Cacao improvement programme, Keravat. Papua New Guinea Agricultural Journal 12: pp. 149-167.
Derivation: Keravat.
Location: Keravat, Papua New Guinea.
Cocoa collection - Fiji Naduruloulou Research Station. G. Prasad, Koronivia Research Station, Nausari, Fiji. Personal Communication.
List of clones held in the Dept. of Agriculture's collection, at Sabah, Tuaran, Malaysia. E.B. Tay, Malaysian Cocoa Board, Malaysia. Personal Communication.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Interaction between cocoa clones and isolates of Oncobasidium theobromae causal pathogen of Vascular Streak Dieback. In: Proceedings of the 12th International Cocoa Research Conference, Salvador, Brazil, 1996. Cocoa Producers' Alliance. (in press).
Malaysia - Malaysian Cocoa Board, Sabah Datafile: DIS_VSDS - Disease reaction to VSD Experiemental Conditions: The interaction between 11 isolates of Oncobasidium theobromae and 11 cocoa clones was studied using a dual culture method. Clones were selected based on origin of selection and locality: DESA 1, DESA 2, RP 3 - local selections from SAFIMA Plantations, Sandakan; PBC 123 - Golden Hope Plantations, from Peninsular Malaysia; K 20 - Trinitario type, Papuan New Guinea selection; BAL 209 - selection of BAL Plantations; BR 25 - Trinitario selected by a grower in Tawau; ICS 95, NA 33, PA 7 and NA 32 - primary clones. Pathogen isolates originated from 3 localities: high disease pressure areas at SAFIMA Plantations and Ulu Dusun Agriculture Research Station in Sandakan; low disease pressure area at the Agriculture Research Centre, Turan, Sabah. The dual culture system cultured together the callus of the cocoa clone and the pathogen isolate. 7-10 days old inoculum freshly isolated on 1.0% water from infected twigs of the various clones was used. Callus initiated from stem tissue was maintained on Murashige and Skoog medium supplemented with kinetin (0.05mg/l) and indole-3-acetic acid (10mg/l). The callus was subcultured once to eliminate explant tissue. Pieces of callus 2x5x5mm were placed into 50ml aliquots of MS medium (which had been autoclaved at 121°C for 15 minutes). 5mm mycelial disks were placed on top of the callus. There were 5 replicates per treatment. Growth in diameter of the colony was measured every 2/3 days for 3 weeks. Character Data: Reaction types are as follows: A - growth of the pathogen was good while that of the callus was reduced; indicative of virulence of the pathogen and susceptibly of the host. B - growth of both the pathogen and the host was good; virulence of the pathogen ineffective and the host relatively resistant. C - growth of both the pathogen and the host was poor; suggestive of a hypersensitive reaction. D - growth of the pathogen was poor while that of the callus was comparative to the control; indicative of virulence being overcome and resistance of the host. E - pathogen isolate grew poorly on the callus and the callus showed enhanced growth; indicative of an interaction where defence mechanism operated may have triggered off compensatory growth and inhibition of the pathogen. Dry weight of mycelium: determined after removal from cocoa callus. Calluses were harvested after dark incubation at 25°C for four weeks. Fungal colonisation of callus: mean of three replicates scored at the end of the experiment. 1,2 = little or negligible growth of the mycelium on the callus, callus apparently healthy; 3,4 = extensive mycelial colonisation but sparse, callus wholly visible, slightly inhibited, some parts discoloured; 5 = extensive colonisation, some parts of the callus enveloped by mycelium, exposed parts discoloured; 6,7 = callus almost completely enveloped by dense mycelium, new growth not visible, callus discoloured.
Data from Applied Agriculture Research Unit (AARU). In: Unpublished Proceedings of MCGC Mini-Seminar on the Performance of Imported Cocoa Clones, 13th October 1992, Kuala Lumpur, Malaysia: pp. 4.
Malaysia - Applied Agriculture Research Datafile: AARU__DS MYS - Applied Agriculture Germplasm: Agronomic characteristics of 120 of the clones held at Applied Agriculture Research. The clones were field budded on 1982 seedlings planting between 1984 and 1987. Environment: No details given.
Results from cocoa butter content determinations using Nuclear Magnetic Resonance (NMR) analysis. G. Lockwood, CDC, U.K. Personal Communication.
Malaysia - BAL Plantations Datafile: BAL2__DS MYS - BAL Plantations (update) Environment: Trials are planted on Table Estate, Tawau. Trial CA81 - planted August 1987 in 3x6 tree plots, 3 replicates randomised blocks, trees spaced at 3.8m x 2.4 m (1,096 trees/ha). Trial CA88 - similar design, planted August 1988. Soil type is fairly fertile young volcanic basalt. Average rainfall is c. 2100 mm/year well distributed, the driest month being February with about 150 mm. Descriptors: Cocoa butter analysis:- samples of a minimum of 2 kg were fermented in net bags placed in the fermentation heap and subsequently fast (i.e. continuously) dried. Determinations were carried out by MacRobertson Foods Pte Ltd. (a division of Cadbury-Schweppes Ltd.) in Singapore using a Nuclear Magnetic Resonance machine.
Data from Applied Agriculture Research Unit (AARU). In: Unpublished Proceedings of MCGC Mini-Seminar on the Performance of Imported Cocoa Clones, 13th October 1992, Kuala Lumpur, Malaysia: pp. 4.
Malaysia - Applied Agriculture Research Datafile: AARU__DS MYS - Applied Agriculture Germplasm: Agronomic characteristics of 120 of the clones held at Applied Agriculture Research. The clones were field budded on 1982 seedlings planting between 1984 and 1987. Environment: No details given.
Results from cocoa butter content determinations using Nuclear Magnetic Resonance (NMR) analysis. G. Lockwood, CDC, U.K. Personal Communication.
Malaysia - BAL Plantations Datafile: BAL2__DS MYS - BAL Plantations (update) Environment: Trials are planted on Table Estate, Tawau. Trial CA81 - planted August 1987 in 3x6 tree plots, 3 replicates randomised blocks, trees spaced at 3.8m x 2.4 m (1,096 trees/ha). Trial CA88 - similar design, planted August 1988. Soil type is fairly fertile young volcanic basalt. Average rainfall is c. 2100 mm/year well distributed, the driest month being February with about 150 mm. Descriptors: Cocoa butter analysis:- samples of a minimum of 2 kg were fermented in net bags placed in the fermentation heap and subsequently fast (i.e. continuously) dried. Determinations were carried out by MacRobertson Foods Pte Ltd. (a division of Cadbury-Schweppes Ltd.) in Singapore using a Nuclear Magnetic Resonance machine.
Results from cocoa butter content determinations using Nuclear Magnetic Resonance (NMR) analysis. G. Lockwood, CDC, U.K. Personal Communication.
Malaysia - BAL Plantations Datafile: BAL2__DS MYS - BAL Plantations (update) Environment: Trials are planted on Table Estate, Tawau. Trial CA81 - planted August 1987 in 3x6 tree plots, 3 replicates randomised blocks, trees spaced at 3.8m x 2.4 m (1,096 trees/ha). Trial CA88 - similar design, planted August 1988. Soil type is fairly fertile young volcanic basalt. Average rainfall is c. 2100 mm/year well distributed, the driest month being February with about 150 mm. Descriptors: Cocoa butter analysis:- samples of a minimum of 2 kg were fermented in net bags placed in the fermentation heap and subsequently fast (i.e. continuously) dried. Determinations were carried out by MacRobertson Foods Pte Ltd. (a division of Cadbury-Schweppes Ltd.) in Singapore using a Nuclear Magnetic Resonance machine.
Results from cocoa butter content determinations using Nuclear Magnetic Resonance (NMR) analysis. G. Lockwood, CDC, U.K. Personal Communication.
Malaysia - BAL Plantations Datafile: BAL2__DS MYS - BAL Plantations (update) Environment: Trials are planted on Table Estate, Tawau. Trial CA81 - planted August 1987 in 3x6 tree plots, 3 replicates randomised blocks, trees spaced at 3.8m x 2.4 m (1,096 trees/ha). Trial CA88 - similar design, planted August 1988. Soil type is fairly fertile young volcanic basalt. Average rainfall is c. 2100 mm/year well distributed, the driest month being February with about 150 mm. Descriptors: Cocoa butter analysis:- samples of a minimum of 2 kg were fermented in net bags placed in the fermentation heap and subsequently fast (i.e. continuously) dried. Determinations were carried out by MacRobertson Foods Pte Ltd. (a division of Cadbury-Schweppes Ltd.) in Singapore using a Nuclear Magnetic Resonance machine.