<p> As interest in new sweetpotato (<i>Ipomoea batatas</i> (L.) Lam.) markets such as starch feedstocks, anthocyanin production, chips and French fries, and other processed food products have increased, breeders have begun developing sweetpotatoes with unique compositions. This dissertation describes a three-pronged strategy to understand the genetic control of sweetpotato composition and modify it using near infrared spectroscopy (NIRS), quantitative inheritance studies, molecular markers, and exotic germplasm.</p><p> In our first experiment, a 5 &times; 5 NCII crossing block with 25 full-sib families was designed to study the inheritance of sweetpotato starch and anthocyanin content. Linear regression modeling was used to determine the effect of general combining ability (GCA) and specific combining ability (SCA) on dry matter, total monomeric anthocyanin (TMA) concentration, fresh yield, and total dry matter and anthocyanin yield. All five traits were moderately to highly heritable with significant general combining abilities. Yield and dry matter yield had significant specific combining abilities and significant differences among parents were discovered for all traits. Yield, dry matter, dry matter yield, and TMA yield were significantly impacted by spatial gradients within the field, but TMA concentration was not. Phenotypic and genotypic correlations among traits indicated that many traits of interest shared either genotypic and/or phenotypic correlations.</p><p> In our second experiment, a nested crossing block was used to estimate the heritability of sweetpotato yield and storage root composition traits in a population incorporating exotic germplasm obtained from the US sweetpotato germplasm repository and a core set of elite US sweetpotato lines crossed in a modification of the NCI design. Yield traits were recorded in the field and biochemical composition was phenotyped using NIRS. Heritability was measured on a half-sib family basis and a full-sib family basis to allow comparison between the commonly used polycross nurseries and paired crossing blocks. Parent offspring regression, which has been commonly used by sweetpotato breeders, was also used to provide another heritability estimate. Starch and sugar contents had relatively high heritabilities on both a GCA (h² > 0.32) and SCA basis (h² > 0.77). Yield traits had low heritability on a GCA basis (h² &lt; 0.16), but moderate heritability on an SCA basis (h² = 0.21 &ndash; 0.51). Heritability trends suggested that polycross nurseries could be effective for modifying sweetpotato composition, while paired crosses would be more effective for the modification of sweetpotato yield. Based on the performance of a wide range of crosses between exotic and heirloom varieties, we hypothesize that the global sweetpotato germplasm base contains many useful alleles for continued sweetpotato improvement. </p><p> Our final study involved a previously described sweetpotato quantitative trait loci (QTL) mapping population developed from a Tanzania x Beauregard cross (Cervantes-Flores 2006). This population was phenotyped using NIRS to identify QTL for sugar and starch content. In Beauregard, six QTL were associated with decreased starch and dry matter content and eight QTL were associated with increased sugar content. One QTL in Beauregard was associated with decreased yield. In Tanzania, two QTL were associated with increased starch and two QTL were associated with decreased starch; there were also two QTL associated with decreased sugars and one associated with increased sugar content; one QTL was associated with decreased culls. In most cases, newly identified QTL co-locate with those previously described.</p><p> Collectively, this research represents a significant effort in sweetpotato to merge molecular markers with NIRS phenotyping, and it has opened the doorway to further developments that merge these two new technologies for sweetpotato improvement.</p>

Water use is an important topic in the global agriculture community and is a critical input in nursery crop production. Several plants in the genus Cornus are important nursery crops. Not only are they economically relevant, they are found in grafted and seedling forms and parents and their hybrid are readily available in the trade, facilitating an assessment of water requirements. Anecdotal information suggests that Cornus taxa have differing stress tolerance and water use requirements. Research was conducted to characterize and model water use among Cornus taxa. Scanning electron microscopy and anatomy‐based micromorphological studies as well as transpiration chamber‐based studies revealed differences in the cuticle, epidermal thickness, stomatal density, total stomatal complex area, and gas exchange. A novel photosynthesis‐based irrigation model was developed and evaluated, first on a model crop, Hibiscus rosa‐sinensis, then with a range of Cornus taxa, including grafted specimens. The model allowed the identification of a setpoint or point at which irrigation is triggered. Producing plants under this model allowed a 27% reduction in water use while maintain growth when compared with controls.

<p> Society's environmental practices often parallel those of our criminal justice system. Both embody "throw-away" cultures that often yield more complex problems than those they were attempting to solve. Programs that provide real meaning-making are necessary to achieve ecological and criminal rehabilitation. Fundamental ecological and personal transformation requires a deep sense of context, purpose, and reconnection extending beyond mere employability. In this research we explored how people come to terms with personal moral obligation, as well as how restorative ecological engagement may be transformational for humans in personal crisis. Primary field data were gathered from incarcerated men inside San Quentin State Prison participating in the Insight Garden Program (IGP), as well as men in the same unit attending other prison programming, or no programming. A mixed-method approach was used, including open-ended interviews and three multiple-choice survey instruments: a locus of control survey, an environmental literacy quiz, and a climate change opinion survey. Each survey revealed strong results (those consistent with recidivism correlations) for IGP participants, followed by those in other programs, in comparison with men in no programming. Qualitative results most strongly illustrated that prison programming, gardening and otherwise, can contribute profoundly toward transformative value reorientation, which is integral to rehabilitation.</p>

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.

Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: Robert E. Lyons, Dept. of Plant & Soil Sciences. Includes bibliographical references.

Thesis (M.A.)--University of Canterbury, 2005. / Typescript (photocopy). "June 2005." Includes bibliographical references (p. 156-167). Also available via the World Wide Web.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains vi, 35 p. Vita. Includes abstract. Includes bibliographical references (p. 29-30).

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Robert E. Lyons, Dept. of Plant and Soil Science. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 1986. / Includes vita. Includes bibliographical references (leaves 159-173). Available online via OhioLINK's ETD Center

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6173. Adviser: Schuyler S. Korban. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.