MAIZE INBRE E D LINES RESISTANCE TO FUSARIUM EAR ROT

1. MAIZE INBREED LINES RESISTANCE TO FUSARIUM EAR ROT Branimir Šimić - The Agricultural Institute Osijek, 31 000 Osijek, CROATIA Jasenka Ćosić - Vlatka Rozman - Anita Liška University of J.J. Strossmayer in Osijek, Faculty of Agriculture in Osijek, CROATIA

2. Introduction • Vital importance of maize as agricultural crop and market competitiveness among hybrids seed breeders set up high standards in new genotypes creation • New maize hybrids - high genetic potential for fertility and resistance to the major disease agents and pests • Fusarium ear rot is one of the most important diseases in all the major maize breeding areas in the world

3. Maize ear infection results in lower maize yield, and poorer quality and accumulation of mycotoxins in grain - risk for human and animal health • Most frequent isolated Fusarium species on maize grain: Fusarium verticillioides F. subglutinans and F. graminearum • Ways of spreading maize ear infection: silk ear stalk damage made by insects

4. Infection, development and intensity of disease are influenced by environmental factors, genotype sensitivity and resistance, and pathogenesis of Fusarium spp. and their mutual interaction • Stressin the period of vegetation affects plant’s vigour - disorders in physiological processes and increase sensitivity to the agents of the disease Objective of the study: • determine differences in sensitivity and resistance of inbreed maize lines grown on two different soil types to Fusarium ear rot

5. Materials and Methods • Six inbreed maize lines of FAO 400 and one line of FAO 300 (OS 138-9) • Two locations and two soil types (Kutjevo; pseudogley and Nova Gradiška; amphigley) • 3-year trial (2001-2003) • Four repetitions following split-plot method (major plot measured 300m2 ; (15x20m) • Standard fertilization was made: Urea 200 kg NPK (7:20:30) 200 kg m-2(ploughed in) KAN 150 kg m-2 in nutrition while cultivating • 120 plants of each genotype were examined measuring intensity of infection in percentage of maize ear infection • Results were processed by Statistica for Windows v. 6.0 • Significant differences among the treatments were determined by ANOVA and LSD test

6. Results and Discussion Table 1 Percentage of maize ears infected with Fusarium spp. regarding locations and years (%)

7. Differences in infection intensity with Fusarium spp. could be explained by the differences in plant nutrition (phosphorus) • Insufficient nutrition with phosphorus affects physiological process →development of pathogenic organisms Increasing of the maize grain yield by: • increasing effect of photosynthesis • advancing metabolism of carbohydrates and water transport • improving reproduction and grain forming phosphorus

8. Statistically significant differences were also determined in inbreed lines sensitive to Fusarium ear rot • The most tolerant inbreed lines: OS 89-9 and OS 86-39, regardless of the year or location examined Table 2. Average occurrence (%) of Fusarium ear rot depending on inbreed line, year and location examined

9. Conclusion • Percentage of the infected maize ears on both locations during 3-year trials was on average 48.3 % • The lowest infection was observed on inbreed line OS 89-9 (33.2%) and inbreed line OS 86-39 (26.4%) • The highest infection was observed on inbreed line OS 138-9 (58.9%) • The source of high inbreed lines tolerance appeared to be crucial for further maize hybrid selection

10. The most tolerant inbreed line: (OS 86-39) FAO 400

11. The Agricultural Institute Osijek 31 000 Osijek, CROATIA University of J.J. Strossmayer in Osijek, Faculty of Agriculture in Osijek, CROATIA Thank you for your attention ! Corresponding author: e-mail address: branimir.simic@poljinos.hr(Branimir Šimić)