Advances in Food Mycology

Fungi and Mycotoxins in Fruit and Cereals 143
Table 2. Fungal infection (%) in Danish wheat and barley seeds and kernels without
surface disinfection during the growth season 2002
Wheat Barley Barley
(Leguan) (Ferment) (Ferment)
Seeda Imm. b Mat. c Seeda Imm. Mat. Seedd Imm. Mat.
Alternaria 42 42 67 40 73 64 0 88 58
Botrytis 0 0 9 5 43 37 0 22 31
Eurotium/
Aspergillus
25 0 1 19 1 0 0 1 0
Cladosporium 0 20 2 0 94 0 1 12 18
Fusarium 0 82 90 0 59 83 0 78 98
Penicillium 98 89 98 41 7 98 1 0 98
a b c d Seed without fungicide treatment; Imm. = Immature; Mat. = Mature; Fungicide
treated seed
Fusarium and Alternaria rose markedly and the storage fungi disappeared.
The change was less dramatic in wheat. The differences in
mycobiota from immature to mature kernels were minor and mostly
the number of fungal infected kernels was stable or rose slightly. The
number of Cladosporium found on immature and mature samples varied
a great deal as high number of Fusarium and Penicillium colonies
often obscured the smaller Cladosporium colonies. Surface disinfection
reduced the numbers of Penicillium and Eurotium colonies by
80-90 %, and of Cladosporium and Fusarium by 40-50 %. Only 10-15%
of Alternaria and Bipolaris could be removed, indicating that the
grains had internal infections with these genera.
Dominant fungi in common to both wheat and barley kernels were
isolates of Alt. infectoria species-group, F. avenaceum, P. aurantiogriseum,
P. cyclopium and P. polonicum. However, barley had higher
infection rates with Bipolaris sorokiniana, P. hordei and P. verrucosum
compared to wheat.
3.3. Fungal Species Associated with Fruit and Cereals
The frequencies of occurrence of fungal species in several cultivars
of apples, cherries, barley and wheat are given in Tables 3 and 4. In our
laboratory, such data have been compiled for more than 15 years. The
differences in the mycobiota between cultivars were in most cases
small. Most often the same fungal species were found and the variation
was quantitative only. As can been seen from Tables 3 and 4, only
a limited number of fungal species are found in both fruit and cereals.
Newly harvested, undamaged apples and cherries were not usually
infected by fungi. When infection was present, fungi mostly belonged