Ethiopian Coffee (Coffea arabica L.) Germplasm Genetic Diversity: Implication in current research achievement and Breeding Program

Abstract

Coffea arabica L. is the dominant coffee species in the world coffee production contributing over 60% of total production. Ethiopian 30% of foreign exchange income earned from Arabica coffee. Arabica coffee has unique aroma, flavor and low caffeine that make it highly demanding coffee species in coffee producing and consuming countries. As Ethiopia is home land for Arabica coffee very enormous genetic variability expected among coffee germplasm which is vital for further improvement to response the existing world’s demand on Arabica coffee. Thus, this review conducted with the intention to assess the genetic diversity among Ethiopian Coffee (Coffea arabica L.) germplasm for the next breeding program and in the current research results achievement. Up to date, about 7,067 coffee accessions were collected by Jimma Agricultural Research Center; but, 15.33% were died due to enormous environmental factors. Those collected from different coffee growing areas are under utilization as germplasm in order to search for desirable traits and genetic improvement. Different methods like Morphological marker and molecular markers which include DNA markers and RNA markers are being under use for genetic diversity studies. From studies conducted in Ethiopia on coffee germplasm collected from forest coffee, semi forest and garden coffee production system across region, clearly indicated that the availability of coffee genetic diversity which is the primarily required for coffee genetic improvement. The current reviewed scholars authenticated that the existence of wider genetic diversity in Arabica coffee collection in terms of yield and other agronomical traits, diseases and insect pest resistance potential. Hence, up to date 7 hybrid and 35 pureline varieties, totally 42 coffee varieties released in Ethiopia for different coffee growing regions. The highest yield potential of pure line and hybrid variety is 2380Kg ha^-1 and 2680 Kg ha^-1 respectively; still, the average national coffee yield is 646Kgha^-1; thus, further extension work and improvement for yield and disease resistance are lacking. The achievement of 60%-120% heterosis in yield, implies that the availability of great opportunity and experts to be confident in Coffea arabica L. genetic potential improvement for economic traits, diseases resistance and insect pest tolerance in Ethiopia specifically and in the World generally.

Key words: - Coffee arabica L., Diversity, Germplasm, Molecular marker and Morphological marker