cell, experimental haploidy, and parasexual hybridization were of general biological significance. The combined efforts of embryologists, geneticists and molecular biologists yielded the discovery of specific genes that control meiosis, egg cell development and early stages of embryogenesis. The tendency to synthesize data of embryology and genetics has become increasingly noticeable. It is connected with the fact that the majority of problems connected with morphogenesis, such as differentiation, specialization, the evaluation of features and the definition of the notionsgene and feature andgenotype and phenotype concern embryology and genetics (embryogenetics) in one way or another. Evolutionary embryology has given rise to a new approach to the study of problems of adaptation in plants. In connection with the problem of preserving biological diversity under conditions of ecological stress, special attention is paid to ecological embryology, revealing the critical periods in early ontogenesis and plasticity and tolerance of reproductive systems at the level of species and population. The study of variability of morphogenesis and phenotype in population (life cycle variations and the diversity of reproductive systems) is the most important point in the population embryology of plants.
Download or read book Revista de biolog a tropical written by and published by . This book was released on 2009 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Natural History of Pollination written by Michael Proctor and published by Timber Press (OR). This book was released on 1996 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This is a brand new, fully updated edition of the natural history classic first published in 1973 as The Pollination of Flowers." "The importance of insects in pollinating flowers is today so well known it is easy to forget that it was discovered little more than two centuries ago: before that, it was believed that the concern of bees with flowers was simply a matter of collecting honey." "But the methods by which pollen reaches the female flower, enabling fertilisation and seed production to take place, include some of the most varied and fascinating mechanisms in the natural world. The Natural History of Pollination describes all the ways in which pollination is brought about: by wind, water, birds, bats and even mice and rats; but principally by a great diversity of insects in an amazing range of ways, some simple, some bizarre." "This book is a unique introduction to a complex yet easily accessible subject of great fascination."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved
