Abstract
Low-temperature tolerance during the bud-bursting stage is an important characteristic of direct-seeded rice. The identification of cold-tolerance quantitative trait loci (QTL) in species that can stably tolerate cold environments is crucial for the molecular breeding of rice with such traits. In our study, high-throughput QTL-sequencing analyses were performed in a 460-individual F2:3 mapping population to identify the major QTL genomic regions governing cold tolerance at the bud-bursting (CTBB) stage in rice. A novel major QTL, qCTBB9, which controls seed survival rate (SR) under low-temperature conditions of 5°C/9 days, was mapped on the 5.40-Mb interval on chromosome 9. Twenty-six non-synonymous single-nucleotide polymorphism (nSNP) markers were designed for the qCTBB9 region based on re-sequencing data and local QTL mapping conducted using traditional linkage analysis. We mapped qCTBB9 to a 483.87-kb region containing 58 annotated genes, among which six predicted genes contained nine nSNP loci. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis revealed that only Os09g0444200 was strongly induced by cold stress. Haplotype analysis further confirmed that the SNP 1,654,225 bp in the Os09g0444200 coding region plays a key role in regulating the cold tolerance of rice. These results suggest that Os09g0444200 is a potential candidate for qCTBB9. Our results are of great significance to explore the genetic mechanism of rice CTBB and to improve the cold tolerance of rice varieties by marker-assisted selection.
Highlights
Rice (Oryza sativa L.) is an important food crop that has adapted to the tropical climate of the world
Chilling injury events have been frequently observed in Northeast China in the past few years (Ma et al, 2017; Shen et al, 2019)
The pre-germinated rice seeds directly planted in the soil are affected by the low temperature of air and/or irrigation water, which considerably reduces the germination rate and can lead to seed death (Fujino and Matsuda, 2010)
Summary
Rice (Oryza sativa L.) is an important food crop that has adapted to the tropical climate of the world. Chilling injury of rice that occurs at high latitudes and high altitudes has severely restricted its production Fast and uniform seed germination and vigorous seedling growth are essential for stable crop growth. The germination rate and early growth of seedlings after germination are the two main characteristics that are directly related to seedling vigor. Cold stress usually damages and delays germination and seedling growth of rice, leading to inferior stand establishment and uneven maturity, especially in areas where direct-seeded
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
