http://hdl.handle.net/1957/19297 2013-05-21T18:41:38Z http://hdl.handle.net/1957/38565 Improving initiation and mineral nutrition for hazelnut (Corylus avellana) micropropagation Hand, Charles R. Corylus avellana L. is a global commodity and a valuable crop for the U.S. Pacific Northwest. A tremendous amount of work has been put into the development of healthy disease free, high yielding and tasty hazelnuts for the in-shell and confectionary markets. Clonal propagation is required to provide nursery trees of these improved hazelnut cultivars. The rapid multiplication provided by micropropagation methods is an important part of meeting the demand. One challenge of hazelnuts micropropagation is the wide variation in growth response among the cultivars. The studies described in this thesis were involved in improving the mineral nutrients in the growth medium and to better determine culture initiation procedures. The first study was designed to determine what mineral nutrients are driving C. avellana in vitro shoot growth using a response surface design. Hazelnut genotypes 'Dorris,' 'Felix,' 'Jefferson', OSU 880.054, and 'Sacajawea' were used. Driver and Kuniyuki Walnut medium (DKW) mineral nutrients were separated into five factors: NH₄NO₃, Ca(NO₃)₂, mesos (MgSO₄ and KH₂PO₄), K₂SO₄, and minor nutrients (B, Cu, Mn, Mo, and Zn). The concentrations ranged from 0.5x to 2.0x the standard DKW concentrations with 33 treatments for use in modeling. Multifactor response surface analysis projected that optimum shoot proliferation was greatly influenced by the NH₄NO₃ to Ca(NO₃)₂ ratios, mesos, and minors. These factors were important to overall quality and shoot length for all genotypes. Improved shoot quality was observed with increased Ca(NO₃)₂, mesos, and minors for most of the cultivars tested. For 'Sacajawea' only the mesos components significantly improved shoot quality. Lower Ca(NO₃)₂ improved shoot multiplication while higher amounts increased shoot length for most cultivars. New media formulations will require higher Ca(NO₃)₂, mesos and minors as well as changes in the NH₄NO₃ to Ca(NO₃)₂ ratios. The second study determined the effects of individual minor-mineral nutrients including nickel on hazelnut shoot growth. Three hazelnut cultivars 'Dorris,' 'Jefferson,' and 'Sacajawea' were used. Six factors at 0.5x to 4.0x DKW concentrations, H₃BO₃, CuSO₄, MnSO₄, Na₂MoO₄, Zn(NO₃)₂, and NiSO₄, were tested in a response surface design with 39 treatment combinations. Ni, not present in DKW, ranged from 0 to 6 µM. Higher concentrations (4x) of B, Mo, and Zn increased overall shoot quality, length and multiplication. There were many significant interactions. High B concentrations significantly improved shoot quality for 'Jefferson'; shoot quality, length and number for 'Dorris'; and shoot length and number for 'Sacajawea'. Increased Mo improved some responses for each cultivar, and it also interacted with Cu and Zn. Interactions of Ni with other minor nutrients resulted in improved shoot quality and length in 'Sacajawea.' Ni interactions were significant for the other cultivars as well, altered the requirements for other nutrients, but did not necessarily improve the overall shoot response. Improved growth and shoot quality in 'Dorris' and 'Jefferson' required increased amounts of B, Mo, and Zn; 'Sacajawea' required increased B, Cu, Zn, and Ni. The diverse responses of these cultivars further confirmed that nutrient uptake or utilization was genotype dependent. Hazelnuts are generally difficult to initiate into culture due to internal microbial contaminants and a general lack of viability of the explants. The third study was designed to determine the effect of nodal position and collection techniques on the viability and contamination of shoot explants. Explants were collected from scion wood grafted onto seedling rootstocks and grown in the greenhouse. Single-node explants were collected from different locations on the scion wood. After surface sterilization, explants were first held in a liquid contaminant-detection medium for one week and the effect on explant viability was evaluated. Node position influenced the number of viable contaminant-free explants. Bacterial contamination increased with the distance from the shoot tip. The use of liquid detection medium as a part of the initiation procedure did not affect viability. Bacteria sampled from surface sterilized explants were identified as Brevundimonas vesicularis, Brevundimonas sp., and two Pseudomonas sp., by 16S ribosomal DNA sequences and API® 20CHB tests. The best procedure for collecting axenic, viable hazelnut explants was to collect from the first three nodes of actively-growing greenhouse plants and use detection medium to identify contaminant-free tissue. As a result of these studies several suggested growth media formulations are now available for use that may produce improved hazelnut shoot quality, multiplication and elongation for a wide range of C. avellana genotypes. Two base macro nutrient formulations, Hazelnut A and B, are likely to be suitable for many genotypes. Three micronutrient formulations provide options for growth of difficult genotypes with and without Ni. Continued optimization and testing of mesos and N components are needed for final medium formulations. Graduation date: 2013 2013-04-18T00:00:00Z http://hdl.handle.net/1957/38263 Mapping QTL for root rot resistance, root traits, and morphological trait in a common bean recombinant inbred population Hagerty, Christina H. Root rot diseases of bean (Phaseolus vulgaris L.) are a problem wherever they are grown, and are a major constraint to dry edible and snap bean production. Root rot is a primary yield limitation of snap bean production in the US, especially within the top three snap bean producing states of Wisconsin, Oregon and New York. Bean root rot pathogens will be present by the end of the first season even when starting with clean ground. The decline in yield can be relatively slow, so growers might not notice or appreciate the hidden yield cost associated with root rot disease. Traditional methods for disease control such as fungicides, crop rotations, cover crops, seedbed preparations have been proven ineffective (either physically ineffective or economically unviable) against root rot. Therefore, genetic resistance is needed. In order to address the need for genetic resistance to root rot in snap beans, the highly root rot resistant line RR6950, a small seeded black indeterminate type IIIA accession of unknown origin, was crossed with OSU5446, a highly root rot susceptible determinate type I blue lake four-sieve breeding line to produce the RR138 recombinant inbred mapping population. In this study we evaluated the RR138 RI population in the F₆ generation for resistance to Fusarium solani root rot in Oregon and Aphanomyces euteiches root rot in Wisconsin. We also evaluated this population for morphological traits and root structural traits including pod height, pod width, pod length, pod wall thickness, strings, seed color, flower color, tap and basal root diameter, and root angle measurements. The RR138 population was also genotyped on the 10K BeanCAP Illumina Beadchip. The Single Nucleotide Polymorphism (SNP) data was used to assemble a high-density linkage map and Quantitative Trait Loci (QTL) for phenotypic data were evaluated. The linkage map produced from this study contained 1,689 SNPs across 1,196cM. The map was populated with 1 SNP for every 1.4cM, spanning across 11 linkage groups. Three QTL associated with A. euteiches root rot resistance were consistently expressed in 2011 and 2012 trials. A. euteiches QTL were found on Pv02, Pv04, and Pv06 and accounted for 7-17% of total genetic variation. Two QTL associated with F. solani were found in 2011 trial on Pv03 and Pv07, account for 9 and 22% of total genetic variation, respectively. We also found several QTL for morphological traits and root structural traits including QTL for pod fiber and pod height on Pv04, pod length on Pv01, strings on Pv01, taproot diameter on Pv05, and shallow basal root angle on Pv05, accounting for 21, 26, 12, 20, 11, and 19% of total genetic variation, respectively. QTL discovered from Oregon data for F. solani resistance did not cluster with QTL for A. euteiches root rot resistance. "SNP0928_7", was highly associated with F. solani resistance on Pv07 and "SNP0508_2", was highly associated with A. euteiches on Pv02. QTL and markers associated with QTL from this study will be of value to snap bean breeders developing root rot resistant lines with processing traits, and provide more information about targeting the mechanism of resistance. Graduation date: 2013 2013-03-13T00:00:00Z http://hdl.handle.net/1957/38183 Assessing the impact of garden education programs on motivational engagement and academic achievement Gupta, Abha School garden programs have become increasingly popular for their diverse, positive benefits. School gardens are often promoted as a relatively low cost means to offer hands-on learning opportunities that may foster academic achievement, particularly in the sciences, however only six studies have been published on the impact of garden education programs on science achievement. Five out of six of these studies focused on elementary age students. One study has identified motivational engagement as the mechanism responsible for fostering academic success. School gardens are more common in elementary schools. However, they may be most beneficial in a secondary school setting, when students tend to lose interest in academics and often perform poorly on national assessments of science. Thus, in this study we evaluated adolescent students at three schools with well-established garden education programs. We used pre-test and post-test measures to see how students' levels of various predictors of engagement (e.g. autonomy, competence, relatedness, and intrinsic motivation), actual engagement (in the realms of academics, science, and the garden), garden learning, and academic achievement measures (e.g. overall grade point average and science grade point average) would change over the course of this study. We also assessed how the different realms of engagement correlated with predictors of engagement, with garden learning, and with academic achievement measures. In addition, we examined correlations among the different realms of engagement. At one of the schools, a non-gardening group participated in the study as a control group. Thus, we also compared the gain scores in predictors of engagement, engagement, and academic achievement between the control and garden group from that school. At all three schools, academic or garden engagement significantly increased for the garden groups. Garden engagement was significantly correlated with academic engagement, science engagement, or both, at each of the three schools for post-test measures. Predictors of garden-based engagement were significantly correlated with academic and/or science engagement at each school, at least for post-test measures. These results show that gardening may have the potential to be a contributor to positive motivational changes that in turn can be related across academic domains. The non-gardening group showed significant gains in predictors of- and engagement itself, while the gardening group either marginally declined or maintained its level. However, the non-gardening group had significantly lower pre-test scores in comparison to the gardening group, which in part accounts for their comparative significant gain. The garden group showed significant increases in predictors of garden engagement and garden engagement itself. These results show that the garden group, comprised of at-risk students, are experiencing positive motivational benefits, which can possibly prevent further decline in their general performance. The lack of improvement in academic achievement suggests that the full academic benefit of garden education programs has yet to be consistently reached. We recommend that researchers use a more refined evaluation test and survey, specific to the garden program at hand and include qualitative measures. Graduation date: 2013 2013-03-18T00:00:00Z http://hdl.handle.net/1957/38093 Breeding an open pollinated broccoli for organic production systems using participatory methods McKenzie, Laurie R. Organic agriculture is an important and growing sector of U.S. and world food production. Consumers are increasingly aware of and interested in the production practices and impacts associated with agriculture and as such, are showing a preference for sustainably produced, raised, and harvested foods. In order to continue to meet the growing demand for organic produce, organic growers need cultivars that are optimally adapted to organic and low input conditions. Quality seed is the foundation of any functional and stable farming system. Unfortunately the lack of organically bred and produced seed is hindering the continued growth and success of organic farming. Meeting the needs of the organic sector has been a challenge for the seed industry; it is an industry that often doesn't understand the specific and unique requirements associated with the diversity of environmental and market demands of organic systems. However, organic farmers and the organic food systems they supply, require a robust organic seed system that is appropriately adapted to regional agronomic challenges and market needs, meets standards and regulations, and encompasses the social and ecological values of organic agriculture. One plausible approach to meeting the cultivar and seed needs of organic and low input production systems is through the use of participatory plant breeding (PPB). PPB is a collaborative approach for identifying and developing genetically diverse plant material and varieties involving partnerships among formal sector breeders and researchers, farmers, extension agents, educators, and end users. Participatory plant breeding fundamentally changes the way that formal breeding programs and farmers manage germplasm and plant genetic resources. Typically, formal breeding programs restrict access to germplasm and breeding materials and only supply farmers with finished varieties. In PPB, farmers are involved in the early stages of creation and evaluation of germplasm and breeding material, and stay engaged with the breeding process until new varieties are created. PPB is an excellent model for breeding specifically for organic systems because organic systems in developed countries have many similarities to low-input agricultural systems in the developing world. Some of these parallels include heterogeneous growing environments, a wide range of end uses and marketing strategies, lack of suitably adapted and/or derived varieties, lack of attention from the formal seed sector, and a reduced reliance on synthetic inputs (compared to conventional systems). Breeding for organic systems is a relatively young field and breeders in the formal sector do not have a good handle on what traits are important for robust production under organic conditions. Thus the opportunity to meld farmers' experience and knowledge with breeders' expertise is an effective way to breed for organic production systems. The purpose of this project was to investigate and explore the opportunities and challenges of organic plant breeding using participatory research methods. This research had three goals: 1) to develop an open pollinated broccoli with contemporary quality traits for organic production systems using participatory strategies; 2) to compare broccoli selections made by formally trained plant breeders and farmer breeders; and 3) to capture the stories and experiences of the formal breeders and farmer breeders involved with this broccoli material in order to contribute to the growing wealth of knowledge on collaborative and organic breeding work. The Oregon State University Vegetable Breeding Program made significant progress towards decreasing the variability of the broccoli project material through three successive years of modified half-sibling selections. Evaluations and selections were based more strongly on quality traits rather than soley on production traits such as yield. Although progress was incremental and statistically verified in only three out of the fifteen quality traits, we observed trends in the data indicating progress towards an increasingly uniform, stable, and reliable open pollinated broccoli with specific adaptation for organic production systems. There were very few differences between broccoli materials developed by formally trained plant breeders and farmer breeders. This was especially true for the three cultivars developed in the Pacific Northwest (PNW) (one in Washington and two in Oregon). The 'East Coast' population, which had been collaboratively selected by formal and farmer breeders in New York, expressed significantly distinct differences from the PNW materials. When the farmer breeder and formal breeder materials were pooled together and compared to pooled check cultivars they expressed significant differences for nearly all traits across all years. This demonstrated that all of the collaboratively developed open pollinated materials are distinctly different from the F1 hybrids currently available. Our work has demonstrated a few of the myriad of positive outcomes achievable with the use of participatory plant breeding for organic production systems. The participatory nature of this project resulted in increased confidence and feelings of empowerment for all involved. Both farmers and breeders felt their involvement was socially beneficial and widened their networking and seed community circles. The farmer-bred cultivar 'Solstice' is now available as a result of Jonathan Spero's work, and a cultivar tentatively named 'Benton' is about to be released for sale through Oregon State University. Our results agree with previous study findings that formal and farmer breeder selections are often not distinctly different; thus providing evidence for continuing to support the involvement and education of farmers in plant breeding, especially in reference to organic production systems. This study demonstrates the potential of collaboratively developed and farmer-bred cultivars to become viable and vibrant open pollinated alternatives to the current open pollinated cultivars on the market today. Graduation date: 2013 2013-03-06T00:00:00Z