AB-QTL analysis reveals new alleles associated to proline accumulation and leaf wilting under drought stress conditions in barley (Hordeum vulgareL.)

Abstract

BackgroundLand plants have evolved several measures to maintain their life against abiotic stresses. The accumulation of proline is the most generalized response of plants under drought, heat or salt stress conditions. It is known as an osmoprotectant which also acts as an instant source of energy during drought recovery process. But, both its role and genetic inheritance are poorly understood in agriculture crops. In the present work, advanced backcross quantitative trait locus (AB-QTL) analysis was performed to elucidate genetic mechanisms controlling proline accumulation and leaf wilting in barley under drought stress conditions.ResultsThe analysis revealed eight QTL associated to proline content (PC) and leaf wilting (WS). QTL for PC were localized on chromosome 3H, 4H, 5H and 6H. The strongest QTL effect QPC.S42.5H was detected on chromosome 5H where drought inducible exotic allele was associated to increase PC by 54%. QTL effects QPC.S42.3H, QPC.S42.4H and QPC.S42.6H were responsible to heighten PC due to the preeminence of elite alleles over the exotic alleles which ranged from 26% to 43%. For WS, QTL have been localized on chromosome 1H, 2H, 3H and 4H. Among these, QWS.S42.1H and QWS.S42.4H were associated to decrease in WS due to the introgression of exotic alleles. In addition, two digenic epistatic interaction effects were detected for WS where the additive effect of exotic alleles imparted a favorable increase in the trait value.ConclusionsThe present data represents a first report on whole-genome mapping of proline accumulation and leaf wilting in barley. The detected QTL are linked to new alleles from both cultivated and wild accessions which bring out an initial insight on the genetic inheritance of PC and WS. These QTL alleles are fixed in the isogenic background of Scarlett, which will allow for positional cloning of underlying genes and to develop drought resilient barley cultivars.

QTLs for earliness and yield-forming traits in the Lubuski × CamB barley RIL population under various water regimes

“…Heading date in barley depends on vernalisation requirements (Takahashi and Yasuda 1956; Sasani et al 2012), photoperiodic response (Roberts et al 1988; Laurie et al 1995) and earliness per se genes (Gallagher et al 1991; Sameri et al 2006). Quantitative trait loci (QTLs) associated with heading date have been mapped on all barley chromosomes (e.g.…”

QTL analysis in Barley Across Environments in Egypt

“…The S42 population was genotyped with a total number of 371 genetic markers containing 106 SSRs according to von Korff et al (2004), 255 DArT following (Sayed et al, 2012) and ten gene-specific DNA markers referred to Wang et al (2010) in order to perform QTL analysis. The linkage map of this population was drawn using MapChart ver.2.2 (Voorrips, 2002).…”

“…The QTL analysis was conducted using a multiple QTL model iteratively extended and reduced by forward selection and backward elimination, respectively using the PROC MIXED procedure in SAS software as per (Sayed et al, 2012). Starting point was the following mixed hierarchical model:…”

<b>Identification of QTL underlying agronomic, morphological and physiological traits in barley under rainfed conditions using SNP markers

“…As a result, drought is by far the most complex and devastating abiotic stress on a global scale and its frequency is expected to increase with climate change (Lakew et al, 2011;Schmit, Mora, Emhart, & Rubilar, 2015). Under this scenario, the development of drought tolerantcultivars is one of the major objectives of breeding programs with a goal of reducing crop losses in agriculture (Sayed, Schumann, Pillen, Naz & Léon, 2012;Ballesta, Mora, Contreras-Soto, Ruiz & Perret, 2015).…”