CORESTA Meeting, Agronomy/Phytopathology, Santa Cruz do Sul, 2005, A 20

Genetic relationships among the newly discovered Nicotiana wuttkei and other Nicotiana species of section Suaveolentes using ISSR polymorphism

DEL PIANO L.; SORRENTINO C.; ABET M.; DI MURO A.; BARBATO L.; SICIGNANO M.; CUCINIELLO A.; COZZOLINO E.
Agricultural Research Council (C.R.A.), Scafati, Italy

Nicotiana wuttkei i s the last discovered species of the Nicotiana genus and described for the first time in 1991 by Clarkson and Symon, as a member of section Suaveolentes . At present there is little and disagreeing information about morphology and cytology of this species. Furthermore its systematic position is not yet clearly defined. The aim of this paper was to assess the genetic relationships among the newly discovered Nicotiana wuttkei and other Nicotiana species, belonging to the section Suaveolentes , using ISSR polymorphism, in order to characterize this species and to make an attempt to define its systematic position. Genomic DNA of Nicotiana wuttkei and 16 Nicotiana species, belonging to section Suaveolentes was extracted and amplified utilizing 15 different 3'and 5' anchored primers. Nine of them were chosen on the basis of the clarity and reproducibility of bands. All these primers revealed polymorphic patterns. A number of bands from 22 to 38 were generated per primer, in the size ranging from 200 to 2000 bp. A dendogram was constructed based on the similarity index matrix, using the arithmetic average of unweighted pair group method (UPGMA) to illustrate the genetic relationships among the Nicotiana species examined. The results, till now obtained, indicate that the Nicotiana velutina is the most related species, in the section Suaveolentes , to Nicotiana wuttkei . To confirm these data, further experiments of amplification with a larger number of ISSR primers are in progress.