The development of sulfonylurea herbicide-resistant birdsfoot trefoil (Lotus corniculatus) plants from in vitro selection

An In Vitro Procedure for Phenotypic Screening of Growth Parameters and Symbiotic Performances in Lotus corniculatus Cultivars Maintained in Different Nutritional Conditions

The establishment of legumes crops with phenotypic traits that favour their persistence and competitiveness in mixed swards is a pressing task in sustainable agriculture. However, to fully exploit the potential benefits of introducing pasture-based grass-legume systems, an increased scientific knowledge of legume agronomy for screening of favourable traits is needed. We exploited a short-cut phenotypic screening as a preliminary step to characterize the growth capacity of three different Lotus corniculatus cvs cultivated in different nutritional conditions as well as the evaluation of their nodulation capacities. This experimental scheme, developed for legume species amenable to grow on agar plates conditions, may represent a very preliminary step to achieve phenotypic discrimination on different cultivars.

An introduction to ALS-inhibiting herbicides

Herbicides that inhibit acetolactate synthase (ALS), the enzyme common to the biosynthesis of the branch-chain amino acids (valine, leucine, and isoleucine), affect many species of higher plants as well as bacteria, fungi, yeasts, and algae. The novel mechanism of action attributed to ALS inhibitors, their effect on the reproduction of some plant species, their potency at extremely low concentrations, and the rapid evolution of resistance to these herbicides in some plants and microorganisms are characteristics that set ALS inhibitors apart from their predecessors. This class of chemicals affects seedling growth. Older plants exhibit varied signs of malformation, stunting, and reduced seed production. These herbicides are so potent that they can affect plants at levels that are undetectable by any standard chemical protocol. Weeds quickly become resistant to ALS inhibitors, presumably because these herbicides have a single mode of action and because many have long residual activity. Concern now is directed towards developing the technology to detect very low concentrations of ALS inhibitors in the environment and their indirect effects on plant and animal health.