We report here the use of RAPD-PCR (Random Amplified Polymorphic DNA - Polymerase Chain Reaction) to identify segregating loci in the haploid progeny of an Armillaria ostoyae basidiocarp and the construction of the first genetic linkage map of this fungus, one of the causal species of Armillaria Root Disease. Upon screening 75 RAPD primers, 18 were found to identify a total of 43 loci segregating with a 1 : 1 Mendelian ratio. These loci were analysed for linkage among 58 monospore progeny. The map constructed with Mapmaker (LOD = 3.0, r = 0.38) was confirmed by GMendel (LOD = 1.5, r = 0.38). This map arranged 30 loci into 6 linkage groups and 4 linkage pairs. Thirteen markers remained unlinked. Using the Kosambi mapping function the linked loci accounted for approximately 450 cM and the genome was estimated to be 1600 cM. This preliminary map covers approximately 28% of the A. ostoyae genome.

No description available.

<p>Roots are developmentally plastic and highly dependent on the immediate environment. By studying root responses to abiotic stress, we have identified novel regulators of developmental modulation. When roots are deprived of phosphate (Pi), developmental programs are modulated to slow primary root growth and expand surface area through emergence of root hairs. By focusing on exposure time-periods of less than two days, we have described very early changes to root development in response to this condition that may reveal new mechanisms of root hair specification and emergence. Also, using transcriptomic analyses with high spatial resolution, we identified a kinase that is specifically induced in root vascular tissue within three hours of exposure and acts to modulate aspects of root development in response to deprivation of Pi. These data suggest that individual tissues play unique roles in whole organ development, and that interpretation of Pi -deprivation responses may change as we develop methods with resolution necessary to understand these roles. Beyond Pi, we compared transcriptomic data for four additional stresses and identified a novel stress-responsive transcription factor that modulates expression of a cell expansion protein. This putative network connection demonstrates the value of using high-dimensional data for inference of regulatory relationships. Overall, we have combined "-omics" approaches with reverse genetics to identify novel developmental regulators and described a phenotypic frame-work with resolution at which cellular mechanisms can be studied.</p> / Dissertation

<I>Phytophthora cinnamomi </I>var. <I>cinnamomi, Pythium ultimum </I>var. <I>ultimum </I>and <I>Pythium undulatum </I>were successfully isolated from naturally regenerating <I>Pinus sylvestris </I>forests across north Scotland. Molecular and morphological characterisation enabled accurate identification of these Oomycetes to the variety level. <I>In vitro</I> and glasshouse pathogenicity trials demonstrated that under artificial temperature, light and water regimes the Oomycetes had the potential to reduce plant growth and cause chlorosis of the <I>P. sylvestris</I> foliage after two months. Soil pH was also determined as having a significant effect on <I>P. sylvestris </I>growth in terms of foliage colour and dry mass. Biological control <I>in vitro </I>experiments with <I>Bacillus subtilis</I> and <I>Pseudomonas fluorescens</I> produced significant inhibition of Oomycete growth but on transfer to the glasshouse trials, antagonism was not observed. This study was undertaken to establish the presence of fine root pathogens, namely those belonging to the Oomycetes, within regenerating <I>Pinus sylvestris</I> forests in northern Scotland. The identify of the pathogens was determined using morphological and molecular biology techniques. The virulence of the fine root pathogens on <I>Pinus sylvestris </I>seedlings (1 + 0) was then determined by a series of <I>in vitro</I> and glasshouse trials. Interactions between soil pH and bacterial biological control agents were also tested against each of the pathogens. Pathogen trials were undertaken to show the potential effect of the Oomycetes on <I>Pinus sylvestris </I>seedlings. The glass house trial was scored on foliage colour and dry weight of seedlings 18 months of age, grown in pH amended Irish moss peat. In comparison to the control, inoculation with <I>P. cinnamomi</I> caused a significantly greater frequency of chlorotic/dead seedlings. In contrast, inoculation with <I>P. undulatum </I>(syn. <I>P. dimorphum</I>) resulted in a greater number of healthy seedlings than the control. No significant difference in the proportion of healthy and chlorotic/dead seedlings was found between the bio-control bacteria groups. pH was found to have a significant effect on seedling growth. At pH 7, compared to pH 3, there was a significant greater likelihood of the seedlings being chlorotic/dead.

No description available.

This thesis investigates the formal and functional properties of the linguistic knowledge of a young bilingual child 'Katla' who successively acquires Icelandic (L1, from birth) and English (L2, from age 1:3). I present new longitudinal natural speech data which I collected in both Icelandic and English from Katla at regular intervals. Audio-recordings were made roughly three times per month at age 1 ;0-4;7 and transcribed in adapted CHILDES/CHAT format. Using a generative framework, I analyse Katla's data qualitatively and quantitatively, focusing on her morphology and syntax during the period 1;6-3;6: determiners and word order in nominals, copula constructions, progressive constructions, imperatives, negation, verb placement, verb inflections, auxiliaries, and periphrastic do. Katla's development is compared with monolingual English-speaking and Icelandic-speaking children, and, where applicable, with other bilinguals. Particular attention is paid to early grammar differentiation and cross- language influence, and to the relationship between child language and input (construction types and frequencies). The empirical results are evaluated in the light of current theories of language acquisition and generative approaches to syntax. Katla's first multi-word combinations (1;6) show productive use of functional morphology (determiners, copulas). Early on, there is evidence of movement into the DP, IP and CP domains, indicating continuity of these functional categories. Moreover, translational equivalents, language-specific functional morphemes and language-specific word orders in Katla's Icelandic and English bear evidence of early language differentiation in successive child bilingualism. The longitudinal development of morpho-syntax largely progresses along separate lines for Katla's two languages; there is no cross- language influence as regards head parameter and movement parameter settings. Some construction transfer occurs where L1 and L2 linear orders are similar. Ensuing implications for transfer and (de)learnability are addressed.

No description available.

All organisms, including plants, experience variability in the environment which puts pressure on organisms to evolve flexible responses. The study of these responses by organisms falls into the discipline of behavioural ecology. In this thesis, I am interested in the foraging behaviour of plant roots and I have two goals. First, I will use foraging theory from the animal literature to determine whether plants forage in ways that are similar to animals. Second, I will show how the adoption of foraging theory for plants can lead to a better theoretical understanding of coexistence of plants. I begin with a discussion of the major differences between plants and animals in their foraging behaviour and how this can be incorporated in to a more general predictive framework of plant foraging behaviour. I follow this discussion with two empirical tests of classic foraging models. First, I test a patch use model from the animal literature to determine if it can predict plant foraging behaviour. My results show that plants foraged for patches using the same strategies used by animals. Second, I test a resource choice model from the animal literature. These data indicated that plants select different types of nitrogen using the same resource choice strategies as foraging animals. These two studies reveal some basic foraging abilities of plants, however the experiments were performed in the absence of resource competition, a condition seldom experienced by plants in nature. To overcome difficulties in studying plant roots grown with neighbours I developed a molecular method for the identification of visually indistinguishable plant roots from competition experiments. Finally, I apply the molecular method to examine whether resource patchiness in soil can increase the intensity of competition experienced by foraging plants, and that the presence of neighbours influences the foraging strategies of plants. Together the results presented in this thesis show that plants use the same basic foraging strategies as animals, and that foraging behaviour can be linked to competition and coexistence of plant species. / Ecology

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1977. / Bibliography: leaves 150-154. / Microfiche. / xvi, 154 leaves ill

Hard red duplex soils (HRDS) cannot sustain economically productive vineyards without careful management. An experiment was conducted at Rosbercon Vineyard, Picola from 1995 to 1998 in a vineyard block of Chardonnay on Ramsey rootstock planted in 1972. The hypotheses tested were: a) transient waterlogging decreases root growth and grapevine performance, and b) hardening of soil decreases root growth and grapevine performance. (For complete summary open document)