In this communication, direction of evolutionary variability of parameters of genome size and structurally functional activity of plants in angiosperm taxa among life forms, are analyzed. It is shown that, in the Cretaceous–Cenozoic era, the nuclear genome of the plants tended to increase. Functional genome efficiency (intensity of functions per pg of DNA) decreased as much as possible from hig...

The zygote in flowering plants usually divides transversely to form a terminal cell, which gives rise to the embryo proper, and a vacuolated basal cell, which often divides rapidly to form a structure known as the suspensor. Angiosperm suspensors vary widely in size and morphology from a single cell to a massive column of several hundred cells (Maheshwari, 1950; Wardlaw, 1955; Lersten, 1983). I...

With increases in both the size and scope of phylogenetic trees, we are afforded a renewed opportunity to address long-standing comparative questions, such as whether particular fruit characters account for much of the variation in diversity among flowering plant clades. Studies to date have reported conflicting results, largely as a consequence of taxonomic scale and a reliance on potentially ...

Theresa M. Culley* Stephen G. Weller Ann K. Sakai Dept of Ecology and Evolutionary Biology, University of California–Irvine, Irvine, CA 92697, USA. *e-mail: [email protected] Although much emphasis has been placed on specialist pollination systems, attention is shifting towards systems in which plants are visited by a variety of pollinators [1,2]. Until recently, examples of generalist pollinatio...

J. S. Sperry,1* U. G. Hacke,y T. S. Feild,z Y. Sano,§ and E. H. Sikkema* *Department of Biology, University of Utah, 257S 1400E, Salt Lake City, Utah 84112, U.S.A.; yDepartment of Renewable Resources, University of Alberta, Edmonton, Alberta T6G 2H1, Canada; zDepartment of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996, U.S.A.; and §Laboratory of Woody Pla...

BACKGROUND AND AIMS Conifers dominated wet lowland tropical forests 100 million years ago (MYA). With a few exceptions in the Podocarpaceae and Araucariaceae, conifers are now absent from this biome. This shift to angiosperm dominance also coincided with a large decline in atmospheric CO2 concentration (ca). We compared growth and physiological performance of two lowland tropical angiosperms an...

Microstructural changes in several very slowly evolving chloroplast introns and intergenic spacers were characterized across a broad range of angiosperms, including most of the major basal lineages. Insertion/ deletion events (indels) in the surveyed noncoding regions of the large inverted repeat (IR) region were shown to be rarer than nucleotide substitutions and thus constitute one of the slo...

In seed plants, the body organization is established during embryogenesis and is uniform across gymnosperms and angiosperms, despite differences during early embryogeny. Evidence from angiosperms implicates the plant hormone auxin and its polar transport, mainly established by the PIN family of auxin efflux transporters, in the patterning of embryos. Here, PaPIN1 from Norway spruce (Picea abies...

UNLABELLED PREMISE OF THE STUDY Seeds of most families in the ancient angiosperm lineage Austrobaileyales produce a full-fledged genetically biparental embryo-nourishing endosperm. However, seeds of fossil and extant Trimeniaceae have been described as having a perisperm, a maternal nutrient-storing and embryo-nourishing tissue derived from the nucellus of the ovule. Because perisperm is als...

The root of the angiosperm tree has not yet been established. Major morphological and molecular differences between angiosperms and other seed plants have introduced ambiguities and possibly spurious results. Because it is unlikely that extant species more closely related to angiosperms will be discovered, and because relevant fossils will almost certainly not yield molecular data, the use of d...