INVESTIGADORES
SOLIS NEFFA viviana Griselda
congresos y reuniones científicas
Título:
Cytotype distribution and genetic structure in a diploid ? tetraploid contact zone of the Turnera sidoides (Passifloraceae, Turneroideae) polyploid complex
Autor/es:
KOVALSKY, I. E.; PAREDES, E.N.; FERNÁNDEZ, S.A.; SOLÍS NEFFA, VIVIANA GRISELDA
Lugar:
Foz do Iguacu
Reunión:
Congreso; International Congress of Genetics; 2018
Institución organizadora:
International Genetics Federation
Resumen:
Turnera sidoides L. (x= 7) complex constitutes a suitable biological model system to study the evolutionary dynamics of polyploids in natural populations. Diploids and tetraploids of this complex overlap in Corrientes (Argentina). In order to investigate the evolutionary forces governing the establishment of polyploids and their coexistence with diploids, we analyzed the frequencies of diploids, triploids and tetraploids in the area of overlapping as well as thecoincidence of genetic structure with cytotype distributions. Ploidy was nferred from estimates of DNA content by flow cytometry, while genetic structure for all cytotypes was assessed using amplified fragment length polymorphisms (AFLPs). We made intra- and intercytotype site comparisons to determine numbers of pairwise differences and calculate FST values. We also performed AMOVA to assess partitioning of genetic variance among populations and cytotypes. Diploids and tetraploids were the most abundant whereas triploids were the least abundant. Most populations were constituted by a single cytotype and were either diploid or tetraploid but never triploid. Cytotypes were spatially segregated, occupying different topographic positions, being diploids most frequent in the Miriñay riverside. At a microsite scale, diploid and triploid individuals coexist alongside male and/or female unreduced gametes producers. Also, some mixed diploidtriploid-tetraploid populations were found. AFLP data revealed significant genetic differentiation between diploids and tetraploids, but modest genetic differentiation between triploids and tetraploids. AMOVA indicated that most of the variation occurred within populations. Genetic structure coincided with cytotype distributions. The contribution of genetic variation and Frequency dependent mating success to the cytotype distribution is discussed.