Discovery of new genomic regions and candidate genes implicated in the natural variation of barley peduncle length and plant height

Abstract

The cereal plant barley (Hordeum vulgare) has high nutritional content and special characteristics that allow it to withstand adverse weather conditions. The peduncle’s developmental properties under dry (drought and heat) conditions make it an ideal attribute for studying its function in tolerance and adaption processes. Thus, we intend to investigate the natural phenotypic and genetic variation of the peduncle length, as well as the genetic reasons underpinning its growth in dry (drought and heat) environments. Under natural drought and heat, the examined characteristic showed a large range of natural variation, showing its involvement in adaptation to such circumstances. A genome-wide association study (GWAS) was carried out to evaluate the relationship between 127,022 single nucleotide polymorphisms (SNPs) and peduncle length at maturity in 184 barley accessions from throughout the world. The genomic research suggest the possibility of 86 marker-trait associations (p-value: > FDR) in various genomic areas, five of which are physically situated on chromosome 3H. The presence of 23 candidate genes was discovered after predicting candidate genes underlying significant relationships. The RNA-sequencing expression profile of candidate genes revealed that the gene HORVU.MOREX.r2.3HG0216310.1, which was identified as a Polynucleotidyl transferase ribonuclease H-like superfamily protein, had the greatest level of expression, indicating its participation in peduncle development under these conditions. Quantifying the current natural variation in peduncles under dry environmental circumstances and identifying the genomic areas linked with the features will serve as the foundation for future genetic research to better understand its function in stress tolerance.