Agro-Morphological, Yield Components and Nutritional Quality Attributes of <i>Vicia faba</i> L. var. <i>Minor</i> Cropped in Tunisian Arid Regions

Abstract

Faba bean (Vicia Faba var. Minor) is of great importance as it is commonly used as an excellent protein source in food and feed. In Tunisia, the wide variability among local genetic resources might be valorized by preservation and breeding programs. For that, the knowledge of the diversity within this crop and its distribution across the oasis could be of great help in managing and improving its germplasm. The objectives of the present study were to assess the phenotypic diversity within a germplasm of 23 populations of local faba bean cropped in Tunisian arid regions. Characterization was undertaken based on 29 parameters related to seeds, plant growth, flowers, and pods characteristic. This agro-morphological characterization was carried out based on UPOV and Bioversity International descriptors. Crude protein (CP), neutral and acid detergent fibers (NDF, ADF), and in vitro dry/organic matter digestibility (IVDMD/IVOMD) parameters were also analyzed. Results revealed a considerable genetic variability for most of the agro-morphological parameters. In fact, significant differences (p<0.05) were revealed by ANOVA for the majority of the analyzed quantitative traits. The coefficient of variation, used as a homogeneity index, was above 1.44 % for all characters, which ensures the predominance of genetic components in the differences among populations. The overall variability was analyzed via multivariate and dimension reduction approaches relatively using hierarchical clustering and PCA methods, in order to classify populations into relatively homogenous groups after the identification of the major traits contributing to the overall diversity. The superior populations with the best precocity (95 DAS), with high total yielding per plant (500 g), and having the highest digestibility (96.5%), the highest CP content (29.6%), and the least NDF content (44.5%) were identified.