Proceedings of the XLV Italian Society of Agricultural Genetics - SIGA Annual Congress
Salsomaggiore Terme, Italy - 26/29 September, 2001
PHENOTIPYC AND MOLECULAR DIVERSITY AMONG LANDRACES OF P. VULGARIS L. AND P. COCCINEUS L. IN MARCHE, ITALY
BULFON D.*, PORFIRI O.*, TIRANTI B.**, SANPIETRO E.*, SICARD D.*
* Dipartimento di Biotecnologie Agrarie ed Ambientali, Università degli Studi di Ancona, Ancona, Italy
** Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali, Università degli Studi di Perugia, Italy
Among the 5 cultivated bean species, P. vulgaris L. and P. coccineus L. (2n=2x=22) are the only two widespread cultivated species in Europe. These two species differ by their life history and reproductive system. The common bean (P. vulgaris) is a predominantly autogamous species. Wild common bean populations are found on a transect extending from Mexico to Argentina. Independent domestication events occurred in Meso-American and Andean wild populations leading to two different cultivated genepools, the Meso-American and the Andean. P. coccineus is an allogamous species that originated from Mesoamerica. The two bean species were introduced in Europe after the Columbus expedition. However, the level and distribution of diversity of cultivated bean in Europe is still poorly studied.
We have investigated the level and distribution of genetic diversity among landraces of the two cultivated bean species P. vulgaris and P. coccineus from Marche, Italy in order to i) obtain a better knowledge on the genetic diversity among existing cultivated beans to develop new strategy for ex situ and in situ conservation ii) identify the gene pool of origin of the cultivated beans from Marche iii) investigate on potential hybridization between the two common bean gene pools and the two Phaseolus species.
Landraces of the two bean species have been collected in the 2000 from farmers , in the Marche provinces of Ancona, Macerata and Pesaro-Urbino. Accessions of Andean and Meso-American P. vulgaris and Meso-American P. coccineus were obtained from Gene Banks. Diversity of landraces was analyzed at phenotypic level (germination types, growth habit, flower colors, pods length, seed colors) and at molecular level using Inter Simple Sequences Repeat (ISSR). Diversity was found among landraces from Marche for all morphological traits. Seed colors were highly variable among P. vulgaris landraces while only two seed colors (white and violet) were found among P. coccineus landraces. Molecular diversity of Marche landraces has been compared with diversity of American accessions and landraces from Umbria.