Análisis de la diversidad morfológica de cacao (theobroma cacao l.) del jardín clonal de la UTMACH

Abstract

The present work consisted of evaluating l29 cacao trees (Theobroma cacao L) that are part of the UTMACH clonal garden in the Santa Inés farm belonging to the Faculty of Agricultural Sciences; with the purpose of knowing its genetic richness and the agronomic potential of interest that may be contained in said population, through a morphological analysis and subsequently a statistical analysis that allows generating information of great importance on the accessions under study. A data collection was made between the months of June and January of a total of 46 variables with respect to three vegetative parts flowers, fruit and seed through the use of different materials such as Pie de rey for the measurement of length and length of cob and seeds , digital scale to determine the weight of the cob and seeds, millimeter sheet for the measurement of the sepal, ligule, pedicel, filament, staminoid, style and ovary, a refractometer for the measurement of the brix degrees comprising the determination of the degree of contained sugars, photoshop program for the most accurate measurement of the different parts of the flower, a microscope for the count of ovules present in each flower and comparison of images established by CATIE to establish in the fruit the shape, roughness, basal construction and apex in the seed the shape and cross section. The data obtained were organized in a general table, from which a statistical analysis was carried out using the SPSS program, resulting in a cube of main components and a dendrogram that uses Euclidean distances to form clusters. In the principal component analysis, it determined 17 variables responsible for 70.33% variability for the study accessions, among which the 14 most discriminating were pedicel length, pedicel width, anthocyanin intensity, sepal length, sepal width , anthocyanin intensity, ligule length, ligule width, anthocyanin intensity, filament length, filament width, anthocyanin intensity, staminoid length, staminoid width; for the cube of main components of the accessions it resulted in a total of 11 accessions with greater variability with respect to the larger group, among them are UTMACH 111, UTMACH 010, UTMACH 598, UTMACH 547, UTMACH 454, UTMACH 312, UTMACH 314, UTMACH 011, UTMACH 001, UTMACH 008 and UTMACH 035; On the other hand, the dendrogram of Euclidean distances resulted in 19 groups, of which groups 17, 18 and 19 are the most distant and are formed by an accession each, in turn the group 19 formed by UTMACH 317 is the most differentiated to others. The information generated by the present work gives way to the conservation of unique and very important genetic material in future plant breeding projects, aimed at obtaining cultivars with agronomic characteristics that guarantee the future of cocoa production in Ecuador and Gold; The agricultural area is increasingly declining and the producers are less and less.