VARIATION ANALYSIS IN STOMATAL DENSITY IN Trichloris pluriflora GERMPLASM UNDER DIFFERENT WATER REGIMES.

TROD M; TOMAS P; CERVIGNI DGL; ZABALA M; MARIONE L; QUIROGA E; GIAVEDONI J

Buenos Aires

Congreso; 5 th International Symposium of Forage Breeding; 2015

Facultad de Agronomía - UBA

Trichloris pluriflora is a perennial warm season grass native of America, valued as forage both for semi-arid and wet conditions. The stomatal density and the relative numbers of stomata on upper and lower leaf surfaces are influenced by water stress during dry periods, which determine the proportion of carbon dioxide exchange through the adaxial and abaxial surfaces.The aim of the study was to identify variations in stomatal parameters associated with changes in the water regime in T. pluriflora. A total of 29 genotypes of six accession were analyzed. The accessions belong of FCA-UNL germplasm collection, and come from different regions of Argentina. Leaf samples were taken from genotypes at reproductive stage, both in EEA-INTA Catamarca (dry environment) as well as FCA-UNL (humid environment) during summer 2014- 2015. Stomata were forming lines along inter-nerve epidermis of the leaf-blade, on both adaxial and abaxial sides. Leaf width did not show variations, but the number of stomata lines showed significant differences among environments, being lower in dry climate. In adaxial side, the number of stomata per unit area was lower in dry environment at all accessions. In abaxial side, the number of stomata per unit area showed significant differences between accessions only in humid environment, and among environments for fifty percent of accessions. The proportion of stomata on the adaxial surface presented differences between accessions within both assay environments. At this trait, only one accession showed statistical differences among environments, reaching the highest and lowest values in dry and humid climate, respectively.The observed variation would be useful for characterization of environmental response ingermplasm collections of T. pluriflora, and a tool for plant breeding programs in this species.