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Browsing by Author "Krishnan, Sarada, committee member"

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    A case study evaluation of edible plants curriculum implemented in an elementary school
    (Colorado State University. Libraries, 2014) Graves, Leila, author; Hughes, Harrison, advisor; Balgopal, Meena, advisor; Bunning, Marisa, committee member; Krishnan, Sarada, committee member
    The main purpose of this study was to describe elementary teachers' attitudes and perceptions toward plant science. The secondary purpose was to create an edible plant curriculum as a vehicle for integrating STEM and 21st Century skills into Common Core Content. Results indicate that teachers and STEM coordinators did find the curriculum to be effective in teaching the interdisciplinary standard-based and inquiry based content and skills targeted. Additionally, the curriculum development process produced a hybrid design framework that facilitated the creation of life science content as a vehicle for integrating STEM into common core content. However, several significant barriers will need to be overcome with regard to the teachers', STEM coordinators' and administrators' perception that plant science and nutrition literacy are "special" content activities versus important STEM content.
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    Environmental stress recovery of horned poppy (Glaucium spp.) using growth regulator treatments
    (Colorado State University. Libraries, 2015) Elghoul, Milad M., author; Hughes, Harrison, advisor; Shahba, Mohamed, committee member; Ocheltree, Troy, committee member; Krishnan, Sarada, committee member
    To view the abstract, please see the full text of the document.
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    Green roof effects on floral phenology and floral nectar resources
    (Colorado State University. Libraries, 2023) Ruszkowski, Kyle M., author; Bousselot, Jennifer, advisor; Hufbauer, Ruth, committee member; Krishnan, Sarada, committee member
    This study investigates the potential for green roofs to support pollinator diversity and abundance in urban ecosystems through the altered floral phenology and floral abundance of plants. I compare floral phenology and the floral abundance of green roof plants to plants grown at grade on the Front Range in Fort Collins, Colorado, and how these changes may affect pollinator biodiversity in urban ecosystems. I employed an independent block design, with one green roof and one ground-level garden, approximately 120 meters apart, with replicate plants of 4 species at each garden. I found the abundance of flowers to be variable, depending on the plant species. However, all species of plants tested bloomed earlier when grown on the green roof than when grown at grade. We found pollinator abundance and diversity to be low at both the green roof and at grade. Nectar quantity and quality are diverse across a landscape and affect the health and behavior of some pollinators. I evaluated nectar volume and nectar sugar concentration between plant replicates grown on a green roof and grown at grade. Volume was measured in situ and sugar concentration was measured both in situ using a refractometer and, in a laboratory, using UPLC-RI. We found that there was no clear difference between nectar volumes of plants grown on the green roof and at grade while nectar sugar concentrations were generally higher in green roof plants.
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    Investigation of flowering phenology, pollinator and invertebrate biodiversity value on urban green roofs and an evaluation of ornamental horticulture crops for pollinator value
    (Colorado State University. Libraries, 2024) Guidi, Michael A., author; Bousselot, Jennifer, advisor; Hufbauer, Ruth, committee member; Krishnan, Sarada, committee member
    Urban green space, green infrastructure, and horticultural installations are gaining recognition for their potential to foster biodiversity. Green roofs are challenging growing environments for plants, characterized by extreme substrate temperatures, high light intensity, limited moisture availability, and limited substrate depth. Plants have a variety of physiological responses to these unique conditions, but little is known about how green roof growing conditions affect ecological characteristics like plant flowering phenology. Similarly, studies are only just beginning to uncover the degree to which green roofs can provision habitat and support urban biodiversity. We evaluated the flowering phenology and made in-situ pollinator observations of 15 plant taxa growing both on green roof systems and at ground level at the Denver Botanic Gardens over two growing seasons. Using the same study sites, we sampled invertebrate diversity on green roof sites and ground level using pitfall traps. Finally, using a large citizen-science dataset, we evaluated differences in pollinator visitation with a specific focus on plant nativity, cultivated origin, growth form. We found that flowering phenology is substantially earlier on green roofs compared to ground level. We also observed a greater number of pollinators on green roofs early in the season, compared to ground level, presumably due to the availability of flora resources among the observed plant taxa. We observed significantly higher substrate temperatures along with wider diurnal temperature amplitude during the growing season that may contribute to this pattern. Invertebrate abundance was substantially higher at ground-level, species richness was similar between the intensive green roof and ground-level, and we observed substantially lower abundance and richness on the extensive green roof. Divergence in flowering phenology between individual plants of the same species on green roofs and plants at ground-level may have implications for organisms that rely on floral resources in urban environments. Earlier flower initiation on green roofs may provide pollinators with unique foraging opportunities and aid targeted conservation where early-season floral resources are limited. Similarly, results from invertebrate sampling suggest that green roofs, especially intensive roofs with high vegetation coverage, species richness, and habitat heterogeneity may offer invertebrate habitat on par with ground-level urban gardens and may even support unique groups of invertebrate taxa. Our results from our citizen science pollinator observations demonstrate that non-native plants showed similar visitation compared to native plants, but origin was important with selections and species having significantly higher pollinator visitation compared to hybrid plants. Shrubs and herbaceous perennials demonstrated high pollinator visitation compared to other plant growth forms.
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    Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.)
    (Colorado State University. Libraries, 2019) Zaid, Salah E., author; Hughes, Harrison, advisor; Krishnan, Sarada, committee member; Brick, Mark, committee member; Davidson, Robert, committee member
    The date palm, Phoenix dactylifera L. is the notable palm which produces a nutrient-rich edible fruit (the date), well known for its unique attributes of medicine and healthy energy. It is a species that has been cultivated since early civilizations in the fertile crescent and later in the Middle East. It is typically cloned with many cultivars (over 3000). A means of accurately identifying specific clones and an understanding of the relationships among major commercial cultivars would provide valuable information for the maintenance, potentially an improvement and continued conservation of superior genotypes. Phylogenetic relationships amid commercial date cultivars are poorly understood, despite their importance. This research aimed at providing applicable knowledge through an expedient technique, by developing an exclusively tailored Simple Sequence Repeat (SSR) panel, custom-made for date palm fingerprinting and molecular identification also named as 'Dates PalmàPrinting'. This assembled modified genotyping by microsatellite markers provides a standardized approach to cultivar identification and a quality control application in date palm micropropagation production. A deeper understanding and relationship of today's major commercial cultivars is incomplete. Improving the development and productivity of this tree species is restricted due to few genetic resources. Only regionally narrowed studies have been conducted but it is more important to have a broader base of such knowledge. The present research reports on 20 selected, commercially important date palm cultivars, consisting of 18 females and 2 males, which are grown throughout the world. The knowledge of relationships among these cultivars is needed, although the date palm genome has been mostly sequenced (90.2 %) with 41,660 gene models representing an 82,354 scaffold. The relationships among the major cultivars remain unclear. Presently, the information on the characterization of these cultivars requires an assessment to better understand the relationships among the superior genotypes. The use of microsatellites, due to their accuracy and high polymorphic capability, have led to fine scaled phylogenies. The phylogenetic relationships were determined using neighbor joining un-rooted trees correlated with genetic structure clustering. Primer selections were achieved from evaluation of 14 nuclear SSR loci isolated from P. dactylifera. Results revealed a high degree of polymorphism observed in the 20 cultivars with fewer common alleles than anticipated. Within the cultivars studied, a broad heterozygosity across base pair (bp) amplification data has led to an understanding of limited inbreeding, accounting for possible adaptation to environmental changes and revealing conserved extensive array of genomic structure. Population structure analysis suggests a large genetic boundary between Northwest African and Middle Eastern cultivars with 6 subpopulations that represent divergences and fragments of admixture in cultivars present in these regions. The possible selection of potential and good quality parents is achievable for improving cultivars by generating population and structure maps. This analysis documents patterns of relationship and provides genetic structure and diversity of gene pool specificity complexes of date palm cultivars.