Worldwide phylogeography of the globally invasive plant: Jatropha gossypiifolia

Dhileepan, Raghu and colleagues recently published their paper 'Worldwide phylogeography of the globally invasive plant: Jatropha gossypiifolia' in Proceedings of the 16th Australian Weeds Conference. They used chloroplast microsatellites to establish patterns of phylogeographic structure in the native and introduced range of Jatropha gossypiifolia, and to determine the origin(s) of introductions and the level of genetic diversity present in native and introduced populations. J. gossypiifolia exhibited limited phylogeographic structure in its native range which was best explained by contemporary movement associated with the ornamental plant trade. Multiple introductions from diverse source locations and no reduction in genetic diversity was found in the introduced range which includes Australia, Africa and Asia. These results have implications for our current biocontrol project.

Impact of control strategies on bellyache bush (Jatropha gossypiifolia L.) mortality, seedling recruitment, population dynamics, pasture yield and cost analysis

Bellyache bush (Jatropha gossypiifolia L.) is an invasive weed that has the potential to greatly reduce biodiversity and pasture productivity in northern Australia’s rangelands. This paper reports an approach to develop best practice options for controlling medium to dense infestations of bellyache bush using combinations of control methods. The efficacy of five single treatments including foliar spraying, slashing, stick raking, burning and do nothing (control) were compared against 15 combinations of these treatments over 4 successive years. Treatments were evaluated using several attributes, including plant mortality, changes in population demographics, seedling recruitment, pasture yield and cost of treatment. Foliar spraying once each year for 4 years proved the most cost-effective control strategy, with no bellyache bush plants recorded at the end of the study. Single applications of slashing, stick raking and to a lesser extent burning, when followed up with foliar spraying also led to significantly reduced densities of bellyache bush and changed the population from a growing one to a declining one. Total experimental cost estimates over 4 successive years for treatments where burning, stick raking, foliar spraying, and slashing were followed with foliar spraying were AU$408, AU$584, AU$802 and AU$789 ha–1, respectively. Maximum pasture yield of 5.4 t ha–1 occurred with repeated foliar spraying. This study recommends that treatment combinations using either foliar spraying alone or as a follow up with slashing, stick raking or burning are best practice options following consideration of the level of control, changes in pasture yield and cost effectiveness.

Persistence of bellyache bush (Jatropha gossypifolia L.) soil seed banks

Bellyache bush (Jatropha gossypifolia L.) is an invasive shrub that adversely impacts agricultural and natural systems of northern Australia. While several techniques are available to control bellyache bush, depletion of soil seed banks is central to its management. A 10-year study determined the persistence of intact and ant-discarded bellyache bush seeds buried in shade cloth packets at six depths (ranging from 0 to 40 cm) under both natural rainfall and rainfall-excluded conditions. A second study monitored changes in seedling emergence over time, to provide an indication of the natural rate of seed bank depletion at two sites (rocky and heavy clay) following the physical removal of all bellyache bush plants. Persistence of seed in the burial trial varied depending on seed type, rainfall conditions and burial depth. No viable seeds of bellyache bush remained after 72 months irrespective of seed type under natural rainfall conditions. When rainfall was excluded seeds persisted for much longer, with a small portion (0.4%) of ant-discarded seeds still viable after 120 months. Seed persistence was prolonged (> 96 months to decline to < 1% viability) at all burial depths under rainfall-excluded conditions. In contrast, under natural rainfall, surface located seeds took twice as long (70 months) to decline to 1% viability compared with buried seeds (35 months). No seedling emergence was observed after 58 months and 36 months at the rocky and heavy clay soil sites, respectively. These results suggest that the required duration of control programs on bellyache bush may vary due to the effect of biotic and abiotic factors on persistence of soil seed banks.

Can competition with pasture be used to manipulate bellyache bush (Jatropha gossypiifolia L.) population biology?

Bellyache bush (Jatropha gossypiifolia L.) is an invasive weed that poses economic and environmental problems in northern Australia. Competition between pasture and bellyache bush was examined in North Queensland using combinations of five pasture treatments (uncut (control); cut as low, medium, and high pasture; and no pasture) and four bellyache bush densities (0, 2, 6 and 12plantsm(-2)) in a buffel grass (Cenchrus ciliaris L.) dominated pasture. The pasture treatments were applied approximately once per year but no treatments were applied directly to the bellyache bush plants. Measurements of bellyache bush flowering, seed formation, and mortality were undertaken over a 9-year period, along with monitoring the pasture basal cover and plant species diversity. Maximum flowering rates of bellyache bush occurred after 9 years (97%) in plots containing no pasture, with the lowest rates of 9% in uncut control plots. Earliest flowering (322 days after planting) and seed formation (411 days) also occurred in plots with no pasture compared with all other pasture treatments (range 1314-1393 days for seed formation to occur). No seeds were produced in uncut plots. At the end of 9 years, mortality rates of bellyache bush plants initially planted averaged 73% for treatments with some pasture compared with 55% under the no-pasture treatment. The percentage of herbaceous plant basal cover in uncut plots was increased 5-fold after 9 years, much greater than the average 2% increase recorded across the low, medium, and high pasture treatments. The number of herbaceous species in uncut plots remained largely unchanged, whereas there was an average reduction of 46% in the cut pasture treatments. Buffel grass remained the species with the greatest basal cover across all cut pasture treatments, followed by sabi grass (Urochloa mosambicensis (Hack.) Dandy) and then red Natal grass (Melinis repens (Willd.) Ziska). These results suggest that grazing strategies that maintain a healthy and competitive pasture layer may contribute to reducing the rate of spread of bellyache bush and complement traditional control techniques such as the use of herbicides.

Growth of Queensland Jatropha gossypifolia biotypes under varying water regimes

Bellyache bush (Jatropha gossypifolia L. (Euphorbiaceae)) is a serious weed of dry tropical regions of northern Australia, with the potential to spread over much of the tropical savannah. It is well adapted to the harsh conditions of the dry tropics, defoliating during the dry season and rapidly producing new leaves with the onset of the wet season. In this study we examined the growth and biomass allocation of the three Queensland biotypes Queensland Green, Queensland Bronze and Queensland Purple) under three water regimes (water-stressed, weekly watering and constant water). Bellyache bush plants have a high capacity to adjust to water stress. The impact of water stress was consistent across the three biotypes. Water stressed plants produced significantly less biomass compared to plants with constant water, increased their biomass allocation to the roots and increased biomass allocation to leaf material. Queensland Purple plants allocated more resources to roots and less to shoots than Queensland Green (Queensland Bronze being intermediate). Queensland Green produced less root biomass than the other two biotypes.

EXPERIMENTAL STUDIES ON AIR-ASSISTED ATOMIZATION OF JATROPHA PURE PLANT OIL

The present study focuses on exploring air-assisted atomization strategies for effective atomization of high-viscosity biofuels, such as pure plant oils (PPOs). The first part of the study concerns application of a novel air-assisted impinging jet atomization for continuous spray applications, and the second part concerns transient spray applications. The particle/droplet imaging analysis (PDIA) technique along with direct imaging methods are used for the purpose of spray characterization. In the first part, effective atomization of Jatropha PPO is demonstrated at gas-to-liquid ratios (GLRs) on the order 0.1. The effect of liquid and gas flow rates on the spray characteristics is evaluated, and results indicate a Sauter mean diameter (SMD) of 50 mu m is achieved with GLRs as low as 0.05. In the second part of the study, a commercially available air-assisted transient atomizer is evaluated using Jatropha PPO. The effect of the pressure difference across the air injector and ambient gas pressure on liquid spray characteristics is studied. The results indicate that it is possible to achieve the same level of atomization of Jatropha as diesel fuel by operating the atomizer at a higher pressure difference. Specifically, a SMD of 44 mu m is obtained for the Jatropha oil using injection pressures of <1 MPa. A further interesting observation associated with this injector is the near constancy of a nondimensional spray penetration rate for the Jatropha oil spray.

Estudo da cicatrização de suturas na bexiga urinária de ratos com e sem a utilização de extrato bruto de Jatropha gossypiifolia intraperitoneal

A cicatrização constitui processo complexo envolvendo diferentes sistemas biológicos e imunológicos , sendo essencial para manter a integridade do organismo. Três fases bem definidas ocorrem, a inflamatória, a proliferativa e a de maturação. A falha ou prolongamento em uma fase pode resultar em retardo da cicatrização tecidual. A sutura dos tecidos e sua cicatrização é um dos fundamentos básicos da cirurgia e a procura de substâncias que melhorem este processo é um desafio constante. O uso de substâncias de plantas têm sido testados por vários autores. Objetivo - Analisar comparativamente as alterações macroscópicas e histológicas proporcionadas pelo uso do extrato bruto da Jatropha gossypiifolia intraperitonial, na cicatrização de suturas realizadas na bexiga urinária de ratos. Material e método Sessenta ratos da linhagem Wistar, adultos, machos foram distribuídos em 2 grupos animais. O procedimento experimental constituiu-se em laparotomia mediana infraumbelical, incisão longitudinal de 1cm na parede ventral da bexiga e síntese em plano único com pontos separados de poliglactina 910 5-0 (Ethicon). O procedimento nos animais do grupo controle (ratos 1 a 30) instilou-se na cavidade peritonial água destilada na proporção de 1ml por kg de peso e no grupo Jatropha (ratos 31 a 60) utiilizou-se o extrato bruto de Jatropha gossypiifolia na proporção de 1ml por kg de peso, que representava 200mg do fototerápico, intraperitoneal. Cada grupo foi dividido em 3 subgrupos de 10 animais sendo estes submetidos à eutanásia no 7 e 14 pós-operatório. Foi feita análise macroscópica e histológica comparativa entre os subgrupos . Resultados - No 7 dia foi observado diferença estatisticamente significativa nas variáveis inflamação aguda, neoformação vascular e colagenização, sendo a primeira maior no grupo controle e as duas últimas no grupo Jatropha; no 14 variáveis inflamação aguda e proliferação fibroblástica apresentaram-se mais intensas com significado estatístico no grupo controle. No 21 dia as variantes se alinharam não havendo diferença estatística na sua comparação. Conclusão - Foi observado homogeneidade na cicatrização nos 2 grupos, contudo, a mesma foi mais intensa no grupo controle. Não se observou, portanto, efeito favorecedor cicatrizante do extrato bruto da Jatropha gossypiifolia intraperitonial, em dose única, na bexiga urinária de rato.

Extração e caracterização de extratos de Jatropha gossypiifolia L.: avaliação da sua atividade antimicrobiana e antioxidante

Trabalho Final de Mestrado para obtenção do grau de mestre em Engenharia Química e Biológica

Potencial antibacterial, actividad citotóxica y mutagénica de krameria ramosissima, larrea tridentata, jatropha dioica y leucophyllum frutescens.

Tesis (Doctor en Ciencias con acentuación en Química de Productos Naturales) UANL, 2014.

Compuestos activos con capacidad hipoglucemiante en cnidoscolus chayamansa (chaya), euphorbia prostrata (hierba de la golondrina) y jatropha dioica (sangre de drago).

Tesis (Doctor en Ciencias con acentuación en Química de Productos Naturales) UANL, 2014.