Poplars and Willows responses to flooding stress

RODRÍGUEZ MARÍA EMILIA; LUQUEZ VIRGINIA MARTHA CRISTINA

Poplars and Willows: Cultivation, Applications and Environmental Benefits

Nova Science Publishers

Año: 2015;

Different species of the genus Populus are of great economic importance as major sources of timber, pulp and fiber. Salix species have become very important sources of biomass for bioenergy. Both are characterized by their fast-growing trees, being asexually propagated, and having several species growing in riparian areas prone to flooding.Flooding is a common stress factor in both natural and planted forestry systems, and it challenges plant growth and fitness. Climate change models predict an increase in the frequency of flooding events globally due to altered precipitation patterns which will cause extreme rainfall events. This would make flooding stress a major environmental threat for plants.Flooding tolerance is related to the ability of the plant to develop adaptive structures to cope with the lack of oxygen caused by the excess of water in the soil. The development of aerenchyma, hypertrophied lenticels and adventitious roots enables the plant to maintain a greater root biomass and foliar area during the episode of stress. This facilitates the possibility of having better stomatal opening and photosynthetic capacity, therefore maintaining a greater availability of photoassimilates. These adaptive features, plus the antioxidant capacity to remove toxic species generated during the flooding period and during the post-flooding reaeration, would ensure the rapid restoration for optimum plant growth after the stress episode.A better understanding of the responses to flooding in poplar and willows could serve as a basis for classical breeding programs or biotechnological developments designed to increase flooding tolerance. The generation of information can also be helpful for the management of wetland ecosystems. This review summarizes the research on morphological, anatomical, physiological and molecular responses to flooding of species belonging to the Salicaceae family.