Mass propagation of tobala mezcal maguey (Agave potatorum Zucc.) in a temporary immersion system compared with a solid medium

Objective: To assess a temporary immersion system for the in vitro propagation of Agave potatorum Zucc., compared with the traditional micropropagation technique that uses a solid medium. Design/Methodology/Approach: The effect of treatments in a solid medium with low and high doses of the BA (Benzylaminopurine) growth regulator (0.5 mg L-1 and 2 mg L-1) on the number of sprouts per explant was assessed in a first phase. Since the best treatment was 2 mg L-1 of BA, three forms of propagation were considered: solid medium, liquid medium in a paper bridge, and liquid medium in a temporary immersion system. Results: From the initial test, an average of 6.6 shoots per explant were obtained with 2 mg L-1 of BA. Regarding the different systems, the solid medium, the paper bridge, and the temporary immersion system recorded 6.4, 7.2, and 14.4 shoots per explant, respectively. Findings/Conclusions: Mass sprout production is higher in the temporary immersion system, as a consequence of the use of a liquid medium that increases the absorption of nutrients and regulators, combined with the injection of air with oxygen that can accelerate cellular processes

Extinction risk of Mesoamerican crop wild relatives

Ensuring food security is one of the world's most critical issues as agricultural systems are already being impacted by global change. Crop wild relatives (CWR)—wild plants related to crops—possess genetic variability that can help adapt agriculture to a changing environment and sustainably increase crop yields to meet the food security challenge. Here we report the results of an extinction risk assessment of 224 wild relatives of some of the world's most important crops (i.e. chilli pepper, maize, common bean, avocado, cotton, potato, squash, vanilla and husk tomato) in Mesoamerica—an area of global significance as a centre of crop origin, domestication and of high CWR diversity. We show that 35% of the selected CWR taxa are threatened with extinction according to The International Union for Conservation of Nature (IUCN) Red List demonstrates that these valuable genetic resources are under high anthropogenic threat. The dominant threat processes are land use change for agriculture and farming, invasive and other problematic species (e.g. pests, genetically modified organisms) and use of biological resources, including overcollection and logging. The most significant drivers of extinction relate to smallholder agriculture—given its high incidence and ongoing shifts from traditional agriculture to modern practices (e.g. use of herbicides)—smallholder ranching and housing and urban development and introduced genetic material. There is an urgent need to increase knowledge and research around different aspects of CWR. Policies that support in situ and ex situ conservation of CWR and promote sustainable agriculture are pivotal to secure these resources for the benefit of current and future generations

Detecting (trans)gene flow to landraces in centers of crop origin: lessons from the case of maize in Mexico

There is much discussion of the probability of transgene flow from transgenic crop varieties to landraces and wild relatives in centers of origin or diversity, and its genetic, ecological, and social consequences. Without costly research on the variables determining gene flow, research on transgene frequencies in landrace (or wild relative) populations can be valuable for understanding transgene flow and its effects. Minimal research requirements include (1) understanding how farmer practices and seed systems affect landrace populations, (2) sampling to optimize Ne/n (effective /census population size), (3) minimizing variance at all levels sampled, and (4) using Ne to calculate binomial probabilities for transgene frequencies. A key case is maize in Mexico. Two peer-reviewed papers, based on landrace samples from the Sierra Juárez region of Oaxaca, Mexico, reached seemingly conflicting conclusions: transgenes are present (Quist and Chapela, 2001, Nature 414: 541–543; 2002, Nature 416: 602) or “detectable transgenes” are absent (Ortiz-García et al., 2005, Proc. Natl. Acad. Sci. USA 102: 12338–12343 and 18242). We analyzed these papers using information on Oaxacan maize seed systems and estimates of Ne. We conclude that if Quist and Chapela’s results showing presence are accepted, Ortiz-García et al.’s conclusions of no evidence of transgenes at detectable levels or for their introgression into maize landraces in the Sierra de Juárez of Oaxaca are not scientifically justified. This is because their samples are not representative, and their statistical analysis is inconclusive due to using n instead of Ne. Using estimates of Ne based on Ortiz-García et al.’s n, we estimate that transgenes could be present in maize landraces in the Sierra Juárez region at frequencies of ~1–4%, and are more likely to be present in the 90% of Oaxacan landrace area that is not mountainous. Thus, we have no scientific evidence of maize transgene presence or absence in recent years in Mexico, Oaxaca State, or the Sierra Juárez region

Traditional Foods, Globalization, Migration, and Public and Planetary Health: The Case of Tejate, a Maize and Cacao Beverage in Oaxacalifornia

We are in the midst of an unprecedented public and planetary health crisis. A major driver of this crisis is the current nutrition transition—a product of globalization and powerful multinational food corporations promoting industrial agriculture and the consumption of environmentally destructive and unhealthy ultra-processed and other foods. This has led to unhealthy food environments and a pandemic of diet-related noncommunicable diseases, as well as negative impacts on the biophysical environment, biodiversity, climate, and economic equity. Among migrants from the global south to the global north, this nutrition transition is often visible as dietary acculturation. Yet some communities are defying the transition through selective resistance to globalization by recreating their traditional foods in their new home, and seeking crop species and varieties customarily used in their preparation. These communities include Zapotec migrants from the Central Valleys of the southern Mexican state of Oaxaca living in greater Los Angeles, California. Focusing on the traditional and culturally emblematic beverage tejate, we review data from our research and the literature to outline key questions about the role of traditional foods in addressing the public and planetary health crisis. We conclude that to answer these questions, a transnational collaborative research partnership between community members and scientists is needed. This could reorient public and planetary health work to be more equitable, participatory, and effective by supporting a positive role for traditional foods and minimizing their harms

Actitud hacia el etiquetado en productos genéticamente modificados en la población urbana de México

The Objective was to study the attitudes of the Mexican urban population on the labeling of transgenic products. Materials and methods a cross-sectional study was conducted in the Mexican urban population with a probabilistic sample of 14,720 people between the ages of 18 and 65 years. The attitudes towards labeling of genetically modified products (GM) were studied and analyzed using a 4-item binary instrument. As results we found that 63.25% of the surveyed people has a habit of reading the labels of the products they consume, 93.69% considered that it is required to report the content of the product in the advertisement, 93.59% considered that GM foods should display the information on the label and 93.23% considered that the Mexican government should legislate to regulate the labeling of products. As conclusions more than half of the respondents read the information on the labels of the products they consume. In addition, they agree that products made with GM products should show in their labeling the corresponding information so that the citizen can choose whether to consume them or not.O objetivo foi estudar as atitudes de população urbana mexicana sobre a rotulagem de produtos geneticamente modificados. Materiais e Métodos Um estudo transversal foi realizado na população urbana mexicano com uma amostra de probabilidade de 14 mil 720 pessoas entre os 18 e os 65 anos. Eles foram estudadas e analisadas atitudes em relação à rotulagem de produtos (GM) com uma ferramenta 4 itens binários. Os resultados revelaram que 63,25% da amostra tem o hábito de ler os rótulos dos produtos que consomem; 93,69% consideraram que a publicidade deve informar o consumidor final sobre o conteúdo; 93.59% sugeriu que os alimentos geneticamente modificados deve exibir as informações no rótulo e 93,23% sentiram que o governo mexicano deve legislar para regular a rotulagem dos produtos. Em conclusão, mais da metade dos entrevistados ler a informação que vem nos rótulos dos produtos que consomem. Além disso, ele concordou que os produtos feitos com plantas e animais geneticamente modificados em seus rótulos mostram a informação relevante para que os cidadãos podem escolher se deseja consumir ou não.Nuestro objetivo fue estudiar las actitudes de la población urbana mexicana con respecto al etiquetado de los productos transgénicos mediante el análisis transversal de una muestra probabilística de 14 mil 720 personas entre 18 y 65 años de edad. Sus actitudes hacia el etiquetado de productos (GM) fueron estudiadas y analizadas con un instrumento de 4 ítems binarios. Entre los resultados se encontró que 63.25 % de la muestra tiene el hábito de leer las etiquetas de los productos que consume; 93.69 % consideró que la publicidad debe informar al consumidor final sobre el contenido; 93.59 % sugirió que los alimentos GM deben mostrar la información en la etiqueta y 93.23 % consideró que el gobierno mexicano debe legislar para regular el etiquetado de los productos. En conclusión, más de la mitad de los encuestados leyó la información que viene en las etiquetas de los productos que consume. Además, estuvo de acuerdo en que los productos elaborados con plantas y animales genéticamente modificados muestren en su etiquetado la información correspondiente para que el ciudadano pueda elegir si los consume o no

Testing assumptions underlying economic research on transgenic food crops for Third World farmers: Evidence from Cuba, Guatemala and Mexico

Transgenic crop varieties (TGVs) are being promoted as essential for improving small-scale Third World (SSTW) agriculture. Most economic research on this topic makes critical, untested assumptions, including that farmers will choose TGVs over other varieties because TGVs are economically optimal and because farmers are risk neutral profit maximizers. We tested these assumptions using data from a survey of 334 farmers in 6 communities in Cuba, Guatemala and Mexico in which farmers ranked 4 real and hypothetical maize varieties for eating and sowing. Our results did not support these assumptions. Most farmers preferred farmer varieties for sowing and especially for eating, avoiding TGVs, a preference associated with being risk averse and with non-monetary preferences. Farmers more integrated into modern agriculture were more likely to choose TGVs. These results suggest that farmers most in need of support and most important for conserving genetic diversity are least favorable toward TGVs, and that alternative ways of improving SSTW agriculture should receive more attention.Transgenic crops Genetic engineering Maize Corn Third World farmers Economic assumptions Risk Cuba Guatemala Mexico