Disturbances in microsporogenesis and pollen grain development in Gagea lutea (L.) Ker. Gaw.

The meiotic division of microsporocytes and pollen grain development in Gagea lutea (L.) Ker.-Gaw. (Liliaceae) with fluorescence microscope (excitation light 400 nm) was observed after squashing the anthers in DAPI solution (fluorochrom dying DNA). Up to 70% of microsporocytes and pollen grains during the microsporogenesis and pollen grain development take a regular course. In the remaining microsporocytes and pollen grains (30%) the disturbances in course of both processes were observed. The most often observed disturbances are "late" chromosomes and a presence of micronuclei. The divisions of microsporocytes in the anther loculi show a big asynchrony, which, like the disturbances during the course of microsporogenesis and pollen grain development, may be caused by the external factors. The microsporogenesis takes place during autumn and winter months: the pollen grains develop in winter. At this time the dividing microsporocytes and developing pollen grains are under the influence of abiotic factors as low temperature and a lack of water. These factors disturb the formation of microtubular cytoskeleton of the dividing microsporocytes and pollen grains, which causes the formation of sterile pollen grains