Random amplified polymorphic DNA markers for DNA fingerprinting and genetic variability assessment of minute parasitic wasp species (Hymenoptera: Mymaridae and Trichogrammatidae) used in biological control programs of phytophagous insects

Abstract

Biological control of insects that feed on our crops has become more practical in recent years by mass release of egg parasitoid microhymenoptera. Trichogramma species are now commercially reared and spread in commercial fields to control specific insect pests. Microhymenoptera species are, however, very small and morphologically indistinguishable within species, although strains of a given species differ in their efficiency to control specific insect pests. Traditional taxonomy is unable to differentiate microhymenoptera species at the strain level. It is becoming increasingly important to develop a reliable system to monitor genetic variations both within and between strains of commercially important microhymenoptera, to detect genetic drift occurring during several generations of multiplication, to protect patents, and to certify the lots of commercially released microhymenoptera. We have developed a system based on DNA markers to rapidly characterize individuals of five species of microhymenoptera from the genus Anaphes and Trichogramma including a new species of Anaphes not previously described. The main components of our system are a rapid and simple DNA micro-extraction method and fast DNA polymorphism analyses based on random amplified polymorphic DNA markers.

Geographical origin of an introduced insect pest, Listronotus bonariensis (Kuschel), determined by RAPD analysis

“…This relatively new technique offers advantages with respect to the amount of material needed and the fact that nothing need be known about the genomic organization of the organism. The technique has generated useful results in the identification of unique individuals (Smith et al, 1992), detection of genetic variability (Chalmers et a!., 1992;Landry et a!., 1993), race identification (Crowhurst et al, 1991) and generation of linkage maps (Paran et al, 1991). The technique is becoming widely used (see Hedrick 1992 for a review of various current applications), and a review of potential applications has been given by Hadrys et al (1992).…”

Características de nuevos cultivos celulares derivados de tejidos embrionarios de Aedes aegypti (Diptera: Culicidae).

“…Después de la remoción mecánica de las células se centrifugó el contenido para retirar el medio de cultivo y, luego, se procedió a efectuar tres lavados consecutivos del sedimento celular con PBS; con el propósito de eliminar los residuos del medio de cultivo sobre la superficie de las células, el precipitado se ajustó a una concentración de 2x10 6 células/ml. Se utilizó, a continuación, el método modificado de Landry et al (38), el cual consistió en adicionar, manteniendo las muestras sobre hielo, al precipitado celular 480 µl de una solución tampón de lisis (200 mM Tris-HCl pH 8,0, 70 mM de EDTA, 2 mM de NaCl, 20 mM de metabisulfito de sodio). El tubo Eppendorf con el contenido se agitó varias veces y, luego, se agregaron 120 µl de solución acuosa de sarcosil de sodio.…”

Partitioning and distribution of RAPD variation in a forest tree species, Eucalyptus globulus (Myrtaceae)

“…They are random pieces of DNA amplified from the genome by a PCR-based technique. RAPDs have been used for genome mapping (Carlson eta!., 1991;Klein-Lankhorst eta!., 1991;Kazan eta!., 1993;Sobral & Honeycutt, 1993), to describe phylogenetic relationships (Puterka et a!., 1993) and to identify cultivars (Hu & Quiros, 1991;Landry et a!., 1993;Mailer eta!., 1994;Yu & Nguyen, 1994). Several studies have used RAPDs to assess levels and patterns of variation (Chalmers et a!., 1992;Huff et a!., 1993;Landry eta!., 1993;Puterka eta!., 1993).…”