Proceedings of the XLVI Italian Society of Agricultural Genetics - SIGA Annual Congress

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 3.08

AFLP FINGERPRINTING OF ECOTYPES OF “POMODORINO DI CORBARA”

MAINOLFI A.*, PENTANGELO A.**, GIORDANO I.**, RANALLI P.*, CARBONI A.*

*) Istituto Sperimentale per le Colture Industriali, Bologna (Italy)

**) Istituto Sperimentale per le Colture Industriali, Battipaglia (Salerno, Italy)

genetic fingerprinting, AFLP, tomato ecotypes

Local ecotypes of tomatoes are traditionally cultivated in Campania region and have an increasing economic importance in the area close to Sarno valley. Probably the more interesting tomatoes are those characterized by the small fruit size (15-20 g), better known as “Pomodorini di Corbara” or “Corbarini”. Most of these ecotypes have an indeterminate growth, with many secondary branches and with little, alternate and unequal leaves. The small fruit shapes may morphologically classify them (oval, round, elongate or pear-shaped). They almost certainly derive from some old tomato varieties such as Lampadina, Fiaschella or Fiaschetto, Principe Borghese, etc., and were mainly used for family consumption during the winter season or for homemade tasteful preserves. While in the past they were cultivated mostly on the hillsides, since more than 10 years industrial processing started operating: the fruits are canned whole, using the same tomato juice.

A research program started in 1995 with the aim to study this typical production, to collect the existing germplasm, to improve its cultivation practices and to characterize the different ecotypes collected.

The AFLP technique was used to visualize 925 amplified DNA restriction fragments. Twenty-one fingerprints, generated by 19 AFLP primer combinations (30-65 peaks detected for each primer combination), were able to monitoring the identity of 19 different ecotypes, 2 ancient varieties characterized by the small dimension of the fruits (Fiaschetto and Principe Borghese), 2 traditional cultivars (San Marzano and Roma) and a modern “Cherry” hybrid (deriving from a cross between a Cherry tomato, Lycopersicon esculentum var. cerasiforme, and common tomato breeding lines). No variation was found within the 19 ecotypes.

Reproducibility of the electropherograms obtained with the ABI PRISM 310 Genetic Analizer was checked and a comparison of the ABI Prism^TM fluorescent dye-labeling and detection technology with the “conventional” autoradiographied sequencing gels confirmed the excellence of this procedure to obtain reliable and informative polymorphic patterns.

Notwithstanding the reduced genetic variability of Lycopersicon esculentum Mill., the AFLP technique was able to discriminate among ecotypes selected by farmers in a relatively small area and demonstrated to give effective informations in requesting the Protected Designation of Origin (PDO) mark.