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 - 3.04

Genetic Diversity in cultivated common bean (Phaseolus vulgaris L.) from BASilicata:Marker-based analysis of morphological and agronomic traits

MASI P.⁾, LOGOZZO G., SPAGNOLETTI ZEULI P.L.

Centro Interdipartimentale per la Salvaguardia delle Risorse Vegetali “Pierino Iannelli” Università degli Studi della Basilicata, Potenza

⁾bio346@unibas.it

genetic diversity, germplasm, land race, common bean

Knowledge of patterns of genetic diversity enhances the efficiency of germplasm conservation and preservation. This study examined the organisation of diversity for morphological and agronomic characteristics in 469 accessions grouped in 29 landraces of common bean (Phaseolus vulgaris L) from eco-geographical differentiated areas of Basilicata (Southern Italy).

Data on growth habit, flower colour, leaf colour, leaf shape, dry pod colour pod shape, pods number, pod weight, pod length, number of seeds per pod and 100-seed weight were analysed by uni and multivariate statistical analysis.

>From five to ten plants per accession were scored. With the exception of growth habit, prevalently indeterminate (78%), all land races appeared to be well differentiated from one another for all characters considered (qualitative and quantitative). The first two canonical variables explain over 65% of the total variation with flower and pod colour and 100-seed weight being the most important characters in the first canonical variable. The multivariate analysis, using the land-race as an initial classification criterion, followed by use of morphological markers, identified the existence of three groups.

The frequency of the phaseolin types within the collection was also investigated. ‘C’ (>70%), ‘T’ (25%) and ‘S’(< 3%) phaseolin types were observed: intra-landrace variation was detected only for “Lattino” landrace (13 of 19 accessions were considered putative hybrids). The results confirm the prevalence of Andean (95%) vs Mesoamerican group (5%) in the cultivated common bean landraces from Basilicata.

The conclusions of this study are: in Basilicata there is a large number of different landraces with their own “genetic identity” and with specific morpho-agronomical and biochemical characteristics respect to others from Italian and Mediterranean areas. These results stress the need and urgency of actions devoted to the preservation of this precious germplasm.