Numerical taxonomic studies on cacao (Theobroma cacao L.) in Trinidad

Bekele, Frances L.; Kennedy, A. J.; David, C. Mc; Lauckner, F. B.; Bekele, Isaac

doi:10.1007/bf00025608

Cited by 20 publications

(13 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This is unlike previous studies where the emphasis was on morphological variation of cacao in field genebank collections (Engels 1983;Bekele et al 1994;Bekele & Bekele 1996;Iwaro et al 2003;Bekele et al 2006). Analysis of variance showed significant morphological variation in cacao accessions maintained in farmers' field collections and also between accessions from the field genebank and farmers' fields in bean and fruit traits.…”

Section: Discussioncontrasting

confidence: 70%

Variation in agro-morphological characteristics of cacao,Theobroma cacaoL., in farmers' fields in Nigeria

Aikpokpodion

2010

New Zealand Journal of Crop and Horticultural Science

View full text Add to dashboard Cite

Knowledge of available variability in a crop species provides a guide for the utilization and conservation of useful variation. Seventeen agro-morphological traits were studied in 184 accessions of cacao, Theobroma cacao L. collected from farmers' fields (138) and field genebank collections (46). Descriptive statistics*univariate analysis of variance (ANOVA)*were used to determine variation among accessions. Multivariate analysis with principal component analysis (PCA) was done and a cluster dendrogram was generated based on the unweighted pair group mean with arithmetic average (UPGMA). The first three principal component axes accounted for 43.6% of total variation observed among accessions studied. Quantitative bean traits*dry bean weight, nib weight, fresh weight, cotyledon length and cotyledon width*and qualitative fruit traits*basal constriction, apex form, ridge colour, fruit shape, flush colour and cotyledon shape*were the most important traits accounting for the variability observed. Six groups of accessions were obtained from cluster analysis. Fruit and bean traits of Upper Amazon Forasteros observed in farmers' accessions provided evidence of a shift from previously grown local 'West African Amelonado' from the Lower Amazon Forastero population. In conclusion, this study revealed some accessions with useful trait combinations in farmers' plantations and indicated a need to conserve the local 'Amelonado' landrace variety to avoid extinction and to preserve the unique flavour of 'West African Amelonado' in cocoa breeding programmes.

show abstract

Section: Discussioncontrasting

confidence: 70%

Variation in agro-morphological characteristics of cacao,Theobroma cacaoL., in farmers' fields in Nigeria

Aikpokpodion

2010

New Zealand Journal of Crop and Horticultural Science

View full text Add to dashboard Cite

show abstract

“…The estimated heritability was very high, 0.8 (Table 1); this trait had the highest level of heritability of all the traits studied. Moreover, the number of ovules per ovary is considered as a clonal descriptor (Bekele et al 1994).…”

Section: Variability and Heritability Of The Traits Studiedmentioning

confidence: 99%

Relations between several traits linked to sexual plant reproduction in Theobroma cacao L.: number of ovules per ovary, number of seeds per pod, and seed weight

Cilas

Machado²,

Motamayor³

2009

Tree Genetics & Genomes

View full text Add to dashboard Cite

Tropical perennial plants cultivated outside their place of origin call for major germplasm characterization and prebreeding work. For cacao breeding, the selection process has to optimize the weight of cacao beans produced per tree by increasing the number of pods produced, the number of seeds per pod (NoSP), and the mean weight of seeds produced (SW). NoSP and SW were studied over nine consecutive years in a collection of more than 200 clones. The number of ovules per ovary (NoOV) was also examined in a subsample of this collection in order to evaluate the ability to predict NoSP. NoSP and SW showed a relatively normal distribution with heritabilities of 0.29 and 0.51, respectively. The composite trait "mean seed weight per pod" showed a generalized extreme value distribution of intermediate heritability (0.43). NoSP and SW were found to be genetically independent. NoOV was highly heritable (h 2 =0.810), but it did not provide good prediction of NoSP. The largest seeds were observed in genotypes derived from crosses between cultivated cacao trees, which had been formerly domesticated. Domestication therefore favored seed size, while for the other traits examined, similar variation was found between wild and domesticated populations.

show abstract

“…The field germplasm collection at ICG,T has been morphologically (Bekele et al 1994;Bekele and Bekele 1998) and agronomically (Iwaro et al 2002;Latchman et al 2000;Umaharan et al 2001) characterised, and the data is available globally, through the International Cocoa Germplasm Database (Wadsworth et al 1997).…”

Section: Introductionmentioning

confidence: 99%

Assessing the Genetic Diversity in the International Cocoa Genebank, Trinidad (ICG,T) using Isozyme Electrophoresis and RAPD

Sounigo

Umaharan

Christopher

et al. 2005

Genet Resour Crop Evol

View full text Add to dashboard Cite

Random amplified polymorphic DNA (RAPD) and isozyme electrophoresis (IE) techniques were used to estimate the level of genetic diversity in a sample of cacao germplasm existing at the International Cocoa Genebank, Trinidad. Twenty-six cocoa populations represented by 459 cocoa genotypes were analysed using IE and 22 populations represented by 353 cocoa genotypes were analysed using RAPD. Despite few differences in the classification of the populations, both techniques revealed three major groups: the indigenous trees, the cultivated Trinitario and the cultivated trees from Ecuador. Two-thirds of the partitioned diversity were found within populations and one-third between the populations, with both techniques.

show abstract

Numerical taxonomic studies on cacao (Theobroma cacao L.) in Trinidad

Cited by 20 publications

References 5 publications

Variation in agro-morphological characteristics of cacao,Theobroma cacaoL., in farmers' fields in Nigeria

Variation in agro-morphological characteristics of cacao,Theobroma cacaoL., in farmers' fields in Nigeria

Relations between several traits linked to sexual plant reproduction in Theobroma cacao L.: number of ovules per ovary, number of seeds per pod, and seed weight

Assessing the Genetic Diversity in the International Cocoa Genebank, Trinidad (ICG,T) using Isozyme Electrophoresis and RAPD

Contact Info

Product

Resources

About