Pollen and seed fertility of three functional male-sterile lines of eggplant with the wild Solanum cytoplasms

To find out the possibilities of propagation by selfing and production of pure lines through anther culture, pollen fertility and seed fertility were investigated in three functional male-sterile lines of eggplant developed by continuous backcross method using wild Solanum species Solanum kurzii, Solanum violaceum and Solanum virginianum as a cytoplasm donor and Solanum melongena ‘Uttara’ as a nucleus donor. Pollen fertility was assessed by pollen stainability in acetocarmine, in Lugol's solution and in vitro germination rate of pollen at three different stages of pollen maturation, such as, 2 days before anthesis, at anthesis and 2 days after anthesis. Pollen stainability with acetocarmine and in vitro germination rate of pollen in all three stages of pollen maturation were comparatively lower in the male-sterile lines. Pollen stainability with Lugol's solution revealed that, the low pollen fertility of the male-sterile lines would be caused by incomplete degradation of starch during pollen maturation. The male-sterile lines showed high percentage of fruit set with large number of seeds in the fruits obtained from selfing. Our results confirm that, it is possible to propagate the male-sterile lines by selfing and to produce pure male-sterile lines through anther culture.

► Pollen and seed fertility of three functional male-sterile eggplants were investigated during pollen maturation.
► Pollen fertility of the male-sterile lines was low but seed fertility was high both in selfing and backcrossing.
► The low pollen fertility was caused by the incomplete starch degradation during pollen maturation.