DESCRIPTIVE AND DISCRIMINATORY SIGNIFICANCE OF POD PHENOTYPIC TRAITS FOR DIVERSITY ANALYSIS OF COCOA GENOTYPES

Daniel B. Adewale, Oluwayemisi O. Adeigbem, Omotayo O. Adenuga, Abigael F. Adepoju, Anna A. Muyiwa, Peter O. Aikpokpodion

Abstract


Intra-specific genetic diversity analysis precedes crop breeding proposal for species improvement. Sixteen and twenty-four parental and hybrid cocoa genotypes were respectively laid out in a randomized complete block design of six replications at Ibadan, Nigeria. A sampling unit of fifteen uniformly ripe pods was collected for assessment from each plot. Six quantitative data from the pods were subjected to statistical analysis. Highly significant (P < 0.0001) variability existed among the 40 genotypes. Range of performance of the genotypes were: pod weight (0.43 – 0.86kg), pod length (15.9 – 27.96cm), pod girth (21.51 – 34.07cm), pod thickness (1.26 – 5.71cm), number of beans per pod (20 - 51) and bean weight per pod (0.017 - 0.41kg). Positive and significant (P < 0.001) correlation existed between pod weight and length, pod girth and bean number/pod. The mean Gower genetic distance among the 40 genotypes was 0.228; the least (0.023) existed between G25 and G30 while the highest (0.529) was between G17 and G35. The first three principal component axes explained 73% of the total variation. Three distinct groups emerged from the Ward clustering technique. Significant (P<0.05) intra and inter cluster variability existed in the study. High genetic diversity lies within the studied population. Pod traits were important descriptors for cocoa genotypes classification.

Keywords


pod value, bean value, genetic distance, eigenvector, eigenvalue, clustering

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References


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Copyright (c) 2013 Daniel B. Adewale, Oluwayemisi O. Adeigbem, Omotayo O. Adenuga, Abigael F. Adepoju, Anna A. Muyiwa, Peter O. Aikpokpodion

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Journal of Plant Breeding and Genetics
ISSN: 2305-297X (Online), 2308-121X (Print)
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