Genetic Mapping Reveals Broader Role of Vrn-H3 Gene in Root and Shoot Development beyond Heading in Barley

Abstract

The aim of the present study was to dissect the genetic inheritance and interplay of root, shoot and heading attributes for a better understanding of these traits in crop production. For this, we utilized quantitative trait loci (QTL) and candidate gene analysis approach using a second filial (F2) population originated from a cross between spring cultivar Cheri and wild barley accession ICB181160. The F2 population comprising 182 plants was phenotyped for root dry weight (RDW), root volume (RV), root length (RL) and shoot dry weight (SDW), tiller number per plant (TIL) and days to heading (HEA). In parallel, this population was genotyped using polymerase chain reaction (PCR) based cleaved amplified polymorphic sequence (CAPS) markers distributed across the whole genome. Marker by trait analysis revealed 16 QTL for root and shoot traits localized on chromosomes 1H, 3H, 4H, 5H and 7H. The strongest and a common QTL effect for root, shoot and heading traits was identified on chromosome 7H at the putative region of Vrn-H3 gene. Later, we have established PCR based gene specific marker HvVrnH3 revealing polymorphism for early heading Vrn-H3 allele in Cheri and late heading allele vrn-H3 in ICB181160. Genotyping of these alleles revealed a clear co-segregation of early heading Vrn-H3 allele with lower root and shoot attributes, while late heading vrn-H3 allele with more TIL and higher root biomass suggesting a primary insight on the function of Vrn-H3 gene beyond flowering. Genetic interactions of vernalization genes Vrn-H3 with Vrn-H2 and Vrn-H1 also suggested the major role of Vrn-H3 alleles in determining root and shoot trait variations in barley. We believe, these data provide an opportunity for further research to test a precise significance of early heading on yield components and root associated sustainability in crops like barley and wheat.

Genetic Dissection of Root System Architectural Traits in Spring Barley

“…Moreover, QTLs associated with RSD and RSA ( qRSD2 , Chr 2H, 18.91 cM; qRSD3 , Chr2H, 56.52 cM; qRSA4 , Chr 2H, 58.92 cM) were located in close proximity to the genes Ppd-H1 (Chr 2H,19.9 cM) and HvCEN (Chr 2H, 58.0 cM) that play a central role in regulating flowering time in barley (Turner et al, 2005; Comadran et al, 2012). In accordance, Arifuzzaman et al (2016) also reported that the heading date gene Vrn-H3 significantly associated with shoot and root biomass, although in our panel no QTL was detected in its vicinity. We assume that selection and breeding may have indirectly selected for root traits when selecting for favorable flowering time and high grain yield.…”

Seminal roots of wild and cultivated barley differentially respond to osmotic stress in gene expression, suberization, and hydraulic conductivity

“…A more vigorous root system, including longer roots together with a high variation of root traits, was in fact reported for several other wild barley accessions from the Middle East (Arifuzzaman et al, ; ; Naz et al, ; Naz, Arifuzzaman, Muzammil, Pillen, & Léon, ). During breeding programs in the last decades, the focus was largely on increasing aboveground traits, such as yield and grain filling, rather than their root growth (Koevoets, Venema, Elzenga, & Testerink, ).…”

Discovering consensus genomic regions in wheat for root-related traits by QTL meta-analysis

“…VERNALIZATION1 ( Vrn1 ), a key regulator of flowering time in cereals, was also involved in root architecture in wheat and barley 61 . QTLs for root traits were also detected in barley in the vicinity of Vrn1 62,63 .…”