title: Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud.
abstract: 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.
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yumin
authors.initials: Y
authors.lastname: Shen
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Hongyang
authors.initials: H
authors.lastname: Ma
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Bian
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Yu
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Haiyuan
authors.initials: H
authors.lastname: Chen
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Linglong
authors.initials: L
authors.lastname: Liu
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Wenwei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, China.
authors.forename: Jiawu
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Food Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, China.
authors.forename: Dayun
authors.initials: D
authors.lastname: Tao
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China. wanjm@njau.edu.cn.|Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. wanjm@njau.edu.cn.
authors.forename: Jianmin
authors.identifier: http://orcid.org/0000-0002-7813-4362
authors.initials: J
authors.lastname: Wan
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000502:physiology; D051479:Plant Infertility / Q000235:genetics* / Q000502:physiology
chemical_list: D018744:DNA, Plant
keywords: Cytological mechanism; Female gamete abortion; Fine mapping; Hybrid sterility; Pollen abortion