ALBERT

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