Biological, serological, and molecular characteristics of the P4 pathotype of pea seedborne mosaic potyvirus (PSbMV) were investigated. The characterization allowed P4 to be differentiated from other pathotypes of the same virus. P4 was distinguished from P1 on the basis of host symptomatology. It induced varied, but often distinctive symptoms in systemically-infected pea (Pisum sativum) cultivars. P4 inoculation of indicator hosts, notably Chenopodium album, resulted in the formation of local lesions. Pathotype P4 was seed transmitted at low frequencies relative to P1. In ten selected pea cultivars, seed transmission of P4 never exceeded 0.7%, while P1 was transmitted at frequencies as high as 33%. In mixed infections with P1, pathotype P4 was seed transmitted at 0- 2% as determined by P4-specific indirect ELISA. However, limited polymerase chain reaction (PCR) data suggest that P4 may be transmitted with P1 at higher rates than indicated by ELISA data. P4 was also aphid transmitted at relatively low rates. Pea aphids (Acyrthosiphon pisum) allowed 3 or 5 min acquisition access periods (AAP's) transmitted P4 at a maximum rate of 16% (3 aphids/plant). P4 transmission required short (1-7 min) AAP's and exhibited no bimodal character within tested parameters. P4 could be serologically distinguished from the other pathotypes using monoclonal and polyclonal antibodies. Tests with cross-reactive P4 antiserum suggest that P4 is more closely related to P2 than P1. P4-specific antiserum was derived by cross-absorbing diluted antiserum with P1- infected pea sap to eliminate P1- reactive antibodies. P1 and P4 RNA was detected and differentiated using pathotype-specific oligonucleotide primers in conjunction with PCR. Viral RNA sequences were amplified in pure preparations as well as crude pea tissue (leaf, root, pollen, and seed) extracts. / Graduation date: 1993

Copies of author's previously published articles inserted. / Bibliography: leaves 128-143. / xi, 143, [44] leaves, [36] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis describes the development of serological and nucleic acid based diagnostic methods for pea-seed borne mosaic virus (PSbMV), the isolation of specific effects on infected pea plants, the collection and biological comparison of new PSbMV isolates from Pakistan, the cloning and sequencing of specific parts of the genome of selected isolates, nucleotide and amino acid sequence comparisons between selected isolates, and the development of a ribonuclease protection assay (RPA) for identifying genomic differences among the PSbMV isolates. It is the first comparison of a range of geographically different isolates of PSbMV on the basis of both biological and molecular properties. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1999

Thesis (Ph.D.)--University of Melbourne, Institute for Land and Food Resources, 2001. / Typescript (photocopy). Includes bibliographical references.

Thesis (M.S.)--Ohio University, August, 2008. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1943. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 41-42).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 57-60.

abstract: The strips in Mark's Feminist Froze to Default in an Implementation String transfer the lives of feminists absent and imagined, overbearing and empathetic--cross dressers, lethal injectors, expats, planets, and Canadian survivalists--in an autumn to characteristic, unsettle, and reassess controller utterances of masculinity. / Dissertation/Thesis / Masters Thesis Creative Writing 2015

Two varieties of Pisum sativum, L, Jade and Olympic, were grown for a period of four weeks from seeding, under constant light intensity and diurnally fluctuating temperatures, while being subjected to varying-artificially induced-degrees of nutrient stress. Net carbon dioxide exchange rates were measured in order to determine the influence of excess or deficient nitrogen and phosphorus concentrations within the nutrient medium. Carbon dioxide assimilation rates, under various degrees of nutrient stress were highly variable, both within the same variety and between varieties tested. Microchemical determinations of chlorophylls a and b, and of inorganic phosphate, nitrate and nitrite were carried out in order to determine the relationship of some physiological aspects of mineral deficiency to carbon dioxide assimilation. Investigations as to changes in stomatal index (I) as a result of nutrient stress also showed a large amount of variation. Results obtained indicated that variety Jade was very sensitive to nitrogen deficiency within the rooting medium, as evidenced by a large increase in stomatal index values with nitrogen deficiency. Olympic showed a greater sensitivity to phosphorus deficiency than did Jade. Neither total chlorophyll content, nor chlorophyll a/b ratio appeared to exert any deciding influence upon net carbon dioxide assimilation. A relationship appeared to exist between CO₂ assimilation and quantities of nitrate and/or nitrite present within the photosynthetic tissues of plants tested. This experiment was unable to fully explain the reason(s) for the great degree of variability of net CO₂ exchange rates extant even between plant specimens growing in the same nutrient medium. Some technical improvements applicable to the present experiments as well as some alternative experimental procedures are discussed. / Land and Food Systems, Faculty of / Graduate

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