Abstract Detail

Ecophysiology

Nolting, Kristen [1], Temme, Andries [2], Donovan, Lisa [3].

Quantifying trait integration and the coordination of trait response to abiotic stress in a mapping population of cultivated sunflower.

There is a long history in plant ecology and evolution of using ecophysiologically relevant traits to understand the strategies plants use to maximize fitness in different environments. Recently, many pairwise trait associations have been detected at broad spatial and taxonomic scales, suggesting there are general trait spectra that reflect global strategies and trade-offs in plant function. However, trait associations observed at global scales are often not present when evaluated locally, especially when measuring trait associations at the scale of populations or individual plants. The inconsistency of trait covariation across scales suggests that it might be useful to evaluate trait associations in the context of whole plant phenotypic integration. In the present work, we take advantage of a published dataset that reported the phenotypic and genetic basis of salinity tolerance in cultivated sunflower using a diverse sunflower association mapping population. In this greenhouse experiment, 239 genotypes were planted in replicates of four and grown in benign (no salt added) and stressful (100mM NaCl) environments. Plants were harvested at the late-vegetative stage and a suite of organ-level, ion, and whole plant traits were measured to evaluate trait associations with tolerance.  We build on this work by evaluating trait complexes using multiple response models to estimate the residual correlations among traits in each environment, while accounting for the genetic relatedness among the genotypes sampled. We can quantify phenotypic integration as an emergent property, and then determine whether the magnitude of integration differs by growth environment (benign versus stressful) or the types of traits included in the phenotypic network (e.g. comparing organ-level and ion-profile trait complexes). Additionally, we can evaluate the multivariate direction of trait shifts in response to stress, and determine the degree to which genotypes respond in consistent ways (e.g. the degree to which plastic responses vary among genotypes). Preliminary analyses suggest that contrary to the expectation in the literature, integration is higher under benign conditions for a suite of traits including organ mass and plant size.   Despite the difference in the magnitude of trait integration within each environment, the multivariate direction of trait shifts among genotypes are remarkably consistent, providing evidence for coordinated plastic trait responses to this abiotic stressor.  A more holistic evaluation of plant function will prove useful as the extent of both trait integration within environments, and coordination of trait responses across environments, is important in predicting ecological persistence and adaptive evolutionary change of plants in natural and agricultural contexts.

1 - University of Georgia, Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, USA
2 - University Of Georgia Athens, Department Of Plant Biology, 2502 Miller Plant Sciences, The University Of Georgia, Athens, GA, 30602, United States
3 - University Of Georgia, DEPT PLANT BIOLOGY , 2052 Miller Plant Sciences, Athens, GA, 30602, United States

Keywords:
functional traits
phenotypic integration
Plasticity
sunflower.

Presentation Type: Oral Paper
Session: ECOPH2, Ecophysiology II
Location: /
Date: Tuesday, July 20th, 2021
Time: 1:45 PM(EDT)
Number: ECOPH2013
Abstract ID:815
Candidate for Awards:None