Análise de crescimento e partição de assimilados em plantas de trigo submetidas a períodos de alagamento e qualidade fisiológica de sementes

Abstract

Waterlogging stress adversely modifies physiology, plant growth and plants development, limiting therefore, the wheat areas productivity. The Triticum aestivum L. plants responses subjected to flooding are not completely understood. A better understanding of growth mechanism under oxygen depletion conditions may contribute to suitable crops management and detect possible problems in the culture development. To assay the flooding susceptibility along the culture ontogeny, the aims were analyze the wheat plants growth and assimilated partition into different flooding periods as well evaluate the seed vigor expression produced by plants subject to waterlogging in pre and post-anthesis. The wheat plants were subjected to flooding for three, four and five days during two stages of the crop cycle: the stem elongation and filling of the seed. To quantify the negative stress under hypoxic conditions in vegetative or reproductive stages, were used a four days waterlogged time to determine which phenological stage were more sensitive to flooding. Flooding negatively affects the wheat plants growth, as verified by the reduction of total dry matter and dry matter production rate. The dry matter partition does not show pronounced variations among the wheat plant structures subjected to flooding in vegetative and seed filling stage. The wheat plants waterlogged causes reduction in seed vigor. Flooding stress in vegetative and reproductive stage of wheat plants cause yield reduction by decreasing the thousand grains weight.