Agung Wahyu Susilo
Indonesian Coffee and Cocoa Research Istitute

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Yield performance of the cocoa clones of Sca 6 and DRC 15 resistant to vascular-streak dieback Agung Wahyu Susilo; Surip Mawardi; Sudarsianto Sudarsianto
Pelita Perkebunan (a Coffee and Cocoa Research Journal) Vol 25 No 2 (2009)
Publisher : Indonesian Coffee and Cocoa Research Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iccri.jur.pelitaperkebunan.v25i2.131

Abstract

Selection on cocoa resistance to vascular-streak dieback (VSD) has identified some resistant clones for breeding purposes. Of the resistant clones, it was selected Sca 6 and DRC 15 which performing good potential for yield. This paper reports results on testing yield potential of the clones in separate trials. Sca 6 was tested in Kottablater Estate (dry climate in the altitude of ± 25 m asl.) and DRC 15 was tested in Mumbulsari Estate (dry climate in the altitude of ± 45 m asl.) both are in Jember. Trials were arranged in the randomized complete block design with 4 blocks. Evaluation for yield performance was conducted during 6 years of harvest and stability performance was analyzed in regression term using year of harvest as the index. The results indicate the yield potential of the clones was quite similar in the level of 1.4 kg/plant and performing stability during evaluation and good adaptability in the location. The yield potential was lower than the high yielding clones but use of Sca 6 and DRC 15 in heavily infasted VSD area should be considered than using of the susceptible clones. Sca 6 performed low potential on a dry-weight bean in the range of 0.65—0.86 g (class C of quality standard) but better performance could be found in the wet area. DRC 15 performed good potential on a dryweight bean of 1.16 g (class AA of quality standard). Fat content analysis of Sca 6 indicate a better performance of beans which grown up in the wet area (58.2%) than in the dry area (49.6%). It was reported the fat content potential of DRC 15 in the level of 50.4%. Key words: Yield performance, vascular-streak dieback, resistant clone, Theobroma cacao L.
Yield performance of the cocoa clones of Sca 6 and DRC 15 resistant to vascular-streak dieback Agung Wahyu Susilo; Surip Mawardi; Sudarsianto Sudarsianto
Pelita Perkebunan (a Coffee and Cocoa Research Journal) Vol 26 No 3 (2010)
Publisher : Indonesian Coffee and Cocoa Research Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iccri.jur.pelitaperkebunan.v26i3.136

Abstract

AbstractThe characteristics of pod related to cocoa pod borer resistance (CPB, Conopomorpha cramerella Snell.) had been identified in a series study. This research has objective to evaluate performance of the characteristics using more diverse of genetic background to select criteria for selection. Genetic materials for this study were 25 cocoa clones which be planted in Central Sulawesi for resistant evaluation. Field evaluation of the resistance were assessed using the variable of the percentage of unextractable bean, number of entry and exit hole larvae by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichome, granule of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months). Correlation between groups of those variables was analyzed using Canonical Correlation. The analysis performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics (0.59; 0.55; 0.43) and the variables of canonical for CPB resistance (0.54; 0.51; 0.39) that would presenting the characteristics of pod related to CPB resistance. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiate the resistant clones (ARDACIAR 10) with the susceptible clones (ICCRI 04, KW 516 and KW 564).Key words : cocoa pod borer, Theobroma cacao L., pod characteristics, resistance
Assessing Genetic Diversity Cocoa (Theobroma cacaoL.) Collection Resistant to Cocoa Pod Borer Using Simple Sequence Repeat Markers Agung Wahyu Susilo; Dapeng Zhang; Lambert Motilal
Pelita Perkebunan (a Coffee and Cocoa Research Journal) Vol 29 No 1 (2013)
Publisher : Indonesian Coffee and Cocoa Research Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iccri.jur.pelitaperkebunan.v29i1.186

Abstract

Breeding  for  cocoa  pod  borer  (CPB)  resistance  on  cocoa  was  initiated  by selecting  the  resistant  genotypes  through  cocoa  farm  in  the  endemic  area.  For breeding  purpose  the  collected  genotypes  should  be  assessed  for  their  diversity  in  constructing  appropriate  mating  design.  This  research  has  objective  to assess  genetic  diversity  of  the  exploratory  collection  using  DNA  fingerprinting. The  tested  clones  were  25  exploratory  collections  compared  to  the  references  of seven  international  clones  from  International  Cocoa  Genebanks,  Trinidad  and12 national clones. DNA of the tested clones was sequenced using 15 SSR markers at Sustainable Perennial Crop Laboratory of Beltsville Agriculture Research Center.Data of  fingerprinting were analyzed  using  GenAlEx program  to  perform number of  alleles,  observed   heterozygosity  (Ho),  expected  heterozygosity  (He)  and genetic  distance.  The  tested  clones  performed  high  genetic  diversity  with  the number  of  alleles  was  98  (6.53  per  locus)  compared  to  the  national  clones  andinternational clones were  95 (6.33 per locus) and 86 (5.73 per locus), respectively. The  observed  heterozygosity  of  the  tested  clones  (Ho  = 0.63)  was  higher  thannational  clones  (Ho  =  0.60)  and  international  clones  (Ho  =  0.49)  then  supported by  the  expected  heterozygosity  (He)  of  the  tested  clones  (He  =  0.71)  also  highin  equal  value  with  international  clones  (He  =  0.74).  Cluster  analysis  grouped the  tested  clones  to  three  main  genetic  groups,  namely  Trinitario,  Forastero  and unidentified  group.  The  CPB-resistant  clones  of  ARDACIAR  10  and  KW  397 were clustered in different group that indicate a far distance of their genetic background.Key words:Genetic diversity, cocoa, CPB resistance, simple sequence repeat marker.
Evaluation the resistance of cocoa clones (Theobroma cacaoL.) Agung Wahyu Susilo; Indah Anita Sari
Pelita Perkebunan (a Coffee and Cocoa Research Journal) Vol 30 No 1 (2014)
Publisher : Indonesian Coffee and Cocoa Research Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iccri.jur.pelitaperkebunan.v30i1.192

Abstract

Acceleration on clonal selection of cocoa resistance to pod rot (Phytophthora palmivora)was carried out by early evaluation of the resistance using laboratory test. This research has objective to select the promising clone resistance to P. palmivora for field evaluation. Trials were carried out at the Laboratory of Plant Pathology at the Indonesian Coffee and Cocoa Research Institute using in-vitro inoculation. Isolate of P. palmivorawere collected from the infected pods at Jatirono Estate, Banyuwangi then inoculated to three mature pods of each tested clones. Trials were carried out in two steps to confirm the stability of performance of the resistance. A total of 41 clones were tested in these trials. However due to the availability of pod sample was limited then at 1st trial 31 clones were tested and at 2nd trial 37 clones were tested, both of the test using 27 same clones. The assessed variables were lesion size on pod surface due to Phytophthorainfection at 1st to 7th day after inoculation. The lesion sizes were significantly different among tested clones that performing any variability of the resistance. The variability were grouped into five groups as the resistant classification by which three clones were identified, namely Jano/IV/4/13 (TSH 858 x ICS 13), Jano next to I/7 and Kate/I/10/18 (Sulawesi 01 x TSH 858) consistently performing lowest size of the lesion compared to Sca 6 that could be selected as the resistant clones for field evaluation. Key words: cocoa clones, resistance, pod inoculation, Phytophthora palmivora
Intensity of vascular streak dieback in different cocoa clones and various agro-climatic conditions Indah Anita-Sari; Agung Wahyu Susilo; Niken Puspitasari; Febrilia Nuraini; Bayu Setyawan; Peter McMahon; Philip Keane
Pelita Perkebunan (a Coffee and Cocoa Research Journal) Vol 33 No 1 (2017)
Publisher : Indonesian Coffee and Cocoa Research Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iccri.jur.pelitaperkebunan.v33i1.249

Abstract

Vascular streak dieback (VSD) is one of the main diseases on cocoa. This disease can produce a heavy damage in susceptible plants. Agro-climatic condition influences the VSD disease severity level. A study on the relationship between agro-climatic condition and VSD disease severity was conducted in eight locations which were selected based on difference in agro-climatic conditions including altitude, rainfall, number of wet, and dry months. Randomized complete block design was used consisting of eight agro-climatic conditions as treatments which consisted of 200 trees samples, and scored for VSD intensity. A study was also conducted on the response of cocoa clones with different level of resistance at different altitude at Kendeng Lembu, Jatirono, Sungai Lembu, Banjarsari, and Sumber Asin Plantations. A split plot design was applied consisting of two factors. The first factor was location including Pager Gunung (highland) and Besaran (lowland). The second factor was clone resistance with two levels: PA 191 (resistant) and BL 703 (susceptible). VSD scores and stomatal characteristics (stomata number, stomata diameter, and stomata aperture) were determined. The results of experiment showed that VSD scoring differed significantly between the eight agro-climatic conditions. The highest VSD score occurred in the lowland (Gereng Rejo, Banjarsari Plantation, 38 m asl.), where the average annual rainfall was 2161 mm, with five dry months. Cocoa trees in Sumber Asin (580 m asl.), with the average annual rainfall of 2302 mm and 8.5 wet months/3.5 dry months were mostly free of VSD disease. Altitude was positively correlated with rainfall, and negatively correlated with VSD severity. Number of wet months was negatively correlated with VSD severity. Conversely, number of dry months was positively correlated with VSD. The result indicated that genotype, environment, or their interaction did not significantly affect number and aperture of stomata. Although stomatal diameter was significantly affected by environment, genotypes or their interaction with environment did not influence this character.