Glyphosate-Based Herbicides Alter the Reproductive Morphology of Rosa acicularis (Prickly Rose)

Abstract

Glyphosate is a broad-spectrum herbicide that is widely used in many different commercial formulations. Glyphosate-based herbicides (GBH) are used in forestry operations to reduce populations of plants that compete with merchantable conifers. Past research has found that low-dose GBH applications caused male sterility in agriculturally relevant plants, sparking a need to determine the potential impacts of forestry-related GBH applications on understory plants. We investigated the effects of GBH on the reproductive morphology of Rosa acicularis, a highly prevalent understory shrub within British Columbia, Canada, growing on three operational forestry cutblocks treated with 1.782 kg a.i./ha of glyphosate, in the Omineca Region, and also in a controlled experiment. We analyzed floral and pollen morphology from treated plants and compared these with untreated plants in both scenarios. Pollen viability of treated plants was reduced by an average of 66%, and >30% of anthers were non-dehiscent compared to controls across our three field sites and experimental plants. We also found alterations in pollen and petal morphology in flowers from treated sites and glyphosate residues present in floral tissues 2 years after GBH applications. It is important to fully understand how long GBH-induced change will impact forest vegetation, to preserve natural forest biodiversity and reduce anthropogenic influences on boreal forest ecosystems.

The effect of herbicides on morphological features of pollen grains in Prunus serotina Ehrh. in the context of elimination of this invasive species from European forests

“…In general, we stated that residues of previously introduced chemicals had an impact on reducing the size of pollen grains, increasing exine thickness and differentiating their shape. Our results are generally consistent with the research by Golt & Wood 37 on Rosa acicularis pollen in the second year after the application of glyphosate-based herbicides. As in our work, those authors indicated significantly smaller dimensions of pollen grains in R. acicularis as a result of herbicide impact.…”

“…As in our work, those authors indicated significantly smaller dimensions of pollen grains in R. acicularis as a result of herbicide impact. Golt & Wood 37 at herbicide-treated sites observed pollen shapes that were not present among the controls. This difference was found in about 15% of pollen grains.…”

“…Pollen sensitivity to stress caused by pesticides, including herbicides, has already been proven many times. Both in laboratory tests and in field observations, regardless of the type of herbicide or the dose applied, viability of pollen grains decreases as a result of pesticide treatment 37 , 56 – 65 . Such experiments, however, rarely go beyond the analysis of pollen germination, ignoring the influence of the chemicals used on the quality of the pollen grains that remained alive.…”

“…For this reason there is a need for research on the possibility of limiting generative reproduction in the fight against this invasive species. A study by Golt & Wood 37 showed that glyphosate was present in Rosa acicularis tissues up to two years after its application. Moreover, it affected petal and pollen morphology in flowers in the next growing season after its use.…”

Glyphosate Pollution Treatment and Microbial Degradation Alternatives, a Review

“…Glyphosate is known as a chelating agent that binds macro-and micronutrients, essential for several plant processes and the resistance to pathogens, sequestering of such nutrient can compromise plant resistance development, but also affect animals and human health [18]. The global increase in the intensive use of glyphosate-based herbicides causes the release and presence of residues of this chemical in the soil, water, and air, compromising the integrity of the surrounding environments and constituting a threat for the organisms that inhabit these polluted areas [19]. In this sense, different studies have evidenced the presence of glyphosate residues in surface soil, and their transport to the deep soil layers or to bodies of water near agricultural fields [20][21][22].…”