Marker-assisted pyramiding of southern leaf blight resistance QTLs qSLB3.1 and qSLB8.1 in maize (Zea mays)

Southern leaf blight (SLB) is one of the major diseases that cause substantial yield losses in maize (Zea mays L.) worldwide. Stacking broad-spectrum resistance genes/QTLs into prevalent cultivars prerequisite for durable disease breeding programme. Therefore, a study was carried at research farm and molecular biology laboratory School Agricultural Biotechnology, Punjab University, Ludhiana, during 2017–21 to introgress SLB QTLs from two donors, viz. CM139 (qSLB3.1) LM5 (qSLB8.1) CM140 inbred using marker-assisted backcross (MABB). Crosses were made between × generate separate F1s. Each F1 backcrossed twice BC2F1 progenies. Foreground selection performed each step linked flanking markers QTL also evaluated resistance. The selected heterozygous plants cross inter-crossed combine qSLB3.1 qSLB8.1 same genetic background. F2 population phenotypically other morphological traits. A total 18 obtained having both with homozygous donor alleles. singly state advanced F3 pyramided lines exhibited 29% lesser severity than either QTL. present results indicated additive effects played an important role among these lines. To our best knowledge, this first report pyramiding associated would serve as potential donors programs.