نتایج جستجو برای: floral borders

تعداد نتایج: 23520  

Journal: :The Plant cell 1996
R C Elliott A S Betzner E Huttner M P Oakes W Q Tucker D Gerentes P Perez D R Smyth

To understand better the role of genes in controlling ovule development, a female-sterile mutant, aintegumenta (ant), was isolated from Arabidopsis. In ovules of this mutant, integuments do not develop and megasporogenesis is blocked at the tetrad stage. As a pleiotropic effect, narrower floral organs arise in reduced numbers. More complete loss of floral organs occurs when the ant mutant is co...

2015
Amelia Asbe Starr C. Matsushita Spencer Gordon H. E. Kirkpatrick Andreas Madlung Martina Stromvik

Angiosperm flowers are usually determinate structures that may produce seeds. In some species, flowers can revert from committed flower development back to an earlier developmental phase in a process called floral reversion. The allopolyploid Arabidopsis suecica displays photoperiod-dependent floral reversion in a subset of its flowers, yet little is known about the environmental conditions enh...

2009
Rainer Melzer Wim Verelst Günter Theißen

The organs of a eudicot flower are specified by four functional classes, termed class A, B, C and E, of MADS domain transcription factors. The combinatorial formation of tetrameric complexes, so called 'floral quartets', between these classes is widely believed to represent the molecular basis of floral organ identity specification. As constituents of all complexes, the class E floral homeotic ...

2006
Jeffrey K. Conner

The diversity of floral forms in nature can be explained largely as adaptations to the diversity of biotic and abiotic selective agents with which different plant species interact. Ecological genetics is the study of the process of adaptation, and therefore is an ideal approach to understanding floral adaptations. Here I review work on selection and genetic variance and covariance of floral tra...

Journal: :Molecular ecology 2016
Elizabeth R Milano Amanda M Kenney Thomas E Juenger

Plant-pollinator interactions are thought to be major drivers of floral trait diversity. However, the relative importance of divergent pollinator-mediated selection vs. neutral processes in floral character evolution has rarely been explored. We tested for adaptive floral trait evolution by comparing differentiation at neutral genetic loci to differentiation at quantitative floral traits in a p...

2014
Chan Zhang Yong-Ping Yang Yuan-Wen Duan

Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Flo...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2014
Mario Vallejo-Marín Catriona Walker Philip Friston-Reilly Lislie Solís-Montero Boris Igic

Floral morphology determines the pattern of pollen transfer within and between individuals. In hermaphroditic species, the spatial arrangement of sexual organs influences the rate of self-pollination as well as the placement of pollen in different areas of the pollinator's body. Studying the evolutionary modification of floral morphology in closely related species offers an opportunity to inves...

Journal: :Plant physiology 2001
M Ohto K Onai Y Furukawa E Aoki T Araki K Nakamura

Although sugar has been suggested to promote floral transition in many plant species, growth on high concentrations (5% [w/v]) of sucrose (Suc) significantly delayed flowering time, causing an increase in the number of leaves at the time of flowering in Arabidopsis. The effect of high concentrations of Suc seemed to be metabolic rather than osmotic. The delay of floral transition was due to ext...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2014
Allan G Ellis Samuel F Brockington Marinus L de Jager Gregory Mellers Rachel H Walker Beverley J Glover

Phenotypic integration, the coordinated covariance of suites of morphological traits, is critical for proper functioning of organisms. Angiosperm flowers are complex structures comprising suites of traits that function together to achieve effective pollen transfer. Floral integration could reflect shared genetic and developmental control of these traits, or could arise through pollinator-impose...

2010
Venkatesan Radhika Christian Kost Wilhelm Boland Martin Heil

Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, no...

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