Wild Phaseolus vulgaris L. accessions containing arcelin codominant alleles 1 through 5 were reconfirmed and characterized for resistance to the Mexican bean weevil, Zabrotes subfasciatus (Boheman) (Coleoptera: Bruchidae). Accession G 02771 (arcelin 5) had the highest level of antibiosis resistance, followed by G 12952 (arcelin 4), G 12882 (arcelin 1) and G 12866 (arcelin 2). Arcelin 3 accessions conferred the lowest levels of resistance. As the presence of arcelin is inherited as a single dominant gene, a backcross breeding program has been used to transfer resistance to the Mexican bean weevil from wild beans to bean cultivars using serological techniques to detect the presence of arcelin and replicated insect feeding tests to measure resistance levels. Progeny containing arcelin 1 showed resistance equal or superior to that of the resistant check. Arcelin 2-derived lines had intermediate levels of resistance while no resistant progenies were obtained from crosses with arcelin 3 and 4 sources. Results are discussed in relation to the deployment of arcelin alleles in bean cultivars.

Arcelin, a seed protein discovered in wild Phaseolus vulgaris L. accessions, gives high levels of resistance to the Mexican Bean Weevil [MBW; Zabrotes subfasciatus (Boheman)]. Five arcelin variants have been described. To better understand the genetic control of arcelin and MBW resistance, an inheritance study was conducted. Bioassay tests for insect response, and biochemical lasts to detect the presence‐absence of arcelin, were performed on the same individual seed. Accessions G12952 (arc‐4) and G02771 (arc‐5) had the highest level of resistance to MBW with no adults emerging from infested seed. Resistance was also found in G12882 (arc‐1) and G12866 (arc‐2), while G12922 (arc‐3) and the commercial cultivar, Pijao, were susceptible to the insect. The genetic study confirmed that all arcelin variants were inherited as a single dominant gene based on biochemical evaluations for presence‐absence of arcelin. Nevertheless, in bioassay tests with MBW, only crosses with arc‐1 and arc‐5 showed a single, completely dominant gene mode of inheritance, with the presence of arcelin being highly associated with resistance to the insect. For arc‐1 and arc‐5, biochemical tests can be reliably used to select for MBW resistance. For arc‐2, a combination of biochemical and bioassay tests is needed. As arc‐4 segregated few resistant individuals, and arc‐3 gave only intermediate to susceptible offspring, the use of these two arcelin variants is not recommended in a routine resistance breeding program. Electrophoretic patterns and bioassay tests of F1 and F2 generations showed that arc‐5 and arc‐1 variants are inherited as a single unit and are codominant.

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The genetic variation and population structure of three populations of Anopheles darlingi from Colombia were studied using random amplified polymorphic markers (RAPDs) 001). The F ST distances and AMOVAs using AFLP loci support the differentiation of the Guyana biogeographic province population from those of the Chocó-Magdalena. In this last region, Chocó and Córdoba populations showed the highest genetic flow.Key words: amplified fragment length polymorphism -Anopheles darlingi -genetic diversity -malaria vectors -random amplified polymorphic DNA -polymerase chain reaction -ColombiaAnopheles darlingi is recognized as the most anthropophillic and endophagous species of Anopheles in the Americas (Fleming 1986), the primary malaria vector in the Neotropics (Conn et al. 2001), and is considered the most important malaria vector in the Amazon Basin . It is most frequently found in the hot and humid lowlands, with a discontinuous distribution from Southern Mexico to Northern Argentina, but not reported in Costa Rica, Nicaragua, and Panama (Linthicum 1988, Manguin et al. 1999. In Colombia, it is found up to an altitude of 450 m in the premontane zone of the Andes (Fleming 1986), which is characterized by three large mountain ranges and variety of geographic features ( Fig. 1) that clearly separate the eastern from the western regions and possibly limit the free gene flow between these regions.Based on the original description of An. darlingi by Root (1926), phenotypic variation and differences in hematophagous behavior have contributed to generating a certain degree of confusion regarding its specific taxonomic status (Galvão et al. 1937, Galvão & Barreto 1938, Galvão 1940, Linthicum 1988, Rubio-Palis 1998. Given the foregoing and the great importance of this species, a series of population studies were conducted, using morphological and molecular tools (Manguin 1999), oriented toward clarifying both taxonomic status and genetic structure within its range of distribution. Lounibos and Conn (2000) recently reviewed the use of molecular markers in the study of the ecology and genetics of An. darlingi. Its biting behavior was summarized by Rosa-Freitas et al. (1992), andZimmerman (1992) demonstrated great variability in post-blood feeding/resting behavior. Depending on the region of study, one, two, and even three peaks of major biting activity have been observed, as well as variation in the extension or time interval of peak hematophagous activity. Hudson (1984) and Klein and Lima (1990) suggest that this indicates the existence of a species complex. Nevertheless, from morphological studies did not reveal substantial differences among populations throughout the area of distribution, including populations in isolated zones (Linthicum 1988, Rubio-Palis 1998, Manguin et al. 1999. According to Linthicum (1988) the diagnostic characters are very constant, even for the Guatemalan and Honduran populations and interpopulational variation is almost equal to intrapopulational variation.Additionally, several studies on this spe...

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