Indução de poliploides em leguminosas forrageiras: uma revisão dos últimos 25 anos

Abstract

The induction of polyploidy represents a promising and beneficial strategy applied to the genetic improvement of forage species in the Fabaceae family. This biotechnological technique, by utilizing antimitotic agents such as colchicine, oryzalin, and trifluralin, demonstrates high applicability in doubling plant genetic material. As a result, there is an observed increase in productivity, stress tolerance, and the nutritional value of legumes, given the advantageous use of these plants as a nutrient source for herbivorous fauna. Over the last 25 years, the period on which this study is based, colchicine has emerged as the most effective agent for doubling Fabaceae species through distinct and promising applications observed in the genera Arachis, Cyamopsis, Glycyrrhiza, Medicago, Stylosanthes, Trifolium, Trigonella, and Vicia, appearing in approximately nine studies found in the literature. The confirmation of induced polyploidy is performed with the aid of tools that generate results through genomic analysis, using equipment such as flow cytometers and, on rare occasions, spectrophotometers. The effects occurring after duplication include impacts on the morphology, physiology, and anatomy of polyploid plants, as well as genomic implications resulting from polyploidization. Results demonstrate morphological alterations such as the 'gigas effect,' leaf anatomical changes regarding stomatal size, increased biomass, better adaptability to adverse conditions, and a greater potential for the nutritional improvement of plants. However, gaps remain in the in- depth knowledge regarding genomic implications and responses to stressors in forage legumes, which present great potential for future research. In this sense, the induction of polyploidy is a biotechnological tool with wide applicability for the improvement of forage species in Fabaceae, capable of enabling greater productivity and resilience aligned with current sustainability demands and global ecological challenges.