engleski

Evaluation of alfalfa germplasm collection by multivariate analysis based on phenotypic traits

Crop improvement depends largely on the availability of diverse germplasm and their efficient utilization. The evaluation, characterization and screening of genetic resources are considered priorities in alfalfa breeding as such information is crucial in choosing material for incorporation into breeding activities. The objectives of this research were to explore the extent and pattern of phenotypic variability in the alfalfa collections, to classify the germplasm into similar groups and to identify the main traits contributing to the overall variability. Twenty seven populations and cultivars of alfalfa of different origin were evaluated for thirteen phenotypic traits on the experimental field of the Agricultural Institute Osijek – Croatia, during three growing seasons (2004-2006). Collected data were centered and scaled to unit variance and analyzed by principal component (PC) analysis. The first four PCs contributed to 89.02% of the total variability among the populations and cultivars. The yields of green mass and dry matter, vigour, growth habit, plant regeneration and length of central leaflet were the most important traits for the genetic variability, representing 58.21% of the total variability in the first PC variable. The second PC explained 16.24% of the total variability and was associated with number of stems, shape of leaf and width of central leaflet. The cluster analysis performed on the two first components grouped the majority of alfalfa cultivars and populations into three clusters of germplasm. In most cases, clustering did not depend on the country of origin. The present investigation revealed that there was wide phenotypic variability for the majority of the assessed traits in the alfalfa collections.

alfalfa colection; phenotypic traits; variability; principal component analysis

nije evidentirano