Tolerance Expression of Maize Genotypes to Exserohilum turcicum in North and South Korea

Abstract

Northern corn leaf blight caused by Exserohilum turcicum Pass is considered the most important disease infecting corn (Zea mays L.) in the Peoples' Republic of Korea (North Korea). It contributes to the food shortage in North Korea. The objectives of the current research were to study resistance expression and responses of corn crosses made between ten hybrids from North Korea and inbreeding lines (S 3 -4 stage) from the Republic of Korea (South Korea). The experiments were conducted in six trials with a total of 184 crosses including two commercial hybrids in each trial. The trials were conducted at two locations in North Korea (Mirim and Eunsan) and one location in South Korea (Gunwi) under natural infestation of E. turcicum. Host plant responses were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). A total of 111 crosses (62.4%) showed significant tolerant or susceptible response variations among three locations; 42 crosses (22.8%) at two locations and 69 crosses (39.0%) at one location, respectively. At least 8 crosses of high level of tolerance and 12 crosses of high level of susceptibility showed significantly different biotic responses (P = 0.05). The results of the current study and historical reviews of E. turcicum epidemics in both North and South Korea suggest that breeding of tolerance with quantitatively inherited genes should be carried out for a sustainable corn production in North Korea.

Identification of early and extra-early maturing tropical maize inbred lines resistant to Exserohilum turcicum in sub-Saharan Africa

“… Pswarayi and Vivek (2008) and Sibiya et al (2013) reported the role of additive gene action in resistance to NCLB. Therefore, the combination of Ht genes and polygenes would result in durable host plant resistance to the pathogen ( Kim et al, 2012 ).…”

Distribution, Etiology, Molecular Genetics and Management Perspectives of Northern Corn Leaf Blight of Maize (Zea mays L.)

“…1; CABI, 2019). Presently NCLB is a potential threat to maize cultivation in Europe, Australia, North-Eastern United States, Sub-Saharan Africa, and in areas of North Korea, India, and China [20,[21][22][23]. Butler [24] first reported the NCLB in India on sorghum, and Mitra [25] reported it from Punjab on sorghum and maize.…”

Inheritance of Tolerance of Maize Inbreds to Exserohilum turcicum in North Korea

“…Depending on the environment, the qualitative resistance of maize to E. turcicum may have a partial effect while quantitative resistance may have a substantial effect. For example, the race-specific gene Ht1 was unable to control E. turcicum in US Corn Belt inbred lines planted in Africa Kim et al, 1990;Kim et al, 2012;Welz 1998) and in Hawaii (Personal Communication, J. L. Brewbaker). CIMMYT inbred line CML191 providing partial resistance with oligogenic or polygenic inheritance in Africa (Schechert et al, 1999;Schechert et al, 1997) remained completely uninfected in an inoculated field trial in Europe (Welz et al, 1999).…”

“…Although many corn genotypes have been released from breeding programs, their reactions to NCLB pathogen in North Korea remain largely unknown. Several authors have suggested that the combination of resistance conferred by Ht genes and general resistance would enhance the level of resistance and result in greater stability and longer protection against E. turcicum (Hooker 1977;Hooker and Kim 1973;Kim et al, 2012;Pratt et al, 1993;Raymundo and Hooker 1982). However, this accumulation needs extra efforts in breeding.…”