Observation on Double Fertilization and Early Embryonic Development in Autotetraploid Polyembryonic Rice

The process of double fertilization and the characters of embryo and endosperm development in an autotetraploid polyembryonic mutant rice IR36-Shuang were studied with a laser scanning confocal microscopy. Some abnormalities including degenerated ovary, abortive embryo sac, single fertilization, double-ovule and double-embryo and so on. were found during double fertilization and embryo development in IR36-Shuang. The rate of the abnormalities was 46.67% in IR36-Shuang, significantly higher than that in the control, an autotetraploid rice line IR36-4X (33.00%). Cytological and embryonic evidences were provided for seed setting decline and the initiation of additional embryo in IR36-Shuang.