Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Apr 29:13:890568.
doi: 10.3389/fpls.2022.890568. eCollection 2022.

Development of Wide-Compatible Indica Lines by Pyramiding Multiple Neutral Alleles of Indica- Japonica Hybrid Sterility Loci

Jie Guo  1   2 , Yun Li  1 , Liang Xiong  1 , Tingxian Yan  1 , Jinsong Zou  1 , Ziju Dai  1 , Guang Tang  1 , Kangli Sun  1 , Xin Luan  1 , Weifeng Yang  1 , Quanya Tan  1 , Haitao Zhu  1 , Ruizhen Zeng  1 , Shaokui Wang  1 , Guiquan Zhang  1
Affiliations

Development of Wide-Compatible Indica Lines by Pyramiding Multiple Neutral Alleles of Indica- Japonica Hybrid Sterility Loci

Jie Guo et al. Front Plant Sci. .

Abstract

Since the development of indica hybrid rice in the 1970s, great success has been achieved in hybrid rice production in China and around the world. The utilization of inter-subspecific indica-japonica hybrid rice has always been considered due to its stronger heterosis characteristics. However, indica-japonica hybrids face a serious problem of sterility, which hinders the exploitation of their heterosis. In the past decades, the genetic basis of indica-japonica hybrid sterility has been well studied. It was found that in sterile indica-japonica hybrids, female sterility was mainly controlled by the S5 locus and male sterility by the Sa, Sb, Sc, Sd, and Se loci. In this study, we developed wide-compatible indica lines (WCILs) by pyramiding multiple neutral (n) alleles of the hybrid sterility loci. First, we identified Sn alleles of the loci in single-segment substitution lines (SSSLs) in the genetic background of indica Huajingxian 74 (HJX74). Then, the Sn alleles of S5, Sb, Sc, Sd, and Se loci in SSSLs were pyramided in the HJX74 genetic background. The WCILs carrying Sn alleles at the S5, Sb, Sc, Sd, and Se loci showed wide compatibility with indica and japonica rice varieties. Therefore, the WCILs will be used to develop inter-subspecific indica-japonica hybrid rice with normal fertility.

Keywords: breeding by design; heterosis; hybrid rice; hybrid sterility; neutral allele.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Genotypes of hybrid sterility loci Sa, Sb, Sc, Sd, Se, and S5 in HJX74. (A) Pollen and spikelet fertility of three parents and their F1 hybrids. (B) Ratios of genotypes at Sa, Sb, Sc, Sd, Se, and S5 loci in the F2 populations from the crosses between HJX74 and testers Taichung 65 (T65) and Guang-lu-ai 4 (GLA4). (C) Chromosome location and genotypes of the genes at the Sa, Sb, Sc, Sd, Se, and S5 loci in HJX74. Vertical bars represent rice chromosomes. P1P1, Genotypes of HJX74; P1P2, Heterozygous genotype; P2P2, Genotype of testers T65 (Sj/Sj) or GLA4 (Si/Si). Capital letters indicate statistical differences at the 0.01 probability level.
FIGURE 2
FIGURE 2
Genotypes and genetic effects of the Sc gene on chromosomal substitution segments of SSSLs with the HJX74 genetic background. (A) Pollen fertility of F1 hybrids from crosses between SSSLs and HJX74. (B) Pollen fertility of F1 hybrids from crosses between SSSLs and testers. I, indica testers; J, japonica testers. (C) Segregation ratios of Sc genotypes in F2 populations from crosses between SSSLs and T65. P1P1, Genotype of T65 (Sj/Sj); P1P2, Heterozygous genotypes; P2P2, Genotypes of SSSLs. **, Significant difference at 0.01 probability level. NS, No significance.
FIGURE 3
FIGURE 3
Genotypes and genetic effects of the S5 gene on chromosomal substitution segments of SSSLs with the HJX74 genetic background. (A) Pollen fertility and spikelet fertility in F1 hybrids from the crosses between SSSLs and different S5 genotypes. (B) Segregation ratios of S5 genotypes in F2 populations from different crosses. (C) Pollen fertility and spikelet fertility in F1 hybrids from crosses between SSSLs (21-06, 23-06, and 27-06) and testers. I, indica testers; J, japonica testers. Capital letters indicate statistical differences at the 0.01 probability level. (D) Segregation ratios of S5 genotypes in F2 populations from crosses between SSSLs and testers. P1P1, Genotype of tester; P1P2, Heterozygous genotypes; P2P2, Genotypes of SSSLs. **, Significant difference at 0.01 probability level. NS, No significance.
FIGURE 4
FIGURE 4
Pyramiding of Sn genes at the Sc and S5 loci in the HJX74 genetic background. (A) Development of WCIL 1121 by pyramiding of Scn in the substitution segment of SSSL 11-03 and S5n in the substitution segment of SSSL 21-06. Scale bar, 2 cm. Vertical bars represent rice chromosomes. Deep parts represent the substitution segments from donors and light parts represent the genetic background of HJX74. (B) Plant types of WCIL 1121 and HJX74. Scale bar, 10 cm.
FIGURE 5
FIGURE 5
Compatibility of WCILs. (A) Pollen grains stained by I2-KI solution in F1 hybrids of four crosses. Scale bar, 30 μm. (B) Spikelet fertility of the panicles in F1 hybrids. Scale bar, 2 cm. (C) Pollen fertility and spikelet fertility of the F1 hybrids from the crosses between WCILs (HJX74 as control) and indica testers (See Supplementary Tables 8–9). (D) Pollen fertility and spikelet fertility of the F1 hybrids from the crosses between WCILs (HJX74 as control) and japonica testers (See Supplementary Tables 10–11). The information about nine WCILs (1121, 1123, 1127, 2221, 2223, 2227, 2721, 2723, and 2727) is given in Supplementary Table 6. HJX74 is a recipient of SSSLs. The 9311 is an indica tester. T65 is a japonica tester. Capital letters indicate statistical differences at the 0.01 probability level.
See this image and copyright information in PMC

References

    1. Birchler J. A. (2015). Heterosis: the genetic basis of hybrid vigour. Nat. Plants 1:15020. 10.1038/nplants.2015.20 - DOI - PubMed
    1. Chen J., Ding J., Ouyang Y., Du H., Yang J., Cheng K., et al. (2008). A triallelic system of S5 is a major regulator of the reproductive barrier and compatibility of indica-japonica hybrids in rice. Proc. Natl. Acad. Sci. U.S.A. 105 11436–11441. 10.1073/pnas.0804761105 - DOI - PMC - PubMed
    1. Cheng S., Cao L., Zhuang J., Chen S., Zhan X., Fan Y., et al. (2007). Super hybrid rice breeding in China: achievements and prospects. J. Integr. Plant Biol. 49 805–810. 10.1111/j.1744-7909.2007.00514.x - DOI
    1. Dai Z., Lu Q., Luan X., Cai J., Zhu H., Liu Z., et al. (2015). Development of a platform for breeding by design of CMS lines based on an SSSL library in rice (Oryza sativa L.). Euphytica 205 63–72. 10.1007/s10681-015-1384-5 - DOI - PMC - PubMed
    1. Dai Z., Lu Q., Luan X., Ouyang L., Guo J., Liang J., et al. (2016). Development of a platform for breeding by design of CMS restorer lines based on an SSSL library in rice (Oryza sativa L.). Breed. Sci. 66 768–775. 10.1270/jsbbs.16044 - DOI - PMC - PubMed