Abstract Detail

Crop Wild Relatives and Land Races: the Sky Islands of Southwest North American Agriculture

Forrestel, Elisabeth J [1], Walker, M Andrew [2], McElrone, Andrew J [1].

Wild grape germplasm and the future of grapevine cultivation: comparative approaches to assessing climatic tolerances in Vitis.

Vitis (grape) is a genus of approx. 70 woody perennial species, andincludes one of the most culturally and economically valuable crops globally. Most attention is paid to Vitis vinifera subsp. vinifera, which includes all wine and table grape cultivars. Yet, it is the wild species that have been crucial to developing disease resistant rootstocks, and that harbor important genetic and functional diversity critical to adapting grapes to changing climates and disease pressures. Historically, wild grapevines of North America have been critical to sustaining grape and wine production throughout the world (i.e., source of rootstock material to mitigate the phylloxera crisis of the late 19th century), and will undoubtedly continue to be so. As the earth warms, and precipitation and water availability become more unpredictable, it will be essential to breed grapes with greater resistance to--or tolerance of-- drought and heat. While grape genomic resources are actively expanding, fewer phenotypic data are available on the physiological tolerances of wild grape species. Utilizing living germplasm collections, we grew and collected physiological and anatomical trait data from a set of 40 Vitisspecies and cultivars. Using X-ray microtomography, we reconstructed the three-dimensional internal structure of leaf tissue. We then employed machine learning algorithms to quantify traits such as mesophyll surface area, which has been found to be closely related to other important gas exchange and photosynthetic parameters relevant to water use and drought responses. We analyzed a phylogenomic dataset to infer relationships of the sampled Vitis accessions, and used this distribution of trees and a set of comparative methods to test for the coordinated evolution of morphological and physiological traits related to drought adaptation. We also tested for associations between the species’ native climate and ecophysiological traits, to assess whether there are varied strategies to dealing with warmer and/or more arid environments, or whether convergent patterns in suites of traits emerge in response to climate. We highlight the importance of the functional and genetic diversity present in wild grapes, with a focus on those native to the Southwest U.S. and Mexico. As the climate changesand wild populations face increased extinction pressure, the study and preservation of the diversity present in living germplasm collections will be essential repositories of both genetic and functional diversity crucial to adapting crops to varying climates.

1 - University of California, Davis, Viticulture and Enology, Robert Mondavi Institute, Davis, CA, 95616, USA
2 - University of California, Davis, Viticulture and Enology, Robert Mondavi Institute, Davis, California, 95616, USA

Keywords:
Vitis
crop wild relatives
drought tolerance
grapevines
phylogenomics
germplasm.

Presentation Type: Symposium Presentation
Session: SYM4, Crop Wild Relatives and Land Races: the Sky Islands of Southwest North American Agriculture
Location: San Luis 1/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 3:45 PM
Number: SYM4006
Abstract ID:780
Candidate for Awards:None