Species differentiation and the underlying genetics of reproductive isolation are central topics in evolutionary biology. Hybrid sterility is one kind of reproductive barrier that can lead to differentiation between species. Here, we analyze the complex genetic basis of the intraspecific hybrid male sterility that occurs in the offspring of two distant natural strains of Arabidopsis thaliana, S...

Risk assessment of gene flow from GM crops into the environment requires both the development of physical transport models and biological models for the assessment of outcrossing probabilities. Our starting point is a Lagrangian approach for pollen dispersal, which describes the concentration statistics in terms of the stochastic properties of the paths of ensembles of particles. Transport of a...

Although there has been much experimental work on floral traits that are under selection from mutualists and antagonists, selection by abiotic environmental factors on flowers has been largely ignored. Here we test whether pollen susceptibility to rain damage could have played a role in the evolution of the reproductive architecture of Davidia involucrata, an endemic in the mountains of western...

Seed set is usually low and differs for different crosses of flower lotus (Nelumbo nucifera Gaertn.). The reasons remain unknown, and this has a negative impact on lotus breeding. To determine the causes, we carried out two crosses of flower lotus, that is, "Jinsenianhua" × "Qinhuaihuadeng" and "Qinhuaihuadeng" × "Jinsenianhua" and pollen viability, pistil receptivity, and embryo development we...

Taxodium Rich is well known for its flooding tolerance and has great ecological economic potential. A comprehensive understanding of pollen characteristics storage capacity important breeding genetic resource conservation the genus. In this study, we observed microsporogenesis ornamentation, studied conditions in vitro germination, compared difference viability T. distichum var. measured by ger...

This paper describes the molecular, kinetic, and physiological characterization of AtSTP6, a new member of the Arabidopsis H(+)/monosaccharide transporter family. The AtSTP6 gene (At3g05960) is interrupted by two introns and encodes a protein of 507 amino acids containing 12 putative transmembrane helices. Expression in yeast (Saccharomyces cerevisiae) shows that AtSTP6 is a high-affinity (K(m)...

Pectin is a complex polysaccharide and an integral part of the primary plant cell wall and middle lamella, contributing to cell wall mechanical strength and cell adhesion. To understand the structure-function relationships of pectin in the cell wall, a set of transgenic potato lines with altered pectin composition was analysed. The expression of genes encoding enzymes involved in pectin acetyla...

The study was conducted in the years 2004 – 2005 using two populations of Adonis vernalis L. occurring in the Adonido-Brachypodietum pinnati community at Pliszczyn near Lublin and in the Brachypodio-Teucrietum community at Stawska Góra near Che3m. The blooming of A. vernalis in the Lublin region occurs from the first days of April to the end of May. The species is characterized by an early, day...

Global climate change, especially, increases in carbon dioxide (CO2) concentration and the associated increases in temperature will have significant impact on the crop production. Grain-sorghum [Sorghum bicolor (L.) Moench] cultivar DeKalb 28E was grown at daytime maximum/nighttime minimum temperature regimes of 32/22, 36/26, 40/30 and 44/34 8C at ambient (350 mmol CO2 mol ) and elevated (700 m...

In flowering plants, mature sperm cells are enclosed in pollen grains formed in structures called anthers. Several cell layers surrounding the central sporogenous cells of the anther are essential for directing the developmental processes that lead to meiosis, pollen formation, and the subsequent pollen release. The specification and function of these tissues are regulated by a large number of ...