Sequencing of S5 gene in autotetraploid rice japonica and indica to overcome F1 hybrids embryo sac sterility

Abstract

Autotetraploid rice is a new germplasm developed through diploid chromosome doubling. Hybrids developed by indica autotetraploid rice crossed by japonica autotetraploid rice has clear biological advantage on F 1 , causing widespread concerns for special research evolution to evaluate and utilize F 1 hybrid vigor. However, the widespread fertility of F 1 indica and japonica autotetraploid rice is low, which makes it difficult to direct utilization of F 1 vigor. In diploid indica and japonica rice, the fertility of F 1 hybrids is also proved to be low. Embryo sac infertility is known to be one of the most important reasons for hybrid sterility and many studies has indicated that the primary cause of F1 sterility was abortion of the embryo sac, which was identified by the genotype of the S5 gene on the chromosome. Previous studies have cloned S 5 based on common wild rice and cultivated rice and S 5 sequence was obtained and studied. In this paper, typical sequence of different materials of S 5 japonica and indica rice group of autotetraploid hybrids observed with whole-mount eosin B-staining confocal laser scanning microscopy WE-CLSM was utilized, to overcome F 1 hybrids embryo sac sterility.