Insights into the genetic mechanism for Turcicum leaf blight resistance of maize

Abstract

An experiment was conducted to study the genetic mechanism of Turcicum leaf blight (TLB) in maize. A set of 56 experimental F1
hybrids was screened for TLB under artificial inoculation condition along with standard susceptible and resistant checks. The results
revealed that, the inheritance of TLB resistance is majorly governed by additive gene action, while the preponderance of non-additive
gene action was displayed by grain yield. The TLB resistance had high narrow sense of heritability. The genetic analysis of parents and
hybrids showed sufficient variation for TLB resistance among the studied material. The lines CTLB-01 and CTLB-02 exhibited a high
general combining ability effect in a negative direction for Area Under Disease Progressive Curve and percent disease index, which were
identified as novel source of durable resistance for TLB. The GGE biplot analysis showed that CTLB-01 and CTLB-02 were genetically
similar for disease resistance and IMIC-68 was identified as ideal tester for disease resistance. The CTLB-02 × IMIC-02 and CTLB-02 ×
IMIC-40 are best crosses for TLB resistance and grain yield. The present findings suggested that the resistance to TLB can be improved
through recurrent selection.