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Assessing morphological characteristics of elite Cocoa accessions (Theobroma cacao L.) in Makira Island, Solomon Islands

Toramo, Elison and Desai, Nandakumar and Amosa, Falaniko and Diczbalis, Yan and Dillon, Natalie L. (2019) Assessing morphological characteristics of elite Cocoa accessions (Theobroma cacao L.) in Makira Island, Solomon Islands. Journal of South Pacific Agriculture, 22 . pp. 30-41. ISSN 1018-7774

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    Abstract

    Characterization in Theobroma cacao L. based on the suggested Australian Center for International Agricultural Research(ACIAR) guidelines is observed to be important to encourage fine quality Cocoa production, and to realize remunerative income. Hence, 40 Cocoa accessions collected from fields distributed under different wards of Makira Island of the Solomon Islands were characterize for nine quantitative and qualitative morphological traits. Among the identified Cocoa accessions,Principal Component Analysis (PCA) grouped all the traits into three major Principal Components (PC) accounted 46.2% of total variation. PC axis one accounted for 23.1% of total variation explained by pod weight, pod circumference, cotyledon length, pod length, cotyledon width, pod external thickness, mature pod ridge color (anthocyanin), pod surface texture, pod surface shape and pod shape. The 12.2% of total variation in PC axis two was considerably attributed by the qualitative traits cotyledon color, pod surface texture , mature pod ridge color (anthocyanin), pod surface shape, cotyledon width, pod shape and tree vigor. While, PC axis three accounted for 10.9% of total variation referred to traits pod neck, pod surface shape, pod surface texture, pod length, tree vigor, pod internal thickness, weight of the bean per pod, pod external thickness, number of beans per pod, pod weight and reaction to black pod. Unweighted Pair Group Mean with Arithmetic Average (UPGMA)classified the 40 accessions in to three clusters. Under Cluster 1, 95.5% of identified accessions were grouped by traits such as cotyledon length and cotyledon width, red pods tree. While, Cluster 2 made up of 5% of total number of accessions with traits least pod weight, least pod external thickness, least cotyledon length and red podded trees. A single accession in Cluster 3 characterized by longest pod and constituted only 2.5% of the total accession. The frequency distribution of the nine qualitative traits confirmed that, 90% of identified accessions exhibited pod surface texture as smooth and slightly rough, 97% with pod surface shape as slightly furrowed with medium furrows and 85% with Amelonado pod shape. Most of the identified Cocoa accessions, grouped into three pod apex shapes traits such as Mammelate, Acute and Obtuse,accounting for 44, 25 and 20%, respectively. Of the total accessions studied, 63% had no anthocyanin on the mature pod ridge. Each of 72% measured as the strength of the accessions to withstand Phytophthora palmivora, and vigorous. The Shannon Weaver Diversity Index characterized and suggested that the Cocoa accessions in Makira Island mainly resemble to Amelonado (bulk) type, usually classified as Forasterio variety.

    Item Type: Journal Article
    Subjects: S Agriculture > SB Plant culture
    Divisions: Faculty of Business and Economics (FBE) > School of Agriculture and Food Technology
    Depositing User: Nandakumar Desai
    Date Deposited: 08 Dec 2020 13:01
    Last Modified: 07 Apr 2021 15:15
    URI: http://repository.usp.ac.fj/id/eprint/12368
    UNSPECIFIED

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