DIVERSE TYPES OF MALE STERILITY IN CASSAVA

Abstract

While screening the gennplasm of cassava lor pollen fertility, diverse types of poUen sterility were noticed. TIle male sterile clones were n10re frequent among the indigenous than exotic genotypes. TIlough the male sterile clones of indigenous origin showed empty anthers, those ofexotic origin, except Ce 539, had lOOCliJ sterile pollen of small size. Male sterility among the indigenous strains resulted from nonseparation 01 microspores lrom the tetrads, whichmay be due to the suppression of callase activity. In the exotics, delayed separation of microspores leads to the production of small sterOe pollen. TIle partial pollen sterility resulted from the cryptic structural hybridity manifested through aberrant pachytene pairing.