Central Tuber Crops Research Institute, Trivandrum 695017.
While screening the germplasm of cassava for pollen fertility, diverse types of pollen sterility were noticed. The male sterile clones were more frequent among the indigenous than exotic genotypes. Though the male sterile clones of indigenous origin showed empty anthers, those of exotic origin, except Ce 539, had 100% sterile pollen of small size. Male sterility among the indigenous strains resulted from nonseparation of microspores from the tetrads, which may be due to the suppression of callase activity. In the exotics, delayed separation of microspores leads to the production of small sterile pollen. The partial pollen sterility resulted from the cryptic structural hybridity manifested through aberrant pachytene pairing.
Male sterility, tapetum, late disjunction, microspores, callase, cassava
