Genetic Diversity of Perennial Ryegrass Wild Ecotypes Based on Agro-Biological Traits

Perennial ryegrasses (Lolium perenne L.) are one of the most valuable forage grasses, characterized by high productivity and good feed quality. Intensive cultivation of ryegrasses has resulted in reduced genetic diversity. Wild ryegrass ecotypes can be used in breeding programmes as parental genotypes with the aim to neutralize this genetic erosion. The objective of this study was to evaluate wild perennial ryegrass ecotypes from Ukraine under Lithuanian climatic conditions. Wild ecotypes were collected in Western and Northern Ukraine in 2008-2009 and planted in 2009-2010 as part of the germplasm collection at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry. Winter survival, re-growth in spring, plant height, beginning of heading, flag leaf length and width, inflorescence length and biomass were assessed. High variation of traits was detected among ecotypes (CV = 22.64-41.41%), except for winter survival, for which the coefficient of variation was average (CV = 18.26%). Principal component analysis was carried out and a dendrogram was computed based on agro-biological traits. In both years of investigation the grouping of ecotypes was mostly influenced by biomass, plant height and date of heading.