Screening of NCLB Disease and QTLs Mapping in Zea mays

Abstract

Northern Corn Leaf Blight (NCLB) is a foliar disease, caused by a fungal pathogen (Setosphaeria turcica) that damages maize crop due to heavy losses in every year. A study was conducted for NCLB and identified quantitative trait loci (QTLs) in maize. Mapping population F2:3 families was developed involving two inbreds viz CM 212 (susceptible) & CM 145 (resistant).The F2:3 families mapping population was evaluated in two environments (BHU, Varanasi and Nagenahalli, Mandya) for resistance to NCLB. In the polymorphic survey about 360 pairs of simple sequence repeat (SSR) primer used between two parents (CM 212 & CM 145)and identified 54 polymorphic markers. Data was recorded for disease severity traits viz Percent Disease Index (PDI), Area Under Disease Progress Curve (AUDPC) based on PDI, Lesion Area, AUDPC based on lesion area in QTL Mapping. The QTLs were identified interestingly, on 4th chromosome viz: 4.03/4.05, 4.08/4.1, 4/4.07 and 4.08/4.1 from observed disease severity in both environments. The initially two QTLs (QTL-1 & QTL-2) detected with trait Percent Disease Index and other two (QTL 3 & QTL 4) detected with AUDPC based on PDI.