Cytological Studies in Species and Interspecific Hybrids of Passiflora Native to Argentina

REALINI MARÍA FLORENCIA; POGGIO, LIDIA; PANNUNZIO, M J; BUGALLO, VERONICA L.; FACCIUTO G.

Foz de Iguazú

Conferencia; 21 st International Chromosome Conference (ICC); 2016

International Chromosome and Genome Society

Passiflora has more than 500 species distributed worldwide.There are 19 natives from Argentina belonging to 4 subgenera with3 basic numbers: Passiflora (11 species) with x = 9, Tacsonioides (1)with x = 9, Decaloba (5) with x = 6, and Dysosmia (2) with x = 10.The aim of this project is to perform a cytological study of Argentinianspecies of Passiflora contributing to a breeding program toobtain ornamental cold tolerant phenotypes. Interspecific crossingswere carried out among 9 species. The meiotic behavior of 8hybrids among P. alata , P. caerulea , P. amethystina , and P. elegansshowed variable chromosome pairing with evidence of crypticstructural hybridity. P. amethystina and P. caerulea were the speciesshowing the highest fertility in their hybrids. The genome sizeof 14 species and 37 hybrids was estimated by flow cytometry andtested by ANOVA. In the species analyzed, the C value varied from0.54 to 2.52 pg, and significant differences were detected amongthe species. The hybrids showed gains and losses of DNA as a resultof the genomic shock from interspecific hybridization. The karyotypesof 7 species were analyzed using DAPI/CMA banding andFISH with 18S rDNA sequence as a probe. Hybridization signalscolocated with DAPI ? /CMA + regions. The number of rDNA sitesvaried from 1 pair in species with x = 6, to 3 pairs in P. amethystinaand P. caerulea with x = 9. The cytogeography of Argentinianspecies was modeled with Maxent software, analyzing 10,309 collectionsites of herbarium specimens worldwide. Species with x =6 and x = 9 were located only in America, while the species withx = 10 were also found in Africa and Oceania. The progress of thiswork will contribute to elucidate the several hypotheses about thebasal number of the genus, the mechanisms involved in chromosomalevolution, and the relationships among the species of Passiflora