Specific features of microsporogenesis in the Siberian larch growing under the conditions of technogenic load

Studies of microsporogenesis in the Siberian larch growing in Krasnoyarsk and its suburbs have shown that meiosis starts in October. Microsporocytes winter at prophase I (leptoneme, diploneme). Reduction divisions in male generative buds are resumed and terminated in spring, in March. However, in the case of thaws during the autumn-winter period, meiotic division proceeds in the larch buds and this leads to the formation of degrading tetrads and pollen. Hence, the organic quiescence is absent in the larch in winter. It was shown that in the larch growing in the city, meiosis proceed more asynchronously than in the background tree stands. An increase of chromosomal aberrations during the reduction division was noted under the conditions of technogenic pollution.__________Translated from Ontogenez, Vol. 36, No. 2, 2005, pp. 128–134.Original Russian Text Copyright © 2005 by Romanova, Tretyakova.