Análisis de la diversidad fenotípica de cacao nacional x trinitario theobroma cacao l en la provincia de El Oro

Ecuadorian cacao has been characterized by its prestige of quality thanks to the National genetic complex that is currently in an advanced process of genetic erosion due to its low production and susceptibility to pests, causing a constant displacement by hybrid cacao high production, moderately resistant to pests, but of low organoleptic quality, causing instability in prices, low competitiveness, and loss of important market niches, destabilizing the national cocoa sector. According to the Ministry of Agriculture and Livestock (MAG, 2017) of 490,000 ha existing in the country, only in three provinces of the country (Los Ríos, Manabí and El Oro) is produced fine and flavor National cocoa with 18, 15 and 5 qq / ha / year respectively, which demonstrates the importance of collecting, characterizing and preserving these genetic materials. In the last 20 years, many producers have replaced their plantations with National or National x Trinitarios types for the CCN-51 hybrid which is characterized by its high production, medium resistance to diseases (Moniliasis and Phytophthora) and low quality, however, this hybrid does not have the organoleptic benefits that the mentioned materials have. The previous situation is worrisome because if the necessary measures are not taken, it will lead to monoculture that in the future will be very susceptible to the incidence of new pests and diseases (among others) and to the mutations of those that currently have moderate tolerance. The comprehensive evaluation of the collection will allow us to establish the relationship between the phenotype and the genotype, better understand the levels of genetic compatibility, to identify "elite" trees that will be the basis for undertaking conservation programs of genetic resources and cocoa breeding programs in the province of El Oro, with materials adapted to the area and of great agronomic value with export possibilities. The objective of this work was to collect and characterize in situ the thin National and aroma-type cocoas that exist in the most representative areas of the Province of El Oro in the company of MAG Coffee and Cacao Program Technicians, with the In order to inventory and analyze the phenotypic diversity of existing cocoa, through the use of 52 morphoagronomic descriptors (14 qualitative and 38 quantitative) proposed by the Tropical Agricultural Research and Higher Education Center (CATIE), the 37 trees evaluated at strategic points were also georeferenced according to the experience of the MAG Technicians in all the cantons with participation in the production of cocoa. The analysis of variance showed significance among the evaluated descriptors, being more relevant in the discrimination between accessions the descriptors related to the morphology of the fruit and the caulinar part of the plant (leaves and shoots) that explain 61% of the total variance accumulated in the analysis of CPA main components, with only 16 of the 52 descriptors being highly discriminating, and the least discriminant ones discarded. Through cluster analysis for multi-state data and using the hierarchical conglomerate method, the clustering dendrogram was obtained using the 16 most discriminating descriptors resulting in the formation of eleven well-defined groups. The obtained results show a high phenotypic variability among the existing cocoa in the Province, highlighting the accessions named Arenillas 1, Piñas 2 and Chilla 3, which showed the greatest phenotypic distance of the 37 evaluated accessions, this being possible due to the conditions that develop , with a high potential for use in future breeding programs and for its propagation and conservation in order to maintain the fine and unique aroma cocoa in the world.

• 1. autor: Jácome Vásquez, Jose Edison (author)
• Format: bachelorThesis
• Wydane: 2018
• Hasła przedmiotowe: CACAO; NACIONAL; DESCRIPTORES; MORFOAGRONÓMICO
• Dostęp online: http://repositorio.utmachala.edu.ec/handle/48000/12430