Molecular mapping of QTLs for resistance to Fusarium wilt (race 1) and Ascochyta blight in chickpea (Cicer arietinum L.)

Abstract

Fusarium wilt (FW) and Ascochyta blight (AB) are two important diseases of chickpea which cause 100 % yield losses under favorable conditions. With an objective to validate and/or to identify novel quantitative trait loci (QTLs) for resistance to race 1 of FW caused by Fusarium oxysporum f. sp. ciceris and AB caused by Ascochyta rabiei in chickpea, two new mapping populations (F 2:3) namely 'C 214' (FW susceptible) 9 'WR 315' (FW resistant) and 'C 214' (AB susceptible) 9 'ILC 3279' (AB resistant) were developed. After screening 371 SSR markers on parental lines and genotyping the mapping populations with polymorphic markers, two new genetic maps comprising 57 (C 214 9 WR 315) and 58 (C 214 9 ILC 3279) loci were developed. Analysis of genotyping data together with phenotyping data collected on mapping population for resistance to FW in field conditions identified two novel QTLs which explained 10.4-18.8 % of phenotypic variation. Similarly, analysis of phenotyping data for resistance to seedling resistance and adult plant resistance for AB under controlled and field conditions together with genotyping data identified a total of 6 QTLs explaining up to 31.9 % of phenotypic variation. One major QTL, explaining 31.9 % phenotypic variation for AB resistance was identified in both field and controlled conditions and was also reported from different resistant lines in many earlier studies. This major QTL for AB resistance and two novel QTLs identified for FW resistance are the most promising QTLs for molecular breeding separately or pyramiding for resistance to FW and AB for chickpea improvement.

An Update on Genetic Resistance of Chickpea to Ascochyta Blight

“…Further, this region also harbors the NAC domain protein for systemic acquired resistance as well as the NB-LRR-type disease resistance protein. In summary, QTLs contributing to A. rabiei (Ar) resistance were identified by many research groups-14 Ar loci located on eight chickpea LGs, named as Ar1a, Ar2a, Ar2b, Ar2c, Ar3a, Ar3b, Ar3c, Ar4a, Ar4b, Ar5a, Ar6a, Ar6b, Ar7a, and Ar8a [10,82,86,88,89,92,[95][96][97][98][99][100][101][102]. These markers will be important for enabling the pyramiding of resistance genes from diverse sources to reduce the time required to generate resistant cultivars.…”

Translational Genomics in Agriculture: Some Examples in Grain Legumes

“…Among these QTL clusters, one QTL cluster corresponding to QTLs for 12 traits and explaining about 60% phenotypic variation has been identified on CaLG04, referred to as a "QTL-hotspot" (Varshney et al, 2013b). Similar mapping efforts have been undertaken for important the biotic stresses like FW (Benko-Iseppon et al, 2003;Cobos et al, 2005;Sabbavarapu et al, 2013), and Aschochyta blight (Anbessa et al, 2009;Aryamanesh et al, 2010;Kottapalli et al, 2009). One agronomic trait under complex genetic control (Buckler et al, 2009;Mouradoy et al, 2002) that has received much attention is flowering time.…”

Genomics-assisted breeding for drought tolerance in chickpea

“…To date, several trait mapping studies have been conducted in the case of chickpea. However, most of these studies focussed on mapping biotic stresses like Fusarium wilt (Benko-Iseppon et al 2003;Cobos et al 2005;Gowda et al 2009; Sabbavarapu et al 2013), Aschochyta blight (Udupa and Baum 2003;Iruela et al 2006Iruela et al , 2007Anbessa et al 2009;Kottapalli et al 2009;Aryamanesh et al 2010) and Botrytis grey mould (Anuradha et al 2011), and agronomically important traits (Gowda et al 2011). Trait mapping studies have been discussed in detail in Varshney et al (2012a).…”