Assessment of Variability for Nutritional Traits of Burr Medic (Medicago polymorpha L.) Genotypes with Different Phenology

Abstract

The objective of this study was to determine compatible genotypes for both grazing and ley farming systems concerning nutritional traits among burr medic (Medicago polymorpha L.) genotypes with different flowering times. Therefore, the variability for nutritional traits of early- (n=13), medium- (n=12) and late-flowering (n=19) genotypes from a breeding study carried out during the 2016-2018 years was assessed using one-way ANOVA and chemometric techniques such as principal component (PCA) and cluster (CA) analyses. Except for the acid detergent protein, calcium and magnesium contents, there were significant differences in the nutritional traits among the genotypes with different flowering times. The medium-flowering genotype had a significant advantage over especially early-flowering genotype in crude protein, acid detergent fiber, metabolizable energy, and relative feed value. There were significantly mutual correlations between most of the studied traits. Consequently, considerable amounts of variability were determined among the genotypes for all the traits under consideration. The 44 genotypes formed three clusters, in which cluster sizes ranged from 3 to 29 accessions per cluster. The PCA 1 and 2 had the highest eigenvalues of 6.44 and 1.35, describing 63.27% and 15.91% of the total variance, respectively. The PCA and CA results indicate that medium- and late-flowering genotypes had the best nutritional traits due to probably high photosynthetic capacity in the conditions of the present study.