In a previous review of male gametophyte development (McCormick, 1993), it was noted that the two areas posed by Mascarenhas (1975) as fruitful areas for future research were the following. What are the differences in the two cytoplasms that determine the different cell fates of the generative and vegetative cells? And what are the functions of pollen-specific proteins? Now, 10 years later, the...

Tobacco (Nicotiana tabacum L.) microspores at the time of mitosis are characterized by the abundant occurrence of 92and 98-kDa glycoproteins (GP92 and GP98). GP92 is a soluble protein while GP98 is bound to the insoluble microspore fraction. Both glycoproteins were isolated by affinity chromatography and SDS– PAGE and analysed by MS. Peptide sequences were determined by l-HPLC/nano-ESI–MS/MS (e...

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...

The meiotic pollen mother cells (PMC) of Tradescantia (spiderwort) are highly synchronized in their prophase I and tetrad stages. Chromosomes of this stage are sensitive to physical or chemical mutagens. Thus high frequency of acentric fragments or sticky chromosomes can be induced with very low level of mutagens. These induced chromosome aberrations become micronuclei (MCN) in the synchronized...

The majority of angiosperms display maternal plastid inheritance. The cytological mechanisms of this mode of inheritance have been well studied, but little is known about its genetic relationship to biparental inheritance. The angiosperm Chlorophytum comosum is unusual in that different pollen grains show traits of different modes of plastid inheritance. About 50% of these pollen grains exhibit...

Colchicine has been applied to young developing anthers of Triticum aestivtim at varying stages of maturity from the last premeiotic mitoses of the archesporial and tapetal cells to the second meiotic divisions of the pollen mother cells. The developmental stage of the archesporium at which colchicine took effect was determined by cytological examination of the ploidy levels of the nuclei of th...

In the course of a study of pollen wall development in the Gramineae two interesting relationships were noted: the locule wall and tapetal cells were bordered by spheroids which were similar chemically (resistant to acetolysis) and morphologically to the pollen exine. The pollen exine as well as the wall of the spheroids was perforated by submicroscopic channels. In the mature anther the sphero...