Study of alfalfa crops by using isozyme markers

Alfalfa with a genetic constitution of 2n=4x=32 and autotetraploid with allogamous fertilization has more genetic diversity. In fact, genetic diversity is critical for breeding selection programs to improve trait, generate new adapted cultivars. The enzymatic markers showing tetrasomic inheritance patterns can be used to perform genetic diversity analysis. The aim of this study was to determine genetic variations levels and clustering based on enzymatic band (0 and 1) in alfalfa populations.
Genetic diversity of 12 alfalfa half-sib families was studied by use enzymatic electrophoresis (rubisco, superoxide dismutase, esterase and peroxidase). 35 individuals of each variety, were investigated in the Agricultural Research Station of University of Tabriz.
For enzyme markers rubisco and superoxide dismutase isozymes showed only one monomorphic band in all populations, but esterase and peroxidase enzymes had polymorphic bands. The resulting data based on presence and absence of enzymatic band (0 and 1) for 11 polymorphic isozymic bands were analyzed. Isozymic analysis showed that there were high levels of intra-family and low level of inter-family diversity. Average heterozygosity, as an index of within-population genetic diversity, was 0.289. Nei’s genetic distances among families were low (0.002 to 0.059). Dendrogram was constructed via the Jaccard similarity coefficient and UPGMA method, that lead to the classification of the alfalfa populations in two groups, with 11 families in one group and only Chaleshte half-sib in the other group were located that were conform the pervious conclusion.
It might be possible to use these enzymes as markers to select alfalfa genotypes in the early breeding stages after the stability of markers were verified in other experiments.