PHYSIOLOGICAL AND GENETIC BASIS OF SALINITY TOLERANCE IN ARGENTINE WHEATGRASS (Elymus scabrifolius (Döll) JH HUNZ).

ZABALA, JUAN MARCELO; MARINONI, LORENA DEL ROSARIO; TALEISNIK, EDITH; CERVIGNI, GERARDO; SCHRAUF, GUSTAVO

Buenos Aires

Simposio; 5th International Symposium of Forage Breeding; 2015

FAUBA, UNNOBA

Elymus scabrifolius (Döll) J.H. Hunz is native grass to Argentina and Uruguay and is valued as aforage resource. Two experiments of initial growth in hydroponic culture were performed ingenotypes with contrasting salinity tolerance. These experiments allowed the determination ofsalinity tolerance limits, relative growth rates and sodium and potassium uptake and transport ratesunder saline stress. Biochemical mechanisms of salinity tolerance were inferred based on the resultsobtained. The genetic control of salinity tolerance was analyzed in hydroponic systems, using F2 yF3 segregating populations derived from two genotypes used in above experiments. Sodiumaccumulation and leaf biomass were used as traits for genetic analysis. Heritabiliy was estimated forthese two traits. Also, a molecular marker analysis (SRAPs) was conducted using parent genotypes,F1 and F2 population, to find association between molecular markers and these traits. Based on theresult obtained, it was verified that sodium exclusion is an important mechanism for salinitytolerance in argentine wheatgrass (agropiro criollo). In the other hand a high heritability and simplegenetic control was found for this trait. Due to the low polymorphism detected, SRAPs markersassociated with salinity tolerance were not found. Other approaches should be used to find QTLs forsalinity tolerance, such as microsatellites recently developed in other Elymus species. The resultswill be usefull as a baseline for the design of traditional breeding programs in order to enhancesalinity tolerance without loss other agronomic traits as vigor and tillering. Furthermore, thedetermination of genetic control will allow identification of genes involved in sodium exclusion.