Genetic diversity in Algerian diploid and tetraploid oats (Avena L.) based on their morphological characters and eco-geographical parameters

Abstract

This study was conducted to determine the different ploidy levels of various species of the genus Avena, located in northern Algeria, using different morphological and eco-geographical parameters. The specific objectives of the investigation were to estimate phenotypic diversity for different morphological descriptors. One hundred and thirty-eight populations of the genus Avena were collected from 98 different sites in northern Algeria. Harvest sites were determined based on latitude, longitude, and altitude. The pluviothermic Emberger quotient (Q2) was identified by combining three climatic factors (P = annual rainfall, M = average of the maximum temperature of the warmest month, and m = average of the minimum temperature of the coldest month). The interpretation of this quotient required the use of the Emberger climate diagram, which placed each station in one of the 54 combinations of bioclimatic Mediterranean climate. To evaluate intra and inter-specific morphological variations and the extent to which they express genomic variations, the ordination-based Principal Component Analysis was performed. The results showed the presence of the following species: A. barbata with 59 accessions, A. wiestï with 27 accessions, 21 accessions of A. hirtula, 13 accessions of A. longiglumis, 9 accessions of A. macrostachya, 3 accessions of A. clauda, 4 accessions of A. eriantha (ex-Pilosa), and 2 accessions of A. ventricosa. Quantitative traits were crucial for distinguishing inter and intra-specific individuals. Morphological variations proved largely to express genomic variation among the species studied, especially in distinguishing between species carrying both A and C genomes. The morphological differences could not convey the genomic differences among species that share the C genome.