osmtp7 pollen viability determination. pollen staining by 1% KI–I

Before flowering, fresh rice spikelets were collected and half the husk was removed for photographing with a microscope. For pollen viability measurement, the pollen grains from equal anthers of the genotypes were collected and stained with 1% KI-I2 solution for 5 min, and then photographed under an optical microscope. Black or yellow color pollen was recorded as normal or abnormal pollen, respectively. Pollen viability ratio = pollen stained with black color/total pollen on the screen × 100.