Desempenho fotossintético, peroxidação lipídica e aspectos morfológicos de papuã exposto a diferentes condições hídricas do solo

Abstract

This paper aimed to elucidate the behavior of Urochloa plantaginea biotype with differential physiological characteristics, which allows a better growth and development in a flooded environment. A completely randomized experimental design was used 2x3, being the factors: populations of Urochloa plantaginea (lowlands and highlands) and soil water conditions (50% and 100% of soil water retention capacity (CRA); water depth 5 cm). Responses related to photosynthetic parameters and lipid peroxidation were verified 24h and 192h after the onset of water conditions. Morphology-relatedvariables were measured at the end of the plant cycle. The lowland biotype compared to the highland biotype showed superior morphophysiological characteristics under soil flooding. It can be emphasized, higher water use efficiency (about 30%), higher plant height, lower aerial part lipid peroxidation and higher aerial part dry matter increment. In addition, the lowland biotype was shown not to vary photosynthetic parameters A, Gs, Ci, E, USA and A / Ci when exposed to the water depth 5 cm, compared with the 100%CRA condition. Both populations survived and ended their cycle producing seeds. Thus, apossible adaptive process of the population to the flooded environment is evidenced.