Ultrastructure of mature male gametes of Nitella hyalina (Charales, Charophyta)

Abstract

This article describes the ultrastructure of male gametes of Nitella hyalina. Microtubular roots did not surround mitochondria completely. The number of microtubules varied from 12 to19 at the level of mitochondria, from 24 to 31 at the level of the nucleus and from 10 to 21 at different levels of the plastids. The three-membered root is clearly discernible only up to the level of mitochondria. At the rearmost level of the gamete, microtubules were separated in bunches of two to six microtubules each. Mature gametes of N. hyalina were compared with those of other species of Chara and Nitella. This comparative analysis suggests that certain male gamete ultrastructure traits are regularly dissimilar at genus level.