HURO/0901/1472.2.2
SZEGED - TIMISOARA AXIS FOR THE SAFE FOOD AND FEED
SZETISA1
2ND PROGRESS MEETING
SZEGED, SEPTEMBER 22-23, 2011
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The content of this page does not
necessarily represent the official
position of the European Union.
Sampling from maize genotypes for the 3rd reporting period
CSISZÁR JOLÁN
AND MEMBERS OF DEPT. OF PLANT BIOLOGY,
UNIVERSITY OF SZEGED,
MESTERHÁZY ÁKOS, TOLDINÉ TÓTH ÉVA ,
CEREAL RESEARCH NONPROFIT KHT, SZEGED
Disclaimer
The content of this page does not
necessarily represent the official
position of the European Union.
Fusarium ear rots
• Fusarium ear rots are the most dangerous food and
feed safety challenges of maize.
• Fusarium and Gibberella ear rots are the two main
diseases, but more than ten further Fusarium spp.
cause ear rots.
• Natural infection is caused by a mixture of the local
Fusarium spp., normally one is dominating.
• In Germany 13 Fusarium species were isolated from
naturally infected maize, the prevalent species
changed between years according to weather.
Á. Mesterházy, M. Lemmens: Breeding for resistance against Fusarium ear rots in corn
- a review
Fusarium ear rots
In Hungary, 16 Fusarium spp. were identified in 1974
and 1975
In 1974 (humid),554 isolates:
In 1975 (dry), 645 isolates:
29% were F. graminearum,
27% F. verticillioides,
6% F. sporotrichioides,
4% F. culmorum,
3.6% F. semitectum,
3% F. fusarioides,
1.62% F. poae, and in low
amounts further 8 Fusarium
spp.
69% were F. verticillioides (earlier
names: F. moniliforme and F.
moniliforme var. subglutinans),
28% were F. graminearum
and all others were represented
by 1-2 isolates only.
F. g.
F. v.
F. c.
The Fusarium spp. produce a large number of
chemically very different mycotoxins
F. acuminatum
T2, MON, HT2, DAS, MAS, NEO, BEA
F. anthophilum
BEA
F. avenaceum
MON, BEA
F. cerealis
NIV, FUS, ZEN, ZOH
F. chlamydosporum
MON
F. culmorum
DON, ZEN, NIV, FUS, ZOH, AcDON
F. equiseti
ZEN, ZOH, MAS, DAS, NIV, DAcNIV, FUS, FUC, BEA
F. graminearum
DON, ZEN, NIV, FUS, AcDON, DAcDON, DAcNIV
F. heterosporum
ZEN, ZOH
F. nygamai
BEA, FB1, FB2
F. oxysporum
MON, BEA
F. poae
DAS, NIV, FUS, MAS, T2, HT2, NEO, BEA
F. proliferatum
FB1, BEA, MON, FUP, FB2,
F. sambucinum
DAS, T2, NEO, ZEN, MAS, BEA
F. semitectum
ZEN, BEA
F. sporotrichioides
T2, HT2, NEO, MAS, DAS
F. subglutinans
BEA, MON, FUP
F. tricinctum
MON, BEA
F. verticillioides
FB1, FB2, FB3
a Fusarium nomenclature according to Nelson et al. (1983).
b Bold
letters indicate the important mycotoxins.
(Mesterházy, Lemmens Breeding for resistance against Fusarium ear rots in corn)
Abbreviations:
AcDON – Mono-acetyldeoxynivalenols (3AcDON, 15-AcDON);
AcNIV – Monoacetylnivalenol, (15-AcNIV);
BEA – Beauvericin;
DiAcDON – Di-acetyldeoxynivalenol (3,15AcDON);
DAcNIV – Diacetylnivalenol (4,15-AcNIV);
DAS – Diacetoxyscirpenol;
DON – Deoxynivalenol (Vomitoxin);
FB1 – Fumonisin B1;
FB2 – Fumonisin B2; FB3 – Fumonisin B3;
FUP – Fusaproliferin;
FUS – Fusarenone-X (4-Acetyl-NIV);
FUC – Fusarochromanone;
HT2 – HT-2 toxin;
MAS – Monoacetoxyscirpenol;
MON – Moniliformin;
NEO – Neosolaniol;
NIV – Nivalenol;
T2 – T-2 toxin;
ZEN – Zearalenone;
ZOH – zearalenols (α and β isomers).
The pathogenicity of the Fusarium spp.
• The pathogenicity of the Fusarium spp. in corn is very
variable.
• F. graminearum and F. culmorum are highly pathogenic; the
very aggressive isolates are present in a considerable
proportion. F. verticillioides and the other Fusarium spp.
display lower pathogenicity.
• The Fusarium spp. produce a large number of chemically very
different mycotoxins.
• The main toxins are:
T2- T-2 toxin, DON – Deoxynivalenol ,
ZEN – Zearalenone, HT2 – HT-2 toxin,
Fumonisins
•
The effect of toxins
• Fusarium toxins have been shown to cause a variety of toxic
effects in both experimental animals and livestock, on some
occasions have been suspected to cause toxicity in humans.
• T-2-and HT-2 toxin often occur together in infected cereals.
T-2 toxin could inhibit synthesis of DNA and RNA, proteins,
affected the permeability of cell membranes, caused changes
in the phospholipid turnover, and haemolysis of erythrocytes,
increased lipid peroxides in the liver of rats, caused apoptosis.
• Ascorbic acid, α-tocopherol , selenium, glutathione precursors
have a protective effect against lipid peroxidation induced by
Toxin
LD50 (mg/kg)
T-2 toxin.
T2-toxin
5-7
HT-2 (trichotecene) 5-7
DON
40 - 50
ZEA
5000
Fusarium infection
The severity of natural infection varies strongly from year to year
• with the locations;
• with length of the vegetation period (earlier hybrids normally
show less ear rot infection and less toxin contamination .
Late-sown or later hybrids tend to be more infected by F.
graminearum and contaminated by DON than early ones.
• Good agronomy praxis can also decrease the risk of fumonisin
contamination .
• The weather conditions - may affect Fusarium spp. in different
ways.
• Maize researchers must use artificial inoculation methods to
inoculate the plant material with fungal spores.
Fusarium resistance
• Until the discovery of the mycotoxins, ear rot diseases were
regarded as a minor problem.
• At present, the majority of the inbreds and hybrids are
susceptible.
• Natural infection is caused by a mixture of the local Fusarium
spp., normally one is dominating.
• There is significant or highly significant resistance differences
to the Fusarium spp. used.
Breeding for Fusarium resistance
• New breeding programmes have been started with the aim of
breeding more resistant hybrids available for human and
animal consumption as food and feed safety problems have
emerged and the economic losses due to Fusarium ear rots
have multiplied.
• Artificial inoculation is used instead of natural infection.
Maize Fusarium resistance breeding
programme in Cereal Research Nonprofit Kht.
(Prof. Mesterházy Ákos, Dr. Tóth Éva)
• Testing the kernel resistance of maize hybrids for different
Fusarium ssp. By the toothpick method:
• The middle of the ear will be inoculated 10 das after
midsilking.
• The spreding of the infection will be rated at harvest:
the infected cob area is estimated as percentage for the about
20 cobs per row infected.
Sampling from maize genotypes for element
content and toxin analysis
Cereal Research Nonprofit Kht.
• I. sampling: 26.08. 2011., Újszeged
• The area was not treated with fungicid
• Two selected hybrids:
Sarolta: earlier was more resistant to Fusarium
Boglár: earlier was more sensitive to Fusarium
• Hybrids are sown in 7 m long rows with 20 cm plant distance.
Five rows from each: one row was control and the four
replicates were treated with F. graminearum, F.culmorum and
F. verticillioides isolates.
Sampling from maize genotypes for element
content and toxin analysis
Cereal Research Nonprofit Kht.
• One parcel for each genotype
• The order of inoculted lines: F.g., F.c., C, F.v.1 (4x)
The most pathogenic was
F. culmorum, followed by
F. graminearum and
the least pathogenic was
F. verticillioides.
Sampling from maize genotypes for element
content and toxin analysis
Cereal Research Nonprofit Kht.
One cob with the leaf and a piece of stem was cutted out.
Sampling from maize genotypes for element
content and toxin analysis
Cereal Research Nonprofit Kht.
• Three cobs from each row,
in 3 replicates
Sampling from maize genotypes
Sampling from maize genotypes for element
content and toxin analysis
Dept. of Plant Physiology
The cobs, leaves and stems were separated
in the laboratorium
Sampling from maize genotypes for element
content and toxin analysis
Dept. of Plant Physiology
The cobs, leaves and stems were separated in the laboratorium
Sampling from maize genotypes for element
content and toxin analysis
Dept. of Plant Physiology
Samples from leaves were taken for further physiological
investigations, materials are stored on -80 °C.
Sampling from maize genotypes for element
content and toxin analysis
Cereal Research Nonprofit Kht.
II. sampling: at the harvest
13.09. 2011., Újszeged
• Onother 3-3 cobs from each row, in 3 replicates.
The samples are stored in 25 °C.
Thank you for your attention!
The effect of toxins II
• DON inhibits the synthesis of DNA and RNA and protein
synthesis at the ribosomal level. The toxin has a haemolytic
effect on erythrocytes. An acute dose of DON can induce
vomiting (emesis) in pigs, whereas at lower concentrations in
the diet it reduces growth and feed consumption (anorexia).
Both effects, which are also seen with other trichothecene
toxins, are thought to be mediated by affecting the
serotonergic activity in the CNS or via peripheral actions on
serotonin receptors
Toxin
T2-toxin
HT-2 (trichotecén)
DON
ZEA
LD50 (mg/kg)
5-7
5-7
40 - 50
5000