A novel locus (Bnsdt2) in a TFL1 homologue sustaining determinate growth in Brassica napus

Kaixiang Li; Liang Xu; Yongpeng Jia; Cuiping Chen; Yanmei Yao; Haidong Liu; Dezhi Du

doi:10.1186/s12870-021-03348-0

A novel locus (Bnsdt2) in a TFL1 homologue sustaining determinate growth in Brassica napus

BMC Plant Biol. 2021 Dec 3;21(1):568. doi: 10.1186/s12870-021-03348-0.

Authors

Kaixiang Li^#¹, Liang Xu^#¹, Yongpeng Jia¹, Cuiping Chen¹, Yanmei Yao¹, Haidong Liu¹, Dezhi Du²

Affiliations

¹ Academy of Agricultural and Forestry Sciences of Qinghai University, Key Laboratory of Spring Rape Genetic Improvement of Qinghai Province, Rapeseed Research and Development Center of Qinghai Province, Xining, 810016, Qinghai, China.
² Academy of Agricultural and Forestry Sciences of Qinghai University, Key Laboratory of Spring Rape Genetic Improvement of Qinghai Province, Rapeseed Research and Development Center of Qinghai Province, Xining, 810016, Qinghai, China. qhurape@126.com.

^# Contributed equally.

Abstract

Background: The determinate growth habits is beneficial for plant architecture modification and the development of crops cultivars suited to mechanized production systems. Which play an important role in the genetic improvement of crops. In Brassica napus, a determinate inflorescence strain (4769) has been discovered among doubled haploid (DH) lines obtained from a spring B. napus × winter B. napus cross, but there are few reports on it. We fine mapped a determinate inflorescence locus, and evaluated the effect of the determinate growth habit on agronomic traits.

Results: In this study, we assessed the effect of the determinate growth habit on agronomic traits. The results showed that determinacy is beneficial for reducing plant height and flowering time, advancing maturity, enhancing lodging resistance, increasing plant branches and maintaining productivity. Genetic analysis in the determinate (4769) and indeterminate (2982) genotypes revealed that two independently inherited recessive genes (Bnsdt1, Bnsdt2) are responsible for this determinate growth trait. Bnsdt2 was subsequently mapped in BC₂ and BC₃ populations derived from the combination 2982 × 4769. Bnsdt2 could be delimited to an approximately 122.9 kb region between 68,586.2 kb and 68,709.1 kb on C09. BLAST analysis of these candidate intervals showed that chrC09g006434 (BnaC09.TFL1) is homologous to TFL1 of A. thaliana. Sequence analysis of two alleles identified two non-synonymous SNPs (T136C, G141C) in the first exon of BnaC09.TFL1, resulting in two amino acid substitutions (Phe46Leu, Leu47Phe). Subsequently, qRT-PCR revealed that BnaC09.TFL1 expression in shoot apexes was significantly higher in NIL-4769 than in 4769, suggesting its essential role in sustaining the indeterminate growth habit.

Conclusions: In this study, the novel locus Bnsdt2, a recessive genes for determinate inflorescence in B. napus, was fine-mapped to a 68,586.2 kb - 68,709.1 kb interval on C09. The annotated genes chrC09g006434 (BnaC09.TFL1) that may be responsible for inflorescence traits were found.

Keywords: Agronomic traits; Bnsdt2; Brassica napus; Determinate inflorescence; qRT-PCR.

MeSH terms

Brassica napus / genetics*
Brassica napus / growth & development*
Flowers / growth & development
Gene Expression Regulation, Developmental / physiology*
Gene Expression Regulation, Plant / physiology*
Haploidy
Plant Proteins / genetics
Plant Proteins / metabolism*

Substances

Plant Proteins