Identification of new sources of resistance to turcicum leaf blight and maydis leaf blight in maize (Zea mays L.).

Turcicum leaf blight (TLB) and Maydis leaf blight (MLB) are amongst the important diseases of maize grown in the North Western Himalayas. To identify new resistance sources and establish durability of known resistance sources, 35 short-duration maize inbred lines were evaluated against TLB after artificial inoculation and MLB under natural conditions during kharif 2011 and kharif 2012. Twelve inbred lines were found resistant against TLB, 19 inbred lines exhibited resistance against MLB and 10 inbred lines found resistant to both TLB and MLB. Principal component analysis (PCA) revealed that grain yield (GY) is negatively correlated with TLB and MLB. Agglomerative hierarchical clustering (AHC) analysis with GY, TLB and MLB revealed the 35 inbred falls into 3 major clusters. In cluster I most of the inbreds were moderately resistant to TLB and resistant to MLB with high yielding potential. In cluster II most of the inbreds are resistant to both TLB and MLB with high GY potential. In cluster III, most of the inbred were highly susceptible to TLB and moderately resistant to MLB with low yielding lines. The AHC classification will be helpful for selection of disease resistance and high yielding inbred for resistance breeding program.