Theme 06: Abiotic Constraints to Forage Production from Grasslands
Description
Rhodes grass (Chloris gayana Kunth), is widely cultivated in the semiarid tropics and favored for its salt tolerance. Nevertheless, productivity decreases significantly under saline conditions, especially in tetraploid cultivars. The purpose of this work was to explore, in tetraploid cultivar Boma, the physiological causes for the observed salt-associated growth reduction. The effects of high salinity (200 mM NaCl) on the components of relative growth rate were analyzed in greenhouse experiments. An early reduction in leaf area expansion was observed, which later resulted in decreased dry matter accumulation. Plant leafiness was reduced by effects both on dry matter allocation to photosynthetic organs and, more significantly, on leaf surface expansion. This caused reductions in the number of tillers, and afterwards, stolons. Photosynthetic production was altered later than leaf area expansion, indicating, as has been seen in other species, that the main effect of salinity was a limitation of leaf growth.
Included in
High Salinity Effects on the Components of Relative Growth Rate in Rhodes Grass
Rhodes grass (Chloris gayana Kunth), is widely cultivated in the semiarid tropics and favored for its salt tolerance. Nevertheless, productivity decreases significantly under saline conditions, especially in tetraploid cultivars. The purpose of this work was to explore, in tetraploid cultivar Boma, the physiological causes for the observed salt-associated growth reduction. The effects of high salinity (200 mM NaCl) on the components of relative growth rate were analyzed in greenhouse experiments. An early reduction in leaf area expansion was observed, which later resulted in decreased dry matter accumulation. Plant leafiness was reduced by effects both on dry matter allocation to photosynthetic organs and, more significantly, on leaf surface expansion. This caused reductions in the number of tillers, and afterwards, stolons. Photosynthetic production was altered later than leaf area expansion, indicating, as has been seen in other species, that the main effect of salinity was a limitation of leaf growth.
