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Thesis (Ph. D.)--University of Hawaii at Manoa, 1982. / Bibliography: leaves 169-177. / Microfiche. / xvi, 177 leaves, bound ill. 29 cm

Bibliography: leaves 169-193. / xxi, 193 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study investigated whether both S. Calospora and Glomus sp. "City Beach" WUM 16 both increase the rate of transfer of phosphate (P) to the plant Allium porrum, and whether the addition of P to the soil has any effect on the uptake rates. The main experiment compared the fungi under two P levels in soils. It was found that in soil with no added P, S. calospora depressed plant growth in the early stages, but was increased in later harvests. G. sp. "City Beach" increased plant growth throughout. In soil with added P, both sets of plants produced growth depressions at early stages. The effect on growth due to mycorrhizal symbiosis was greater in plants grown in soil with no phosphate added. There were no significant differences between the two fungi with reflexes of P across the interfaces. There were however temporal differences. The isolate of S. calospora did promote a positive plant growth response in A. porrum and transfer P to the plant. Mycorrhizal arbuscules were examined and visualised using Laser Scanning Confocal Microscope and 3D reconstructions performed. This allowed the surface area and volume of the arbuscules to be quantified in order to investigate differences between the fungi. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2000?

Low soil fertility has been identified to be among the major causes of low pasture quantity and quality. Scarcity of high quality forage mainly during the dry season threatens animal productivity in some areas of South Africa, thus the need for identifying livestock feed alternatives. Pigeon pea is a woody legume that has continually been an important shrub in agroforestry and can provide protein-rich livestock feed during times of shortage. Soil fertility to support the production of pigeon pea can be enhanced by application of fertilisers. Therefore, this study was carried out firstly, to determine the effect of phosphorus fertiliser on the growth performance and biomass production of three pigeon pea varieties, and secondly, to investigate the influence of phosphorus application on the nutrient and anti-nutrient content of three pigeon pea varieties. The field experiment was done at the University of Fort Hare research farm in Alice, South Africa. The factors investigated were three pigeon pea varieties namely Chitedze 1, Chitedze 2 and CIMMYT 1 and three phosphorus fertiliser application rates of 0, 40 and 60 kg P/ha. The study was a 3× 3 factorial experiment set up in a randomised complete block design and was replicated three times. The growth performance attributes evaluated in this study include the number of branches, plant height and root collar diameter. Root collar diameter was not significantly (p>0.05) different among the pigeon pea varieties and phosphorus levels. Likewise, the application of phosphorus was not significant (p>0.05) on plant height and the number of branches of all the varieties. However, when P level was varied, there were significant differences among the varieties, and so were the interaction (p<0.05) between variety and phosphorus on plant height and the number of branches. There was no significant (p>0.05) difference among the phosphorus levels on the fresh leaf yield of Chitedze 1 and Chitedze 2, but phosphorus application at 40 kg P/ha increased the fresh leaf yield of CIMMYT 1. Phosphorus application at 60 kg P/ha increased (p<0.05) the dry matter content of Chitedze 1 and Chitedze 2. Furthermore, the results of the trial show that the application of 40 kg P/ha and 60 kg P/ha increased (p<0.05) the dry matter yield of the varieties CIMMYT 1 and Chitedze 2, respectively. The effects of phosphorus application on the nutrient composition of the three pigeon pea varieties varied. The composition of hemicellulose of all the varieties was significantly (p<0.05) increased by the application of 40 kg P/ha. Conversely, the concentration of crude protein, phosphorus, copper and iron, and the calcium to phosphorus ratio of all the pigeon pea varieties was not significantly (p>0.05) affected by phosphorus application and there was no interactive effect of variety and phosphorus. The proximate compositions of fat, total non-structural carbohydrates, ash, neutral detergent fibre, acid detergent fibre, cellulose, neutral detergent insoluble nitrogen, acid detergent insoluble nitrogen of the pigeon pea varieties varied significantly (p<0.05) at different phosphorus application levels. There was an interactive (p<0.05) effect of variety and the level of phosphorus on the concentration of calcium (Ca), potassium (K), magnesium (Mg), sodium, zinc, manganese, and the K/(Ca+Mg) ratio. The digestible dry matter, dry matter intake and the relative feed value were significantly (p<0.05) different among the pigeon pea varieties at varying phosphorus levels. The anti-nutrient composition of Chitedze 2 was not significantly (p>0.05) affected by phosphorus application but the concentration of phenols and saponins of Chitedze 1 was significantly (p<0.05) increased when 60 kg P/ha was applied, but these anti-nutrients were reduced (p<0.05) for CIMMYT 1 at 60 kg P/ha. It can be concluded that phosphorus application influences the biomass production and chemical composition while the optimum phosphorus level vary among the pigeon pea varieties.

In the glasshouse, two cultivars of alfalfa growing in non-sterile soil were evaluated for their response to inoculation with 4 VA mycorrhizal fungi and 3 strains of Rhizobium meliloti. Alfalfa cultivar Hayden PX-1 had significantly greater dry stem weights (p = 0.05) when inoculated with Glomus fasciculatum, G. deserticola or an undescribed Glomus sp. compared to mycorrhizal controls. Alfalfa cultivar Lew HI Nod had significantly less dry stem weights when inoculated with G. fasciculatum, G. mosseae or the undescribed Glomus sp. Addition to R. meliloti did not impart increased growth responses with either alfalfa cultivar probably due to the high nitrogen content of the soil. In the field, alfalfa cultivar Hayden PX-1 was both transplanted and direct-seeded. Transplanted alfalfa had been preinoculated with VA mycorrhizal fungi and R. meliloti. Inocula containing VA mycorrhizal fungi and R.meliloti were Layered below the seed in direct-seeded plots. Phosphorus, as treble super phosphate, was also added as a treatment. At first harvest, transplanted alfalfa inoculated with the undescribed Glomus sp. had significantly greater (p = 0.05) dry whole plot weights compared to controls regardless of R. meliloti or phosphorus treatments. Inoculation of alfalfa with G. deserticola significantly increased dry whole plot weights over controls but significantly (p = 0.05) only with added R. meliloti and phosphorus. Second harvest data maintained the trend for yield increases over controls with addition of the undescribed Glomus sp. and G. deserticola; however, only significantly (p = 0.05) with inoculation with the undescribed Glomus sp. including R. meliloti and phosphorus. Yield increases were not obtained for the final three transplanted alfalfa harvests or for any of the direct-seeded alfalfa harvests. Statistically significant differences in phosphorus and protein content of alfalfa were not found between any of the treatments. Also, differences were not found in soil populations of R. meliloti in mycorrhizal inoculated plots compared to control plots.

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Includes bibliographical references. / xviii, 171 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1994

Includes bibliographical references.

Bibliography: leaves 89-104. In this study an EMS-mutated Arabidopsis mutant pho2, which accumulates Pi in leaves, was used to study Pi uptake and transport by comparing it to wild-type seedlings. The study aimed to define the physiological lesions in pho2 mutant and to obtain evidence regarding the function of the PHO2 gene in P nutrition in higher plants. Accumulation of Pi in leaves of pho2 was found to reside in the symplast and was not related to Zn-deficiency. The physiology of the pho2 mutant is consistent with either a block in Pi transport in phloem from shoots to roots or an inability of shoot cells to regulate internal Pi concentration. Southern block analysis revealed that the two transporter genes, APT1 and APT2 were not responsible for the pho2 mutant. Data from the mapping of the PHO2 gene along with information from the Arabidopsis genome sequencing will form the basis for cloning the PHO2 gene in the future.