Water relations and gaseous changes in the precocious selection of Eucalyptus clones for environments with varying soil water availability.

Abstract

This study had as objective to evaluate the answers of the water relations and of the gaseous changes in four eucalyptus clones (97, 11, 75, 84), established in plastic vases, in way to subsidize the precocious selection of this genetic materials for the establishment in areas with varying soil water availability. Plants grew in vases, with water content at field capacity, during a period of 150 days, after that until the end of the experiment that lasted about 250 day, soil water regime was diversed. Water deficit regimes promoted reduction in the photosynthesis values, stomatal conductance, transpiration, efficiency in the use of the water and leaf water potential of the clones in the end of the experiment. Clone 11 presented the smallest photosynthesis value, stomatal conductance and transpiration when submitted to the water deficiency. The clones 97 and 75 presented the largest photosynthesis values and leaf water potential, in plants submitted to the alternated water regime of irrigation and deficit, showing to be the most suitable for planting in areas with high soil water deficiency.