Maurizio Minelli

Characterization of Some Italian Common Bean (Phaseolus Vulgaris L.) Landraces by RAPD, Semi-random and ISSR Molecular Markers

Randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and a semi-random PCR system were used to analyze the genetic diversity of 16 Italian common bean landraces and their relationship to four commercial cultivars. Of the primers tested, 8 ISSR, 6 RAPD and 7 semi-random primers produced polymorphic and reproducible DNA fragments. A higher proportion of polymorphic bands were observed using ISSR (85%) and semi-random (90%) primers than RAPD (69%) method. The combination of any two semi-random markers allowed the identification of all 20 bean genotypes. In contrast ISSR (except for primer (CAC)3GC) and RAPD markers appeared to be less informative as more than two markers were necessary to achieve the same diagnostic level. Moreover, 7 ISSR, 2 RAPD and 8 semi-random exclusive bands were identified as putative population-specific markers. Semi-random and ISSR derived dendrograms showed similar tendencies in terms of genetic relatedness, whereas clustering of genotypes within groups was not similar when compared with the RAPD technique. Despite the different ability to resolve genetic variation among the investigated landraces, two major clusters with less than 60% (ISSR) and 40% (RAPD and semi-random) genetic similarity were formed with all three marker systems. The two groups were correlated with the phaseolin patterns and seed size of the landraces. The analysis showed that the cultivar ȁ8Lingua di Fuocoȁ9 and most of the landraces (13 out of 16) collected in Italy belong to the Andean gene pool, whereas only the three populations from Pratomagno belong to the Middle American gene pool.

Direct determination of aliphatic acids in honey by coelectroosmotic capillary zone electrophoresis

SUMMARY Coelectroosmotic capillary zone electrophoresis has been employed for the rapid analysis of 8 aliphatic acids usually present in honey. Polycationic surfactants (hexadimethrine bromide (HDB), cetyltrimethylamonium bromide (CTAB) and tetradecyltrimethyllammonium bromide (TTAB)) have been added to the electrolyte buffer dynamically coating the inner surface of the capillary and causing a fast anodic electroosmotic flow, known as coelectroosmotic flow. The composition of the running buffer (50 mM sodium phosphate adjusted to pH 8 with 1.0 M sodium hydroxide, 25% 2-propanol and 0.001% HDB) and the instrumental parameters (voltage of −20 kV with a hydrodynamic injection for 15 s and an UV detection at 210 nm) have been optimized. Finally, the applicability of the method has been demonstrated for the determination of the aliphatic acids in several kinds of honey without any sample pretreatment.

Characterization of Italian populations of Lolium spp. resistant and susceptible to diclofop by inter simple sequence repeat

Abstract Three Italian Lolium weed populations, one susceptible and two resistant to diclofop, were characterized by the technique of inter simple sequence repeats (ISSR). The goal of this study was to taxonomically identify these Lolium populations as well as to evaluate evidence for introgression of ISSR fragments from Festuca and the potential role of this introgression in the diclofop response. ISSR analysis confirmed the genomic background of the weed populations to be consistent with that of Lolium. However, the great range of variation in ISSR banding patterns highlighted that the three ryegrass accessions are mixed populations made up of individuals resulting presumably from intrageneric and intergeneric hybridization in the Lolium–Festuca complex. Two Festuca genus-discriminating and 20 Festuca species-discriminating ISSR markers were screened among all the three ryegrass populations. The resistant Tuscania population carried the highest percentage of Festuca genome (16.8%) followed by the resistant Roma (13.6%) and susceptible Vetralla (7.6%) populations. On the basis of these data some influence of Festuca genome in diclofop resistance levels of studied ryegrass populations could be hypothesized. Nomenclature: Diclofop; ryegrass, Lolium LOL; fescue, Festuca FES.