Eco-geographic Distribution and Microcenters of Genetic Diversity in Faba Bean (Vica Faba L.) and Field Pea (Pisum Sativum L.) Germplasm Collections from Ethiopia

Abstract

Ethiopia is considered an important center of secondary diversity for both faba bean (Vicia faba L.) and field pea (Pisum sativum L.). However, areas of eco-geographic distribution and the microcenter of genetic diversity are not well known. Two separate trials consisting of 160 faba bean and 148 field pea accessions were conducted at Holetta and Kulumsa in 2001. Simple and alpha-lattice designs with 2 replications were used for faba bean and field pea, respectively. Cluster analysis grouped faba bean accessions
into eight and field pea into five different classes. Mahalanobiss D² analyses showed significant genetic distances between most of the clusters in both crops. Accessions from the northern parts of the country showed tendencies of being grouped together, indicating that their genetic background may be related. Accessions from the southern parts of the country were distributed over most of the clusters showing more genetic diversity compared to those from the northern parts. This indicates that the distribution of genetic diversity among accessions is not uniform across different eco-geographical regions in Ethiopia and the microcenter of genetic diversity for both crops may be located in the southern part of the country. The existence of more genetic diversity in one region compared to the other could be due to differences in the level of variability among the original introductions to
different regions, the nature and degree of both human and natural selections after introduction, and effects of ecological and agricultural conditions as major forces of evolution. Future collection, conservation and utilization programs should focus on the southern part to safeguard and exploit the tremendous genetic diversity. However, a comprehensive study involving both morpho-agronomic traits and molecular markers
would be needed for a more comprehensive conclusion.

Keywords: Cluster Analysis; Eco-geographic Distribution; Faba bean (Vicia faba L.); Field pea
(Pisum sativum L.); Genetic Diversity; Mahalanobis\'s Distance (D2); Microcenter of Genetic
Diversity

East African Journal of Sciences Vol. 1 (1) 2007: pp. 10-24