ISSR AND SSR ANALYSIS OF ITALIAN COMMON BEAN 'CONTRONE' ECOTYPES

The ‘Controne’ bean (Phaseolus vulgaris L.) is a valuable crop grown near the Calore River, in the province of Salerno (Campania, Italy). The aim of this research was to evaluate genetic variability by Inter Simple Sequence Repeats (ISSR) and Simple Sequence Repeats (SSR) molecular markers in bean ‘Controne’ populations, and to study genetic relationships with some commercial and local Italian cultivars, in order to characterize this typical crop. Nine bean ‘Controne’ populations, coming from farms in and around Controne, two Controne ecotypes, belonging to CRA-ORT collection, eight commercial and seven local Italian bean cultivars were examined. ISSR analysis of bean genotypes was performed with 11 primers previously selected on the basis of clarity and reproducibility of bands. Among the genotypes examined a total of 218 bands were produced, 215 of them (99%) were polymorphic. When only ‘Controne’ populations were examined 108 bands were scored and 41 (38%) were polymorphics. SSR analysis of bean genotypes was performed utilizing 20 primer pairs, chosen from the recent literature on bean. Among the genotypes examined a total of 72 bands were produced, 71 of them (99%) were polymorphic. When only ‘Controne’ populations were examined 28 bands were scored and 9 (32%) were polymorphic. Almost all ‘Controne’ bean populations showed high genetic similarity with both SSR and ISSR markers. The cluster analysis, based on SSR markers, grouped the populations of ‘Controne’ bean together with ‘Coco’ varieties. ISSR markers were able to distinguish all different varieties examined, in particular ‘Coco’ varieties (morphologically very similar to ‘Controne’ bean) which are clearly separated from ‘Controne’ bean. From ISSR results, all ‘Controne’ bean populations were distinguished except ‘Controne’ C3, C4 and C5. ‘Controne’ C1 and C11 were the most different among ‘Controne’ populations examined. These results suggest that populations C1 and C11 should be excluded from the genetic pool of ‘Controne’ bean.