Air pollutant exposure poses a health risk to humans and impacts negatively on agriculture. High levels of air pollution resulted in extensive crop damage and yield reduction in Europe and USA. The Highveld region in South Africa, a very important area for maize and soya production, has already been declared an air pollution hot spot, with SO2 being the most concerning air pollutant. Most of the SO2 over the Highveld originates from the burning of coal for power generation. Developing countries, such as South Africa, are highly dependent on agriculture for food security and high levels of air pollution pose serious risks to the agricultural industry. Currently very little information is available on the effects of air pollution on crop production in South Africa. This study aimed to establish exposure-response relationship for SO2 on soybean and the quantification thereof on the morphological, physiological and biochemical characteristics. Two soybean cultivars were used, namely: LS 6164 and PAN 1666. The plants were fumigated for 7 hours, 7 days a week with 0 (carbon filtered control; CF), 25, 75 and 150 ppb SO2. The effect of SO2 was investigated on the growth, photosynthetic capabilities, photosynthetic gas exchange, peroxidase activity and lipoxygenase activity of the cultivars. Foliar injuries and interveinal chlorosis were visible with increasing levels of SO2 as well as a decrease in biomass accumulation, especially in root biomass; a more prominent feature of LS 6164. The number of nodules of both cultivars decreased insignificantly as the levels of SO2 increased. The number of pods per plant and the average weight of 30 seeds indicated a downward trend with an increase in SO2 concentration. The chlorophyll content of PAN 1666 was lower compared to LS 6164. PAN 1666 had the largest reduction in stomatal conductance at 150 ppb SO2 fumigation. The photosynthetic vitality index indicated that LS 6164 was more sensitive to SO2 inhibition from 25 ppb SO2 and higher, whereas PAN 1666 mostly became sensitive to SO2 from 75 ppb SO2. A decrease in the ability to absorb light energy, the trapping of excitation energy to transfer electrons beyond QA-, and the reduction of end electron acceptors all contributed to the decline in the vitality index. Sulphur content increased significantly in the 75 ppb and 150 ppb treatments of both cultivars. Induced peroxidase and lipoxygenase activity was seen in both cultivars, especially at higher concentrations of SO2 treatments. PAN 1666 had a higher rate of peroxidase and lipoxygenase activity compared to LS 6164. The implication for SO2 on crop production in the highly industrial Highveld area was demonstrated to be potentially of great concern. The dose-response relationships plotted for OJIP parameters emphasized that SO2 is an inhibitor of photosynthesis and phytotoxic of nature. Both cultivars experienced limitations from 75 ppb, especially at the 150 ppb SO2 concentration. From these results it appears that PAN 1666 is more adapted to SO2 compared to LS 6164 and levels of 75 ppb SO2 and higher become toxic to these plants. / Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013

Air pollutant exposure poses a health risk to humans and impacts negatively on agriculture. High levels of air pollution resulted in extensive crop damage and yield reduction in Europe and USA. The Highveld region in South Africa, a very important area for maize and soya production, has already been declared an air pollution hot spot, with SO2 being the most concerning air pollutant. Most of the SO2 over the Highveld originates from the burning of coal for power generation. Developing countries, such as South Africa, are highly dependent on agriculture for food security and high levels of air pollution pose serious risks to the agricultural industry. Currently very little information is available on the effects of air pollution on crop production in South Africa. This study aimed to establish exposure-response relationship for SO2 on soybean and the quantification thereof on the morphological, physiological and biochemical characteristics. Two soybean cultivars were used, namely: LS 6164 and PAN 1666. The plants were fumigated for 7 hours, 7 days a week with 0 (carbon filtered control; CF), 25, 75 and 150 ppb SO2. The effect of SO2 was investigated on the growth, photosynthetic capabilities, photosynthetic gas exchange, peroxidase activity and lipoxygenase activity of the cultivars. Foliar injuries and interveinal chlorosis were visible with increasing levels of SO2 as well as a decrease in biomass accumulation, especially in root biomass; a more prominent feature of LS 6164. The number of nodules of both cultivars decreased insignificantly as the levels of SO2 increased. The number of pods per plant and the average weight of 30 seeds indicated a downward trend with an increase in SO2 concentration. The chlorophyll content of PAN 1666 was lower compared to LS 6164. PAN 1666 had the largest reduction in stomatal conductance at 150 ppb SO2 fumigation. The photosynthetic vitality index indicated that LS 6164 was more sensitive to SO2 inhibition from 25 ppb SO2 and higher, whereas PAN 1666 mostly became sensitive to SO2 from 75 ppb SO2. A decrease in the ability to absorb light energy, the trapping of excitation energy to transfer electrons beyond QA-, and the reduction of end electron acceptors all contributed to the decline in the vitality index. Sulphur content increased significantly in the 75 ppb and 150 ppb treatments of both cultivars. Induced peroxidase and lipoxygenase activity was seen in both cultivars, especially at higher concentrations of SO2 treatments. PAN 1666 had a higher rate of peroxidase and lipoxygenase activity compared to LS 6164. The implication for SO2 on crop production in the highly industrial Highveld area was demonstrated to be potentially of great concern. The dose-response relationships plotted for OJIP parameters emphasized that SO2 is an inhibitor of photosynthesis and phytotoxic of nature. Both cultivars experienced limitations from 75 ppb, especially at the 150 ppb SO2 concentration. From these results it appears that PAN 1666 is more adapted to SO2 compared to LS 6164 and levels of 75 ppb SO2 and higher become toxic to these plants. / Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013

Recent work has described how gas exchange can occur through sea ice. First, carbon fluxes over sea ice surfaces have been measured. Second, sea ice brine has an elevated capacity over seawater to absorb CO2(g) due to its cold temperature and chemical equilibrium promoting carbon phase changes. Sea ice pCO2 profiles were collected using a new method of remotely sampling gas in situ via diffusive membranes placed within growing sea ice. Gas analysis was complimented by measurements of local meteorology and ice chemistry. The work was part of the CASES 2004 project. The observed elevation in sea ice pCO2 coupled with the mobility of the brine points to the role that brine plays in Arctic carbon transport. The gas transport links the Arctic atmosphere and ocean and indicates that a thinning and receding ice cover may not result in creating a negative feedback to the increasing atmospheric CO2(g) concentration.

Diving vertebrates are constrained by an aquatic existence because they carry a limited store of oxygen whilst submerged and must return to the surface to breathe. Therefore, oxygen stores must be used efficiently in order to maximise aerobic dive duration. The ability to use additional, non-pulmonary gas exchange to obtain oxygen from the water provides a mechanism to alleviate the use of body oxygen stores and extend dive duration. The partitioning of gas exchange between aerial and aquatic modes is predicted by the theory of optimal breathing. As the cost of obtaining oxygen by one mode increases, the reliance on this mode should decrease whilst the reliance on the alternate mode should increase. A number of environmental, physiological and ecological factors can affect metabolic rate and/or the partitioning of gas exchange between aerial and aquatic modes, with consequences for dive duration. The overall aim of this study was to examine the effects of temperature, specific dynamic action and predation on respiratory partitioning and diving behaviour in the Arafura filesnake, Acrochordus arafurae. Filesnakes provide an excellent model to address the aims of this study because they are fully-aquatic and respire bimodally, utilising both aerial and aquatic (cutaneous) gas exchange. Metabolic rate and diving behaviour are usually thermally dependent in diving ectotherms. Given this knowledge, we tested whether A. arafurae was capable of up-regulating cutaneous oxygen uptake to compensate for the temperature induced increases in metabolic rate. Metabolic rate had a Q10(20-32°C) of 2.33, however cutaneous oxygen uptake was independent of temperature and all elevated metabolic demands were met by increasing aerial oxygen uptake. Consequently, maximum dive duration was reduced by 70%, from 77 min at 20°C to 28 min at 32°C. The temperature independence of cutaneous oxygen uptake suggests that blood PO2 remained stable across temperatures and the increased blood flow expected with an elevated metabolic rate did not enhance the capacity for oxygen uptake (diffusion limited rather than perfusion limited). Although cutaneous oxygen uptake was not regulated, its contribution to extending dive duration was significant. When the ability to respire aquatically was removed (severe hypoxia), dive duration was reduced by up to 30%. Acrochordus arafurae feeds infrequently on large, high-protein meals thus the postprandial metabolic response was significant. Meal size and fast length (13 days or one month) were both positively related to the peak metabolic scope. After fasting for one month, peak rate of oxygen consumption was up to 12-fold standard metabolic rate (SMR) with the largest meal size. By comparison, an animal that was fasted for 13 days and fed an equivalent meal size incurred a six-fold increase in SMR. The energetic costs of digestion (specific dynamic action, SDA) increased with meal size, but fast length had no effect, suggesting the up-regulation of gut function was not a significant cost in the SDA. Pulmonary and cutaneous gas exchange increased with elevated metabolic demands however pulmonary oxygen uptake was the dominant mode. Despite the increase in cutaneous oxygen uptake during digestion, maximum dive duration decreased by between 50% and 90% of fasted values. The significant reductions in dive duration following feeding may have implications for predator vulnerability. Diving animals are most vulnerable to predation at the water’s surface. The theory of optimal diving under predation predicts that animals should make shorter, more frequent surface intervals or longer, less frequent surfacing intervals to minimise exposure to predators. Acrochordus arafurae is prone to aerial (birds of prey) and aquatic (crocodiles, large fish) predation. Simulated avian predation did not change dive or surface duration or proportion of time at the surface or spent active. However, a greater number of longer dives were observed with fewer long surface intervals suggesting an increase in the use of cutaneous oxygen uptake. The nocturnal diving patterns of A. arafurae provide an in-built anti-predator strategy. The threat of aquatic predation by a large fish produced atypical anti-predator responses; A. arafurae became increasingly active, reduced dive duration and increased surface interval which was indicative of a foraging response. The field diving behaviour of adult A. arafurae was determined using acoustic telemetry and interpreted in the context of environmental and ecological conditions. The mean dive duration was 6.6 min, with 85% of dives less than 10 min in duration. The maximum dive duration was 153 min. There was no diel pattern in dive duration. Snakes were located at an mean depth of 0.62 m, however, they occasionally ventured to greater depths (up to 6 m) but very infrequently. Snake body temperature reflected water temperature and fluctuated by approximately 1°C on a daily basis. The short and shallow dives of A. arafurae minimise travel costs associated with surfacing and may be an anti-predator strategy. Metabolic rate and respiratory partitioning is dependent on physiological and ecological factors with consequences for dive duration. Temperature and postprandial induced increases in metabolic demands were met by increasing the reliance on aerial gas exchange given the limitations of cutaneous gas exchange; and dive duration was substantially reduced as a result. Ecological factors, such as predation, can increase the cost of surfacing and promote the use of aquatic gas exchange. However, changes to behaviour, including habitat choice, residence depth and the employment of a diving strategy that does not maximise dive duration may be just as effective at minimising the costs and maximising the gains of a dive.

Crop yields are coming under pressure to continue to grow in the face of climate change, competition, disease and pressure to reduce inputs. Photosynthetic efficiency is being targeted for improvement to increase yields. This study examined the variation in parameters of photosynthetic efficiency including canopy structure (leaf length, canopy angle, and chlorophyll content and growth rate) and gas exchange (photosynthetic rate, stomatal density and chlorophyll fluorescence) in Spring Barley (Hordeum vulgare ssp vulgare). These were first established for modern cultivars representing the most widely grown lines in the last 60 years. As cultivars are developed from a small pool of parents they may have limited genetic variation available for breeding. Landraces have been suggested as sources of variation. Using field and growth cabinet based studies the photosynthetic efficiencies of canopy structure and gas exchange were established for a range of European landraces under high and low nutrient inputs. This study demonstrated that in modern cultivars the leaf length increased with year of release from 23.2 to 29.6 cm and the chlorophyll content decreased from 46.9 to 34.8 SPAD units. Once the ear had emerged no difference was seen in canopy structure or photosynthetic rate. There was variation in landrace canopy establishment rate, leaf angle and number of leaves present within the canopy. The landraces from Northern European latitudes pushed though booting and reached full canopy establishment up to 8 days sooner than those from Southern Europe. This may be a response to a shorter growth season at Northern latitudes requiring the canopy to be established quickly. The landraces held the leaves within their canopy in a more horizontal position than the Southern European lines with leaf angle ranging from 18-45 degrees at GS39 and 31-84 degrees at GS59. This regressed negatively with temperature so it may be that a vertical canopy structure is beneficial in areas with higher temperatures. The photosynthetic rate of the landraces showed no variation but when chlorophyll fluorescence examined the efficiency of photosystem II (PSII) there was a positive regression of Fv/Fm ratio with latitude. This suggested that lines from Southern Europe were experiencing a greater stress with a ratio of up to 0.822 compared to those lines from the North with ratios from 0.767. The stomatal density of the landraces showed a large difference in ranges from 22-41 stomata between the lines. When high and low nutrient inputs were compared reductions from a ratio of 0.48 to 0.47 in Harvest Index and from 55g to 52g in 1000 grain weight were seen. The chlorophyll content of the lines was also reduced from 41.7 to 39.2 SPAD units at GS39 and from 44.9 to 39.8 SPAD units at GS59 by the reduction in nutrient inputs which may be a result of less N available for the production of chlorophyll. In conclusion there is variation present in canopy structure in European landraces that may be useful for future breeding or in identifying landrace collections which could be targeted for traits of interest in photosynthetic efficiency. These landraces may provide traits which could be used to develop cultivars which are locally adapted to climate and environmental conditions.

ARAÚJO, Ana Paula Bezerra de. Influência da irrigação com água salina em sistema consorciado milho/feijão-de-corda. 2015. 98 f. : Tese (doutorado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2015. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-08-04T12:31:02Z No. of bitstreams: 1 2015_tese_apbaraujo.pdf: 1648606 bytes, checksum: 0e9585605ef3b3fec872c84bfc426b84 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-08-04T12:31:35Z (GMT) No. of bitstreams: 1 2015_tese_apbaraujo.pdf: 1648606 bytes, checksum: 0e9585605ef3b3fec872c84bfc426b84 (MD5) / Made available in DSpace on 2016-08-04T12:31:35Z (GMT). No. of bitstreams: 1 2015_tese_apbaraujo.pdf: 1648606 bytes, checksum: 0e9585605ef3b3fec872c84bfc426b84 (MD5) Previous issue date: 2015 / Changes in the microclimate in a intercropping can also change the responses of plants to some abiotic factors, including, salinity. The aim of this study was to evaluate the influence of salinity of irrigation water on gas exchange, ion levels, growth, productivity and efficiency of land use in single and intercropped systems, using plant corn and beans-in-corda. The experiment was conducted for two years following a design in randomized blocks in split plots, and the plots formed by the year of cultivation (2012 and 2013), the subplots by salinity of irrigation water (0.9, 2.5 and 5.0 dS m-1), and the split of crop systems (bean-to-rope, corn and more bean-to-string corn in consortium). The irrigated crops were conducted during the dry seasons of the years 2012 and 2013, and samples were taken soil samples before and after each crop, and after the passage of the rainy seasons of 2013/2014. To facilitate the description of the results, the thesis was divided into two chapters. The first is related to growth and productivity. The variables analyzed were: biomass production, productivity and efficiency of land use. The second is related to gas and mineral nutrition exchanges. The variables analyzed were: stomatal conductance, photosynthesis, transpiration, water use efficiency, levels of Na+, K+ and Cl+ in the leaves and stem. The accumulation of salts in the soil increased in proportion to the electrical conductivity values of irrigation water, with the highest observed in maize, a fact explained by the longer cycle and increased the employed irrigation depth in this culture. Rainfall totals recorded in the rainy seasons of 2013 and 2014 were sufficient to promote the leaching of excess salts below the root zone of crops. The accumulation of salts in the soil did not influence gas exchange and efficiency of water use, but caused an increase in the levels of Na+ in the leaves and stems. Despite the differences observed in the levels of Na, one can not relate them the variables of gas exchange, since they were not affected by the irrigation water salinity. The effects of salts on the production of total biomass and productivity of the plants were more expressive in plants under monoculture, especially in the bean-to-rope culture. The microclimate condition of intercropping system may have contributed to reduce the influence of salinity on productivity, mainly of bean-to-rope culture, resulting in higher values of efficient land use. / As alterações no microclima em um cultivo consorciado podem também alterar as respostas das plantas a alguns fatores abióticos, dentre eles, a salinidade. O objetivo do presente trabalho foi avaliar a influência da salinidade da água de irrigação sobre as trocas gasosas, teores de íons, crescimento, produtividade e eficiência do uso da terra em sistemas de monocultivo e consórcio, utilizando-se plantas de milho e feijão-de-corda. O experimento foi realizado durante dois anos seguindo um delineamento em blocos ao acaso, em parcelas subsubdivididas, sendo as parcelas formadas pelo ano de cultivo (2012 e 2013), as subparcelas pela salinidade da água de irrigação (0,9, 2,5 e 5,0 dS m-1) e as subsubparcelas pelos sistemas de cultivo (feijão-de-corda, milho e milho mais feijão-de-corda em consórcio). Os cultivos irrigados foram conduzidos durante as estações secas dos anos 2012 e 2013, e foram realizadas coletas de amostras de solo antes e após cada cultivo, e após a passagem das estações chuvosas de 2013/2014. Para facilitar a descrição dos resultados, a tese foi dividida em dois capítulos. O primeiro é referente ao crescimento e produtividade. As variáveis analisadas foram: produção de biomassa, produtividade e eficiência do uso da terra. O segundo é referente às trocas gasosas e nutrição mineral. As variáveis analisadas foram: condutância estomática, fotossíntese, transpiração, eficiência do uso da água, teores de Na+, K+ e Cl+ nas folhas e caule. O acúmulo de sais no solo aumentou proporcionalmente aos valores de condutividade elétrica da água de irrigação, sendo os maiores observados na cultura do milho, fato explicado pela maior duração do ciclo e maior lâmina de irrigação empregada nesta cultura. Os totais de chuvas verificados nas estações chuvosas de 2013 e 2014 foram suficientes para promover a lixiviação do excesso de sais abaixo da zona radicular das culturas. O acúmulo de sais no solo não influenciou as trocas gasosas e a eficiência do uso da água, mas provocou aumento nos teores de Na+ nas folhas e caules. Apesar das diferenças observadas nos teores de Na, não se pode relacioná-las as variáveis de trocas gasosas, visto que estas não sofreram influência da salinidade da água de irrigação. Os efeitos dos sais sobre a produção de biomassa total e produtividade das plantas se mostraram mais expressivos nas plantas sob monocultivo, notadamente na cultura do feijão-de-corda. A condição microclimática do sistema de consórcio pode ter contribuído para reduzir a influência da salinidade na produtividade, principalmente da cultura do feijão-de-corda, resultando em maiores valores do uso eficiente da terra.

Submitted by Jordan (jordanbiblio@gmail.com) on 2017-05-05T13:55:14Z No. of bitstreams: 1 DISS_2015_Magdiel Josias do Prado.pdf: 1377746 bytes, checksum: c0558030ad829d4b3388055267457759 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2017-05-18T16:23:32Z (GMT) No. of bitstreams: 1 DISS_2015_Magdiel Josias do Prado.pdf: 1377746 bytes, checksum: c0558030ad829d4b3388055267457759 (MD5) / Made available in DSpace on 2017-05-18T16:23:32Z (GMT). No. of bitstreams: 1 DISS_2015_Magdiel Josias do Prado.pdf: 1377746 bytes, checksum: c0558030ad829d4b3388055267457759 (MD5) Previous issue date: 2015-02-23 / CNPq / O Pantanal norte de Mato Grosso é caracterizado por quatro períodos sazonais: a enchente, a cheia, a vazante e a seca. Esses períodos determinam uma intensa variação na disponibilidade de água e no grau de oxigenação do solo da região, agindo como um filtro seletivo que permite que somente as espécies com capacidade de adaptação consigam ali sobreviver. Considerando esses aspectos, o objetivo com esta pesquisa foi o de analisar a capacidade adaptativa de duas espécies do gênero Combretum, o C. lanceolatum Pohl ex Eickl e o C. laxum Jacq, que figuram como espécies invasoras na região. Dois aspectos fisiológicos foram levados em consideração para tal avaliação, o intercâmbio gasoso e as relações hídricas. Para ambos os aspectos analisados foram medidas as variáveis inerentes em cada um dos quatro períodos sazonais. Para as medições de intercâmbio gasoso foi utilizado um analisador de gás infravermelho portátil, modelo LI-6400 (LI-COR, Inc., Lincoln, NE, USA) e para análise das relações hídricas foi utilizado uma bomba de pressão do tipo Scholander. Observou-se que a sazonalidade climática, afetou de forma particular o intercambio gasoso das espécies em estudo. Apesar de ambas as espécies ocorrerem de forma extensiva no Pantanal, o que por si é um indicador da adaptabilidade das mesmas ao local, as estratégias fisiológicas adotadas pelas mesmas são diferentes. Do ponto de vista da assimilação do carbono, enquanto o período de vazante causa redução na taxa fotossintética de C. lanceolatum, é o período seco que causa esse mesmo efeito no C. laxum. Enquanto a redução na taxa fotossintética líquida no C. laxum pode estar associada a um efeito estomático, porque nesse período, independentemente das espécies, é quando se verifica o menor valor da condutância estomática; para o C. lanceolatum a redução deve estar mais relacionada com aspectos não estomáticos. Nas relações hídricas observou-se que a capacidade de ressaturação de ambas as espécies variou com a sazonalidade, sendo mais efetivos durante os períodos de enchente e cheia e menos efetivos durante a vazante e a seca. Ambas as espécies não apresentaram variações significativas do conteúdo relativo de água a plena turgência e do módulo volumétrico de elasticidade da parede celular. As variações no potencial osmótico à turgescência plena e à turgescência insipiente não revelam claramente a busca por um ajuste sazonal dessas variáveis. Aparentemente a relativa constância dos valores das variáveis das relações hídricas verificada para ambas as espécies ao longo dos períodos sazonais sugere uma adaptação à qualquer variação extrema na disponibilidade de água no ambiente. / The North Pantanal of Mato Grosso is characterized by four seasonal periods: the flood, full, the ebb and dry. These periods determine an intense variation in water availability and the degree of oxygenation of the soil of the region, acting as a selective filter that allows only the species with adaptability able to survive there. Considering these aspects, the aim of this study was to analyze the adaptive capacity of two species of the genus Combretum, C. lanceolatum Pohl ex Eickl and C. laxum Jacq, listed as invasive species in the region. Two physiological aspects were taken into account in this assessment, the gas exchange and water relations. For both aspects analyzed were measured variables inherent in each of the four seasonal periods. For gas exchange, measurement was performed using a portable infrared gas analyzer, Model LI-6400 (Li-COR Inc., Lincoln, NE, USA) and water relations analysis was used a pressure type pump Scholander. It was observed that the seasonality, affected in a particular way the gas exchange of the species studied. Although both species occur extensively in the Pantanal, which in itself is an indicator of the adaptability of the same location, the physiological strategies adopted by them are different. Carbon assimilation of view, while the ebb period causes a reduction in photosynthetic rate of C. lanceolatum, is the dry season, which causes the same effect on C. laxum. While the reduction in net photosynthetic rate in C. laxum may be associated with a stomatal effect because this period, regardless of species, when there is the lowest value of stomatal conductance; for C. lanceolatum the reduction must be more related to aspects not stomatal. In water relations noted that the resaturation capacity of both species with varied seasonally, being more effective during flood periods and full and less effective during ebb tide and dried. Both species showed no significant changes in relative water content at full turgor and bulk modulus of elasticity of the cell wall. Changes in osmotic potential at full turgor and swelling incipient not clearly reveal the search for a seasonal adjustment of these variables. Apparently, the relative constancy of variable water relations values observed for both species along seasonal periods suggests an adaptation to any extreme variation in water availability in the environment.

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-06-05T16:39:15Z No. of bitstreams: 1 arquivototal.pdf: 4186223 bytes, checksum: 3758454784531cdb854ab4f824e31065 (MD5) / Made available in DSpace on 2016-06-05T16:39:15Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4186223 bytes, checksum: 3758454784531cdb854ab4f824e31065 (MD5) Previous issue date: 2015-12-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Brazil has 47 endemic species of strawberry guava (Psidium spp.), being an important center of genetic diversity of this genus. In the Caatinga biome, the occurrence of the species P. schenckianum Kiaersk, P. guineense Swartz. (most often) and Psidium grandifolium Mart. have been reported. These species have great potential for economic exploitation of the fruit, which is rich in vitamin C and can be consumed fresh or processed in the form of juices, sweets, jams, jellies and ice cream. It also presents outstanding antimicrobial activity, pharmacological and antioxidant as well as essential oils. In addition, strawberry guava are the main sources of resistance to nematode (Meloidogyne enterolobii), which is the main pathogen of guava (P. guajava). This resistance can be transferred to the Paluma guava (cv. GP). However, the strawberry guava is endangered in its natural environment and presents limitations in vegetative propagation by conventional methods, making impossible cloning the resistant plants. Micropropagation is a viable propagation technique of species susceptible to extinction and difficult vegetative propagation. Protocols allowing the cloning of this species for future studies should be improved. Thus, the aim of this research is to develop a protocol for micropropagation of Psidium spp., determining the culture medium, conditions of gas exchange, type of explant and concentration of growth regulators. Seedlings of three access of strawberry guava and cultivar guava paluma (cv.GP) were grown under the following conditions: JADS culture medium, MS and WPM to determine the culture medium; and medium JADS sealed with lids without membrane (SM), one membrane (1M) and two membranes (2M) with carbon dioxide exchange rates (TTCO2) 14; 21 and 25 μL L-1, respectively, to determine the best seedling growth in TTCO2 Psidium spp. After this, different explants of Brazilian guava trees were transferred to regeneration media with different concentrations of indolbutyric acid (IBA): 0, 2.46, 4.92 and 9.84 mM in rooting induction and benzyladenine (BA): 0.0, 2.2 and 4.44 mM; BA + naphthaleneacetic acid (NAA): 2.22 uM BA + 0.054 uM ANA; and 4.44 uM BA + 0.054 uM ANA in regeneration shoots of the following explants: nodal and apical segments in semi-solid culture, stem segments in liquid culture, organogenesis internodal segments, and leaf sections in semi-solid cultureof a P. guineense access and induction of organogenesis in liquid culture using root segments of a P. schenckianum access and three accessions of P. guineense. Seedlings of strawberry guava and cv. GP showed better growth in JADS culture medium. TTCO2 (25 μL L-1) resulted in the growth of seedlings with improved morphophysiological and anatomical characteristics and biosynthesis of compounds of reserve in leaves from both species (P. guineense and P. guajava). This condition is the most indicated for the development in in vitro propagation protocols of Psidium spp. It was not necessary the addition of IBA in the rooting of shoots. Shoots were obtained with and without addition of plant hormones in stem segments, apical segments, nodal and root segments in P. guineense accesses from direct organogenesis, maintaining the same ploidy of the seedlings of this species. In stem segments, the greater number of shoots was observed with 2.22 and 4.44 mM of BA. Shoots were elongated, rooted and acclimatized with 100% survival, showing that the in vitro regeneration protocol established is efficient. This is the first micropropagation protocol established to strawberry guava / O Brasil possui 47 espécies endêmicas de araçazeiros (Psidium spp.), constituindo-se num importante centro de diversidade genética do gênero. No bioma Caatinga, já foram reportadas a ocorrência das espécies Psidium schenckianum Kiaersk., P. guineense Swartz. e P. grandifolium Mart., com maior frequência das duas primeiras. Estas espécies apresentam grande potencial de uso de seus frutos, por serem ricos em vitamina C, podendo ser utilizado no consumo in natura ou industrializado, na forma de sucos, doces, compotas, geleias e sorvetes. Apresenta ainda, marcante atividade antimicrobiana, farmacológica e antioxidante além de possuir grande quantidade de óleos essenciais. Além disso, os araçazeiros são as principais fontes de resistência ao nematoide (Meloidogyne enterolobii), principal patógeno que acomete a goiabeira (P. guajava), a qual pode ser transferida para a goiabeira Paluma (cv. GP). Contudo, os araçazeiros encontram-se em risco de extinção em seus ambientes naturais e apresentam dificuldades na propagação vegetativa pelos métodos convencionais, impossibilitando a clonagem das plantas resistentes. A micropropagação é uma técnica viável para propagação de espécies passíveis de extinção e de difícil propagação vegetativa, devendo-se desenvolver protocolos que possibilitem a clonagem desta espécie para estudos futuros de melhoramento. Dessa forma, objetivou-se com a presente pesquisa desenvolver um protocolo para micropropagação de Psidium spp., determinando o meio de cultura, condições de trocas gasosas, tipo de explante e concentração de fitorreguladores. Plântulas de três acessos de araçazeiros e da cultivar de goiaba Paluma (cv. GP), foram crescidas nas seguintes condições: meios de cultura JADS, MS e WPM para determinação do meio de cultura, e em meio de cultura JADS, vedados com tampas sem membrana (SM), uma membrana (1M) e duas membranas (2M) com taxas de trocas de dióxido de carbono (TTCO2) de 14; 21 e 25 μL L-1, respectivamente, para determinar a melhor TTCO2 no crescimento de plântulas de Psidium spp. Após determinada estas condições, diferentes explantes de araçazeiros foram induzidos a regeneração in vitro, utilizando diferentes concentrações de ácido indolbutírico (AIB) (0; 2,46; 4,92 e 9,84 μM) na indução de rizogênese; benziladenina (BA) (0,0; 2,2 e 4,44 μM) e BA + ácido naftalenoacético (ANA) (2,22 μM BA + 0,054 μM ANA e 4,44 μM BA + 0,054 μM ANA) na regeneração de brotos dos seguintes explantes: segmentos nodais e apicais em meio de cultura semi-sólido, segmentos caulinares em meio de cultura líquido, organogênese de segmentos internodais, e secções foliares em meio de cultura semi-sólido, de um acesso de P. guineense e indução de organogênese em meio de cultura líquido, utilizando segmentos radiculares de um acesso de P. schenckianum e três acessos de P. guineense. As plântulas de araçazeiro e da cv. GP apresentaram melhor crescimento em meio de cultura JADS. Maiores TTCO2 (25 μL L-1), resultaram no crescimento das plântulas com melhores características morfofisiológicas e anatômicas, e na biossíntese de compostos de reservas nas folhas de ambas as espécies (P. guineense e P. guajava), sendo esta condição a mais indicada para o desenvolvimento de protocolos de propagação in vitro de Psidium spp. Não foi necessária adição de AIB no enraizamento das brotações. Foram obtidas brotações com e sem adição de fitorreguladores, em segmentos caulinares, segmentos apicais, nodais e, em segmentos radiculares nos acessos de P. guineense, a partir de organogênese direta, mantendo a mesma ploidia das plantas oriundas de sementes desta espécie. Em segmentos caulinares, maior número de brotações foi observado com 2,22 e 4,44 μM de BA. As brotações foram alongadas, enraizadas e aclimatizadas com 100% de sobrevivência, permitindo inferir que o protocolo de regeneração in vitro estabelecido é eficiente. Este é o primeiro protocolo de micropropagação estabelecido para araçá.

Made available in DSpace on 2015-03-26T13:39:55Z (GMT). No. of bitstreams: 1 texto completo.pdf: 5375296 bytes, checksum: c7ea1e4a6904287d34cf3114d66369d3 (MD5) Previous issue date: 2013-03-18 / Brazil is the largest producer of passion fruit, with 920.158 million tonnes achieved during the year 2010, an area of 62,243 ha (IBGE, 2012). The passion fruit is the most cultivated in Brazil, with over 90% of the planted area and volume sold across the country, 60% of this production is intended for the fresh market. However, the soil diseases reduces the life crop, forcing the crop traveling into practice. The genetic resistance may prevent the premature death of the plants, providing training to healthier crops, uniform and enduring. Among the alternatives to be fetched, we highlight the use of wild species as resistant rootstocks. This study aimed to quantify the influence on the agronomic characteristics of yellow passion fruit (Passiflora edulis Sims) rootstocks of wild P. mucronata and P. gibertii. The characteristics evaluated were: percentage of graft survival, plant height, height of first flowering, number of leaves, number of nodes, diameter of the rootstock and grafting, histological analysis of the graft region, rate of occurrence of us days to flowering, gas exchange and physical and chemical qualities of the fruit. It was observed that the rootstock P. mucronata showed better conformation anatomical and histological region exertia and positively influenced the number of leaves, number of nodes, the time of first flowering, number of flowers and the rate of occurrence of us. When wild species were used as rootstock, developed these early buds and fruits originated more elongated than the non-grafted, but within the standards of marketing. The species P. mucronata showed the best performance as a rootstock. / O Brasil é o maior produtor mundial de maracujá, com 920.158 mil toneladas alcançadas durante o ano de 2010, numa área de 62.243 ha (IBGE, 2012). O maracujá amarelo é o mais cultivado no Brasil, com mais de 90% de área plantada e volume comercializado em todo o país; 60% dessa produção se destinam ao mercado in natura. No entanto, as doenças do solo reduzem a vida útil das lavouras, forçando à prática do cultivo itinerante. A resistência genética pode evitar a morte prematura das plantas, fornecendo formação de lavouras mais sadias, uniformes e longevas. Entre as alternativas a serem buscadas, destaca-se a utilização de espécies silvestres resistentes como porta-enxertos. Este trabalho buscou quantificar a influência sobre as características agronômicas do maracujazeiro-amarelo (Passiflora edulis Sims) dos porta-enxertos silvestres P. mucronata e P. gibertii. As características avaliadas foram: porcentagem de sobrevivência dos enxertos, altura da planta, altura da primeira floração, número de folhas, número de nós, diâmetros do porta-enxerto e do enxerto, análise histológica da região do enxerto, taxa de ocorrência de nós, dias até a floração, trocas gasosas e qualidades físicas e químicas dos frutos. Foi observado que o porta enxerto P. mucronata apresentou melhor conformação anatômico-histológica da região da exertia e influenciou positivamente o número de folhas, o número de nós, a altura da primeira floração, o número de flores e a taxa de ocorrência de nós. Quando as espécies silvestres foram empregadas como porta-enxerto, essas desenvolveram botões florais mais precocemente e originou frutos mais alongados que os pés-francos, porém dentro dos padrões de comercialização. A espécie P. mucronata foi a que apresentou o melhor desempenho como porta-enxerto.

Orientador: Rumy Goto / Banca: João Domingos Rodrigues / Banca: Manuel Abílio de Queiróz / Banca: Max José de Araújo Junior / Banca: Dimas Menezes / Resumo: Conduziu-se o experimento em cinco ambientes protegidos, tela termo refletora, tela de sombreamento branca, tela de sombreamento preta, tela difusora e céu aberto, sendo cada ambiente de 10mx24m, com pé direito de 3,0 m, estrutura tipo "Sombreiro", no município de Juazeiro, BA, em área experimental do Departamento de Tecnologia e Ciências Sociais (DTCS) da UNEB (Campus III), entre julho a dezembro de 2006. O delineamento experimental foi de blocos ao acaso, em cinco ambientes com quatro repetições e dois tratamentos por bloco, representados por dois híbridos de tomateiro de crescimento determinado, fruto tipo Caqui e Santa Cruz, D-4768 e C-5240, respectivamente, e análise realizada em grupos de experimentos, com parcelas de 2,0m x 3,6m (7,2m2). A utilização das telas de sombreamento reduziu a intensidade da energia radiante, proporcionando melhor qualidade e distribuição da radiação solar dentro dos ambientes protegidos, resultando melhor performance da cultura, quando comparada com o cultivo a céu aberto. O melhor desempenho dos genótipos foi registrado nos ambientes: tela difusora e tela de sombreamento preta, respectivamente, que apresentaram a menor transmitância da radiação global, evitando-se o excesso de radiação incidente na cultura, melhorando fisiologicamente todos os processos da distribuição de fotoassimilados nas plantas, com conseqüente aumento da produção. / Abstract: The experiment was carried out under four shading houses covered with different shade nets (heat reflector net, white shade net, black shade net and net diffuser) and open field. Each environment measured 10mx24 m, 3.0 m tall, in shade net structure, in the county of Juazeiro- BA, in the Experimental Field of UNEB - DTCS (Departamento Tecnologia e Ciências Sociais), in the period between July and December of 2006. The experiment was carried out in a randomized block design, in five environments with four replications and two treatments (two tomato hybrids) in each block. The two hybrids of tomato presented plants with a determined growth (hybrids D-4768 and Santa Cruz C-5240). The plot size was 2.0m x 3.60 m (7.2m2). The use of screens reduced the intensity of the radiant energy, what brought about a better distribution of the solar radiation within the protected environments. This resulted in a better crop performance when compared with open sky crops. The best genotype performance was registered for the environments diffuser screen and black screen, respectively. They showed the smallest transmittance of the global radiation, avoiding excess of incident radiation on the crop, improving physiologically the distribution of assimilate in the plants, which consequently increased the production. / Doutor