ESTIMATION OF GENETIC PARAMETERS IN COFFEA CANEPHORA VAR. CONILON
Journal: International Journal of Life Science Study (IJLSS)
Author: Bayisa Asefa Bikila1*, Ney Sussumu Sakiyama2
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Coffea canephora presents a wide genetic variability, with one of the widest geographic natural distribution within the subgenus Coffea. Hence, genotypic parameters analysis in Coffea canephora has importance, especially for genetic materials from Brazil. For this study, a total of 69 Coffea canephora Var. Conilon clones which are maintained at the Coffee Germplasm Collection of EPAMIG/UFV (Universidade Federal de Vicosa; Oratorios site) in Minas Gerais, Brazil were used. For the evaluation, a randomized complete block design with 5 replications and one plant per plot was used. Data on 11 quantitative traits recorded on tree basis include vigor, reaction to rust, reaction to cercospoera, number of ortotropics branches, number of plegiotropics branches, plant height, diameter of crown, stem diameter (caul), maturity, fruit size and production of fruits(yield) during 2011 to 2014. Hence, the objective of this study was to estimate genetic parameters and identify the existing variability among Coffea canephora species (Var. Conilone clones) using the mixed model methodology (REML/BLUP) through the Selegen software. The results showed a low genetic coefficient of variation (CVg%) among the clones of Conilon Variety for all the traits evaluated. Relatively, the highest coefficients of genetic variation obtained were 13.58%, 17.17% and 19.522% for number of Ortotropics branches Rust and fruit size, respectively, indicating the relative importance of these traits for the improvement of this variety. On the other hand, relatively highest residual coefficient of variation (CV%) of 72.75%, 45.53%, 33.27% and 30.25% were recorded for yield, number of plegiotropices branches, rust and number of Ortotropices branches, respectively implying that these traits seem to be highly influenced by the environmental variation. The estimated repeatability for most of the traits was lowest indicating the irregularity of the superiority of the individuals among the measurements for these characters of the clones which demonstrate that genotype selection based on those traits is not reliable strategy. Generally, there was low interaction with year, as observed by the genotypic correlation across measurement (rgmed) for most of the characters evaluated (ranged from 0.044 for yield to 0.955 for Cercospora ) demonstrating that selection can be performed at any of the development stages used for measurement.