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SESSION 4: GENETICS OF HOSTS – PLANT RESISTANCE TO FUSARIUM,
VARIETY DEVELOPMENT
P106 - Genetic variation for ear rot resistance and
mycotoxin content of Polish maize elite inbreed lines
after inoculation with Fusarium graminearum and F.
verticillioides
E. Czembor 1 , A. Waśkiewicz 2 , Ł. Stępień 3
1 Plant Breeding and Acclimatization Institute – NRI, Radzikow, 05-870 Blonie, Poland; 2 Department of
Chemistry, Poznan University of Life Sciences, Wojska Polskiego 75, 60-625 Poznań, Poland;
3 Department of Pathogen Genetics and Plant Resistance, Institute of Plant Genetics, Polish Academy
of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland
E-mail: e.czembor@ihar.edu.pl
Poland is the fifth European producing country of maize, with an increasing area.
Ear rots caused by Fusarium are important diseases affecting yield and causing
grain mycotoxin contamination. This country has variable weather conditions –
with big differences between regions and years. It is influenced by a mild oceanic
climate from the west and a dry continental climate from the east. Because of this
Fusarium graminearum and F. verticillioides are two ear rotting species commonly
connected with maize kernel samples and their prevalence depends on
environmental conditions. Inbreed lines which are commonly used in Polish
breeding programmes belong mostly to 2 distinct genetic categories: flint and
dent. However, lines from Lancaster, IDT and SSS groups are also introduced.
One hundred inbreed lines were evaluated across 2011 – 2012. Ear rot resistance
was determined separately after inoculatation with F. graminearum and F.
verticillioides using tooth-picks and under natural infection. Disease severity and
selection pressure after inoculation with F. graminearum was higher than after
inoculation with F. verticillioides. Lancaster, IDT, SSS and SSS/IDT groups were
characterized as a most susceptible. Under natural infection differences between
inbreeds were also significant. Based on the obtained results group of the most
resistant and most susceptible genotypes were taken to determine mycotoxin
content in the kernel samples and rachis fractions (DON, ZEA and FBs) using
HPLC method. The correlation coefficients between toxin content and disease
scores were highly significant. Additionally the presence of Fusarium species,
which colonized kernels under natural infection was determined (based on the
SCAR-PCR markers and the translation elongation factor (tef-1alpha) sequences
analyses). F. verticillioides was the prevalent species (>75% of samples tested
contained this pathogen). The ability of F. proliferatum and F. verticillioides to
produce fumonisins was confirmed by the identifiaction of the FUM1 gene
presence.
Keywords: ear rot resistance, maize inbreed lines, toxin content, sources of
resistance
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