Goosegrass: Morphophysiological Characterization Under Water Excess Conditions

Capim Pé-de-Galinha: Caracterização Morfofisiológica em Condições de Excesso Hídrico

ABSTRACT:

Eleusine indica (L.) Gaertn. (goosegrass) is a grass species that has global prominence as a weed in areas typical of the soybean crop. However, its dispersion in recent years has been reported expressively for areas of poorly drained soil, in which irrigated rice is cultivated (lowlands). Little is known on its behavior and biology in this different ecosystem. This study aimed to evaluate if Eleusine indica can survive and withstand flooding. The experimental design was a completely randomized (two-way), in which two E. indica biotypes, one from the uplands (without flooding) and the other from the lowlands (with flooding), were submitted to three soil water conditions: 50 and 100% water retention capacity and soil under water depth. Photosynthetic and gas exchange parameters (photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration, water use efficiency, and assimilation rate by Rubisco) were determined. Morphological diversity of biotypes was evaluated through descriptors. The existence of typical lowland biotype could not be characterized. However, both biotypes were able to survive, develop, and generate seeds in a flooded environment in the irrigated rice system.

Keywords:
adaptation; Eleusine indica; Oryza sativa; invasiveness.