Sperm cells were isolated from corn (Zea mays L.) tricellular pollen grains. They were released using a light osmotic chock, and separated from pollen contaminants (especially starch grains) by a Percoll gradient centrifugation. Isolated sperm cells (3 x 10(6) per milliliter) show a high viability score (90%) as demonstrated with the fluorochromatic reaction. They appeared as spherical cells wh...

Palmer amaranth is resistant to several herbicides, including glyphosate, and there is concern that the resistance traits can be transferred between spatially segregated populations via pollen movement. The objective of this study was to describe the physical properties of Palmer amaranth pollen, specifically size, density, and settling velocity (Vs), that influence pollen flight. The mean diam...

That sexual selection can be an active force in plant evolution is still under debate. When the number of pollen grains deposited onto a stigma exceeds the number of available ovules, competition among pollen grains for fertilizations will result in selection on traits that increase siring ability (e.g. pollen tube growth rate). The pistil can be regarded as an arena for pollen competition, whe...

Positively charged, oligolamellar liposomes were able to enter the pea pollen grains during the germination process in vitro. Large, identifiable liposomes could be found at a low frequency in living, germinated pollen grains and pollen tubes. Protoplasmic streaming inside the germinated pollen apparatus, where it appears as moving strands, exerts violent, formative effects on the liposomes. Up...

the present research was conducted to determine the percent self-incompatibility in some asian pear (pyrus serotina rehd.) as well in european pear (pyrus communis l.) cultivars. the experiment was carried out during 2006 and 2007 growing seasons. pollen grains were collected and tested for viability using in-vitro pollen culture. for microscopic examination of pollen tube growth in the style, ...

The development of fully differentiated plants from individual pollen grains through a series of developmental phases that resemble embryogenesis beginning with the zygote was demonstrated during the mid-1960's. This technology opened the door to the use of haploid plants (sporophytes with the gametic number of chromosomes) for plant breeding and genetic studies, biochemical and metabolic studi...

Pollen tube reception involves a pollen tube-synergid interaction that controls the discharge of sperm cells into the embryo sac during plant fertilization. Despite its importance in the sexual reproduction of plants, little is known about the role of gene regulation in this process. We report here that the pollen-expressed transcription factors MYB97, MYB101 and MYB120 probably control genes w...

Fifty two genotypes were evaluated to find out the genetic variability, character association, and path coefficient for reproductive traits of exotic rice germplasm in experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur during December 2008 to May 2009. The analysis of variance showed significant variation for all the characters indicating wide geneti...

Pollen represents an important nitrogen sink in flowers to ensure pollen viability. Since pollen cells are symplasmically isolated during maturation and germination, membrane transporters are required for nitrogen import across the pollen plasma membrane. This study describes the characterization of the ammonium transporter AtAMT1;4, a so far uncharacterized member of the Arabidopsis AMT1 famil...

Hybrid incompatibility plays an important role in establishment of post-zygotic reproductive isolation. To unveil genetic basis of hybrid incompatibilities between diverged species of genus Oryza AA genome species, we conducted genetic dissection of hybrid sterility loci, S22(t), which had been identified in backcross progeny derived from Oryza sativa ssp. japonica (recurrent parent) and South ...