Two perennial species of wild geranium (Geranium nervosum Rydb. and G. richardsonii Fisch, and Trautv, [Geraniaceae]) which grow throughout the mountainous regions of western North America were studied to determine the factors influencing the life stage development and distribution of these plants. Attempts were also made to provide some information to assist in the taxonomy of this genus. Geranium richardsonii is found in wet meadows and along streambanks throughout its distribution, Geranium nervosum frequents rocky hillsides and drier meadows throughout its range. Seeds of Q. nervosum had 65o/, germination in the stratification pretreatment. Geranium richardsoniiseeds required scarification to reach 60% germination, Both species germinated in excess of 80% when scarified and stratified. Overwinter survival experiments indicated that Q. richardsonii could survive only in a wet meadow environment while G. nervosum could survive and establish in ail three environments examined, wet meadow, dry hillside, and aspen (Populus tremuloides) grove. Both G. richarasonii and Q. nervosum appeared to be limited by the same environmental factors although the degree of response was different. The seedling stage was the most responsive to environmental stress. Both Q. richardsonii and Q. nervosum seedlings had an optimum temperature range for survival of 20-25°C although they could and did adapt to lower temperatures. Seedlings of neither species could survive soil water potentials (Ψs) of -10 bars or lower. The adult stage of both species was more tolerant of stress and G. nervosum adults could survive (Ψs) of -25 to -30 bars. Geranium richardsonii was less tolerant and appeared to Ψs limited by both Ψs and temperature in its distribution at the Forestry Field Station. The critical factors influencing the distribution G. nervosum and Q. richardsonii were similiar but the species reacted to them in different ways. Geranium richardsonii was able to survive in environments that were highly saturated with water and under heavy cover. Geranium nervosum, although limited by temperatures above 32°C, was able to live in drier conditions by virtue of a tap root system. Hence, although the distribution of these two species was similiar, they were seperated by their response to environmental conditions.

Developing foliar growth of ivy geraniums (Pelargonium peltatum) bleaches white after exposure to temperatures greater than 30°C. This study investigated chloroplast development in ivy geraniums under heat stress comparing a heat sensitive cultivar, Temprano™ Lavender, and a heat tolerant cultivar, Contessa™ Red. Using transmission electron microscopy and spectrophotometry, foliar bleaching under heat stress was found to be due to an absence of developed chloroplasts within the bleached new growth accompanied by lower chlorophyll content. To determine whether heat stress related foliar bleaching could be prevented, cytokinin and gibberellins were applied in combination, at different rates before, during or after a heat stress event. Applying 50 to 100 ppm gibberellins before heat stress reduced bleaching in new growth. Gibberellins applied at 50 ppm within a week of a heat stress event decreased bleaching. Net photosynthesis and chlorophyll fluorescence was greater in non-heat stressed plants than heat stressed plants.

The development of whitening of the youngest leaves of actively growing ivy geranium (Pelargonium peltatum L.) has been observed as the season changes from late spring to summer. This study was conducted to determine the specific environmental causes of whitening, if micronutrients deficiencies cause similar whitening, whether low night temperatures can reverse whitening, and whether salicylic acid affects growth and whitening in ivy geraniums. Two cultivars, ‘Beach’ and ‘Butterfly’, with different susceptibility to whitening were chosen for this study. Elevated air temperature, but not elevated root-zone temperature, was found to be the environmental cause of whitening in ivy geranium. Elevated air temperatures severely reduced plant growth, leaf area, fresh weight, and dry weight in both cultivars. Elevated air temperature reduced photosynthetic pigments and their ratios in ivy geranium. Carotenoids and pheophytins decreased in ‘Butterfly’ at elevated air temperature. Foliar total Fe levels indicated no inhibition of Fe-uptake at elevated temperatures. Applications of Fe-chelate at elevated temperatures helped chlorophyll synthesis in ivy geraniums. Deficiency treatments of all micronutrients, Fe, Mn, Zn, S or Mg did not result in whitening in either cultivar of ivy geraniums. Salicylic acid did not affect whitening of ivy geraniums. It did not affect growth, leaf area, fresh or dry (stem, leaf or total) weight, fresh: dry weight ratio, leaf area ratio, specific leaf area or foliar nutrient (Fe, Mn, Zn, Mg and S) content in either cultivar. Cultivars varied in their response to low night temperature. ‘Beach’ reduced its plant growth and fresh to dry weight ratio whereas ‘Butterfly’ did not. Fe-chelate application did not reduce growth, leaf area, fresh weight, dry weight or fresh:dry weight ratio of either cultivar. Although Fe-application did not reduce whitening in ivy geraniums, it helped to preserve chlorophyll, particularly chlorophyll b as indicated by Chl a:b ratio in ‘Beach’. Whitening in ivy geranium is a heat stress response initially exhibited by young, developing leaves and is caused by elevated air temperatures. Whitening is the result of impaired photosynthetic pigments synthesis and/or degradation.

No description available.

Faculty of Health Sciences School of pharmacy 0002280t jacquilalli@yahoo.co.uk / Despite commercial interest and ethnobotanical data, the chemical composition and pharmacological activities of a number of indigenous Pelargonium species remain unexplored. Twenty-one Pelargonium species, from the section Pelargonium, were included in this study. The volatile compounds of 13 species were extracted by hydrodistillation and their chemical compositions determined by gas chromatography coupled to mass spectroscopy (GC-MS). The essential oil data was chemotaxonomically informative confirming taxonomic relationships between P. graveolens and P. radens; P. papilionaceum and P. vitifolium and between P. panduriforme and P. quercifolium. New chemical affinities were established among P. betulinum, P. hispidum and P. scabrum; P. capitatum (provenance WSBG), P. glutinosum and P. quercifolium (provenance SBG) and among P. graveolens, P. radens and P. tomentosum. The non-volatile compounds were extracted with acetone and the extracts were analysed using high performance liquid chromatography (HPLC). The representative flavonoid patterns of the Pelargonium species indicated that P. betulinum, P. capitatum, P. graveolens, P. hispidum, P. panduriforme and P. vitifolium have numerous similarities in their chemical profiles. Pelargonium scabrum and P. sublignosum share definite chemical patterns. The HPLC fingerprints of P. papilionaceum and P. vitifolium were chemically diverse. A microdilution bioassay was performed on the acetone extracts and the essential oils to assess their antimicrobial (both bacterial and fungal) potential. The essential oils and extracts were more selective for the Gram-positive test pathogens than for the Gram-negative bacterium. The crude extracts of P. glutinosum (provenance SBG), P. pseudoglutinosum, P. scabrum and P. sublignosum exhibited considerable antimicrobial activity against the Gram-positive bacteria (B. cereus and S. aureus) with P. pseudoglutinosum exerting the highest activity (MIC = 0.039 mg/ml). The essential oils showed reduced antimicrobial activity compared to the plant extracts. Using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, exceptional anti-oxidant activity was observed for the crude extracts of P. betulinum and P. crispum (IC50 values of 4.13 μg/ml and 4.49 μg/ml, respectively, compared to ascorbic acid, IC50 = 4.72 μg/ml). The essential oils of P. quercifolium showed the greatest inhibition of 5-lipoxygenase activity (IC50 = 33.24 μg/ml v - 38.67 μg/ml). The antimalarial activity of the non-volatile extracts was evaluated against the choloroquine-resistant Gambian FCR-3 strain of Plasmodium falciparum using the hypoxanthine incorporation assay. Pelargonium panduriforme (provenance SBG) exerted the greatest activity (IC50 = 1.34 ± 0.29 μg/ml). Other species possessing similarly potent antimalarial activity included P. citronellum (provenance NBG), P. citronellum (provenance SBG), P. quercifolium (provenance SBG) and P. radens. A microculture tetrazolium salt reduction (MTT) assay was used to determine the cellular toxicity of the acetone extracts and essential oils against transformed human kidney epithelium (Graham) cells. The acetone extracts of P. sublignosum and P. citronellum (provenance NBG) displayed the highest toxicities (IC50 = 11.89 ± 1.54 μg/ml and 19.14 ± 0.98 μg/ml, respectively). Pelargonium vitifolium (IC50 = 178.48 ± 5.44 μg/ml) and P. tomentosum (provenance SBG) (IC50 = 195.13 ± 7.90 μg/ml) appeared to be non-toxic. The Pelargonium essential oils proved to be considerably toxic (IC50 ≤0.10 μg/ml - 30.30 ± 1.81 μg/ml). The flavonoid derivatives detected in the Pelargonium acetone extracts may have contributed to their positive biological activities. The results from the MTT assay suggested that the antimicrobial and antimalarial activity of the extracts may be ascribed to general cytotoxic effects. The pharmacological properties manifested by the extracts and essential oils of certain Pelargonium species substantiates their use in traditional medicines and validates their commercial exploitation in the perfumery, cosmetic, food and pharmaceutical industries; however, their toxicity profiles must be considered

Pelargonium peltatum, ivy geranium, experiences foliar bleaching at temperatures exceeding 30° C. Contessa™ Red (heat tolerant) and Temprano™ Lavender (heat susceptible) were compared. Established plants underwent temperature treatments of 15/20° C or 25/30° C night/day with moisture treatments of 80% or 30% substrate volumetric water content (VWC). Photosynthesis, leaf greenness and growth data were collected at days 0, 7 and 11. No differences in photosynthetic rate nor a decrease in greenness in developed leaves occured in either cultivar due to high temperature or drought. Contessa™ Red had overall greater growth and leaf greenness than Temprano™ Lavender. Greenness and growth increased similarly for both cultivars at 80% VWC. Any decrease in foliar bleaching due to drought was likely due to a decrease in growth. A second study using Temprano™ Lavender indicated foliar bleaching occurs in newly emerging, developing leaves.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free state, 2014 / The main objective of the study was to determine the effect of different potassium concentrations and water quality (salt) compared with the current scientifically accepted potassium threshold level and standardised water quality on the yield, oil composition and leaf morphology of rose geranium (Pelargonium graveolens L.) when grown in different potting-bag sizes and root media under temperature controlled condition. To achieve this objective, two trials were conducted. The first experiment evaluated potassium concentrations at 1.3, 3.3, 5.3 and 7.3 mmol L-1 and potting-bag size of 5 and 10 L. Treatments were arranged in a randomised complete block design assigned in a split plot layout. The main plots consisted of potassium concentration and the pottingbag sizes were allocated to sub-plots. Plant height, potassium content, linalool, geraniol, geranyl formate and the citronellol to geraniol ratio (C:G) were affected by potassium. Plant height, number of branches, the branch to height ratio (B:H), foliar fresh mass (FFM) and oil yield were significantly increased when 5 L potting bags were used. Plant foliar mass was significantly increased by the interaction between 5.3 mmol K L-1 and 5 L potting bags. In the second experiment salt levels applied at 1.6, 2.4, 3.2 and 4.0 mS cm-1 and root media (sand and sawdust) were evaluated. A split plot experimental layout was also used in this trial, with the salt levels allocated to the main plots. The sub-plots were allocated to the root medium. High salt level of 4.0 mS cm-1 reduced the number of leaves, plant height, number of branches, B:H ratio, leaf area, chlorophyll content and foliar fresh mass significantly. The number of leaves, leaf area and FFM were significantly increased where sawdust was used. Time of the day significantly affected stomatal conductance, and the opening of most stomata occurred at 10:00. Geranyl formate and the C:G ratio were significantly affected by salt at 4.0 mS cm-1. Salt induced the development of capitates trichomes. The abaxial leaf surface had a higher number of trichomes than the adaxial leaf surface. A strong polynomial (r2=0.97) relationship was found between capitates trichomes and salt levels. High densities of capitates trichomes were found at high salt level of 4.0 mS cm-1. Although the development of asciiform trichomes was induced, it was at an insignificant level. Trichome densities are therefore not affected by salt. It was therefore concluded that the application of 5.3 mmol K L-1 concentration and the use of 5 L potting bags improves the yield and oil quality of rose geranium. It was evident from this study that rose geranium might Salt induced have some degree of tolerance to salt. It was therefore concluded that rose geranium is a moderately salt-sensitive crop.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Kimberly A. Williams / Ivy geranium (Pelargonium peltatum L’Herr ex. Ait.) and tomato (Solanum lycopersicum L.) are two economically important greenhouse crops known to be affected by non-pathogenic lesions on leaf tissues. These physiological disorders are often termed edema (oedema) or intumescences, but several other names have been used including enations, non-pathogenic galls or tumors, and neoplasms. These lesions, characterized by small protrusions on leaf tissues that become necrotic over time, are considered to be the result of environmental factors. Our research focused on determining what environmental factors affect these disorders on ivy geranium and tomato. The physiological disorder of ivy geranium is thought to be the result of water uptake exceeding transpiration, resulting in a build-up of water and solutes in leaf tissue that results in the blister-like protrusions in the epidermal layer. Current convention suggests that susceptible plants be grown in an environment that promotes transpiration with low humidity and infrequent watering. Over four experiments, we evaluated the effects of four root medium water contents, five rates of supplemental calcium application and two vapor pressure deficit (VPD) environments on three cultivars of ivy geranium. Our results indicate that high root medium water contents do not increase the incidence of edema on ivy geranium, but increase overall plant growth. Supplemental calcium had no affect on edema or growth, while our VPD results were inconclusive. These results suggest that current convention regarding cultural practices that abate the disorder be revisited. In tomato var. hirsutum ‘Maxifort’, the physiological disorder is characterized by individual epidermal cells swelling, which is unlike the disorder in ivy geranium where solutes build up across a group of epidermal cells. The environmental factors we focused on were two root medium water contents and supplemental UVB light. Our results suggest that root medium water content may play a role in development of tomato intumescences based on visual observation, and UVB light supplementation helps prevent the lesions from forming.

<p>African medicinal plants are commonly used throughout Africa to treat a variety of ailments including wounds and ulcers, cough and chest complaints, gingivitis, fever and gonorrhoea, indication all related to infection and inflammation. In screening several plant species from an inventory of common medicinal plants from both South and West Africa for diverse medicinal purposes, 6 plants were selected because of their interesting and useful ethnomedicinal values.</p>

<p>African medicinal plants are commonly used throughout Africa to treat a variety of ailments including wounds and ulcers, cough and chest complaints, gingivitis, fever and gonorrhoea, indication all related to infection and inflammation. In screening several plant species from an inventory of common medicinal plants from both South and West Africa for diverse medicinal purposes, 6 plants were selected because of their interesting and useful ethnomedicinal values.</p>