Evaluation of grain morphometry and gliadin diversity among twenty accessions of the genus Aegilops from the National collection of Bulgaria
¹Agricultural Academy, Institute of Plant Genetic Resources ‘Konstantin Malkov’, 2 Druzhba Str., BG4122 Sadovo, Bulgaria
²Institute of Field and Vegetable Crops, 30 Maksima Gorkog str., SRB21101 Novi Sad, Serbia
*Correspondence: gergana_desheva@abv.bg
Abstract:
The objective of the study was to evaluate the genetic diversity in twenty Aegilops accessions belonging to five plant species with respect to specific grain morphometric parameters and gliadin proteins, employing digital image analysis and A-PAGE electrophoresis. The considerable variation was observed among accessions for grain morphometric traits – area, perimeter, length, width and colour of grain. A total of 96 gliadin polymorphic bands were identified, with the number of bands varying between 13 and 22 per accession. The overall genetic diversity in the samples based on the patterns observed for each of the four gliadin regions showed that the ω, γ and β regions had high genetic variation index (H = 0.950), while α regions (H = 0.938), respectively. The mean genetic diversity estimate was high (H = 0.947). The average genetic similarity between all 20 genotypes ranges from 0.14 to 0.93 with a mean of 0.56, indicating that the studied accessions exhibited considerable genetic variability. The study found that the clustering of Aegilops genotypes was not linked to their geographic origin. Two-dimensional Principal Coordinates Analysis (PCoA) based on the gliadin and morphometric analyses revealed wide genetic dissimilarity between most of the genotypes, explaining 97.16% of the variations, with the model explaining 97.16% of the observed variation. Of this, PCo1 accounted for 93.65% and PCo2 for 3.51%. Genotypes with analogous genomes were grouped in close proximity within the phylogenetic tree, indicating that their evolutionary relationships may have originated from the same parental lineage.
Key words:
A-PAGE, Aegilops, diversity, gliadins, grain morphometry