ARTICLE 1 – research

OPTIMIZATION OF ANCESTRY INFORMATIVE MARKERS (AIMS) TO CHARACTERIZE THE COMPOSITION OF THE ARGENTINE POPULATION

OPTIMIZACIÓN DE MARCADORES INFORMATIVOS DE ANCESTRÍA (AIMS) PARA CARACTERIZAR LA COMPOSICIÓN DE LA POBLACIÓN ARGENTINA

Patiño J., Lozano M., Russo M.G., Dejean C.B., Avena S.

The Argentine population exhibits a complex genetic structure resulting from historical admixture processes among Western Eurasian, Indigenous, and Sub-Saharan African components, with marked regional variations across the country. To characterize the population composition of the Buenos Aires Metropolitan Area (AMBA), we optimized a panel of 30 ancestry informative markers (AIMs), combining multiplex APLP-PCR, RFLP-PCR, and Alu insertion techniques. We analyzed 50 unrelated blood donor samples from public and private hospitals, using STRUCTURE and ADMIX programs to estimate ancestral contributions at the individual and population levels. Results showed predominance of the Western Eurasian component (84.0%), followed by Indigenous (12.5%) and Sub-Saharan African (3.4%) ancestries. Through technique optimization and standardization, we excluded five AIMs in Hardy-Weinberg disequilibrium; various tests confirmed that this exclusion did not significantly alter the estimates, validating the panel’s robustness. This work demonstrates that the selected 30 AIMs provide reliable ancestry estimates in admixed populations, offering a cost-effective and highly efficient molecular tool for determining individual and population genetic ancestry that overcomes the limitations of previous methods based on varying marker quantity and quality. Notably, these applications extend beyond biological anthropology, as local ancestry identification is also relevant for biomedical and pharmacogenetic studies in Argentina, where European homogeneity is often erroneously assumed.

Key words: genetic diversity, autosomal markers, admixture
Language: Spanish

ARTICLE 2 – research

CARACTERIZACIÓN MORFOLÓGICA Y MOLECULAR DE UNA COLECCIÓN DE GERMOPLASMA DE Stevia rebaudiana BERT.

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF A GERMPLASM COLLECTION OF Stevia rebaudiana BERT.

Budeguer C.J., Erazzú L.E., Camadro E.L.

Stevia rebaudiana Bertoni (Asteraceae) (2n=2x=22) is a species native from Paraguay where it is known as Ka’a-He-é (sweet herb) because of the intense sweet flavor of its leaves. Such flavor is due to a series of diterpene glycosides or steviol glycosides, mainly stevioside and rebaudioside-A, which are 300 and 400 times sweeter than sucrose. This species is cultivated for the industrial obtainment of steviol glycoside crystals, utilized as dietary natural sweeteners, and dry leaves for adding to food. To establish an active S. rebaudiana gene bank for breeding purposes, plants from four Argentinian provinces were introduced in EEA Famaillá, INTA, Tucumán, in 2013 and 2021 -two introductions per province from Tucumán, Jujuy, and Misiones, and one from Formosa-. Of these, 75 were subjected to morphological characterization and 73 to molecular characterization using 18 EST-SSR. In the multivariate analysis for morphological traits, measures overlapped in the introductions from Tucumán, Jujuy, and Misiones, whereas the introduction from Formosa differed from the rest in leaf size and plant height. In the molecular analysis, the introductions exhibited diversity for number of alleles, heterozygosis, and percentage of polymorphic loci, except for the introduction from Formosa, which presented uniform molecular profiles. In the analysis of the molecular variance (AMOVA), 77% of the total variation corresponded to differences among plants within introductions, 15% to differences among provinces (geographical origin), and 8% to differences among introductions within provinces. The observed morphological variability and molecular diversity allow to conclude that the analyzed S. rebaudiana germplasm could be of value to initiate a breeding program.

Key words: EST-SSR molecular markers, genetic diversity, morphological variability, Stevia.
Language: Spanish