5 pp. / Realizing that the Arizona citrus industry might someday have to deal with widespread ACP control, the Arizona Citrus Research Council approved a trip to Florida and Texas to investigate how ACP control was accomplished in those two states. The trips were to McAllen, Texas on 9-12 Nov 2011 and to Immokalee Florida on 17-18 Nov. 2011. In McAllen, I interviewed Dr. Mamoudou Setamou, extension entomologist for Texas A&M – Kingsville and his staff, and Mr. Ray Prewitt, president of Texas Citrus Mutual. In Florida, I interviewed Mr. Ron Hamel, manager of the Gulf Citrus Growers, and Dr. Mongi Zekri, southwest Florida Multi-County Citrus Agent, housed at the Hendry County Extension Office in LaBelle., FL. The author hopes that some of this information can be used in the development of an Area Wide Spray Plan in Arizona.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (Ph.D.) - University of Glasgow, 2008. / Ph.D. thesis submitted to the Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, 2008. Includes bibliographical references. Print version also available.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references (p.41-45).

No abstract available / Thesis (DSc)--University of Pretoria, 1945. / gm2014 / Plant Science / Unrestricted

A high-throughput sequencing pipeline to characterize Citrus tristeza virus isolates was developed. Three alternative viral templates (total RNA, double-stranded RNA and virus particles) were first tested on a single, previously characterized GFMS12 sub-isolate for their enrichment qualities, and combined with random RT-PCR amplification were subjected to Illumina paired-end sequencing. Double-stranded RNA was found to be most useful and was selected for further characterization of additional isolates (glasshouse-kept and field-derived). A novel South African genotype, named CT-ZA3 was assembled de novo and shown to be the dominant component in all GFMS12 sub-isolates tested. Genotype distributions within field-derived isolates collected from commercial orange (Citrus sinensis) orchards revealed a mixed infection status, dominated by a resistance breaking (RB)-like component (Tai-SP) coupled with a minor, VT-like (mild) (Kpg3) component. Based on read mapping patterns from field isolates, it is further suggested that two previously unknown recombinants may be present: a SP/Kpg3 and HA16-5/Kpg3 combination. This study underlined the effectiveness of next-generation sequencing for genotype discovery as well as whole-genome characterization of CTV isolates to a level of detail previously unreachable with classical methods such as SSCP and Sanger sequencing of multiple clones. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Microbiology and Plant Pathology / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (MSc Agric (Plant Pathology))--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

4 pp. / Budding Citrus Trees, Irrigating Citrus Trees / Citrus trees are not particularly cold hardy, but they are most likely to survive cold temperatures if they are planted in the proper location. This publication focuses on how to help citrus trees survive the winters of Arizona. Topics include site selection and long-term / short-term strategies used to protect citrus trees from frost and freeze.

The regulation of citrus fruit color by various concentrations of sugars, sugar metabolites, and nitrogen compounds was investigated in peel segments of Citrus paradisi Macf. (cv. Marsh) cultured on modified media of Murashige and Tucker. Green and yellow peel segments were cultured for degreening and regreening studies, respectively, and chlorophyll level in the individual peel segments was measured with a reflectometer. Degreening was significantly promoted by 150 mM sucrose, 300 mM glucose and fructose, or 50 mM citrate but not by 300 mM of the hexoses galactose and mannose, 300 mM of the pentoses xylose and ribose, or 25, 50, and 100 mM succinate. Regreening was significantly inhibited by 150 mM sucrose, 300 mM glucose and fructose, or 50 mM citrate and malate. Succinate and α-ketoglutarate at concentrations of 50 mM did not inhibit regreening. The inhibition of regreening by 300 mM sucrose was reduced by 33 percent with the glycolytic inhibitor iodoacetic acid at 1 mM but not by DL-glyceraldehyde at 50 mM. Neither ethanol nor potassium bicarbonate inhibited regreening, suggesting that the regulation of citrus fruit color is specific to sugars or sugar metabolites. However, pyruvate did not promote degreening or inhibit regreening because it was probably not absorbed from the media by the flavedo of the peel. These results suggest that sucrose, glucose, fructose, and citrate maintain carotenoid synthesis and accumulation in both cultured green and yellow peel segments but cause the loss of chlorophyll from green peel segments. Treatment of either the green or yellow segments with sucrose or citrate may increase the partitioning of these compounds into the mevalonic acid pathway to provide carbon for synthesis or carotenoids, resulting in degreening of the green peels and maintaining the yellow color in the yellow peels. Malonate inhibited regreening when incorporated in media at concentrations of 4 mM. This inhibition was reversed by 60 mM glutamine but not by 5 mM glutamine or KNO₃. The action of malonate on regreening may be a specific effect of malonate on plastid development rather than by modifying the partitioning of sugar metabolites into the carotenoid synthetic pathway.

Obligately anaerobic bacteria of the genus Bacteroides are important and abundant inhabitants of the rumen and hind gut of mammals. They are the most numerous group in the rumen and play a major role in fibre degradation with the rumen. They are phylogenetically remote from the better studied groups of facultatively anaerobic gut bacteria (eg. enterobacteria), but are closely related to the colonic Bacteroides. Interstrain conjugal transfer of a plasmid, pRRI4 (coding for tetracycline (Tc) resistance), from the multiple plasmid bearing B.ruminicola strain 223/M2/7 to F101, a rifampicin resistant mutant of B.ruminicola B 14, was demonstrated. pRRI4 was demonstrated to be self transmissible and carried the genes coding for TcR in B.ruminicola. Transformation of B.ruminicola F101 to TcR with pRRI4 was achieved using electroporation at frequencies up to 106 per mug DNA. Four other B.ruminicola strains were not transformed with this plasmid nor was a strain of B.uniformis. Similar procedures gave transformation of B.uniformis strains, but not B.ruminicola strains, with the E.coli:Bacteroides shuttle vectors pDP1 and pE5-2 at frequencies up to 107 per mug DNA. A nuclease assay was developed to determine the nuclease activity of a number of rumen bacteria and high nuclease activity in all B.succinogenes and five B.ruminicola strains was demonstrated. E.coli and B.uniformis strains were also transformed using electroporation by the shuttle vector, pRRI207, which has been constructed from a cryptic B.ruminicola plasmid (pRRI2, 3.4kbp) cut with EcoRI* , an E.coli vector plasmid (pHG165, 3.37kbp) carrying the pUC8 multiple cloning site, and the 4.2kbp Cc-EmRTc R* EcoRI region of pDP1. pRRI207 is capable of transforming B.uniformis, B.distasonis and B.ruminicola to clindamycin (Cc) resistance and E.coli to TcR (only expressed aerobically), and was the only construct from eleven different constructs obtained based on pRRI2 able to do so.