Cell wall composition and nutritional quality through seasons of the saltgrass Distichlis laxiflora growing in halophytic and mesophytic meadows

The genus Distichlis comprises halophytic perennial C4 grasses which grow in very extreme conditions. It is distributed throughout almost the entire American continent. Despite these interesting characteristics, studies on these plants are relatively scarce, and their ecological and productive value deserves to be further explored. In this work, nutritional aspects, and composition of the cell walls of the aerial part (leaves and shoots) of D. laxiflora Hack were studied. Their changes over four samplings in different seasons, in two nearby sites: a halophytic meadow (H), and a mesophytic meadow (M), were analyzed. Photosynthetic efficiency and K/Na ratio were determined as stress indicators. Plants of sites H and M have similar cell wall content except for spring when plants from site H show lower values. Also, the spring samples present a markedly higher in vitro digestibility for site H. In agreement, samples from site H contain lower amounts of glucuronoarabinoxylans and β-glucans. The protein content is lower in site H, except for spring, and with a maximum in summer for site M.This work shows some changes in the cell walls of D. laxiflora in response to salinity, and these changes influence the digestibility of this material. Spring, coinciding with the regrowth cycle of this plant and with the worst stress indicators, is the season when plants of the halophytic site show the highest nutritional quality for grazing cattle.

Fil: Fernández, Paula Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina

Fil: Vago, María Elena. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Ciencias Agrarias; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos. Cátedra de Química de Biomoléculas; Argentina

Fil: Ezquiaga, Juan Pedro. Chacra Experimental Integrada de Chascomús; Argentina

Fil: Maiale, Santiago Javier. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; Argentina

Fil: Rodriguez, Andres Alberto. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; Argentina

Fil: Acosta, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

Fil: Gortari, Maximiliano. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; Argentina

Fil: Ruiz, Oscar Adolfo. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; Argentina

Fil: Ciancia, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina