Abnormality in male organ development and fertility of photoperiod-sensitive genic male sterile rice plants under short day condition

Ten photoperiod-sensitive genic male sterile rice (PGMSR) lines were studied to observe the development of male organs of their short day (SD) plants. The results were shown as follows: 1) The self seed-setting rate and the percentage of fertile pollen of these PGMSR lines were much lower than those of the controls. 2) All the male sterile line plants had variant barriers in anther dehiscing and pollen scattering. In addition, some of their stigmas were devoid of pollen, and some self pollen grains on their stigmas germinated weakly. 3) Female fertility of those plants was believed to be normal through observation in their embryo sac development and cross seed-setting rate. The authors deduced that the male sterile gene expression becomes the major factor for low rate of self seed-setting of PGMSR plants under SD condition.