The Genetic Architecture of Barley Plant Stature

Abstract

Plant stature in temperate cereals is predominantly controlled by tillering and plant height as complex agronomic traits, representing important determinants of grain yield. This study was designed to reveal the genetic basis of tillering at five developmental stages and plant height at harvest in 218 worldwide spring barley (Hordeum vulgare L.) accessions under greenhouse conditions. The accessions were structured based on row-type classes [two- vs. six-rowed] and photoperiod response [photoperiod-sensitive (Ppd-H1) vs. reduced photoperiod sensitivity (ppd-H1)]. Phenotypic analyses of both factors revealed profound between group effects on tiller development. To further verify the row-type effect on the studied traits, Six-rowed spike 1 (vrs1) mutants and their two-rowed progenitors were examined for tiller number per plant and plant height. Here, wild-type (Vrs1) plants were significantly taller and had more tillers than mutants suggesting a negative pleiotropic effect of this row-type locus on both traits. Our genome-wide association scans further revealed highly significant associations, thereby establishing a link between the genetic control of row-type, heading time, tillering, and plant height. We further show that associations for tillering and plant height are co-localized with chromosomal segments harboring known plant stature-related phytohormone and sugar-related genes. This work demonstrates the feasibility of the GWAS approach for identifying putative candidate genes for improving plant architecture.

Genetics of barley tiller and leaf development

“…A recent GWAS study using a 9 k gene‐based SNP chip (Comadran et al ) has shown that grouping accessions according to photoperiod sensitivity ( Ppd‐H1 vs ppd‐H1 ) and row type ( VRS1 vs vrs1 ) allows detection of novel QTLs for tiller number (Alqudah et al ). Another GWAS study on 97 two‐rowed spring barley lines also detected several QTLs for tillering at different developmental stages (Neumann et al ).…”

“…Analysis of tiller number in barley revealed the presence of significant genetic variation in both germplasm collections and bi-parental populations (Abeledo et al 2004;Borr as et al 2009;Alqudah and Schnurbusch 2013;Alqudah et al 2016). A considerable effect of row type on tiller number was demonstrated under various growth conditions (Alqudah and Schnurbusch 2013).…”

Ppd-H1integrates drought stress signals to control spike development and flowering time in barley

“…While RWC levels fully 363 Taken together, the results demonstrated that Ppd-H1 interacts with drought to control 482 the development and morphology of the shoot and spike. Ppd-H1 has already been 483 associated with a number of shoot and spike-related traits in barley and acts as a key 484 gene to coordinate the development of different plant organs with reproductive timing 485 (Digel et al, 2015(Digel et al, , 2016Alqudah et al, 2016Alqudah et al, , 2018Ejaz and von Korff, 2017;Shaaf 486 et al, 2019;Pham et al, 2019). Furthermore, our results suggested that Ppd-H1 487 controlled the plasticity of reproductive development in response to drought.…”

QTL mapping uncovers a semi-dwarf 1 (sdw1) allele in the barley (Hordeum vulgare) ND23049 line

“…On chromosome 3H, our QTLs were found to reside at approximately 52.7 cM (midpoint between TP24767 and TP76839) and 106.5 cM (midpoint between TP51167 and TP4712) respectively (Table 1). Based on the genetic positions reported by Alqudah et al (2016) for the Uzu1 and Sdw1 loci on the same map, our QTLs mapped within close proximity to HvBRI1/uzu1 and HvPRR95 in CLE253). When combined, DH lines were very short as they were 20 cm shorter than the shortest of the two parents (ND23049).…”