Search

Currently, genetically modified (GM) crops are an important part of world agriculture, offering numerous benefits to farmers. This study investigates the dynamics of the cultivated area with GM crops, especially with genetically modified (GM) soybean, for the period 2014-2018, by country and by transgenic trait, using ISAAA and FAOSTAT databases. In the studied period, the top 5 GM crops countries were USA, Brazil, Argentina, Canada and India which totalled 166.1 million hectares or 89.5% of the global area. Regarding GM soybean, the top 5 countries were USA, Brazil, Argentina, Paraguay and Canada which cultivated 89.9 million hectares or 96.8% of the global area with this crop. The linear regression and the Pearson correlation coefficient have pointed out a general increasing trend for both cultivated areas. The USA and Brazil occupied the leading position in world with 32.93 and 32.55 million hectares of GM soybean, respectively. Herbicide tolerance (HT) has been consistently the dominant transgenic trait for GM soybean in USA, Argentina, Paraguay and Canada. In Brazil, the cultivated areas with stacked HT/IR traits have been larger than the areas cultivated with a single HT trait, in the last 3 years. As a conclusion, the global area of GM soybean will continue to increase due to its important economic role in the agriculture development and environmental benefits. [ABSTRACT FROM AUTHOR]

Ipomoea species are troublesome weeds in crop systems through Brazil. Drought stress typically reduces glyphosate efficacy by reducing the foliar uptake of herbicides and their translocation. Using both glyphosate tolerant (GT) and sensitive (GS) plants from Ipomoea grandifolia, I. indivisa and I. purpurea species, this research aimed to (a) correlate amounts of epicuticular wax and tolerance to glyphosate in plants and (b) determine the effect of drought stress (DStress) on changes in the quantity and chemical composition of plant epicuticular waxes. The dose that causes 50% inhibition of growth (GR50) of the biotypes varied between 62 and 1208 (I. grandifolia), 159 and 913 (I. indivisa), and 389 and 1925 g a.e. ha−1 of glyphosate (I. purpurea). There was low inverse correlation (–0.46) between the amount of epicuticular wax and the sensitivity to glyphosate. GT biotypes of the species presented greater plastic capacities than GS biotypes for increasing the amount of epicuticular wax under DStress. The three Ipomoea species exhibited different chemical profiles of waxes supported by IR spectra, which allows for their differentiation. For I. grandifolia and I. purpurea, there was an increase in the polar components in the state without DStress, while for the species I. indivisa, no differences in infrared spectra were detected between the two water conditions. [ABSTRACT FROM AUTHOR]

Soybean is a major source of vegetable protein and oil in the world. Worldwide demand continues to be high and production has more than doubled in the past 20 years to a total of 264.2 million metric tons in 2011 (National Agricultural Statistics Service 2012). Much of this increase has been due to increased planting in Argentina and Brazil. But, there have been genetic gains as well. We now have powerful genetic tools and these will be useful in gene discovery and in developing selectable markers for those genes. But for traits that are quantitative and multigenic, marker assisted selection may not be practical. We are facing unprecedented changes in our climate which will require resourceful use of the new genetic tools along with standard plant breeding methodology to maintain soybean productivity and quality. [ABSTRACT FROM AUTHOR]