Growth responses of Lotus tenuis to flooding intensity

MANZUR ME, STRIKER GG, GRIMOLDI AA, INSAUSTI P

Chascomús

Taller; IV Taller interdisciplinario sobre aspectos genéticos, moleculares y fisioecológicos de Lotus spp. y sus simbiontes; 2008

INTECH-CONICET

Flooding is an essential component of the disturbance regime affecting the vegetation dynamics of the Flooding Pampa Grasslands, with variable intensity among years. Lotus tenuis is an exotic species introduced in these grasslands, which presence is highly desirable because their forage quality. The aim of this work was to examine the effects of different flooding levels on the growth of Lotus tenuis during a 30 days period, and their relation with the aerenchyma formation and functionality under intense flooding leading to plant submersion. Four treatments were applied by 30 days following a completely randomized design with six replicates: control: watered daily to field capacity, waterlogged: soil saturated with water but without water above soil surface, flooded: water maintained at 6 cm above soil surface, and submersion: plants were completely underwater without emerging leaves. Plants were established in grassland soil pots of 4L. At the end of experiment tissue porosity (shoot and root), shoot number and plant biomass were measured. Results showed that constitutive shoot porosity was higher with amounts of 26% for most treatments, and was increased only by flooding until 40% (p