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Habitando la escuela. Educación y transculturación en Rapa Nui 1914-1965Garrote Ramos, José Ignacio January 2013 (has links)
Antropólogo Social / El presente documento consiste en una exposición de los resultados de un estudio cualitativo y etnohistórico concerniente al impacto sociocultural que tuvo la escuela de Rapa Nui entre el año de su instalación en 1914 y el año 1965, fecha en que el sistema social rapanui sufrirá una fuerte modificación producto de la entrada de la administración civil chilena. Como expondremos en los próximos capítulos, el acelerado cambio social y cultural experimentado por la comunidad rapanui en el siglo XX, se habría ocasionado por múltiples factores sociales, económicos, políticos y culturales. En virtud de lo anterior –y luego de una revisión extensa de la literatura disponible-, en la realización de nuestra memoria hemos buscado profundizar en el sistema educativo formal que se desarrolló en este intervalo, entendiéndolo como uno de los aspectos más influyentes en los procesos de cambio cultural que se produjeron en Rapa Nui durante el siglo precedente, y por ende, como un enclave necesario para comprender la cultura rapanui contemporánea
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Plant mediated effects of earthworms on aphid dynamicsKadir, Nawzad January 2014 (has links)
The individual and combined effects of the endogeic and epigeic groups of earthworms on the growth of Chinese cabbage (Brassica rapa), and on the subsequent growth and development of the generalist sap-sucking herbivore Myzus persicae were determined in separate pot experiments. Many previous studies have investigated the relationship between soil biodiversity and aboveground plants, but few researches have considered the indirect interaction between soil biota and above-ground aphids. In this study the individual effects of Aporrectodea rosea and Allolobophora chlorotica and the combined effects of A. rosea and A. chlorotica, Aporrectodea caliginosa and Satchellius mammalis, A. chlorotica and S. mammalis, and A. rosea, A. caliginosa, Lumbricus rubellus and S. mammalis on plant morphology and physiology and aphid development (nymphs day-1, fecundity and number of adults) were investigated. Plant growth was affected by the presence of A. rosea which caused increases in plant biomass, height of plant, leaf surface area and specific leaf area (SLA). Mean number of leaves per plant was unaffected by worm density. In contrast, increasing density of A. chlorotica had no effect on any aspect of plant performance. The combined effect of A. rosea and A. chlorotica resulted in a similar increase in plant biomass to A. rosea alone. While the combined effects of A. caliginosa and Satchellius mammalis, A. chlorotica and S. mammalis and A. rosea, A. caliginosa, L. rubellus and S. mammalis caused increases in all plant parameters except leaf number. Additionally, the individual effect of A. rosea and the combined effects of A. caliginosa and S. mammalis, A. chlorotica & S. mammalis and A. rosea and A. caliginosa, L. rubellus and S. mammalis resulted in increased in leaf nitrogen concentration. Aphid development was also affected by the presence of earthworms. The nymphs day-1, fecundity and numbers of adults were significantly increased with increases in earthworm densities. The interaction between all groups of earthworms and their influence on aphid growth showed that the combined effect of two different groups was greater than the individual groups. Proteomic techniques were used to compare protein patterns in the plants. The combined effects of A. caliginosa and S. mammalis, A. chlorotica and S. mammalis, A. rosea, A. caliginosa, L. rubellus and S. mammalis earthworms on plant resulted in differences in number and kind of protein between plant treated with earthworms and the control, but no significant difference in proteins volume. Effects of earthworms on plant growth and aphid development are shown to be modified by increasing density and interactions between different species and functional groups of earthworms.
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Ethical perspectives and cultural differences regarding repatriation and management of human skeletal remains : Rapa Nui case study / Etiska perspektiv och kulturella skillnader inom repatriering och hantering av mänskliga kvarlevor : En fallstudie på Påskön.Gustafsson, Olivia January 2020 (has links)
Rapa Nui (Easter Island) is an island in the Pacific Ocean which has been colonised over a long period of time. Colonisers have exploited the island through looting and trading Rapanui (the Indigenous people) human skeletal remains. Around ninety percent of the stolen Rapanui human skeletal remains have been located at museums and collections around the world on Rapanui initiative. Through the Rapa Nui Ka Haka Hoki Mi Ate Mana Tupuna Repatriation Program the Rapanui are now working on the return of the alienated human skeletal remains to the Island. This thesis is an analysis of semi structured interviews with inhabitants on Rapa Nui involved in repatriation and ethics of human skeletal remains. It has been carried out through a qualitative method using semi-structured interviews together with participant observation. The thesis is part of Martinsson-Wallin´s STINT-project ‘Sustainable Visits in Rapa Nui – Glocal Perspectives’. Based on the interviews, the analysis and results are divided into five themes: I) treatment of human skeletal remains, II) what laws exists in treating human skeletal remains, III) the possibility to narrow laws and concretize ethical perspectives before and during a repatriation, IV) theories in post-colonialism and V) recurrent issues between the law of the Indigenous peoples and the national law. Comparison with other cases of repatriation such as Sámi follows in Chapter 7. The results of the analysis show that according to the Rapanui, archaeological artefacts and human skeletal remains should be repatriated. Today the involved parties, the Rapanui and the institutions that are keeping collections from Indigenous cultures, are more willing to redress previous events. Such as, colonialization, violence, and social inequality but there is still a lot of respect and understanding that must be developed within several actors.
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Yield response of African leafy vegetables to nitrogen, phosphorus and potassium: The case of Brassica rapa L. subsp. chinensis and Solanum retroflexum Dun.Van Averbeke, W, Juma, KA, Tshikalange, TE 05 June 2007 (has links)
In this study the growth and yield response of Solanum retroflexum Dun. (nightshade) and Brassica rapa L. subsp. chinensis
(non-heading Chinese cabbage) to N, P and K availability in the soil and the interaction effects of these three nutrients were
determined by means of pot experiments in a greenhouse. S. retroflexum was most sensitive to the availability of nitrogen
in the soil. Sufficient nitrogen needed to be available to achieve optimum growth but adding too much adversely affected
biomass production, suggesting a fairly narrow optimum range for nitrogen availability. The production of the crop was also
dependent on the adequate availability of phosphorus and potassium but any adverse effects due to excess availability were less distinct than for nitrogen. In the case of B. rapa subsp. chinensis, an optimum availability range was identified for N and K and a critical level of availability for P. The decline in biomass production caused by adding N in excess of the optimum
was reversed by applying both P and K at rates that were in excess of the respective optima.
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Genetic study on Brassica rapa and Brassica napus for seed color and identification of molecular markersCheema, Kuljit Kaur Unknown Date
No description available.
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The influence of pollinator diversity and behaviour on pollen movement in Brassica rapa chinensis (Pak-Choi) crops, and its significance for gene escapeMesa, Laura A. January 2008 (has links)
The overall aim of the study was to assess the risk of gene flow from Brassica crops by insectmediated pollen transport. I measured the viability of pollen in Brassica flowers throughout crop development and compared this with the viability of pollen transported by insects inside and outside one early- and one late-season crop. In order to evaluate the relative importance of different species in pollen transport, I measured abundance of flower visitors during crop development, and measured the foraging behaviour of five key pollinator species throughout the growing season, in relation to variation in microclimate, crop phenology and the relative abundance of other pollinator species competing for flower resources. Flower visiting insects of Brassica rapa crops were highly diverse, and their abundance and diversity changed with crop phenology. I found similar abundances at the family level for both crops studied, although capture rates were greater in the early- than in the late-season crop. Across flowering development, the greatest numbers of insects were captured at the peak of flowering for both crops. During the flowering period, Diptera was the most abundant order collected, followed by Hymenoptera. The most abundant family in Hymenoptera was Apidae which tracked crop development in both fields, with greater numbers of insects captured inside than outside the field. Standardized-count pollen loads were smaller in Diptera than in Hymenoptera. Of the five key pollinator species sampled, Lasioglossum sordidum (Hymenoptera: Halictidae), Apis mellifera (Hymenoptera: Apidae) and Bombus terrestris (Hymenoptera: Apidae) transported similar pollen loads, which were much greater than those carried by Eristalis tenax (Diptera: Syrphidae) and Melangyna novae-zealandiae (Diptera: Syrphidae). The numbers of insects captured outside of the crop were 10% and 33% of the totals captured inside for the early- and the late-season crop, respectively. The proportion of insects entering versus leaving the crop varied considerably across species, crops and trap location (i.e., whether traps were inside or 50 m outside the border of the crop). However, it is worth noting that not uncommonly more insects were attracted into the crop early in the season, staying there rather than leaving, and then when flowers started to disappear there was a massive escape of insects leaving. This research provides evidence for the influence of crop age on the foraging behaviour of key pollinators and for species-specific variation in the foraging behaviour of Brassica visitors with crop development. Temporal variation in the rate and variability of movement between flowers, and the duration and variability in time spent on each flower, throughout the growing season differed markedly between pollinator species. Flower density, plant density, and the abundance of other insects contributed to the observed variation in pollinator behavioural activity for A. mellifera, E. tenax, M. novae-zelandiae and L. sordidum. Bombus terrestris had the greatest rates and variability of movement, and the greatest rates of flower visitation among all key pollinators studied. Therefore B. terrestris might contribute to gene flow to a greater extent than other key pollinators. Additionally B. terrestris had the greatest variability in the rate of movement, increasing the risk of pollen movement over long distances. In summary, I found that (i) insect abundance and diversity changed with crop phenology and Diptera was the most abundant order collected, (ii) flower density, plant density, and the abundance of other insect pollinators were important factors explaining pollinator behaviour for all key pollinators, except B. terrestris, (iii) B. terrestris might contribute to gene flow to a greater extent than other key pollinators, because it has a greater rate of flower visitation and a greater flight distance between flowers than other pollinators, and (iv) pollen viability tended to decrease with crop development and declined sharply even just 50 m outside the edge of the crop.
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The influence of pollinator diversity and behaviour on pollen movement in Brassica rapa chinensis (Pak-Choi) crops, and its significance for gene escapeMesa, Laura A. January 2008 (has links)
The overall aim of the study was to assess the risk of gene flow from Brassica crops by insectmediated pollen transport. I measured the viability of pollen in Brassica flowers throughout crop development and compared this with the viability of pollen transported by insects inside and outside one early- and one late-season crop. In order to evaluate the relative importance of different species in pollen transport, I measured abundance of flower visitors during crop development, and measured the foraging behaviour of five key pollinator species throughout the growing season, in relation to variation in microclimate, crop phenology and the relative abundance of other pollinator species competing for flower resources. Flower visiting insects of Brassica rapa crops were highly diverse, and their abundance and diversity changed with crop phenology. I found similar abundances at the family level for both crops studied, although capture rates were greater in the early- than in the late-season crop. Across flowering development, the greatest numbers of insects were captured at the peak of flowering for both crops. During the flowering period, Diptera was the most abundant order collected, followed by Hymenoptera. The most abundant family in Hymenoptera was Apidae which tracked crop development in both fields, with greater numbers of insects captured inside than outside the field. Standardized-count pollen loads were smaller in Diptera than in Hymenoptera. Of the five key pollinator species sampled, Lasioglossum sordidum (Hymenoptera: Halictidae), Apis mellifera (Hymenoptera: Apidae) and Bombus terrestris (Hymenoptera: Apidae) transported similar pollen loads, which were much greater than those carried by Eristalis tenax (Diptera: Syrphidae) and Melangyna novae-zealandiae (Diptera: Syrphidae). The numbers of insects captured outside of the crop were 10% and 33% of the totals captured inside for the early- and the late-season crop, respectively. The proportion of insects entering versus leaving the crop varied considerably across species, crops and trap location (i.e., whether traps were inside or 50 m outside the border of the crop). However, it is worth noting that not uncommonly more insects were attracted into the crop early in the season, staying there rather than leaving, and then when flowers started to disappear there was a massive escape of insects leaving. This research provides evidence for the influence of crop age on the foraging behaviour of key pollinators and for species-specific variation in the foraging behaviour of Brassica visitors with crop development. Temporal variation in the rate and variability of movement between flowers, and the duration and variability in time spent on each flower, throughout the growing season differed markedly between pollinator species. Flower density, plant density, and the abundance of other insects contributed to the observed variation in pollinator behavioural activity for A. mellifera, E. tenax, M. novae-zelandiae and L. sordidum. Bombus terrestris had the greatest rates and variability of movement, and the greatest rates of flower visitation among all key pollinators studied. Therefore B. terrestris might contribute to gene flow to a greater extent than other key pollinators. Additionally B. terrestris had the greatest variability in the rate of movement, increasing the risk of pollen movement over long distances. In summary, I found that (i) insect abundance and diversity changed with crop phenology and Diptera was the most abundant order collected, (ii) flower density, plant density, and the abundance of other insect pollinators were important factors explaining pollinator behaviour for all key pollinators, except B. terrestris, (iii) B. terrestris might contribute to gene flow to a greater extent than other key pollinators, because it has a greater rate of flower visitation and a greater flight distance between flowers than other pollinators, and (iv) pollen viability tended to decrease with crop development and declined sharply even just 50 m outside the edge of the crop.
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Estudio etnobotánico del bosque nativo y su vinculación con cuatro pueblos originarios presentes en el museo de la vivienda tradicional localGutiérrez Pilquiman, Yessenia Tamar January 2017 (has links)
Memoria para optar al Título
Profesional de Ingeniera Forestal / El presente estudio fue realizado con el propósito de analizar y comprender el vínculo existente entre cuatro pueblos indígenas, rapa nui, mapuche, pehuenche y selk’nam y las especies vegetales presentes en su medioambiente, para poder integrar y dar a conocer estos conocimientos a través de las muestras museográficas del Museo de la Vivienda Tradicional Local. Para esto se seleccionó la información que presentó alguna relación etnobotánica con los pueblos del estudio, además se vinculó la flora representativa de los sectores de interés para El Museo y se organizó la información obtenida mediante una diferenciación de especies para su estudio etnobotánico en relación con la museografía, con el objetivo final de crear un listado de especies vegetales con potencialidad para ser incluidas en la muestra representativa de El Museo, a través de un catálogo etnobotánico.
Los métodos usados para lograr los objetivos antes mencionados tienen su base en un análisis etnobotánico cualitativo, que se desarrolló con la revisión bibliográfica de antecedentes etnográficos y etnobotánicos de los cuatro pueblos de estudio. La información obtenida sobre las especies vinculadas a los pueblos del estudio, se organizó mediante la diferenciación etnobotánica en función de los criterios museográficos, pensando en una comprehensión para los visitantes del museo. Para definir la importancia de las especies para la muestra representativa del Museo, se usó de un análisis multicriterio con matrices de clasificación en función de criterios museográficos. Además, mediante el manual de métodos y criterios para la evaluación y monitoreo de la flora y la vegetación se identificó la flora existente en las zonas de interés del Museo.
El estudio demostró que existe un amplio conocimiento y vinculación entre cada pueblo indígena y su medioambiente, al utilizar las diversas especies vegetales presentes en su entorno, para distintos fines. Según la puntuación obtenida por las especies para cada cultura, se determinó que la primera posición era ocupada por Drimys winteri en el caso de la cultura mapuche, Araucaria araucana para los pehuenche, Nothofagus betuloides para los selk’nam y Saccharum officinarum para los rapa nui. / The present study was carried out with the purpose of analyzing and understanding the link between four indigenous peoples, rapa nui, mapuche, pehuenche and selk'nam and the plant species present in their environment, in order to integrate and make known this knowledge through of the museographic samples of the Museo de la Vivienda Tradicional Local. For this, the information that presented some ethnobotanical relationship with the study villages was selected. In addition, the representative flora of the sectors of interest to the Museum was linked and the information obtained through a species differentiation was organized for its ethnobotanical study in relation to the museography, with the final objective of creating a list of plant species with the potential to be included in the representative sample of the Museum, through an ethnobotanical catalog.
The methods used to achieve the mentioned objectives are based on a qualitative ethnobotanical analysis, which was developed with the bibliographic review of ethnographic and ethnobotanical antecedents of the four villages of study. The information obtained about the species linked to the study villages was organized through ethnobotanical differentiation according to the museographic criteria, thinking about an understanding for the museum visitors. In order to define the importance of the species for the representative sample of the Museum, a multicriteria analysis was used to classify matrices according to museographic criteria. In addition, the manual of methods and criteria for the evaluation and monitoring of flora and vegetation identified the flora existing in the areas of interest of the Museum.
The study showed that there is a wide knowledge and connection between each indigenous people and their environment, using the various plant species present in their environment, for different purposes. According to the score obtained by the species for each culture, it was determined that the first position was occupied by Drimys winteri in the case of the mapuche culture, Araucaria araucana by the pehuenche culture, Nothofagus betuloides by the selk'nam people and Saccharum officinarum by the rapa nui people.
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Potencial produtivo de acessos de espécies brássicas sob condições tropicais / Productive potential of accessions of brassicas species under tropical conditionsBassegio, Doglas [UNESP] 10 March 2017 (has links)
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Previous issue date: 2017-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O gênero Brassica é a terceira maior fonte de óleo vegetal do mundo, com oleaginosas cultivadas no Hemisfério Norte. No Brasil, apesar do aumento nos últimos anos, a espécie Brassica napus L., não é um cultivo tradicional, devido as limitações de fotoperíodo e altas temperaturas. Outras espécies do gênero, como é o caso da Brassica juncea L. e Brassica rapa L., amplamente cultivadas em zonas de baixa precipitação e fertilidade, podem ser opções de cultivo em áreas marginais de sequeiro em condições tropicais, visto que possuem alto teor de óleo com características propicias para o biodiesel, além de menor sensibilidade ao ambiente. Os objetivos deste trabalho foram caracterizar germoplasma de Brassica juncea L. e Brassica rapa L., avaliar o potencial produtivo e a divergência genética de acessos em Botucatu – SP, Brasil. Os experimentos tiveram início em outono-inverno de 2012, com a avaliação de 424 acessos de Brassica juncea L. e 209 de Brassica rapa L. quanto ao florescimento e produção de sementes. Em outono-inverno de 2015 e 2016 acessos de brássicas e um híbrido comercial da espécie Brassica napus L. foram avaliados, em experimentos em blocos ao acaso com três repetições, em relação aos componentes da produção, à produção grãos e óleo e a divergência genética. Do total de acessos introduzidos e avaliados, apenas 51 (12%) de Brassica juncea L. e 59 (28%) de Brassica rapa L. produziram sementes, devido ao efeito de fotoperiodo. Os componentes da produção variaram entre acessos e espécies, com destaque para precocidade e teor de óleo de acessos da espécie Brassica rapa L.; e o número de síliquas e a produtividade de grãos e óleo de acessos da espécie Brassica juncea L.. A produtividade de grãos e óleo foi em média 15% superior nos acessos de Brassica juncea L. em relação a espécie Brassica rapa L., com destaque para o acesso PI 180266 com 2056 kg ha–1 de grãos e 805 kg ha–1 de óleo. A variabilidade genética entre os acessos de brássicas possibilitou a formação de grupos de acessos para futuros ganhos em melhoramento genético. Conclui-se que os acessos selecionados confirmam a hipótese do potencial produtivo sem efeito de fotoperíodo em condições tropicais, o que demonstra que podem ser opções para cultivo em áreas onde a Brassica napus L. não está bem adaptada. / Brassica is the third largest source of vegetable oil in the world, with oilseeds grown in the Northern Hemisphere. In Brazil, despite the increase in recent years, Brassica napus L., is not a traditional crop due to limitations of photoperiod and high temperatures. Other species of the genus, such as Brassica juncea L. and Brassica rapa L., widely cultivated in low rainfall zones and fertility, may be cultivation options in marginal rainfed areas under tropical conditions, since they have high oil content with characteristics conducive to biodiesel, in addition to lower sensitivity to environment. The objectives of this work were to characterize the germplasm of Brassica juncea L. and Brassica rapa L. and to evaluate the productive potential, as well as the genetic divergence of accesses in Botucatu – SP, Brazil. The experiments started in autumn-winter of 2012, with the evaluation of 424 accessions of Brassica juncea L. and 209 of Brassica rapa L. regarding flowering and seed production. In the autumn-winter of 2015 and 2016, Brassica napus L. and commercial Brassica napus L. were evaluated in randomized blocks with three replicates, in relation to the production components, grain and oil production, and divergence genetic. Of the total number of accesses introduced and evaluated, only 51 (12%) of Brassica juncea L. and 59 (28%) of Brassica rapa L. produced seeds, due to the effect of photoperiod. The components of the production varied between accesses and species, with emphasis on precocity and oil content of Brassica rapa L.; and the growth and number of siliques of the specie Brassica juncea L. The yield of grains and oil was on average 15% higher in the accessions of Brassica juncea L. in relation to the species Brassica rapa L., with emphasis on access PI 180266 with 2056 kg ha–1 of grains and 805 kg ha–1 of oil yield. The genetic variability among the accessions of brassicas allowed the formation of groups of accessions for future gains in genetic improvement. It is concluded that the selected accessions confirm the hypothesis of the productive potential without photoperiod effect in tropical conditions, which demonstrates that they can be options for cultivation in areas where Brassica napus L. is not well adapted.
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Modulation of brassica rapa L. antioxidant activities by exogenous methylglyoxal under zirconium stressBless, Yo-Neal January 2016 (has links)
>Magister Scientiae - MSc / With a decrease in water availability and arable land, and the ever-increasing reports of toxic chemical pollutants, it is crucial to elucidate plants’ mechanisms of adaptability to these abiotic stressors. South Africa alone accounts for approximately 30% of global Zirconium (Zr) production. However, reports on Zr-induced stress in plants are sparse. Increased mining activity leads to soil contamination which subsequently has harmful effects on crop plants. Under normal conditions B. rapa crop plants flourish, they are rapid in their cycling and circumvent the seed dormancy stage which enables them to have high yields over relatively short periods. However, when unfavourable conditions arise, such as exposure to toxic chemicals and metal ions like Zirconium, the development and growth of B. rapa L., much like other crop plants is affected. More specifically, the damaging effects of Zr is not only attributed directly; as with substitutions of biometals [like Iron (Fe)] in various biomolecules rendering them inactive, but more as a consequence of the production of toxic molecules such as reactive oxygen species (ROS) and methylglyoxal (MG). ROS such as superoxide anion (O₂⁻) and hydrogen peroxide (H₂O₂ ) are known to have signalling roles in plants with reports on their involvement in alleviating seed dormancy and seedling development. However, the signalling roles of MG are not known with regards to plant cells and have been reported more so in animal cells; playing vital roles in fat signalling in diseases such as diabetes. Furthermore MG, in plant and animal cells, directly converts oxygen (O₂) to O₂⁻ and thus increases the cell’s oxidative imbalance, leading to cell damage if O₂⁻ is not rapidly dismutated to H₂O₂ and H₂O by superoxide dismutase (SOD). In turn, H₂O₂ is more stable than O₂⁻ and consequently is more toxic to cells over time. Therefore, H O must be removed as well by a collection of enzymes, such as ascorbate peroxidase (APX) and catalases (CAT). In this study, possible stress-signalling of MG in seedlings under normal conditions and Zr-stress were investigated to establish whether MG at a low dose (6 μM) would benefit seedling growth and development, via a proposed preinduction of the B. rapa L. antioxidant system. Therefore, it was proposed that ROS accumulation due to the exogenous application of MG, would incite the activation of antioxidants and thus mitigate the effects of Zr stress. Physiological tests to determine dry weights (figure 3.2.3) and germination percentage (figure 3.2.2) revealed that MG-treated seedlings yielded an improved biomass and early development compared to Zr-treated seedlings and the control. Membrane damage as assessed by lipid peroxidation viz. Malondialdehyde [MDA] (figure 3.2.4) and conjugated dienes [CD] (figure 3.2.5) also indicated less damage in MG-treated seedlings compared to the Zr-treated set. The chlorophyll content observed was prominent (table 3.1). MG-treated seedlings exhibited a 40% and 15.5% increase compared to Zr-treated seedlings and the control respectively. Moreover cell viability had improved in MG-treated seedlings compared to the control, and in MG+Zr-treated seedlings only a slight increase in cell death occurred despite Zr being present. O₂⁻, H₂O₂ and •OH (figure 4.2.1 – 4.2.3) were investigated in B. rapa L. seedlings in response to Zr and MG by spectrophotometric biochemical assays, as well as their scavenging enzymes, MG accumulation and Gly-I activity. Furthermore, BrGLY1 gene expression and Zr-uptake by ICP-OES were performed. Seedlings treated with MG and Zr respectively showed an increase in ROS. However, all of the ROS observed in MG+Zr-treated seedlings were markedly lower compared to Zr-treated seedlings. SOD and CAT activity observed in MG+Zr-treated seedlings had decreased compared to Zr-treated seedlings, whereas APX activity had increased. Gly-I activity and BrGlyI gene expression had increased across all treatments, showing an elicited response to oxidative stress, due to the observed upregulation, as a result of the accumulated MG. The observed Zr-uptake in MG+Zr-treated seedlings was inhibited by 5-fold compared to Zr-treated seedlings. Clear signs of stress were evident in seedlings treated with Zr compared to the control and MG- treated seedlings, the MG-supplemented (MG and MG+Zr) seedlings displayed a vast improvement comparatively. Modulation of antioxidant activity observed in this study is indicative of an incited response to oxidative stress (figure 4.2.4 – 4.2.6). MG revealed distinct involvement in stress-signalling, ROS levels had increased, although not as severely as with Zr-treated seedlings, but seemingly enough to activate antioxidants without eliciting damage. Furthermore, the proposed early-onset activation of antioxidants has been observed in B. rapa L. seedlings of this study, and as such has resulted in improved growth, development and seed germination. The results of this study has therefore negated the previous reports on MG-toxicity (at high concentrations), and has shed light on further properties of this ubiquitous and inevitably-occurring metabolite at low levels. / National Research Foundation (NRF)
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