Random Amplified Polymorphic Dna Of Screwworm Fly Populations (diptera: Calliphoridae) From Southeastern Brazil And Northern Argentina

The screwworm fly Cochliomyia hominivorax is one of the most important agents of traumatic myiasis throughout neotropical regions. In this work, we optimized the technique of RAPD-PCR for these species and used it to study the genetic variability among seven populations (six from southeastern Brazil and one from northern Argentina) of C. hominivorax. RAPD fingerprints showed high variation for 12 primers used, revealing 209 presumptive loci of which 198 were polymorphic. Marker pattern relationships for these different populations were used to determine genetic relatedness, as well as to examine potential patterns of gene flow. Our interpretation of Lynch and Milligan's analogue of Wright's F((ST)) was that C. hominivorax populations are genetically subdivided (F'((ST)) for pooled samples = 0.122). Our data suggested that the subdivision detected in C. hominivorax populations by RAPD can be explained by the interplay of random factors affecting allele frequency changes. 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Podridão por Fusicoccum em mangas submetidas a baixas doses de radiação gama Fusicoccum rot in mangoes submitted to low doses of gamma irradiation

O objetivo deste trabalho foi avaliar o efeito da radiação gama em doses baixas no controle pós-colheita da podridão por Fusicoccum em manga 'Tommy Atkins', bem como avaliar o efeito desse método sobre as características físico-químicas da fruta. Frutos aparentemente livres de doenças no estádio de maturação 1,5 foram inoculados com 10 &#956;L de suspensão de Fusicoccum parvum a 10(6) conídios mL-1. Após a inoculação, os frutos foram irradiados com as doses de 0,24, 0,35 e 0,45 kGy e armazenados a 13ºC, durante 15 dias, seguidos de mais seis dias em temperatura ambiente, a 25ºC. A dose mais alta de radiação gama foi eficiente em retardar o desenvolvimento da doença em razão do atraso causado na maturação das frutas. Não houve efeito significativo da radiação sobre as características físico-químicas das frutas. Os frutos mantiveram características ideais para comercialização, mesmo após o armazenamento refrigerado, com a presença de filme plástico, por 15 dias.<br>This study aimed to evaluate the effect of gamma irradiation in low doses on the postharvest control of 'Tommy Atkins' mango rot caused by Fusicoccum, and to evaluate the effect of this method on the physicochemical characteristics of the fruit. Fruits in ripening stage 1,5 and apparently free of disease were inoculated with 10 &#956;L of a Fusicoccum parvum suspension at 10(6) conidia mL-1. They were gamma irradiated with the doses 0.24, 0.35 and 0.45 kGy, and stored under 13°C for 15 days, followed by a further six days at room temperature, 25°C. The higher dose of gamma radiation was effective in delaying the disease development due to fruit delayed maturation. No significant effect of radiation was observed on fruit physicochemical characteristics. Fruit maintained ideal commercialization features even after cold storage, in the presence of plastic film, for 15 days