QTL -Hotspot Matters a Lot for Enhancing Yield Under Drought Conditions in Chickpea.

"QTL-hotspot" matters a lot for enhancing yield under drought conditions in chickpea

Rajeev K Varshney

International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India

^*Address for correspondence: r.k.varshney@cgiar.org

Chickpea (Cicer arietinum) is the second largest cultivated grain food legume globally. Terminal drought stress, Fusarium wilt and Ascochyta blight are serious yield constraints for chickpea production. We are using next generation genomics and genetics approaches to develop improved chickpea varieties with enhanced resistance to biotic stresses and tolerance to drought stress.  In this context, large-scale genomic resources including draft genome sequence, re-sequencing of >1000 chickpea lines, comprehensive transcriptome assembly, high density genetic and BIN maps, QTL maps as well as physical maps have been developed. By using linkage mapping approach, one “QTL-hotspot” harboring QTLs for several drought tolerance related traits has been identified on linkage group 04 (CaLG04). This “QTL-hotspot” has been successfully introgressed in several elite chickpea cultivars using marker-assisted backcrossing (MABC) approach.  Several introgression lines have shown higher yield as compared to recurrent parent under rainfed as well irrigated conditions. Similarly by using MABC approach, several introgression lines with enhanced resistance to FW and AB have also been developed. Furthermore, genomic selection (GS) approach by phenotyping and genotyping a training population of 320 elite breeding lines is also being used to develop superior lines with enhanced yield under drought stress. In brief, the identified "QTL-hotspot" has been found very promising for enhancing yield under drought stress conditions and eventually to enhance genetic gains in chickpea improvement in sub-Saharan Africa and Asia.