Determining Salt Tolerance Among Sunflower Genotypes.

Much of the cultivated land throughout the world is salt-affected due to natural processes and agricultural practices. Due to the exacerbation of this soil issue, development of saline tolerant sunflower (Helianthus spp.) germplasm is needed.  Although cultivated sunflower is classified as a moderately salt tolerant crop, highly tolerant varieties can be of value.  The goal of this study was to develop rapid screening protocols and characterize the salt tolerance of sunflower genotypes. Seeds were germinated in petri dishes with varying concentrations of NaCl solution.  Radicle lengths and germination rates were ascertained. This technique identified genotypes significantly more salt tolerant than others. Two field locations were chosen to screen germplasm for tolerance through physiological maturity; College Station, TX, with low salt concentrations and Pecos, TX, with high concentrations of salt in the soil and water. Due to insect infestation in both locations in 2010, seed yields could not be accurately measured and thus compared between sites.  Vegetative growth measurements showed a significant genotype by environment interaction.