Markers for pollen fertility in intersubspecific hybrid rice

Since an allele S5n was identified and used to overcome the sterility in hybrid rice breeding, many intersubspecific hybrids harbored the S5n allele had been tested for their yield potential. Such hybrids showed pronounced heterosis and high yield potential, but some of them had an unstable or low seed set. The reason for the low seed set was attributed to the partial pollen sterility.