Association mapping for root architectural traits in durum wheat seedlings as related to agronomic performance

Abstract

Association mapping provides useful insights on the genetic architecture of quantitative traits across a large number of unrelated genotypes, which in turn allows an informed choice of the lines to be crossed for a more accurate characterization of major QTLs in a biparental genetic background. In this study, seedlings of 183 durum wheat elite accessions were evaluated in order to identify QTLs for root system architecture (RSA). The QTLs identified were compared with QTLs detected for grain yield and its component traits, plant height and peduncle length measured in a previous study where the same accessions were evaluated in 15 field trials with a broad range of soil moisture availability and productivity (Maccaferri et al. in J Exp Bot 62:409–438, 2011). The following RSA features were investigated in seedlings at the four-leaf stage: seminal root angle, primary root length, total root length, average root length, root number and shoot length. Highly significant differences among accessions were detected for all traits. The highest repeatability (h2 = 0.72) was observed for seminal root angle. Out of the 48 QTLs detected for RSA, 15 overlapped with QTLs for agronomic traits and/or grain yield in two or more environments. The congruency of the effects of RSA traits and agronomic traits was evaluated. Seminal root angle and root number appear the most promising traits for further studies on the adaptive role of RSA plasticity on field performance in environments differing for water availability. Our results provide novel insights on the genetic control of RSA and its implications on field performance of durum wheat.Electronic supplementary materialThe online version of this article (doi:10.1007/s11032-014-0177-1) contains supplementary material, which is available to authorized users.

Genetic diversity, population structure and association analysis in linseed (Linum usitatissimum L.)

“…In case of linseed different types of DNA based markers includingAFLP,RAPD,retrotransposon,ISSR,SSRs,SNPetc. havebeenusedforevaluatingthegenetic diversityandlinkage mapping (Cloutier et al 2010;Oh et al 2000;Spielmeyer et al 1998).OverothertypesofDNAmarkers,SSRsarewidelyused forgeneticdiversityandstructureanalysisinseveralcropplants (Cheng et al 2015;Yan et al 2009;Cane et al 2014;Cui et al 2013). In the present investigation, we applied 50 widely distributed SSRs to evaluate the genetic diversity and identify diverseaccessions/groupofaccessionsamongalargesetof168 accessionsoflinseed.Atotalof337allelesweredetectedfrom50 SSRswithanaverageof6.74allelesperSSRs.Thisaverageallele numberwasfoundtobehigherthanthatreportedearlier (RooseAmsalegetal.2006;Dengetal.2011;Palietal.2014;Soto-Cerda etal.2012Cloutieretal.2012b).Thehigherallelenumber mightbeduetothelargeanddiversesetofaccessionsandwidely distributed SSRs used in the present study.…”

A comparative study of root system architecture in seedlings ofBrachypodium spp.using three plant growth supports

“…One of the main problems of using artificial PGS for characterizing the root phenotype is that root development might not be the same as in the ground. Nevertheless, studies in bean, maize, rice and soybean all indicate a relationship that exists between the results obtained for different RSA characteristics in the field and in artificial systems (Bengough et al 2004;Sanguineti et al 2007;Zhu et al 2011;Canè et al 2014). The present work shows that, for all three species of Brachypodium taken as a whole, the type of PGS (Fig.…”

“…Different authors have reported intergenotypic differences for several characteristics of the root system of rice (Price et al 1997), bread wheat (Waines and Ehdaie 2007) or durum wheat (Sanguineti et al 2007, Canè et al 2014. Pacheco-Villalobos and Hardtke (2012) observed variation in the RSA of different accessions of Brachypodium and Ingram et al (2012) studied two accessions of B. distachyon that showed different RSA behaviour in different nutrient media: while one maintained the growth of auxiliary roots in low N conditions, the other maintained lateral root growth in low P conditions.…”

“…al. 1997;Ren et al 2012;Christopher et al 2013;Canè et al 2014). Marker-assisted selection (MAS) has also been used to introduce QTL that control different RSA characteristics in some rice varieties into the genomes of other rice varieties (Steele et al 2006(Steele et al , 2013.…”

Genomics Approaches to Dissect the Genetic Basis of Drought Resistance in Durum Wheat

“…Although AM has mostly targeted traits with a genetic basis less complex than drought tolerance (e.g. resistance to biotic stress), some studies have targeted drought-adaptative traits and grain yield in durum wheat grown under varying water regimes (Sanguineti et al 2007 ;Maccaferri et al 2011 ;Canè et al 2014 ;Graziani et al 2014 ).…”