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Showcase College of Agricultural Human and Natural Resource Sciences

Dissecting the genetic architecture of Aphanomyces root rot resistance in lentil by QTL mapping and genome-wide association study

Dissecting the genetic architecture of Aphanomyces root rot resistance in lentil by QTL mapping and genome-wide association study

Primary author: Yu Ma
Co-author(s): Afef Marzougui; Clarice Coyne; Sindhuja Sankaran; Dorrie Main; Lyndon Porter; Deus Mugabe; Jamin Smitchger
Faculty sponsor: Dorrie Main

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Lentil (Lens culinaris Medikus) is an important source of protein for people in developing countries. Aphanomyces root rot (ARR) has emerged as one of most devastating diseases affecting lentil production. In this study, we applied two complementary QTL analysis approaches to unravel the genetic architecture underlying this complex trait. A recombinant inbred line (RIL) population and an association mapping population were genotyped using genotyping by sequencing (GBS) to discover novel SNPs. QTL mapping identified 19 QTL associated with ARR resistance, while association mapping detected 38 QTL and highlighted accumulation of favorable haplotypes in most of the resistant accessions. Seven QTL clusters were discovered on six chromosomes and five putative genes involved in plant disease response were detected. Expression analysis revealed four of them, encoding an ABC transporter A family protein, a cytochrome P450 family 71 protein, a chalcone-flavanone isomerase family protein, and pectin esterase, were differentially expressed between resistant and susceptible accessions. This indicates genes involved in secondary metabolism and cell wall modification are potentially associated with ARR. Our findings provide valuable insight into the genetic control of ARR and genetic and genomic resources developed here can be used to accelerate development of lentil cultivars with high levels of partial resistance to ARR.

Moving to Better Health Care? Evidence from the Impact of Medicaid Expansion on Homeless Individuals in the U.S.

Moving to Better Health Care? Evidence from the Impact of Medicaid Expansion on Homeless Individuals in the U.S.

Primary author: Ashutosh Kumar
Faculty sponsor: Ben Cowan

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Homeless individuals grapple with varied health problems but have limited access to health care. This study extends the literature on health care and homelessness and provides the first causal evidence of the impact of the Medicaid expansion on migration of homeless individuals from non-expansion to expansion states. The Medicaid expansion, adopted by 26 states and Washington DC and rejected by 24 states in January 2014, expanded coverage to previously uninsured homeless individuals. Besides health care, the expansion equipped homeless service providers with extra flexibility to tackle homelessness through several supportive services and housing-related activities, absent in non-expansion states. Using the state level data, released by the Department of Housing and Urban Development (HUD), on the homeless population from 2009-2018, estimates from a difference-in-differences model suggest migration of homeless individuals, where expansion states saw statistically significant 4.4 percent increase, while non-expansion states simultaneously experienced a 22.6 percent decline. Furthermore, utilizing the difference in coverage status of homeless individuals vis-a-vis homeless people in families (who had pre-expansion coverage), estimates from a triple difference (DDD) model also confirm a significant migration. Previous studies documenting the positive impact of Medicaid expansion on a number of outcomes – improved coverage and health care utilization, reduced financial hardships and medical bills sent to collection, and increased household savings – compliment the results of this study. This paper provides additional evidences that Medicaid expansion had no significant impact on the number of homeless veterans or on indicators like bankruptcy, unemployment rate and poverty rate.

Licensed to Silence: Search for the Host Defense Silencer in Cassava Torrado-like Virus

Licensed to Silence: Search for the Host Defense Silencer in Cassava Torrado-like Virus

Primary author: Jenyfer Jimenez
Co-author(s): Ying Zhai

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Cassava (Manihot esculenta Crantz, Euphorbiaceae) is an important staple food crop for Africa, Asia and Latin America. Cassava torrado-like virus (CsTLV, Family Secoviridae), is found in mixed virus infections associated with severe disease symptoms in leaves and roots of CsTLV, a major viral pathogen of cassava, has been reported in Argentina, Colombia, and Peru. Virus infection leads to significant reduction in the accumulation of total sugars in cassava storage roots. While CsTLV has become an important constraint to cassava production, little is known about how the virus evades the host defense. A better understanding of the virus biology and molecular biology would lead to improved diagnostics which are critical in producing virus-free, clean planting material.
Plant viruses encode RNA silencing suppressors (RSS) to counteract the RNA silencing-based plant defense system. However, no such RSS has been identified in torradoviruses. To further advance the characterization of CsTLV, we first used bioinformatics software to identify the candidate genes for functional characterization of virally coded RNA silencing suppression. Viral coat protein genes were cloned and each gene was separately expressed using agroinfiltration in transgenic Nicotiana benthamiana line 16c plants, using the green fluorescent protein as the visual reporter/marker.
Results indicated that none of the three different coat protein genes from CsTLV showed RSS activity. Future studies will include testing for RSS activity of the three coat protein genes in different combinations.

Fitness outcomes of competitive interactions of Azotobacter vinelandii depend on nitrogen fixation ability and frequency

Fitness outcomes of competitive interactions of Azotobacter vinelandii depend on nitrogen fixation ability and frequency

Primary author: Chandra Jack
Co-author(s): Maren Friesen

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Cooperation is a core feature of sociality. It is one of the key forces behind the transition to multicellularity, the expansion of ecological niches, and increased genetic biological diversity. Altruism can only survive if both parties gain a benefit through increased fitness. The presence of cheaters, individuals that benefit from the relationship but do not provide any in return, can ultimately lead to the collapse of a population because those individuals have higher fitness compared to cooperative members. Prior to industrialized agriculture, over 90% of the nitrogen used by terrestrial plants was due to biological fixation of nitrogen by soil microbes but that number has dropped dramatically with increased application of external nitrogen. We can apply our understanding of microbial sociality to nitrogen-fixing bacteria to determine the correlation between fixation efficiency and fitness. In this study, we compete lab-generated mutants of Azotobacter vinelandii, that vary in their ability to fix nitrogen, at different frequencies to determine the correlation between fixation efficiency, fitness, and population frequency. We expect our results to show frequency-dependent selection where strains that do not fix as much nitrogen (cheaters relative to their competitive partner) will have the highest fitness when they are rare. Our results will also be used to develop models that can predict the outcomes of competitions based on growth rates which we hope to extrapolate to natural isolates. If we can unlock the complexity of microbial interactions, we can boost biological nitrogen fixation and decrease the economic and ecological toll of chemical fertilization.

Adaptive livestock vaccine decision-making among agro-pastoralists: results from modelling cognition and decision dynamics in an agent-based model.

Adaptive livestock vaccine decision-making among agro-pastoralists: results from modelling cognition and decision dynamics in an agent-based model

Primary author: Richard Iles
Co-author(s): Matthew Sottile; Ofer Amram; Eric Lofgren; Craig McConnel

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Livestock disease transmission through animal interactions represents a form of dynamic environmental systems. The inclusion of human behaviour to vaccinate livestock in a dynamic natural and cognitive environment is instructive to understand adaptive human behaviour and design effective livestock disease policies, particularly in low-income settings. Moreover, enhancing the behavioral realism of decision making models in agent-based models (ABM) is required. The current study models livestock vaccination decision making among agro-pastoralists in central Kenya. Our ABM integrates four sub-models: i) the Random Field Ising Model (RFIM) for decision making amongst connected heads of households; ii) a traditional SIRV disease model for Rift Valley fever (RVf) and Contagious Bovine Pleuropneumonia (CBPP); iii) a model for herd birth/death dynamics, and iv) herd movement. A logit transformed RFIM used in this work to link human memory and cognition, with social network pressure and public information concerning disease risks. The research question of interest is: ‘how do memory and cognition parameters in a logit transformed RFIM affect livestock vaccine choice?’. Three rounds of cognition and household survey data from Kenya (2017-2018) is used to calibrate parameters in the RFIM. Results from the logit transformed RFIM show that increases in the memory parameter, at higher levels of cognition has a disproportionate effect on the choice of the annual booster CBPP vaccine, in contrast to RVf which requires a once-for-life vaccine.

Development of a Functional Maternity Hospital Gown Through User-Centered Design

Development of a Functional Maternity Hospital Gown Through User-Centered Design

Primary author: Chanmi Hwang
Co-author(s): Lindsay McCoy

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Maternity hospital gowns are usually made according to a one-size-fits-all standard with full back openings which are physically and emotionally uncomfortable, not functional, and revealing. The purpose of this research was to understand the design requirements of patients and practitioners in order to develop a functional and sustainable maternity hospital gown design. The researchers applied user-centered design (UCD) methods to develop a new design based on data from market research (23 birthing institutions and 25 leading retailers) and focus group interviews (15 postpartum women). The researchers created a two-piece stretchy gown with an adjustable waist and a washable nursing breast pad insert system which contributed to the gowns overall fit, mobility, closure access, modesty, and tactile comfort. Through wear trials (5 women) and an online survey (501 women and 42 practitioners), participants found the prototype to be successful in enhancing physical and psychological comfort throughout different stages of labor and postpartum, resulting in a novel maternity gowns concept that address many needs of both patients and practitioners. The resulting technical package includes the order of operations, bill of materials, marker layout, and cost analysis for the new design which can be tested for mass production. Future research may explore partnering with a manufacturing company such as Medline, the largest manufacturer and distributor of medical supplies, to conduct a patient satisfaction survey after implementing the new design.

Letting Go and Staying Connected: A theoretically guided, developmentally targeted, and empirically supported intervention for parents of students transitioning to college

Letting Go and Staying Connected: A theoretically guided, developmentally targeted, and empirically supported intervention for parents of students transitioning to college

Primary author: Laura Hill
Co-author(s): Brittany Cooper; Matt Bumpus; Kevin Haggerty; Richard Catalano; Martie Skinner

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Early adulthood is a critical developmental period when many youth transition from living at home with parents to the relative autonomy of college. This transition results in increased opportunity both for positive growth and identity development as well as increased risky substance use and sexual behaviors. This developmental transition also presents opportunities for prevention. Research shows that parents continue to influence young adult behavior even at a distance; however, few studies have tested parent-college student interventions. We created a parent-student handbook intervention that provides parents with tools designed to help them support their students as they transition to living away from home, by providing encouragement, communicating clear expectations, and supporting growth in students’ autonomy.

Data for the present study come from the efficacy trial of the self-directed handbook for parents of first-year college students. In the summer before college, parent-student dyads were randomly assigned to one of three conditions: control (N=313), parent handbook (N=278), or parent handbook plus booster texts (N=323). We collected data on substance use early in the students’ first fall semester at WSU.

Among students who reported substance use in high school, students in the handbook condition reported significantly lower increases in frequency of 30-day alcohol use, binge drinking, marijuana, and co-use once they came to college. Students who had reported no previous use were significantly less likely to report initiation of alcohol, marijuana, or co-use of both once they came to college. Results suggest that this low-cost intervention significantly reduces new students’ risk behaviors.

Multi-spectral Imaging in Winter Wheat Variety Improvement

Multi-spectral Imaging in Winter Wheat Variety Improvement

Primary author: Andrew Herr
Faculty sponsor: Arron Carter

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Multispectral imaging with unmanned aerial vehicles is a promising high-throughput phenotyping technology that has shown to help understand the causal mechanisms associated with crop productivity. This imaging technology can accurately predict complex agronomic traits like grain yield within a given generation, creating the potential to fast-track selections in plant breeding and increase genetic gains. Unfortunately, multispectral imaging has not been evaluated at selecting performance across years, limiting our understanding of predicting across environmental variation. The objective of this study is to determine the effectiveness and efficiency of prediction across years and locations within a breeding program. Spectral reflectance indices such as NDVI and NWI will be used to evaluate Washington State University winter wheat breeding lines between 2017 and 2020. Data will be collected using a DJI Phantom drone, equipped with a MicaSense camera, and data collected at heading date. Lines are observed from single location, single replication preliminary yield trials to multi-location, replicated advanced yield trials. Lines advanced in the breeding program will be evaluated across 20 different location-year trials. The indices collected from these trials will be used in indirect selection to estimate how well they predict performance of breeding lines across multiple location-years. Additionally, indices will be used as fixed effects in mixed models and genomic prediction modeling to further estimate their usefulness in genomie selection. The proposed research will be vital for plant breeder’s to understand the usefulness of multispectral imaging to improve winter wheat varieties while using fewer resources.

Community Wealth Building: How the Local Investment Network (LIN) model is transforming the Methow Valley

Community Wealth Building: How the Local Investment Network (LIN) model is transforming the Methow Valley

Primary author: Anthony Gromko
Co-author(s): Trevor Lane; Christina Sanders

Primary college: Agricultural, Human and Natural Resource Sciences — Extension
Campus: Everett

Abstract:

A Local Investment Network (LIN) is an innovative, community-led peer-to-peer investment network that connects local investors who have capital with local business owners who need capital. It brings residents together around a common goal: to build wealth in their community by keeping local capital rooted in their local economy.

The Association of Washington Cities (AWC) partnered with Washington State University (WSU) Extension on a project to implement Local Investment Networks around Washington State. The results of the project have shown that one Local Investment Network in particular, the Methow Investment Network, has had significant immediate success. In its first couple of years it has received over 100 inquires from local businesses, accepted 13 formal applications for funding, added 47 local investors to its network, funded nine businesses for a total of $1,500,000 and created 32 new jobs. The unique characteristics of the Methow Valley draw in urban audiences for relocation, tourism, or second homes. This dynamic urban-rural interdependence has set the stage for its Local Investment Network to thrive.

Honey We Shrunk the World: Climate Change and Shrinking Salamanders in Palouse Prairie Wetlands

Honey We Shrunk the World: Climate Change and Shrinking Salamanders in Palouse Prairie Wetlands

Primary author: Erim Gomez
Co-author(s): Rodney Sayler
Faculty sponsor: Rodney Sayler

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Global warming is projected to reduce the future body size of many species among mammals, birds, and amphibians. Plethodontid (lungless) salamanders are particularly susceptible to the effects of warming temperatures and environmental desiccation because adults require moist skin for respiration. We studied growth dynamics of long-toed salamanders (Ambystoma macrodactylum) originating from 27 Palouse Prairie wetlands to evaluate the working hypothesis that growth was influenced by wetland hydroperiod (duration of flooding) and that larval salamanders in ephemeral wetlands that dried up in summer would be forced to undergo metamorphosis more quickly and emerge onto land at a smaller adult body size compared to larvae occupying more permanent wetlands that allow longer developmental periods. We used machine-learning modeling techniques to compare the size and growth of larvae and adults among wetlands and found that larval size distributions were smaller in shallow, ephemeral wetlands and larger in permanent wetlands and artificial ponds that retained water throughout summer. In addition, statistical models for adult structural size and weight reveal that even after two seasons of growth in captivity with ad libitum food, adult salamanders originating from ephemeral ponds still remained smaller and lighter on average than salamanders originating from permanent wetlands. If future climate change shortens wetland hydroperiods, it may result in reductions in salamander body size and possibly contribute to higher mortality and reduced reproductive success and fitness in salamander populations in Palouse Prairie wetlands.