Evaluation of the Impact of Genetically Modified Cotton After 20 Years of Cultivation in Mexico

Abstract

For more than 20 years cotton has been the most widely sown genetically modified (GM) crop in Mexico. Its cultivation has fulfilled all requirements and has gone through the different regulatory stages. During the last 20 years, both research-institutions and biotech-companies have generated scientific and technical information regarding GM cotton cultivation in Mexico. In this work, we collected data in order to analyze the environmental and agronomic effects of the use of GM cotton in Mexico. In 1996, the introduction of Bt cotton made it possible to reactivate this crop, which in previous years was greatly reduced due to pest problems, production costs and environmental concerns. Bt cotton is a widely accepted tool for cotton producers and has proven to be efficient for the control of lepidopteran pests. The economic benefits of its use are variable, and depend on factors such as the international cotton-prices and other costs associated with its inputs. So far, the management strategies used to prevent development of insect resistance to GM cotton has been successful, and there are no reports of insect resistance development to Bt cotton in Mexico. In addition, no effects have been observed on non-target organisms. For herbicide tolerant cotton, the prevention of herbicide resistance has also been successful since unlike other countries, the onset of resistance weeds is still slow, apparently due to cultural practices and rotation of different herbicides. Environmental benefits have been achieved with a reduction in chemical insecticide applications and the subsequent decrease in primary pest populations, so that the inclusion of other technologies—e.g., use of non-Bt cotton- can be explored. Nevertheless, control measures need to be implemented during transport of the bolls and fiber to prevent dispersal of volunteer plants and subsequent gene flow to wild relatives distributed outside the GM cotton growing areas. It is still necessary to implement national research programs, so that biotechnology and plant breeding advances can be used in the development of cotton varieties adapted to the Mexican particular environmental conditions and to control insect pests of regional importance.

The environmental price of fast fashion

“…In the environment, agrochemicals leach into the soil, where they cause a decrease in soil biodiversity and fertility, interrupt biological processes and destroy microorganisms, plants and insects 55 . Despite the substantial human and environmental impacts of pesticide application, non-target species have become increasingly problematic 56 (such as the whitefly Bemisia tabaci), leading to increased insecticide application. While the introduction of genetically modified cotton led to a reduction in external pesticide application, reduction appears to have been a temporary phenomenon in major cotton-producing countries such as India, Brazil, China and the USA 52 .…”

Detección del promotor 35S mediante PCR tiempo-real: indicador de transgenicidad en alimentos y Gossypium sp.

“…En el caso del algodón, la tasa de polinización cruzada es baja (menor del 10 %), sin embargo, este valor varía dependiendo de las condiciones climáticas y ecológicas propias del lugar. El riesgo de flujo de genes en algodón ocurre principalmente por dispersión de semillas transportadas a través del agua y el viento (Rocha-Munive et al, 2018). Se asume y espera que en las áreas de producción autorizadas haya un estricto control de las normas de bioseguridad durante la siembra, la cosecha y el transporte de las semillas de algodón GM, desde las compañías que las producen en el extranjero hasta los campos de cultivo, y de ahí hasta el lugar donde se procesan las motas que contienen las semillas GM cosechadas; sin embargo, es probable que después de la cosecha las medidas de bioseguridad se flexibilicen, lo que aumenta las posibilidades de propagación de estas semillas al ambiente (Rocha-Munive et al, 2018).…”

“…El riesgo de flujo de genes en algodón ocurre principalmente por dispersión de semillas transportadas a través del agua y el viento (Rocha-Munive et al, 2018). Se asume y espera que en las áreas de producción autorizadas haya un estricto control de las normas de bioseguridad durante la siembra, la cosecha y el transporte de las semillas de algodón GM, desde las compañías que las producen en el extranjero hasta los campos de cultivo, y de ahí hasta el lugar donde se procesan las motas que contienen las semillas GM cosechadas; sin embargo, es probable que después de la cosecha las medidas de bioseguridad se flexibilicen, lo que aumenta las posibilidades de propagación de estas semillas al ambiente (Rocha-Munive et al, 2018). Los resultados obtenidos en este estudio sugieren que hubo un movimiento de semillas GM fuera de las áreas autorizadas para su siembra, las cuales representan un posible evento de contaminación de las poblaciones silvestres de algodón con secuencias derivadas de OGM.…”

Gossypium hirsutum Salt Tolerance Is Enhanced by Overexpression of G. arboreum JAZ1

“…Cotton, an economic crop that is important to many national economies, is relatively salt-tolerant (Rocha-Munive et al, 2018). However, it will still be unable to meet the challenge of increasing salinization; therefore, breeding new cotton varieties with greater salinity tolerance is a high priority in plant biotechnology programs (Shao et al, 2005).…”