Guidelines were published in issue no. 200 of the Technical Communication series and are the result of research developed in partnership with the University of Warwick A protocol to extract DNA from samples of peanut shells (Arachis hypogaea, L.) and the hulls of other Arachis species is one of the results of the activities developed by Fábio de Oliveira Freitas, a researcher from Embrapa Genetic Resources and Biotechnology, at the University of Warwick (United Kingdom), where he has been for the last 16 months as a visiting researcher. The guidelines are in Comunicado Técnico 200, issue number 200 of the Embrapa series "Technical Communication", and are fruit of research whose primary focus was studies on peanut evolution and characterization. The researcher's initial idea was to analyze archaeological samples found in three locations in Brazil (Unaí - MG, Varzelândia - MG, and Campos - RJ), conceded by the Instituto de Arqueologia Brasileira (or IAB, the Brazilian Institute of Archaeology), and two samples from Argentina (Salta and Catamarca) and two from Peru (Bermejo), conceded by Argentina's IBONE. The age of the oldest samples, from Peru, was estimated with the use of the AMS (Accelerator Mass Spectrometry) dating technique to be 2,500 years old. After extracting DNA from the shells using a protocol especially developed for that purpose, it was possible to compare the samples as well as the microorganisms, contaminants and soils that had come with the peanuts. "One of the questions that are expected to be answered by the study is whether Peru would have been as a second center of domesticaton of the species, since the only peanut origin that has already been proven by science so far would be the region that ranges from the North of Argentina to Southern Bolivia, 5,000 years back", asserts the researcher Fábio Freitas. The study also analyzed "modern” samples of 12 peanut varieties harvested in the Xingu Indigenous Park, in the Brazilian state of Mato Grosso. Previous morphology and genetics studies, lead in partnership with the researchers Jose Francisco Montenegro Valls and Márcio de Carvalho Moretzsohn, both from Embrapa Genetic Resources and Biotechnology, discovered that the samples from the region are very different from domesticated peanut samples that are easily found in other regions of Brazil. According to Fábio, there are indications that the peanuts found in Xingu are from another lineage and have a distinct origin compared to peanuts found in the rest of the country. “We know that Xingu peanuts have been used a lot since remote times by the Kayabi indigenous people, whose ethnic group prehistorically migrated from the Western extreme of Brazil (Acre) and from Bolivia to where they currently live. Since that area is close to Peru, we believe that the origin of that peanut can have a higher level of kinship with part of the archaeological samples originating from Peru than with other archaeological samples found further South”, the researcher says. Parallelly, the behavior of the Xingu peanut samples was analyzed as they were sown in "terra preta" (Amazonian dark earth) and managed and harvested by the natives, and samples were planted at Embrapa Rice and Beans (Santo Antônio de Goiás, in the Brazilian midwestern state of Goiás), and thus submitted to distinct soil and climate conditions. In this case, the idea was to identify the plant's genetic responses when it is submitted to distinct environments, through the identification and comparison of methyl regions of the samples' genetic material. The next research stage will be analyzing the data using biocomputing tools and compare them with what has already been described in the world's scientific literature, so as to confirm or disprove the hypotheses that were formed during the analyses. Researcher participated in studies on the evolution of maize and the search for native cotton in Bangladesh During the work developed in partnership with the University of Warwick, with Dr. Robin Allaby as advisor, the researcher Fábio Freitas was invited to participate in two other studies. The first one, developed by the Smithsonian Institution (USA), aimed at studying the genetic response of different samples of maize (Zea mays) harvested in the US, Mexico and the Caribbean, and planted for eight generations in water stress conditions. As Fábio joined such research on maize, South American maize samples from Embrapa Maize and Sorghum's gene bank that had been stored at the University of Manchester (United Kingdom) were included. That case also comprised archaeological samples, from different geographical regions (Mexico, Peru, Argentina, Chile and Brazil), with ages that range from 5000 years (Mexico - maize's place of origin), to some with 1000 years (Peru and Chile) and 650 years of age (Brazil). In that research, the focus was on the evolutionary study of the species. Another important piece of research conducted at the University of Warwick began after the Embrapa researcher met a community leader from Bangladesh, an Asian country that borders India and that, before the arrival of English colonists in the 18th century, produced a traditional cotton variety (Gossypim arboreum var Neglecta) whose fiber was used to manufacture noble fabrics and was traded in several parts of the old world. “It was a very prosperous region, with large plantations of this traditional cotton, which was manually weaved by local artisans”, Fábio reports. British rule brought power looms, and the local cotton, whose fiber was considered short for industrial standards, did not adapt to the new machinery. Little by little, the variety ceased to be sown to make way for long-fiber cotton (G. hirsutum), and, with time, it was lost. The colonial period lasted until 1947, and after the country's independence and the withdrawal of the British industry, cotton production declined, causing major economic and social impact in the region. More recently, the population has shown interest in rescuing traditional cotton and artisanal fabric manufacturing practices. “They made a large effort of collecting cotton samples with smallholders in the region, but they could not identify which of them was the cotton variety used before colonization, and they asked Warwick researchers for help”, explains Fábio. The variety was found with the support of Kew Royal Botanic Gardens's herbarium, which has exsicatas of this variety that had been harvested by the British in the colonial period. Once the samples (aged between 100 and 200 years) were obtained, the plant DNA was extracted and compared with the samples Bangladeshi smallholders harvested, which enabled the identification of the variety that was sought, the one traditionally used to produce muslin. Bangladesh is today a poor country, whose population mostly lives in rural areas and is dedicated to agriculture. However, the country is one of the largest producers of jute fiber, used to make fabric and ropes, and thus it has an important textile industry. “We hope that the rescue of muslin cotton increments the existing textile industry and helps to improve the country's economy”, Fábio states. As the species has been identified, Bangladesh now has the challenge of collecting more muslin varieties and starting the process of seed multiplication and distribution to farmers in the country, in a process of cultural rescue. Translation: Mariana de Lima Medeiros.