Source: UNIVERSITY OF ARIZONA submitted to
UNDERSTANDING THE GENETIC BASIS OF LOCAL ADAPTATION IN PERENNIAL GRASSES OF THE SONORAN DESERT
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
MCINTIRE-STENNIS
Reporting Frequency
Annual
Accession No.
0227490
Grant No.
(N/A)
Project No.
ARZT-1392510-M12-198
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2011
Project End Date
Sep 30, 2014
Grant Year
(N/A)
Project Director
Smith, S.
Recipient Organization
UNIVERSITY OF ARIZONA
888 N EUCLID AVE
TUCSON,AZ 85719-4824
Performing Department
Natural Resources & the Environment
Non Technical Summary
This research fits into our long-term goal of developing a better understanding of how evolutionary processes affect adaptation in key plants of southwestern rangelands and how anthropogenic factors may influence evolutionary processes in these plants. This builds on work we began nearly 15 years ago to understand the genetic and developmental basis for local adaptation in sideoats grama. Most of this research has focused on response to livestock herbivory using a population present in a geological grazing refuge in Pinal County. In this research we have shown that exposure to livestock grazing was associated with heritable changes in plant development linked to grazing resistance, grain production, and in fine-scale genetic structure. Throughout this period we have always been curious about the longer-term evolutionary drivers that have shaped the genetic variation present within contemporary sideoats grama. This study would investigate one of these: grain production and its response to drought.
Animal Health Component
0%
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20307801080100%
Knowledge Area
203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants;

Subject Of Investigation
0780 - Grasslands, other;

Field Of Science
1080 - Genetics;
Goals / Objectives
Assess the genetic basis for open-pollinated grain production in populations of sideoats grama (B. curtipendula var. caespitosa) in greenhouse experiments where genotypes are exposed to varying amounts of water stress.
Project Methods
This research will be conducted using genotypes from two populations of sideoats grama from environments with different annual precipitation. One population originates in the Kofa Mountains in western Arizona where annual precipitation is estimated to be 217 mm. The other population exists on Table Top Mountain in central Arizona. Annual precipitation at this site is estimated to be 341 mm. These two populations were selected because one has evolved on a site (Kofa) where extreme drought may be expected to occur fairly regularly while the other represents a more typical precipitation regime for sideoats grama in central and southern Arizona. Using seed collected from these populations we will grow twenty randomly selected genotypes from each. These will be separated into ramets and these will be grown for use in greenhouse experiments to evaluate genetic variation in grain production under two levels of moisture application (treatments). One treatment will involve thorough irrigation every 1-3 days such that plants will likely never experience significant drought stress. The other treatment will include irrigation about every 5 days and will be scheduled based on the elicitation of drought stress symptoms (primarily changes in leaf morphology and color). Inflorescences will be regularly harvested from each genotype when mature and evaluated for spikelet, floret, and grain number. This will be conducted over at least three regrowth-flowering-defoliation cycles during the experimental period. Residual shoot biomass will be preserved and subjected to carbon isotope discrimination analysis to confirm the efficacy of the irrigation treatments.

Progress 10/01/11 to 09/30/14

Outputs
Target Audience: Researchers interested in the reproductive biology and evolution of C4 grasses. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One graduate student was associated with this project and did receive significant experiences. However, it is important to note that other than funds to support the PI's salary, no actual research funds were provided by the Experiment Station for this project. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We have shown that open-pollinated grain production is very low in greenhouse-grown plants of sideoats grama. This was observed across a range of soil moisture treatments and fertility (expressed as grains/spikelet) was not related to soil moisture. Flow cytometric analysis of accessions of sideoats grama from southern Arizona that were used in this research are high polyploids (> 4x), and sexual reproduction is almost exclusively apomictic. It is important to note that other than funds to support the PI's salary, no actual research funds were provided by the Experiment Station for this project.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2013 Citation: Smith, S.E., Ma. G. Mendoza, G. Z��iga, K. Halbrook, and D.N. Byrne. 2013. Predicting the distribution of a novel bark beetle and its pine hosts under future climate conditions. Agric. and Forest Entomology 15:212-226.
  • Type: Journal Articles Status: Accepted Year Published: 2013 Citation: Soleri, Daniela, Margaret Worthington, Flavio Arag�n-Cuevas, Steven E. Smith, and Paul Gepts. 2013. Farmers' varietal identification in a reference sample of local Phaseolus species in the Sierra Ju�rez, Oaxaca, Mexico. Econ. Bot. 64:283-298.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Pavliscak,L.L., J.S. Fehmi, and S.E. Smith. 2014. Assessing emergence of a long-lived monocarpic succulent in disturbed, arid environments: Evaluating abiotic factors in effective Agave restoration by seed. Arid Land Res. Manage. DOI: 10.1080/15324982.2014.909905.
  • Type: Other Status: Published Year Published: 2013 Citation: Smith, S.E. 2013. Plant reintroduction in a changing climate. Promises and perils. Restoration Ecol. 21:661-662 (Book review).


Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Researchers interested in the reproductive biology and evolution of C4 grasses of the southwestern USA and northern Mexico. Researchers interested in apomictic reproduction may be specifically interested in our findings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? One graduate student was associated with this project (K. Halbrook) and did receive significant experiences. However, it is important to note that other than funds to support the PI's salary, no actual research funds were provided by the Experiment Station for this project. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Continue our research insofar as funds will allow.

Impacts
What was accomplished under these goals? Assess the genetic basis for open-pollinated grain production in populations of sideoats grama (B. curtipendula var. caespitosa) in greenhouse experiments where genotypes are exposed to varying amounts of water stress. Our research also addressed the cellular basis for apomictic reproduction in this species, which was not a goal of the original project. The work led by Kandres Halbrook established that this species is facultatively apomictic and pseudogamous. Flow cytometric analysis of individual grains demonstrated a relatively wide tolerance for sperm and endosperm anueploidy in B. curtipendula. Dr. Halbrook's research also established that the primary character used to separate the three varieties of B. curtipendula (caespitosa, tenuis and curtipendula) exhibits extreme phenotypic plasticity. Recognition of these varieties is not biologically justifiable.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Smith, S.E., Ma. G. Mendoza, G. Z��iga, K. Halbrook, and D.N. Byrne. 2013. Predicting the distribution of a novel bark beetle and its pine hosts under future climate conditions. Agric. and Forest Entomology 15:212-226.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Soleri, Daniela, Margaret Worthington, Flavio Arag�n-Cuevas, Steven E. Smith, and Paul Gepts. 2013. Farmers' varietal identification in a reference sample of local Phaseolus species in the Sierra Ju�rez, Oaxaca, Mexico. Econ. Bot. 64:283- 298.
  • Type: Journal Articles Status: Submitted Year Published: 2014 Citation: Halbrook, K., S.E. Smith, K.E. Lacey, M.S.A. Binney, M.J. Benson, L.M. Broduer, and C.L. Rigdin. Pseudogamous apomixis, relative ploidy, and fertility in Bouteloua curtipendula (Poaceae). Am. J. Botany


Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Our research aims to assess the genetic basis for open-pollinated grain production in populations of sideoats grama (B. curtipendula var. caespitosa). In 2012 we began greenhouse experiments using genotypes from two different sites in Arizona (Kofa National Wildlife Refuge and Table Top Mountain). Ramets will be exposed to different irrigation regimes in 2013. In 2012 we also recorded data on the production of rhizomes and stolons of greenhouse-grown plants. These data may be useful as we interpret results of upcoming drought-response experiments. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
At this point, the research project is still in development. There are no outcomes or impacts beyond our own research program.

Publications

  • Halbrook, Kandres. 2012. Bouteloua curtipendula (Poaceae): Reproductive biology, phenotypic plasticity, and the origins of an apomictic species complex. Ph.D. Dissertation. University of Arizona. http://arizona.openrepository.com/arizona/handle/10150/243112 (accessed 1 March 2013).