Estimation of Genetic Variability, Heritability and Genetic Advance of Some Wollega Coffee (Coffea arabica L.) Landrace in Western Ethiopia Using Quantitative Traits

Arabica coffee is the predominant commodity in contributing for foreign exchange in Ethiopia and improvement for yield and other desirable traits is highly momentous. Estimating genetic diversity is a prerequisite activity in plant breeding program for crop improvement. This study was designed to determine the extent of genetic variability among Wollega coffee landrace and importance of gene revealed in traits. The 26 genotypes were tested during the 2016/2017 cropping season at Mugi and Haru sub- enters using RCBD. The combined analysis manifested significant difference among genotypes only in node number per primary branch (NNPB), fruit traits and Coffee leaf rust (CLR) although significant difference recorded for 18 and 22 of the 23 traits at Haru and at Mugi, respectively. The difference between environments was significant for all traits, except for CLR, yield (YLD), leaf, some fruit and bean traits. Performance at Haru was less than at Mugi for all traits showed significant difference. Genotype x environment (GEI) was significant for all traits excluding NNPB, leaf length (LL), fruit width and CLR indicating inconsistency performance of Coffee genotypes. At Haru, high phenotypic coefficient of variation (PCV>20%) recorded for YLD (25.5%), CLR (110.0%) and number of secondary branch (NSB) (22.0%), but High genotypic coefficient of variation (GCV>20%) recorded only for CLR (99.6%). At Mugi, High PCV and GCV (>20%) recorded for YLD (38.6%) and CLR (98.4%). Heritability ranged from 10.0% (YLD) to 88.0% (BW) while genetic advance (GAM) ranged from 1.5% (LL) to 32.4% (NSB) at Haru. At Mugi, Heritability ranged between 31% (CLR) and 84.0% (bean thickness) and between 3.3% (LL) and 44.0% (YLD) for GAM. The present results elucidate the existence of moderate genetic diversity among genotypes for some traits at individual location indicating the possibility of improvement for desired traits via selection. For further diversity analysis, molecular characterization methods need to be carried out.