engleski

Pathotypes of Exserohilum turcicum Pass. and resistance of maize hybrids

When race2 appeard in 1994, monitoring of the pathogens throughout the wide maize growing area in Croatia was initiated. Determination of the pathotypes on differential test assortment in the greenhouse proved that 18 isolates collected in 1995 were of the race 2 and other three of the race 1. Race 2 was found on maize seed fields in Lukač, Suhopolje, Gradina, Donji Miholjac, Senkovec, Gutmanovci, Nova Gradiška, Slavonski Brod, Otok and in disease monitoring nursary in Pitomača. All the nine isolates from 1996 belong to race 2 and were collected from disease monitoring nurseries at locations Rugvica, Botinec, Varaždin, Kutjevo and Koška. Evidently, race 2 is dominant at present, which is a result of a wide exploitation of the Ht1 gene. Already in 1996 a large number of maize hybrids was tested for resistance to both races. The hybrids with monogenic resistance to race 1: Bc408B, Bc492, Bc592, Bc608R and Bc 6661 are susceptible to race 2 of E. turcicum. No commercial hybrid was found to have monogenic resistance to this race. The hybrids with polygenic resistance, Bc278, Bc2811, Marista, DK524, Helga and Podravec 36 are equally resistant to both races of E. turcicum.

maize; Exserohilum turcicum; pathotypes; resistance

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