Lens orientalis Contributes Quantitative Trait Loci and Candidate Genes Associated With Ascochyta Blight Resistance in Lentil

Rama Harinath Reddy Dadu; Ido Bar; Rebecca Ford; Prabhakaran Sambasivam; Janine Croser; Federico Ribalta; Sukhjiwan Kaur; Shimna Sudheesh; Dorin Gupta

doi:10.3389/fpls.2021.703283

Lens orientalis Contributes Quantitative Trait Loci and Candidate Genes Associated With Ascochyta Blight Resistance in Lentil

Front Plant Sci. 2021 Aug 26:12:703283. doi: 10.3389/fpls.2021.703283. eCollection 2021.

Authors

Rama Harinath Reddy Dadu^{1

2}, Ido Bar³, Rebecca Ford³, Prabhakaran Sambasivam³, Janine Croser⁴, Federico Ribalta⁴, Sukhjiwan Kaur⁵, Shimna Sudheesh⁵, Dorin Gupta¹

Affiliations

¹ School of Agriculture and Food, Faculty of Veterinary and Agriculture Sciences, Dookie College, The University of Melbourne, Dookie, VIC, Australia.
² Grains Innovation Park, Agriculture Victoria, DJPR, Horsham, VIC, Australia.
³ Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia.
⁴ Centre for Plant Genetics and Breeding, School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia.
⁵ Agriculture Victoria, AgriBio, Centre for Agri Bioscience, Bundoora, VIC, Australia.

Abstract

Australian lentil production is affected by several major biotic constraints including Ascochyta blight (AB), caused by Ascochyta lentis, a devastating fungal disease. Cultivation of AB resistant cultivars, alongside agronomic management including fungicide application, is the current most economically viable control strategy. However, the breakdown of AB resistance in cultivars, such as Northfield and Nipper, suggests the need for introgression of new and diverse resistance genes. Successful introgression entails an understanding of the genetic basis of resistance. In this context, a biparental mapping population derived from a cross between a recently identified AB resistant accession ILWL 180 (Lens orientalis) and a susceptible cultivar ILL 6002 was produced. A genetic linkage map was constructed from single-nucleotide polymorphism markers generated using a genotyping-by-sequencing transcript approach. Genetic dissection of the mapping population revealed a major quantitative trait loci (QTL) region nested with three QTLs on linkage group 5 and explained 9.5-11.5 percent (%) of phenotypic variance for AB resistance. Another QTL was identified on LG2 with phenotypic variance of 9.6%. The identified QTL regions harbored putative candidate genes potentially associated with defense responses to A. lentis infection. The QTL analysis and the candidate gene information are expected to contribute to the development of diagnostic markers and enable marker-assisted resistance selection in lentil breeding programmes.

Keywords: Ascochyta blight; Lens orientalis; candidate genes; genetic linkage map; lentil; quantitative trait loci.