Advances in Food Mycology

Fungi and Mycotoxins in Fruit and Cereals 149
fungicides decreased Botrytis infection and had some effect on
Cladosporium numbers, but no effect on Alternaria, Fusarium and
Penicillium. The number of Alternaria, Fusarium and Penicillium
infected apples also increased after spraying and continued to increase
until apples were picked. In cherries, the same fungal species were seen
in mature cherries as in flowers (Table 1). Application of fungicides
had an effect on all the fungal genera found in flowers; Alternaria
infections decreased by 50-65%. Alternaria and Cladosporium numbers,
however, increased again before harvest in sour cherries, while
the numbers of Alternaria remained constant in sweet cherries, probably
due to the early drop of immature cherries, which had 100%
infection with Alternaria. Our results show that the mycobiota of
apples and cherries are similar at genus level, but different in species
composition. Alternaria tenuissima species-group, P. expansum and
P. solitum dominate in apples, whereas A. arborescens species-group,
and Stemphylium spp. dominate in cherries (Table 3).
Analyses of the mycobiota in cereals from sowing to harvest showed,
in contrast to fruit, that the initial mycobiota present in the untreated
seed played only a small role in the subsequent mycobiota on mature
kernels, though it may play a great role in the viability of the seed
(Table 2). The two untreated seed samples contained a high number of
Alternaria, Penicillium and Eurotium species. Surface disinfection
removed 80-90% of the Penicillium and Eurotium numbers, while the
same only could be done for 40-45% of the Alternaria. Furthermore,
the Penicillium species in the seed and in the immature kernels were different.
In the seed P. chrysogenum, P. cyclopium and P. freii were found,
whereas P. aurantiogriseum, P. polonicum and P. verrucosum were found
in mature kernels growing from the untreated seed. The only fungi that
were found in larger amounts in seed and recovered in more than 50%
of the harvested cereal samples belonged to A. infectoria species-group.
The numbers of Alternaria and Fusarium found in the three mature
samples were low (less than 60%) and high (more than 80%), respectively,
compared with other reports (Andersen et al., 1996; Kosiak
et al., 2004). A very wet period in June and July 2002, during the growing
season in Western Denmark was probably responsible.
Comparisons of the mycobiota from two mature barley samples grown
from fungicide treated and untreated seed showed few differences.
As fruits mature and are harvested, fungi such as Botrytis, Monilia
and Zygomycetes are known to cause fruit spoilage in orchards as well
as in storage, whereas Cladosporium and Epicoccum are known for their
discolouration of cereals in the field. These fungi cause economical
losses, but none of them are associated with production of mycotoxins.