Sexual polyploidization, as a result of 2n gamete formation, is thought to be the main process involved in the origin of polyploid plants (Bretagnolle & Thompson, 1995). These gametes, possessing the somatic rather than the gametophytic chromosome number, can be formed either during microsporogenesis (2n pollen, big pollen, diplandroidy) or megasporogenesis (2n eggs, diplogynoecy). In general, ...

In this study, ultrastructures of anther wall and sporogenous tissue of Leucojum aestivum were investigated during different developmental stages. Cytomictic channels were seen between pollen mother cells during prophase I. Polar distribution was described in the organelle content of pollen mother cells and microspores in early phases of microsporogenesis and also in pollen mitosis. Active secr...

COMPARISON of microsporogenesis and microspore development A in a triploid Tradescantia has shown significant deviations from the normal diploid behavior. Occasional dicentric chromatids a t meiosis are found in diploid Tradescantias, but inversion crossovers in the triploid are much more frequent. An analysis of microspore development in a triploid Tradescantia shows that chromosome number has...

This study investigated patterns of cytoskeletal organization during microsporogenesis in Chondrilla juncea L., an autonomous apomict with a triploid chromosome number (2n = 15). The distribution of microtubules and organelles is not typical. The microtubules do not form a normal phragmoplast and consequently the organelle equatorial plate observed in many taxons is not present. The organelles ...

During microsporogenesis, the microsporocyte (or microspore) plasma membrane plays multiple roles in pollen wall development, including callose secretion, primexine deposition, and exine pattern determination. However, plasma membrane proteins that participate in these processes are still not well known. Here, we report that a new gene, RUPTURED POLLEN GRAIN1 (RPG1), encodes a plasma membrane p...

To obtain detailed information about gene expression during stamen development in Arabidopsis (Arabidopsis thaliana), we compared, by microarray analysis, the gene expression profile of wild-type inflorescences to those of the floral mutants apetala3, sporocyteless/nozzle, and male sterile1 (ms1), in which different aspects of stamen formation are disrupted. These experiments led to the identif...