Taxonomic evaluation of Italian populations of Lolium spp. resistant and susceptible to diclofop‐methyl

Abstract

A comprehensive research project was set up to characterize by different approaches some Italian populations of Lolium spp. susceptible and resistant to diclofopmethyl. The present study was aimed at the taxonomic identification of these Lolium populations on the basis of the electrophoretic analysis of seed reserve proteins. Electrophoresis confirmed the great range of variation detected by preliminary morphological analysis. Approximately half the individuals in each population could be classified as belonging to Lolium multiflorum or Lolium rigidum, the most common Lolium species present in the area. However, electrophoretic patterns revealed a significant number (40-60%) of hybrid individuals in all populations. The origin of these offtypes was postulated as resulting from both intrageneric hybridization among different Lolium species and intergeneric hybridization between Lolium and Festuca genera. No significant differences were detected in the taxonomy of herbicide-susceptible and -resistant populations.

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

“…The RM biotype was treated with chlorsulfuron for 3 yr (1989-1990-1991) and with diclofop for 2 yr (1992)(1993), while from 1984 to 1994 the TU biotype was treated with diclofop every 2 yr. Herbicide field history was not available for the susceptible biotype (VT). Alphanumeric codes, original location, response to diclofop, resistance index, and cross-resistance of the investigated biotypes are given in Table 1 (Dinelli and Lucchese 1999;Dinelli et al 2002). For each reference species, the seeds were sampled from three to five registered cultivars.…”

“…In the first group, all Lolium spp. were grouped with two Festuca species of subgenus (Semikohov et al 1981, Butkute andKonarev 1982;Aiken et al 1998;Dinelli et al 2002).…”

“…rigid ryegrass species, others were identified as intrageneric hybrids (among different Lolium species) and intergeneric hybrids (between Lolium and Festuca genera), and a few plants showed some typical traits of Festuca species (presence of forked ears) (Dinelli et al 2002). However, the morphological and biochemical approaches did not allow the estimation of how much of the Festuca genome had been transferred in the investigated ryegrass populations (Bravin et al 2001a;Dinelli et al 2002).…”

“…Until the 1990s, most knowledge on the taxonomy and phylogenetic relationships of the Festuca-Lolium complex came from cytological studies and interspecific crosses (Terrel 1966;Malik et al 1967). More recent works have used morphological and seed-protein analysis (Bulinska- Radomska and Lester 1988;Dinelli et al 2002), chloroplast DNA restriction-site analysis (Yaneshita et al 1993), restriction fragment length polymorphism (RFLP) (Xu et al 1995), or random amplification of polymorphic DNA (RAPD) (Stammers et al 1995) markers. A polymerase chain reactionbased method, which deserves increased attention as a molecular marker, is inter simple sequence repeats (ISSR), where primers are designed for the common sequences of simple sequence repeats (SSR or microsatellites) ubiquitous in eucaryotic genomes (Lagercrantz et al 1993).…”

Estudio fisiológico y genético de biotipos de <i>Lolium perenne L.</i> resistentes a glifosato

“…Dentro de la comunidad de malezas de una amplia región de Italia, se han evaluado diferentes ecotipos de ryegrass de variable sensibilidad a diclofop-metil. En cada población se encontró un 40-60 % de híbridos tanto intra-genéricos como producto del cruzamiento con Festuca spp, sin embargo no se hallaron relaciones entre la afinidad taxonómica de las plantas y la resistencia al mencionado herbicida (Dinelli et al, 2002).…”