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Comparative Transcriptomics in Stress-Induced Rice
Get PDFRice is an important crop that feeds almost half the world population. As climate change models predict floods, drought and extreme temperatures in rice production areas, the need to better understand the genetic basis of adaptation and tolerance to abiotic and biotic stresses is vital to sustain our food supply. To elucidate stress-tolerance casual genes, we designed a time-series transcriptome experiment on two contrasting varieties of Oryza sativa subspecies indica and japonica in the drought (abiotic) and sheath blight (biotic), respectively. These varieties were chosen based on their contrasting tolerant and sensitive characteristics. Using a systems biology approach, our goal was to identify genes expressed and genetic variants inherited in response to stress tolerance. Discoveries from these projects will help accelerate the genetic gains in breeding stress resilient rice varieties.
In both studies, plants from the susceptible and tolerant varieties were subjected to either inoculated sheath blight (SB) or drought-induction. Plant materials was collected on untreated and treated (early, late and in the biotic stress very late) timepoints post-treatment. The total mRNA was isolated from treated and untreated samples for Next Generation Sequencing (NGS) at CGRB facility at OSU. This was followed by statistical and transcriptome data analysis.
The sequence data generated was analyzed against the reference rice genome and between the two experimental varieties. Analysis includes, calling genetic variation, de-novo assembling transcript (mRNA) isoforms, differential gene expression levels, and identifying stress-induced pathways specific to each variety and tolerance level. The statistically significant results of these analyses were further annotated using various standardized ontologies and by aligning against previously studied quantitative trait loci (QTLs) for stress tolerance traits. The selected set of genes were further queried against functional annotations including predicted consequential disruption of gene function or structure due to genetic variation. This resulted in 1-4 genes with favorable gene-expression response under stress that also carried significantly important genetic variation disrupting the gain/loss of gene function. Thus, identifying functional markers and candidate genes for introducing in developing new stress-tolerant rice varieties
Adversarial Attacks in Natural Language Question-Answering
Get PDFQuestion Answering in natural language processing has achieved significant progress in recent years. Yet, training and testing set methodology to evaluate the language models has proved inadequate. Adversarial examples aid us in finding loopholes inside these models and provide insights into their inner workings. In this work, an evaluation based on human-in-the-loop adversarial example generation is explored. In recent published work on adversarial question-answering, perturbations are made on the questions without changing the background context on which the question is based. In the current work, the complementary idea of perturbing the background context while keeping the same question is examined. From the user study, novel adversarial examples crafted by humans exposed the weaknesses of the models. This thesis puts forth a typology of the successful attacks as a baseline for stress-testing QA systems. It also describes a system to automatically generate adversarial examples based on the identified attacks
The Global Overturning Circulation Since the Last Glacial Maximum Based on Marine Authigenic Neodymium Isotopes
Get PDFThe Global Overturning Circulation (GOC) is a major component of the global climate system. Understanding its behavior is pertinent to our prediction of climate change in the future. The lack of long-term observations of GOC in the modern instrumental era necessitates studies of GOC using paleoceanographic records. Of great interest to climate scientists is the history of GOC since the Last Glacial Maximum (LGM, ~22,000 years before present). This is because this period experiences the last major natural global warming event accompanied by an increase of atmospheric CO2 comparable to that since the industrial revolution, and because this period was characterized by centennial to millennial scale abrupt climate transitions, making it a potential analog of the present human-induced global warming.
The neodymium isotope composition (εNd) of authigenic phases in marine sediments has been used as a circulation proxy to reconstruct past change of GOC, but our incomplete understanding of the processes regulating the distribution of εNd in the ocean has so far hampered the application of this proxy, such that there is not yet a globally consistent description of past GOC history using this tracer.
In this dissertation, I develop new methods to extract authigenic phases from marine sediments for εNd analysis. The methods are designed specifically for sediments from the Pacific Ocean, which often contain disperse volcanic materials that usually cause significant contamination to extracted Nd when using existing methods developed for the other ocean regions. Using a suite of geochemical tools, I identify the sources of extracted Nd, and show that the methods are capable of extracting authigenic Fe-Mn oxyhydroxides with negligible contamination from detrital sediments including volcanic materials. However, when applying the methods to sediments from the Gulf of Alaska, I find that the authigenic εNd from modern core top samples are consistent more positive than the local bottom water, suggesting that in site diagenesis of volcanic materials affects the εNd of authigenic phases. Differences of εNd between authigenic phases and bottom water are widespread in the global ocean, thus questioning the traditional assumption that authigenic phases passively record bottom water εNd. I suggest that this difference is evidence that there exists a significant sedimentary source of Nd to the ocean, which is linked to the diagenesis of authigenic phases and detrital sediments. I propose a conceptual model to describe how authigenic phases acquire their εNd signatures through interactions with bottom water, pore water and detrital sediments. The two key factors controlling the interactions are the benthic exposure time and the reactivity of detrital sediments. I show that this conceptual model is applicable to the distributions of seawater and authigenic εNd in the Pacific Ocean.
With the new method and conceptual model, I generate two new authigenic εNd records using cores from the Gulf of Alaska at intermediate and abyssal depths, and reconstruct the Pacific circulation since the LGM. I synthesize the existing Pacific authigenic εNd records using a box model, in which I separate the non-conservative component from the preformed-conservative mixing component of εNd. Using the non-conservative component of εNd, I estimate the Pacific circulation rate, together with benthic radiocarbon (14C) records from the same sites. The results show that the transport of Southern Ocean deep waters to the Pacific reduced to ~half of today in the LGM, but increased later in the Northern Hemisphere stadial events to ~2-fold of today during the deglaciation. The inferred circulation changes imply accumulation of respired carbon in the glacial deep Pacific and its subsequent release during the deglaciation, supporting the conclusion that the Pacific circulation plays a key role in the global carbon cycle since the LGM.
Extending the conceptual model globally, I synthesize published authigenic εNd records from the global ocean since the LGM. The dominant modes of variability in these records are extracted using Principal Component Analysis. The first Principal Component (PC1) is related to the LGM-Holocene difference of εNd: the glacial deep ocean has consistently more positive εNd than the Holocene, and the magnitude of this increase was highest in the subpolar North Atlantic, decreasing toward the Southern Ocean and further so in the Pacific and Indian Oceans. This change is interpreted as the result of an increase of the preformed εNd of the deep water produced in the North Atlantic, linked to the southward shift of the deep water formation location in the LGM. The second Principal Component (PC2) is related to the abrupt changes during the Northern Hemisphere stadial events: in these events North Atlantic and North Pacific εNd converge. This mode of change is interpreted to be the consequence of strengthening of Southern Ocean overturning circulation, which overcomes the effect of the reduction of North Atlantic overturning, leading to overall stronger overturning of the global deep ocean. The PC1 and PC2 related mechanism are quantified using a global εNd box model. The reconstructed GOC since the LGM correlates to changes of atmospheric CO2 and ocean heat transport, giving key evidence to the long-standing hypothesis that links GOC to these climate variables
A Rapid β-/γ Autoradiographic Imaging Method for Post-detonation Nuclear Forensics and Radiological Emergency Response
No full textIn a radiological emergency scenario, the capability to rapidly visualize radiation emitted from debris, contamination, or absorbed in biological samples, while visualizing the non-radioactive (or “conventional” image) features within a field of view, will provide critical information to support optimization of further analysis, sample collection, and decision making. This research developed and assessed a novel autoradiographic method based on electron multiplying charge couple device (EMCCD) sensor and inorganic scintillator-based method as a faster, cheaper, and more portable alternative to traditional autoradiographic imaging technology. A series of known activity calibration sources and spheroid surrogate nuclear debris particulate on the micro- to millimeter scale were studied to determine the optimal imaging parameters and experimental setup to provide the highest quality autoradiographic images. Both autoradiographic and non-radioactive features could be distinguished from a single, rapid exposure in these experiments. The autoradiographic method was tested with samples of surrogate nuclear debris particles (0.750-1.35 mm in diameter) for exposure times of ≤3000 seconds (50 minutes). Various reflectors for emitted light were tested within the experimental setup to assess potential improvements in exposure time, spatial resolution, and signal-to-noise ratio (SNR) of the captured images
Feasibility Study of a Thermal Spectrum Thorium Breeder Reactor Without Chemical Reprocessing
Get PDFThis thesis presents a feasibility study of a thorium fueled thermal spectrum breeder-burner reactor that operates without chemical reprocessing. Materials were evaluated for their potential as moderators using standard analytical methods. These materials were then used as moderators to evaluate criticality and enrichment in an infinite fuel pin lattice. The criticality and heavy metal mass of the system as a function of burnup were then used to calculate a neutron balance for each case. The neutron balance indicated that there are insufficient neutrons available in an infinite lattice to operate in a breed-and-burn configuration. A core model was developed to confirm the results of the infinite lattice. Design bounds were developed from the lattice investigation, and used by an optimization routine to evaluate reactor cores with one-quarter symmetry. The black-box optimization program, Gnowee, coupled to the neutronics and depletion code, SCALE, was used to facilitate the process. This procedure required the development of an automated core generation tool that could read the output perturbations from Gnowee and translate that into a new input for SCALE, and a tool to read the output of SCALE to inform the objective function and constraints in Gnowee. None of the core configurations operated with breeding while remaining critical. A two-region infinite lattice using annular fuel pins with enriched breeder blankets was used to test alternative fuel swapping schemes. The two-region infinite lattice analysis indicated that fuel in an annular geometry with an enriched blanket could remain critical while breeding in a breeder-burner configuration
Making the Connection: Linking Stress Physiology of Juvenile Northern Spotted Owls to Environmental Variation and Long-term Survival
Get PDFThe northern spotted owl (Strix occidentalis caurina; spotted owl) is of conservation concern and endemic to mature forests of the Pacific Northwest. Adult survival has a strong effect on population growth rate, but juvenile survival and recruitment are also important components of population change. Despite the importance of this life stage, estimates of survival in the first year of life, factors related to survival, and the contribution of juveniles to later life-history stages and population stability are unknown. A better understanding of stressors during these missing life stages can provide insights on long-term population demographics. Environmental variation may affect survival of juvenile spotted owls, thus understanding how increasing temperatures and precipitation affect the less–studied life–history stages of this threatened species will give us insight and considerations for future management, particularly in areas predicted to experience increased temperatures and storm severity as climate patterns change.
The development of new tools and modeling techniques allows researchers to look for new ways to evaluate animal populations. Individual physiology is a common tool for ecologists interested in how an individual’s environment affects life history and demographics. Corticosterone is a steroid hormone integral to a variety of physiological pathways and resource allocation, such as metabolism, immunity, and cognition. Thus, it is associated with life history and environmental changes as well as fitness metrics in many taxa. In avian species, circulating corticosterone diffuses into developing feathers (FCORT) and can be extracted, measured, and used as an indicator of challenging conditions faced during feather growth that may have life-long ramifications. In addition, models that incorporate changes in ecological states or life history stages increase the accuracy of demographic models for spotted owls. Using multi-state mark recapture models, it is possible to estimate survival for non-territorial floaters, the probability of recruiting into the territorial breeding population, as well as evaluating individual and landscape characteristics that may affect these important demographics. Here I focused my study on juvenile spotted owls captured and banded after fledging but prior to natal dispersal on seven demography study areas in Washington and Oregon during 2001–2017. The goals of this study were to determine: 1) the environmental or individual variables associated with variation in juvenile feather corticosterone and 2) the relationship between corticosterone extracted from feathers and survival of non-territorial birds or recruitment into the territorial breeding population.
First, I quantified FCORT levels in 4,720 feathers from 1,056 juvenile spotted owls and used an information-theoretic approach to examine the environmental, temporal, and individual factors related to patterns of FCORT (Chapter 2). The final model set contained four competitive models with the negative relationship of juvenile mass at banding as the most important predictor of FCORT. Increasing temperatures and higher amounts of precipitation prior to and during fledging was related to increased FCORT, suggesting that this period may present an energetic challenge for juvenile spotted owls. The relationship between FCORT and precipitation was modified by juvenile mass, where increasing mass decreased the positive relationship between FCORT and precipitation, suggesting that some component of body mass, such as fat stores or surface to volume ratios were important for juveniles while fledgling.
Second, I used long-term, capture-mark-recapture data across 17 years and seven study areas in Oregon and Washington to estimate apparent survival and recruitment of 1,061 non–territorial and territorial spotted owls (Chapter 3). I also examined the relationship between demographics and juvenile feather corticosterone levels, juvenile mass at banding, day of year on which a juvenile was banded, and barred owl presence. Of the 1,061 owls included, 381 of those eventually recruited into the territorial breeding population. The mean age of recruitment was 2.2 years, but almost half (49%) recruited into the territorial population at age one. There was weak to moderate support for a difference in survival for non-territorial and territorial birds, and survival of both territorial states varied annually. There was a quadratic relationship between apparent survival of non-territorial floaters and feather corticosterone, with the highest survival observed for those birds with intermediate levels of corticosterone. Non-territorial survival also had a positive linear relationship with juvenile mass at banding and a negative linear relationship with banding date. These results also indicated that recruitment probability decreased over the course of the study and heavier juveniles at banding had a higher probability of recruiting into the territorial population.
This study established a link between developmental conditions, individual physiology and long-term demographics. My findings indicated that the fledging period is an important and sensitive period in spotted owl development, in which small climatic changes can be associated with changes in physiology and these physiological differences can be associated with survival probabilities. In addition, juvenile mass explained variation in physiological differences in juveniles as well as bolstering survival and recruitment. Understanding the long-term ramifications of developmental conditions is important to building accurate demographic models, predicting population stability in response to environmental changes and informing conservation strategies. The first step is identifying the landscape variables associated with individual variation in development and the connections to long-term demographics
On the Volcanic and Geodynamic Evolution of the Shatsky Rise and the Louisville Seamount
No full textLarge igneous provinces (LIPs) and intraplate seamounts reflect of anomalous mantle melting and illuminate interior processes of the Earth. These features are in all ocean basins and show the mantle’s evolution over time, then can provide information on plate tectonic processes, such as plate motion over time, spreading ridge formation, and continental breakup. This dissertation examines both of these features temporal and spatial evolution and interprets their geodynamic significance.
Large igneous provinces are massive basaltic mountains thought to be formed from hot anomalies that ascend from the bottom of either the upper or lower mantle and impinge at the base of and then extrude upon the lithosphere. Alternatively, LIPs are thought to be derived from rapid adiabatic melting solely within the upper mantle. I present a study of the geochronology of Shatsky Rise, an oceanic plateau with an area the size of California or Japan, to help refine the origin of LIPs. Previous geochronology studies have limited age analyses and the overall age progression was limited to paleomagnetic reversals and interpretations. Previous studies also speculated that Tamu massif is the initial plume ‘head’ and the subsequent massifs, Ori and Shirshov, were a result of a plume tail and they represented age progressive volcanism. The samples presented here were collected from International Ocean Drilling Project (IODP) Expedition 324 and the Ocean Drilling Project Leg 198. The drill cores that penetrated up to 160 meters into the igneous basement of Tamu, Ori, and Shirshov Massifs. Based on the 70 new 40Ar/39Ar ages from these massifs, we find that the age difference between the uppermost lavas collected from the drill cores on Tamu massif are within 1 Ma of the age of the oceanic crust it overlays. The study concludes that Tamu and Ori massif were emplaced within 1 Ma of their underlying oceanic crust and that their formation is closely linked to crustal generation. Shatsky Rise does not represent age progressive volcanism but is linked to mid-ocean ridge processes.
Our investigation into Shatsky Rise focused on the initial timing and duration of hotspot volcanism, whereas the following study investigates around the characteristics of a long-lived primary hotspot, the Louisville seamount trail, and how the seamounts within formed and reflect absolute plate motion and hotspot mobility. We analyzed 70 samples from IODP Expedition 330 for 40Ar/39Ar geochronology which covered an age range from ~74 Ma to 51 Ma. Louisville is the south Pacific analog to the Hawaiian-Emperor seamount trail and has been active from ~80 Ma to 1 Ma but has no known active hotspot. We broadly look at known seamount lifespans from Louisville and Hawaii to determine the duration of seamount volcanism. Hawaii has an overall lifespan of ~6-7 Ma whereas Louisville seamounts show an age range of ~4-5 Ma. The ages from samples do not accurately reflect the inception age of a given seamount but are representative of a later stage of volcanism. We conclude that past plate motion models do not accurately reflect the age progression of the Louisville seamount trail.
The final study presented here collates the new age data from Louisville seamount trail and the seamount lifespans to better interpret the geography of seamounts over the past 80 Ma within the Pacific Plate. We built a plate motion model that searches for stage poles that fit the age progression and geometry of both Louisville and Hawaii seamount trails within a ‘fixed’ and ‘moving’ hotspot reference frame. Our results find that a fixed hotspot solution is viable for describing Louisville and Hawaiian-Emperor from 45 Ma to 0 Ma. Prior to 45 Ma, the Hawaiian hotspot and an average of ~4° of southward latitudinal movement while Louisville hotspot motion was limited to ~1°.
These studies cover three major areas of oceanic volcanism research and provide crucial information on emplacement characteristics of Large Igneous Provinces and intraplate hotspot volcanoes and how their behavior can provide insights to mantle processes and the absolute plate motion of the Pacific plate. All the hotspot motion models confirmed that the Hawaiian hotspot has a latitudinal motion of ~4 degrees and that there is limited hotspot motion of ~1 degree for Louisville. The amount of west to east motion is very limited
Higher Education Diversity Work and its Discontents: Theorizing Student Social Media Activism as Counter-hegemonic Network of Practice
Get PDFDiversity and inclusion represent central challenges and opportunities in the transnational field of higher education, as the number of students enrolled in higher education has expanded exponentially over the past century and universal access to tertiary education has emerged as a development imperative. Within this context, diversity has emerged as a dominant focus in an inclusion agenda propelling contemporary higher education transformation. Consequently, colleges and universities around the world have established institutional initiatives and practices that aim to increase the participation of diverse groups. Critical incidents of student activism beginning in 2014 and defined by activists’ use of social media, reveal discrepancies between institutional commitments to diversity and inclusion and student experiences of exclusion. The aim of this project was to critically examine the productive tension between student activism and institutional diversity work in higher education. This dissertation is comprised of two studies, reported in manuscript form. In the first manuscript I employ a critical theoretical lens and use student activism as an analytical counterpoint to explore the logics of diversity work. I draw from Bourdieu and Gramsci to conceptualize the dynamics of power and change at work in higher education and to question the ways that institutional diversity work might serve to maintain regimes of exclusion. To identify the logics of institutional diversity work, I reviewed media archives and academic literature on the #MustFall and #ITooAm movements and the critical scholarship of institutional diversity work and inductively coded this literature, developing themes that intersect student activism and institutional diversity work. Four overarching logics emerged and are described: 1) tensions in diversity discourse, 2) a bureaucratic approach to diversity practices, 3) an institutional diversity capital paradox, and 4) “thin” institutional responsiveness to student resistance. The second study examined a single critical incident of student activism at an accessible Hispanic Serving Institution (HSI), defined by the hashtag #DiversityisNotInclusion. Adopting a Community of practice theoretical model, this study utilized social network analysis (SNA) and critical discourse analysis (CDA) to explore the networked interactions of student activists around a common concern and to examine the ways that activists used social media as an instrument of resistance within the context of diversity discourse and practice. Research findings indicate that student activists used #DiversityisNotInclusion to create and maintain (organize) an inclusive social space within which they narrated their experiences of identity-based exclusion at SU (counter storytelling). Additionally, students used the hashtag to circulate their counter-stories in order to pragmatically amplify their demands for institutional change (amplifying). This dissertation extends the literature on student activism by examining activists’ use of social media as an instrument of resistance. In addition, it contributes to the critical scholarship of diversity work in higher education and offers an agenda for researchers interested in pursuing the emergent line of inquiry at the intersection of student activism and institutional diversity work
Device Fabrication and Characterization for Biological and Radiation Sensing
Get PDFAmorphous indium gallium zinc oxide (IGZO) thin film transistors (TFT) has revolutionized the display industry enabling smaller pixel sizes and higher refreshing rates than traditional amorphous Si: H TFTs. These attributes of IGZO were leveraged to make a field-effect sensing (FES) platform capable of sensing various biomarkers. The sensitivity and selectivity of the sensor to glucose was achieved by functionalizing the IGZO back channel surface with aminosilane groups which were further cross-linked with glucose oxidase (GOx) enzymes. The sensor was integrated with a microfluidic channel, and the sensor response was studied with respect to varying glucose concentrations. An analysis of the sensitivity of the sensor for various gate voltages (VG) was conducted to determine the optimal VG to operate the sensor for continuous glucose sensing. These sensing platforms can be made completely transparent and are compatible for integration onto flexible substrates enabling transparent active-matrix sensing arrays (TASA) where multiple biomarkers can be sensed which will aid next-generation internet of things (IoT) hardware for human health monitoring and analytics.
Lead selenide (PbSe) nanocrystalline (NC) particles have a large Bohr radius (~ 46 nm) which enables high quantum confinement effects in relatively larger diameter NC PbSe. As a consequence, the efficiency of charge multiplication (CM) on impact ionization (II) is enhanced for NC compared to bulk PbSe. In addition, a relatively high density of these NC PbSe enables complete transfer of high energy radiation in a relatively thin sensing layer. However, the radiation sensing capability and electronic transport for NC PbSe radiation detectors is impeded by long-chain stabilizing organic ligands on the NC surface as well as the current fabrication methods. In this research, a biphasic ligand exchange process was integrated to the detector fabrication protocol to improve electrical conductivity by reducing interparticle distance and improved packing efficiency. In addition, the fabrication complexity of the radiation sensors was greatly reduced due to solution based ligand exchange, which can be scalable in achieving thick, crack free NC PbSe films. Improved conductivity and Schottky like behavior, which are desirable for good radiation sensing, were demonstrated in the fabricated NC PbSe radiation detector
Half-Sib Selection for Higher Betalains Concentration and Lower Total Dissolved Solids in Table Beets (Beta vulgaris)
Get PDFBetalains are a group of compounds that are major natural food colorants used by the food processing industry. These secondary compounds are found in only a few orders of plants with the Caryophyllales being the source of several domesticated crops. In particular, the family Chenopodiaceae in general and table beets (Beta vulgaris) specifically are the primary source for betalains for commercial extraction. Table beets are preferred because of high pigment concentration in the enlarged root in a crop that is relatively easy to grow, harvest and process. The primary betalains found in table beet are betacyanins (red pigments) and betaxanthins (yellow pigments). The food colorant industry is mainly interested in the betacyanin betanin, but betanin content is highly correlated with betalains so that selection for total betalains will result in an increase in betanin. Beets are also an economic source of sugars (primarily sucrose), which resulted in the development of sugar beets that are unpigmented but have sugar content of more than 20%. Table beets with moderately high sugar content have better flavor for culinary processes, but high sugars reduce efficiency of the extraction process of betalains for food colorants. Sucrose content in table beet is highly correlated with total dissolved solids (TDS), which can be easily measured with a refractometer whereas quantification of sucrose is more involved. Table beets with high betanin and low TDS are being sought by the food concentrate industry. The objective of this study was to breed for high betalain pigment and low TDS in table beets. While quantification of betalains can be performed by UV-Vis spectrophotometry, the process is laborious and not suited to evaluating large numbers typically found in a breeding program. As a substitute for direct measurement of betalains, selection based on colorimeter measurements using the CIE L*a*b* color coordinate system was investigated. Parents were obtained from the USDA National Plant Germplasm System and from commercial sources. Twelve plant introduction accessions were chosen based on passport data in the GRIN database that indicated that they were pigmented and possessed low (<5%) sucrose content. Also selected were commercial lines with strong and uniform pigmentation, but moderately high TDS content. Six rounds of half-sib mass selection were performed to select simultaneously for increased pigment and decreased TDS. The process involved growing plants in the field in a late summer – early fall trial, evaluating pigment and TDS content of 10 roots per family and placing selected roots into cold storage (2°C) where they were vernalized for a minimum of 11-12 weeks. Roots were then transferred to the greenhouse in January and allowed to bolt, flower and random mate. Seeds were harvested in May and June and used for the next cycle field trial. From the accessions and cultivars grown in the field in 2014 - 2019, samples of 10 roots from each accession were taken for pigment and TDS analysis. From 20 - 30% of the individuals with high pigment and low TDS were retained in each cycle. In 2019, remnant seed from previous cycles along with the current cycle (cycle 5) were included in a replicated field trial so that all cycles could be evaluated in the same environment and heritability and gain from selection could be calculated. In conjunction with the colorimeter measurements, betalains were quantified in 2019 using UV-Vis spectrophotometer, and correlations between colorimeter and spectrophotometer data were calculated. For betalains, family means for CIE L* had a steady decease throughout the years indicating selection for lower L* resulted in families with darker pigmentation. TDS family averages, on the other hand, showed essentially no change over cycles. When reviewing data across years, two factors that may have influenced TDS levels were year to year environmental variation and the fact that betalains are usually present as a glycoside such that any increase in the amount of betalains will be associated with additional glyosidic content. Colorimeter measurements were converted to Royal Horticultural Society colors and RGB (Red-Green-Blue) color values. Over time, the half-sib population showed an increase in the purple-red and grey-purple groups. The population had a high narrow-sense heritability of 0.74, and also a relatively high change from selection of 0.75 per cycle for L*. TDS had low h2 and change from selection of 0.16 and 0.062% per cycle, respectively. In the case of the correlation of UV-VIS spectrophotometer data with colorimeter measurements, evaluation of six lines in the 2019 population showed a strong negative relationship between colorimeter and spectrophotometer values. However, there was a weak regression coefficient (r2=-0.03) for L* vs. betanin among families of the entire 2019 population. Overall, selection based on L* resulted in transgressive segregation for betanin, with some families outperforming commercial cultivar. Thus, the colorimeter appears to have utility as a technique for rapid and high throughput betalain measurement