Phenotypic diversity of Ethiopian grass pea (Lathyrus sativus L.) in relation to geographical regions and altitudinal range

Fifty grass pea (Lathyrus sativus L.) populations collected from different administrative regions and altitude classes in Ethiopia, were evaluated for variations of five morphological traits. Shannon-Weaver diversity index was calculated for traits, populations and altitude classes. Monomorphism was recorded in flower color (blue) for most of the populations. Olive seed colour was dominantly distributed in all regions with mean frequency of 50% while black seed colour is rare with mean frequency of 4% in Ethiopia. Much variability was observed within populations. High diversity values for pattern of testa colour and leaflet size were recorded in populations of highland origin (>2550 m.a.s.l.). Shannon's diversity index is highest in Gondar (H = 0.65) followed by Tigray region (H = 0.64) even though there was no significant variation in H values between regions. These regions with high diversity are recommended for immediate in situ and ex situ conservation.