Abstract
Disease resistance is a key factor for yield stability and economic efficiency in maize. The aim of the present study was to evaluate the degree of resistance of sterile (S) and fertile (N) maize hybrids Kneja 307, Kneja 435 and Kneja 442, as well as inbred lines (AC9434, N192, XM4418, K4652, KB0155, KB11), to widespread diseases caused by Exserohilum turcicum, Ustilago maydis and Fusarium spp., expressed as northern leaf blight, common smut and stalk and ear fusarium, and to assess the influence of agrometeorological conditions on disease development. The assessments were conducted over three growing seasons.
The results showed high and stable resistance of the studied genotypes to leaf blight and common smut, limiting the importance of these diseases as yield-limiting factors. Cytoplasm type did not have a significant effect on resistance to diseases caused by Exserohilum turcicum, Ustilago maydis and ear fusarium; however, in the case of stalk fusarium, certain differences were observed between genotypes with normal and S-type cytoplasmic male sterility, suggesting an interaction between the genetic background and the cytoplasm.
The highest and most stable resistance was demonstrated by the hybrid Kneja 435, as well as by the lines KB0155 and AC9434. In contrast, the hybrid Kneja 442 and the lines N192 and XM4418 were characterised by reduced resistance, particularly to diseases caused by Fusarium spp. Differences in resistance were more pronounced under conditions favourable for disease development.
Keywords: maize, disease resistance, Fusarium spp.; Exserohilum turcicum, Ustilago maydis, cytoplasm type, cytoplasmic male sterility