Evaluation of salt tolerance and resin production in coastal and central valley accessions of Grindelia species (Asteraceae)

The objective of this study was to evaluate the effect of NaCl on growth of Grindelia accessions from coastal and inland habitats. Gas exchange, biomass and resin production, and cation accumulation were studied for two accessions of Grindelia stricta from coastal estuaries, one accession of G. camporum from the northern part of the Central Valley, and one accession of G. camporum from the South Coast Ranges. A greenhouse experiment was conducted in which these accessions were grown for 140 days in sand culture at 5, 125, 250, and 550 mM (~ sea water) NaCl. No major differences in salt tolerance were found between coastal and inland accessions— both species used in this study were found to be miohalophytes. Survival at 550 mM was 10% or lower for three of the four accessions. Gas exchange (net CO 2 uptake and transpiration) was reduced at salinities above 125 mM, and biomass production was significantly affected by salinity. However, we observed moderate growth rates at salinities up to 250 mM. We also noted a trend toward increased surface resin with increased salinity, but more experiments are needed to thoroughly evaluate this response. Grindelia is a potential crop plant which is tolerant to high salinity but our results indicate that biomass production would be significantly reduced if Grindelia were cultivated in saline soils. Se evaluó el efecto del NaCl sobre el crecimiento de cuatro entradas de Grindelia de ambientes costeros Y mediterráneos. Se estudió el intercambio de gases, la producción de biomasa y resina, y la acumulación de cationes para dos entradas de Grindelia stricta provenientes de estuarios costeros, una entrada de G. camporum de la parte norte del Central Valley, y una entrada de G. camporum del South Coast Ranges. Se realizó un ensayo de invernáculo en el que se cultivaron estas entradas por 140 días en un medio de arena con 5, 125, 250, y 550 mM NaCl. No se encontraron diferencias significativas en cuanto a tolerancia a la salinidad entre entradas de la costa y tierra adentro— ambas especies usadas en este estudio podrían ser consideradas miohalófitas. Se observo supervivencia de 10% o menos en tres de las cuatro entradas a 550 mM NaCl. El intercambio de gases (absorción neta de CO 2 y transpiración) se redujo a niveles de salinidad superiores a 125 mM y la salinidad afectó significativamente la producción de biomasa. Sin embargo observamos un crecimiento moderado a salinidades de hasta 250 mM. También observamos una tendencia a a