Patterns of pollen abortion in some cytoplasmic male sterile lines of rice

Abstract

Pollen grains of five cytoplasmically male sterile (CMS) lines were stained in 1% iodine/potassium iodide solution. On the basis of their shape and staining pattern, pollen grains were classified into four categories, viz., unstained withered sterile, unstained spherical sterile, stained round sterile and stained round fertile. Using this system of classification, the CMS lines were classified into three types characterized by the relative frequency of the different classes of pollen grains. The stage at which pollen abortion occurs in a line seems to depend on the genetic distance between the cytoplasmic and nuclear parents.