Botryodiplodia sp. - Crops for the Future

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autoclave is used for liquid sterilization is due to the lower temperature. Many chemicals are degenerating at a temperature more than 121 °C. Figure 18: Autoclave at ITI Figure 19: Laminar flow cabinet at ITI For the sterilization of the surface of the working place and the workers hands a 70 % ethanol solution is used. It is also used for the working utensils such as scalpel and forceps while working by dipping them into the alcohol solution and flaming them afterwards in the Bunsen burner flame. To sterilize the laminar flow cabinet or the incubator a so called fumigation should be done by filling a little amount of a 8 % formaldehyde dilution into a beaker or Petri-dish and keep it for more than a hour, when possible over night, in the closed incubator or laminar of flow cabinet. In all experiments which are described in this report the work was done under sterile conditions by using the above mentioned methods. The work with micro-organisms always takes place in so called laminar flow cabinet (Figure 19). This is a half closed or manual closable glass cabin in which a constant air flow takes place and the air gets filtered to avoid contaminations. The medium which was used for all workings and experiments was a Potato-Dextrose-Agar (PDA) medium. The medium was prepared fresh, immediately before every single trial series. 24
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. 25
Page 1: Control of Post Harvest Disease (Bo
Page 4 and 5: List of Figures Figure 1: The Sri L
Page 6 and 7: 1 Summary Experiments were undertak
Page 8 and 9: 3 Sri Lanka The Democratic Socialis
Page 10 and 11: 3.2 Climate The climate of Sri Lank
Page 12 and 13: valuable consultations in industria
Page 14 and 15: Rambutan trees are either dioecious
Page 16 and 17: However, the most important genus i
Page 18 and 19: 6.2.1.2 Annona muricata Annona muri
Page 20 and 21: Figure 9: Annona squamosa Figure 10
Page 22 and 23: Characteristically for this fungus
Page 24 and 25: Figure 15: Phialides of Trichoderma
Page 28 and 29: Figure 21: Soil sampling in a rambu
Page 30 and 31: 9.1.4 Isolation of the pathogen Mat
Page 32 and 33: The effectivity of the BC-agent was
Page 34 and 35: Figure 29: Experimental series of a
Page 36 and 37: Two of the Trichoderma sp. with a h
Page 38 and 39: Results of the sporulation experime
Page 40 and 41: 12 References ALAM, M.S., BEGUM, M.
Page 42 and 43: ONG, P.K.C., ACREE, T.E. and LAVIN,
Page 44 and 45: Figure 36: List of bio-control agen
Page 46: Tmu III Galagedera • Mycelial gro

Botryodiplodia sp. - Crops for the Future

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