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You searched for +publisher:"Colorado State University" +contributor:("Davidson, Robert"). Showing records 1 – 2 of 2 total matches.

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Colorado State University

1. Zaid, Salah E. Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.).

Degree: PhD, Horticulture and Landscape Architecture, 2020, Colorado State University

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… Advisors/Committee Members: Hughes, Harrison (advisor), Krishnan, Sarada (committee member), Brick, Mark (committee member), Davidson, Robert (committee member).

Subjects/Keywords: genetic diversity; microsatellites; simple sequence repeats; genetic structure; date palm; phylogenetics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zaid, S. E. (2020). Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.). (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/199734

Chicago Manual of Style (16th Edition):

Zaid, Salah E. “Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.).” 2020. Doctoral Dissertation, Colorado State University. Accessed August 12, 2020. http://hdl.handle.net/10217/199734.

MLA Handbook (7th Edition):

Zaid, Salah E. “Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.).” 2020. Web. 12 Aug 2020.

Vancouver:

Zaid SE. Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.). [Internet] [Doctoral dissertation]. Colorado State University; 2020. [cited 2020 Aug 12]. Available from: http://hdl.handle.net/10217/199734.

Council of Science Editors:

Zaid SE. Molecular investigations in date palm genetic structure and diversity among commercially important date palm cultivars (Phoenix dactylifera L.). [Doctoral Dissertation]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/199734

2. Houser, Andrew Joseph. Understanding blackleg in seed potato operations and the development of management strategies for the control of blackleg and tuber soft rot, caused by Pectobacterium SPP.

Degree: PhD, Horticulture and Landscape Architecture, 2018, Colorado State University

Pathogenic bacteria in the genera Pectobacterium and Dickeya are of major concern in many potato growing regions around the world and are the causal organisms of blackleg and tuber soft rot. Bacteria in these genera are pectolytic, meaning they utilize pectin, of which potatoes are a good source. Crystal Violet Pectate (CVP) media was used in this project to detect the presence of pectolytic bacteria. If this bacteria is present, pits will form on the media. Pitting refers to the presence of a concave indentation in the media resulting from actively growing pectolytic bacteria. This project evaluated different stages of seed potato production to determine possible bacterial reservoirs during a seed cutting operation, optimal timeframe for bacterial screening of potato seed, and the use of different crop rotations to manage these bacteria. In addition, a summary of the findings from this project was used to develop a grower friendly blackleg/tuber soft rot management guide. The first objective was to evaluate two seed cutting operations and determine whether reservoirs of bacteria were present and could act as possible sources of contamination. Pectolytic bacteria are often spread through the seed cutting process. Cutter surfaces exposed to pectolytic bacteria include cutting knives, belts, rollers, etc. This study evaluated two seed cutting operations for their potential to limit the spread of pectolytic bacteria. Grower 1 used a Milestone seed cutter while grower 2 used a hot cutter with heat sterilized blades. There were no statistical differences between the Milestone and hot seed cutter at reducing the spread of pectolytic bacteria than the Milestone cutter. However, when individual cutter surfaces were compared, there was a higher percentage of pectolytic bacteria on the stationary knives of grower 1 (26.7 % pitting) compared with the hot cutter knives from grower 2 (1.0% pitting). Results from this study show that the use of heat to sterilize cutting blades reduces the amount of pectolytic bacteria better than stationary knives that were not sanitized. The second objective was to determine an optimal timing for estimating bacterial levels in a seed crop. Pectolytic bacteria that cause potato blackleg (Pectobacterium spp. and Dickeya spp.) can often be detected in field-grown, early generation certified seed potato lots, even though the origin seed stocks were tested as free of the bacteria. Because of this, growers have a need for a predictive tool to assist in making good, appropriate decisions about any given seed lot. This project used a crystal violet pectate (CVP) - tuber poke method to screen early generation potato seed to predict possible outbreaks of blackleg. Potato samples from several certified seed operations were tested using this method and compared with summer inspection blackleg readings. Results showed operations that differed in the number of blackleg outbreaks also differed in % pitting when a sample from the same seed crop was tested. At early generations, an increase in % pitting on CVP… Advisors/Committee Members: Davidson, Robert (advisor), Manter, Dan (committee member), Stromberger, Mary (committee member), Wallner, Steve (committee member).

Subjects/Keywords: certified seed; potato; Pectobacterium; blackleg

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Houser, A. J. (2018). Understanding blackleg in seed potato operations and the development of management strategies for the control of blackleg and tuber soft rot, caused by Pectobacterium SPP. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/191252

Chicago Manual of Style (16th Edition):

Houser, Andrew Joseph. “Understanding blackleg in seed potato operations and the development of management strategies for the control of blackleg and tuber soft rot, caused by Pectobacterium SPP.” 2018. Doctoral Dissertation, Colorado State University. Accessed August 12, 2020. http://hdl.handle.net/10217/191252.

MLA Handbook (7th Edition):

Houser, Andrew Joseph. “Understanding blackleg in seed potato operations and the development of management strategies for the control of blackleg and tuber soft rot, caused by Pectobacterium SPP.” 2018. Web. 12 Aug 2020.

Vancouver:

Houser AJ. Understanding blackleg in seed potato operations and the development of management strategies for the control of blackleg and tuber soft rot, caused by Pectobacterium SPP. [Internet] [Doctoral dissertation]. Colorado State University; 2018. [cited 2020 Aug 12]. Available from: http://hdl.handle.net/10217/191252.

Council of Science Editors:

Houser AJ. Understanding blackleg in seed potato operations and the development of management strategies for the control of blackleg and tuber soft rot, caused by Pectobacterium SPP. [Doctoral Dissertation]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/191252

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