Li H, Cheng X, Zhang L, Hu J, Zhang F, Chen B, Xu K, Gao G, Li H, Li L, Huang Q, Li Z, Yan G, Wu X.

Front Plant Sci. 2018 Jun 12; 9:796. doi: 10.3389/fpls.2018.00796. eCollection 2018.

Abstract

Lodging is a persistent problem which severely reduce yield and impair seed quality in rapeseed (Brassica napus L.). Enhancing stem strength (SS) has proven to be an effective approach to decrease lodging risk. In the present study, four interrelated stem lodging-related traits, including stem breaking resistance (SBR), stem diameter (SD), SS, and lodging coefficient (LC), were investigated among 472 rapeseed accessions. A genome-wide association study (GWAS) using Brassica 60K SNP array for stem lodging-related traits identified 67 significantly associated quantitative trait loci (QTLs) and 71 candidate genes. In parallel, a gene co-expression network based on transcriptome sequencing was constructed. The module associated with cellulose biosynthesis was highlighted. By integrating GWAS and gene co-expression network analysis, some promising candidate genes, such as ESKIMO1 (ESK1, BnaC08g26920D), CELLULOSE SYNTHASE 6 (CESA6, BnaA09g06990D), and FRAGILE FIBER 8 (FRA8, BnaC04g39510D), were prioritized for further research. These findings revealed the genetic basis underlying stem lodging and provided worthwhile QTLs and genes information for genetic improvement of stem lodging resistance in B. napus.

See: https://www.ncbi.nlm.nih.gov/pubmed/29946333

Figure 1: Correlation analysis among stem lodging-related traits. SBR, stem breaking resistance (N); SD, stem diameter (mm); SS, stem strength (N/mm²); LC, lodging coefficient; E1, Wuhan in 2015; E2, Yangluo in 2015; E3, Wuhan in 2016; E4, Yangluo in 2016; and E5, Changsha in 2016. The magnitude of correlation is indicated by different colors of number at the left diagonal and circles at the right diagonal. The circles marked by cross indicate no significantly correction was observed between traits (P > 0.05).