Botryodiplodia sp. - Crops for the Future

250 ml PDA was made up as follows:
Material:
• Bunsen burner
• Screw cap bottle (300 ml)
• Measuring cylinder (500 ml)
• Funnel
• Cloth for filtering
• Beaker (500 ml)
• Heating plate
Chemicals:
• 50 g potatoes
• 5 g glucose
• 5 g agar
After washing, removing the skin and cutting into little quarters the potatoes have to boil in
250 ml distilled water for 20 minutes. After boiling the solution has to be filtered through a
funnel using a layer of muslin made up to a volume of 250 ml with distilled water. The
solution is decanted into the screw cap bottle and the glucose and the sugar are added. After
autoclaving the pH of the medium can be adjusted by adding 1.6 ml sterile tartaric acid per
100 ml PDA to avoid bacterial growth. Lastly, the PDA is poured into sterile petri dishes
(plates). In doing so the neck of the PDA-filled bottle should be held into the Bunsen burner
flame once in a while to avoid contaminations. 250 ml
PDA should be enough for 15 plates.
During the experiments the cultures where stored in
incubators which were set up to a temperature of 28 °C
(Figure 20). The Trichoderma sp. cultures were put into an
extra incubator. The reason for this is that Trichoderma sp.
contaminate other cultures due to the very small and
numerous conidia very easily.
9.1.2 Soil sampling
Figure 20: Incubator at ITI
Soil samples from under rambutan and annona trees were taken in various regions of Sri
Lanka. The samples were taken within the soil area which was covered by the crown of the
tree. Out of this area four samples were taken randomly (Figure 21). Only the top soil to a
deepness of 2 cm was taken and filled into plastic bags which were labelled and closed with a
loose burl to guarantee an air exchange.
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