Genetic analysis of maydis leaf blight resistance in subtropical maize (Zea mays L.) germplasm

• Published in: Journal of genetics 2020-12, Vol.99 (1), Article 89
• Main Authors: Jeevan, B., Gogoi, Robin, Sharma, Devender, Manjunatha, C., Rajashekara, H., Ram, Dama, Mishra, K. K., Mallikarjuna, M. G.
• Format: Article
• Language: English
• Subjects: Analysis; Animal Genetics and Genomics; Autosomal dominant inheritance; Biomedical and Life Sciences; Corn; Cultivars; Disease resistance; Disease susceptibility; Epidemics; Epistasis; Evolutionary Biology; Genetic analysis; Genetic aspects; Genetic research; Genotypes; Germplasm; Leaf blight; Life Sciences; Microbial Genetics and Genomics; Plant Genetics and Genomics; Population genetics; Research Article; Zea mays
• ISSN: 0022-1333; 0973-7731
• DOI: 10.1007/s12041-020-01245-3

Knowledge on the genetics of maydis leaf blight (MLB) is crucial to breed the resistant maize cultivars to combat disease epidemics as a sustainable and cost-effective approach. The present investigation was framed to understand the genetics of MLB resistance in subtropical maize. Two contrasting genotypes CM119 (susceptible) and SC-7-2-1-2-6-1 (resistant) were used to generate six genetic populations, namely P 1 , P 2 , F 1 , F 2 , BC 1 P 1 and BC 1 P 2 , and evaluated in three target environments for MLB resistance under artificial epiphytotic condition. The CM119 and SC-7-2-1-2-6-1 showed susceptible and resistant reactions with mean disease reaction of 3.89–3.98 and 1.88–2.00, respectively. The derived generations, namely F 1 , F 2 , BC 1 P 1 and BC 1 P 2 showed mean disease reaction of 2.15–2.28, 2.44–2.51, 2.19–2.24 and 2.22–2.28, respectively in the test locations. The segregating generations (F 2 : 0.35–0.37; BC 1 P 1 : 0.24–0.29 and BC 1 P 2 : 0.17–0.20) showed variation for MLB disease resistance over the parental and first filial generations (P 1 : 0.11–0.17; P 2 : 0.08–0.13 and F 1 : 0.12–0.14). The genetic analysis of MLB resistance revealed the nonallelic interactions of duplicate epistasis type across the test locations. Among the gene interactions, dominance × dominance [l] effect was predominant over additive × additive [i] and additive × dominance [j] effects. The segregation analysis and the prediction of the number of major loci revealed at least two major genes associated with MLB tolerance in subtropical maize. Our investigation paved the foundation for the improvement of subtropical maize germplasm of MLB resistance.