Localization of 45S and 5S rDNA sites in genitors and hybrids of ornamental Passiflora

SOUZA, M. M.; URDAMPILLETA, J. D.; FORNI MARTINS, E. R.

Corrientes

Congreso; III Simposio Latinoamericano de Citogenética y Evolución, XL Congreso Argentina de Genética; 2011

Universidad Nacional del Nordeste

The passion fl owers are considered ornamental plants because of the exotic beauty of their fl owers and variant foliage. Since their introduction to the Old World, seventeenth century, they have been used to decorate European glasshouses and gardens. Among the countries with largest representativeness is Brazil, a center of origin for about 200 Passifl ora species and the largest center of geographic distribution of the genus is located in the northern central region of the country. Interspecifi c hybridization is used to produce single plants, and the genotypes used in selection of plants with ornamental characteristics are hybrid progenies. Thus, the aim of this work was to locate 45S and 5S rDNA sites in the genitors Passifl ora gardneri vs. P. gibertii and their hybrids (HD15). The material was treated with 1.0 M HCl before enzymatic digestion using enzyme Pectinex® SP ULTRA. FISH was carried out using a 45S rDNA probe (pTa71) labeled with biotin and detected with avidinfl uorescein isothiocyanate, and using a 5S rDNA probe obtained from total genomic DNA of P. cacaoensis by PCR (primers 5’-GTGCGATCATACCAGC(AG) ( C T ) TA AT G C A C C G G - 3 ’ and 5 ’ - G A G G T G C A A C A C G A G G ACTTCCCAGGAGG-3’) that was labeled with digoxigenin-11-dUTP and detected with antidigoxidenin- rhodamine. Sites with strong staining and without nonspecifi c signals were observed. Passifl ora gardneri showed six 45S rDNA sites, P. gibertii showed four 45S rDNA sites and all hybrids analyzed showed fi ve 45S rDNA sites. All genotypes showed two 5S rDNA sites. The use of 45S rDNA probe was successful to confi rm the interspecifi c hybrid from progeny HD15.