Copies of author's previously published articles inserted. Bibliography: leaves 128-143. 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.

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

Reprinted June 1, 1937

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Thirty-four cultivars of pea (Pisum sativum) were assayed for tumorigenesis after inoculation with Agrobacterium tumefaciens strain B6. The response of the 34 cultivars fell into 3 significantly different groups based on tumor weights: high, medium, and low susceptibility. The least susceptible cultivar, Sweet Snap, also formed the smallest tumors in comparison to 5 other cultivars when inoculated with 5 other strains of Agrobacterium. Preliminary experiments indicate that neither chemotaxis, binding, vir-gene induction, nor T-DNA expression are limiting factors in Sweet Snap's reduced susceptibility. In an inheritance study, the F1, F2, and F3 progeny from an initial cross between Sweet Snap and Wando (a more susceptible cultivar) formed tumors that were intermediate in weight between the two parents.

Includes bibliographical references (leaves 82-92). Five isolates of pea seed-borne mosaic virus were compared by host range and symptomatology on 16 pisum sativum cultivars lines, 21 lines of Lathyrus and Lens spp. and several indicator species

Corrigendum inserted at the back. Includes bibliographical references (leaves 133-158). Ch. 1. General introduction -- ch. 2. General materials and methods -- ch. 3. Biological characterisation of Australian PSbMV isolates -- ch. 4. Developing nucleic acid based diagnostics for PSbMV -- ch. 5. Detection of PSbMV isolates by RT-PCR and RFLP analysis -- ch. 6. Developing an internal control for PSbMV RT-PCR -- ch. 7. Molecular analysis of the PSbMV VPG -- ch. 8. PSbMV sequence and phylogenetic analysis -- ch. 9. General discussion Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays.

Includes bibliographical references (leaves 82-92). / xii, 92 leaves : ill., photos ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Five isolates of pea seed-borne mosaic virus were compared by host range and symptomatology on 16 pisum sativum cultivars lines, 21 lines of Lathyrus and Lens spp. and several indicator species / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1993

Corrigendum inserted at the back. / Includes bibliographical references (leaves 133-158). / xvi, 158 leaves : ill., col. map ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied and Molecular Ecology, 2001