Screening and genetic studies of certain maize genotype for resistance to southern corn leaf blight in india Omprakash, Rajesh Singh, Rajeshwar Nandan, Dan Singh Jakhar, KN Chourasia

Screening and genetic studies of certain maize genotype for resistance to southern corn leaf blight in India


Omprakash1, Rajesh Singh1, Rajeshwar Nandan1, Dan Singh Jakhar1, KN Chourasia2

1Department of Genetics and Plant Breeding, IAS, BHU, Varanasi-221005

2Department of Genetics and Plant Breeding, GBPUAT Pantnagar-263145


Received: 26 August 2016                                Revised Accepted: 15 October 2016




Southern Corn Leaf Blight (SCLB) incited by Helminthosporium maydis, is a serious disease of Maize. The 53 maize inbreds were screened for SCLB during rainy season consequently for two year 2013 and 2014. A standard visual scale of 1 to 5 is being used by CIMMYT pathologist was considered appropriate for disease scale. Based on disease scale Percent Disease Index (PDI) and Area under Disease Progressive curve (AUDPC) considered as disease trait for screening of maize germplasm as well as estimation of Genetics of SCLB. On an average over four environments 25 resistance, 17 partial resistances, 3 susceptible lines were identified. In general there were less diseases in E1 (Varanasi in Northern India) than E2 (Nagenhalli in Southern India) though equal load of inoculums were applied in both the cases. Genetics of Helminthosporium maydis were studied in three crosses viz, CM- 212 (P1) x V- 336 (P2), CM- 212 (P1) x V- 338 (P2) and CM212 (P1) x CM145 (P2) using Scaling test, Joint Scaling Test and Jinks and Jones (1959) six parameters model. Diseases scores of P1, P2, F1, F2, B1 and B2 generations of the 3 crosses were used for genetics studies. All the effects (additive, dominance, additive x additive, additive x dominance and dominance x dominance) were important for expression of SCLB in all three crosses. Study of generation mean analysis revealed that all three crosses exhibited duplicate type of epistasis. Thus analysis revealed that SCLB resistance could be population non specific, although various types of gene effects were observed.


Key Words: Resistance, Screening, Southern corn leaf blight, Zea mays L.