Adh1 first intron polymorphisms in Argentinean populations of Ceratitis capitata

Sb Lanzavecchia,Mi Remis,Ro Zandomeni,Jl Cladera

doi:10.1111/j.1570-7458.2010.01002.x

Abstract

AbstractDNA size polymorphisms were utilized in a study of 24 natural populations of Ceratitis capitata Wiedemann (Diptera: Tephritidae) from Argentina. The first intron of alcohol dehydrogenase 1 gene (Adh1) was amplified using exon priming intron crossing‐polymerase chain reaction. Three size variants were detected among the 307 samples analyzed. To better differentiate the size variants, further digestion of PCR products with the EcoRI restriction enzyme was carried out. Complete nucleotide sequences of the three‐allele variants were obtained and single changes, insertions, deletions, and EcoRI recognition sites were located. Population allele frequencies were analyzed and a global mean heterozygosity (He) of 0.33 was obtained. In most populations, observed allelic frequencies conformed to Hardy–Weinberg expectations. Significant differences between provinces and sampling sites within these provinces, and among some populations were found. The average number of insects exchanged among populations (Nm) was estimated and high values were observed between Argentina and populations from two African countries (Morocco and Kenya), Australia, and Hawaii (Kauai). Pest introduction sources and dispersion patterns in Argentina are discussed based on these results as well as on available bibliographical data.

Highlights

Ceratitis capitata Wiedemann (Diptera: Tephritidae), commonly known as the medfly, is one of the most important fruit and vegetable pests with an extensive variety of host species (Liquido et al, 1991)
Digestion with EcoRI facilitated the differentiation between similar-sized variants (2 515 and 2 461), which were separated using agarose electrophoresis (Figure 1B)
We suggest that 2 515 corresponds to variant 2 670 described by Gomulski et al (1998) and we provide its nucleotide sequence here

Summary

Introduction

Ceratitis capitata Wiedemann (Diptera: Tephritidae), commonly known as the medfly, is one of the most important fruit and vegetable pests with an extensive variety of host species (Liquido et al, 1991). It has been able to adapt to a variety of environmental conditions and has migrated from its origin in equatorial Africa to tropical and temperate regions around the world (Carey, 1991). Its presence in Argentina was first recorded in an orchard near the city of Buenos Aires (Vergani, 1952). It was later reported in the commercial orchards of the north-eastern and north-western regions of the country (cf Segura et al, 2006). It causes significant economic losses in infested areas, mainly because of direct damage to the fruit and the restrictions

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Conclusion