Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud
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Hybrid sterility locus S37 between Oryza glaberrima and Oryza sativa results in both pollen and embryo sac sterility.
Interspecific crossing between African cultivated rice Oryza glaberrima and Oryza sativa cultivars is hindered by hybrid sterility. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL)-S37 using Dianjingyou1 (DJY1) as the recipient parent and an African cultivated rice variety as the donor parent. Empty pollen and embryo sac sterility were observed in F1 hybrids between DJY1 and NIL-S37. Cytological analyses showed that pollen abortion in the F1 hybrids occurred at the late binucleate stage due to a failure of starch accumulation in pollen grains. In addition, partial abortion of the embryo sac in the F1 hybrid was observed during function megaspore developing into mature embryo sac. Molecular analysis revealed that the semi-sterility was largely caused by the abortion of male and female gametophytes carrying the S37 allele from DJY1. A population of 25,600 plants derived from the hybrid DJY1/NIL-S37 was developed to fine map S37. Based on the physical location of molecular markers, S37 locus was finally delimited to a region of 205 kb on the short arm of chromosome 1 in terms of reference sequences of cv. Nipponbare. Interestingly, an about 97-kb DNA segment was deleted in the NIL-S37 based on BAC clone information of O. glaberrima. Fifty-four open reading frames (ORF) were predicted in this 205-kb region of DJY1, whereas only 31 ORFs were in that of NIL-S37. These results are valuable for cloning of S37 gene and further breaking reproductive isolation between Oryza glaberrima and Oryza sativa cultivars, as well as marker-assisted transferring of the corresponding neutral allele in rice breeding programs.
KeywordsHybrid sterility Female gamete abortion Pollen abortion Cytological mechanism Fine mapping
Microspore mother cell
Open reading frame
Simple sequence repeat
Transmission ratio distortion
Whole-mount stain-clearing laser scanning confocal microscopy
This research was supported by the grants from the Ministry of Agriculture Key Laboratory of the middle and lower reaches of the Yangtze River japonica rice biology and genetic breeding, National Transform Science and Technology Program (2013ZX08001004-002), the Chinese National High Technology Research and Development Program (“863” Program, Nos. 2014AA10A604).
Compliance with ethical standards
Conflict of interest
The authors declare no competing financial interests.
- Chen JJ, Ding JH, Ouyang YD, Du HY, Yang JY, Cheng K, Zhao J, Qiu SQ, Zhang XL, Yao JL, Liu KD, Wang L, Xu CG, Li XH, Xue YB, Xia M, Ji Q, Lu JF, Xu ML, Zhang QF (2008) A triallelic system of S5 is a major regulator of the reproductive barrier and compatibility of indica-japonica hybrids in rice. Pro Natl Acad Sci USA 105:11436–11441CrossRefGoogle Scholar
- Doi K, Taguchi K, Yoshimura A (1998) A new locus affecting high F1 pollen sterility found in backcross progenies of japonica rice and African rice. Rice Genet Newsl 15:146–148Google Scholar
- Doi K, Taguchi K, Yoshimura A (1999) RFLP mapping of S20 and S21 for F1 pollen semi-sterility found in backcross progeny of Oryza sativa and O.glaberrima. Rice Genet Newsl 16:65–68Google Scholar
- Jones M, Mande S, Aluko K (1997) Diversity and potential of Oryza glaberrima Steud. in upland rice breeding. Breeding Sci 47:395–398Google Scholar
- Sanguinetti CJ, Dias NE, Simpson AJG (1994) Rapid silver staining and recover of PCR products separated on polyacrylamide gels. Biotechniques 17:915–919Google Scholar
- Sarla N, Swamy B (2005) Oryza glaberrima: a source for the improvement of Oryza sativa. Curr Sci 89:955–963Google Scholar
- Taguchi K, Doi K, Yoshimura A (1999) RFLP mapping of S19, a gene for F1 pollen semi-sterility found in backcross progeny of Oryza sativa and O. glaberrima. Rice Genet Newsl 16:70–71Google Scholar
- WARDA (West Africa Rice Development Association) (2006) Providing what’s needed. In: WARDA annual report 2005–2006, pp 8–11Google Scholar