Abstract Detail

Physiology & Ecophysiology

Tran, Vivian  [1], Temme, Andries [1], Donovan, Lisa [1].

Evaluating Salinity Tolerance in Wild, Landrace, and Domesticated Helianthus annuus.

Soil salinity is an abiotic stress that limits plant growth and productivity in both native and agricultural systems. There is a general expectation that the genetic capacity for abiotic stress tolerance decreases during the process of domestication. Based on this expectation, one strategy to enhance abiotic stress tolerance in crops would be to use wild relatives as a potential source of genes for increased tolerance. However, the actual degree of tolerance, which can be quantified by the reduction in growth under stress, remains unknown in many domesticated species and its wild progenitors for numerous stresses. In this study, we compared three groups of Helianthus annuus for response to salinity stress: wild populations from a range of habitats (6 populations), ancient landraces domesticated for Native American use (3), and domesticated modern cultivars (6). In a greenhouse study, potted seedling were exposed to either control or 100 mmol salinity stress for three weeks. The three groups had different growth overall, with landraces accumulating the most biomass in either treatment and having the largest absolute decrease in biomass in response to salinity. However, based on the proportional decrease of biomass accumulation in response to the stress treatment, which factors out overall vigor, there were no differences between wild populations, landraces, and modern cultivars of H. annuus. Wild populations did shift biomass below ground in response to salt stress while landraces and cultivated accessions did not. In contrast, stomatal conductance decreased only in cultivated accessions. The varying trait shifts between groups suggest that despite the lack of differences in tolerance, wild populations, landraces, and cultivated accessions may have different mechanisms to respond to salt stress. There did appear to be a lot of variation in salt tolerance among the wild populations and among cultivated lines that may provide further insight into the mechanistic basis of salt tolerance and thus for improving H. annuus cultivars.

1 - University of Georgia, Department of Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, United States

Keywords:
salinity
Abiotic Stress
Helianthus
Sunflower
Salt Tolerance
domestication.

Presentation Type: Poster
Session: P, Physiology & Ecophysiology
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPE011
Abstract ID:917
Candidate for Awards:None