This thesis researches the power dynamics related to the intrinsic relationship between the expansion of avocado plantations and its effects on the water system in Chile's municipalities of Quillota, La Cruz, and La Calera. The study adopts a mixed methodology. Stakeholders involved in the water framework were interviewed through online interviews. To support and backup the interviews’ findings, a Supervised Classification through the QGIS program was performed to analyse spatial patterns of the avocado plantations in the study area. Concepts related to power and power sustained by the political ecology theory form the theoretical framework that supported the analysis. In particular, the notions of water governance and water scarcity; on the other side, Antonio Gramsci’s concepts of power, hegemony, and ideology were adopted. The case study identified the neoliberal ideology, which manifests in the conflict between power and subaltern groups in the access and distribution of water resources. The nexus between avocado trees and hydrological supplies produces a discriminating socio-economic system that protects and safeguards powerful social actors at the expense of vulnerable categories and “neoliberalising” the local environment. Moreover, a potential counter-hegemony linked to public participation in the water framework was recognized, opening up for future research.

Phytochemicals are recognized as playing an important role in cancer prevention by fruits and vegetables. The avocado is a widely grown and consumed fruit that is high in nutrients and low in calories, sodium, and fats. Studies have shown that phytochemicals extracted from the avocado fruit selectively induce cell cycle arrest, inhibit growth, and induce apoptosis in precancerous and cancer cell lines. Our recent studies indicate that phytochemicals extracted with chloroform from avocado fruits target multiple signaling pathways and increase intracellular reactive oxygen leading to apoptosis. This review summarizes the reported phytochemicals in avocado fruit and discusses their molecular mechanisms and targets. These studies suggest that individual and combinations of phytochemicals from the avocado fruit may offer an advantageous dietary strategy in cancer prevention.

Perú se ha ido consolidando como un proveedor importante de palta Hass en el mundo, con un crecimiento sostenido y positivo en los últimos 5 años, esto gracias a la alta demanda de este producto en el mundo, la cual se ha logrado con mecanismos de promoción organizados por el gobierno y por los propios productores, además de que los productores peruanos han sabido adaptar su oferta, y así la palta peruana ha ido ganando un nombre en el mundo, ha tenido muy buena aceptación de los consumidores y ha logrado posicionarse como un producto de alta calidad. En el marco de la Alianza del Pacífico, aun cuando Chile es productor de palta Hass, este se ha convertido en el principal importador de palta Hass de Perú, debido a que la oferta peruana no es competencia directa sino una oferta complementaria. Chile tiene un consumo per cápita de 7 a 8 kilos por año y es el segundo consumidor más grande del mundo, lo afirma el director del Departamento de Producción Agrícola de la Facultad de Ciencias Agronómicas de la Universidad de Chile, Thomas Fichet. El mercado chileno representa un mercado atractivo en términos de volumen; sin embargo, al ser productores y exportadores, conocen muy bien el producto y tienen requisitos muy exigentes con respecto a la calidad, además de que intentan salvaguardar su producción local, no sólo en términos de producto final sino también de plantas, por ejemplo salvar sus sembríos de alguna plaga, es por eso que se han elaborado “protocolos complicados” (calificados de esta manera por exportadores peruanos entrevistados) pero llevaderos para la exportación desde Perú; estos protocolos tienen muchas exigencias que muchas veces dificulta la exportación a este país. Exigencias de etiquetado y rotulado, muestreos y revisiones en línea de producción, ambientes separados en las cámaras de frío, son algunos de los exigentes requisitos que plantea el país sureño para permitir el ingreso de palta Hass peruana, todos estos detallados en el Protocolo de Exportación. Es por eso por lo que el presente trabajo de investigación tiene como objetivo analizar si las barreras no arancelarias afectan las exportaciones a Chile de palta Hass en los últimos 5 años en el marco de la Alianza del Pacífico. / Peru has consolidated as an important supplier of Hass avocado in the world, with a sustained and growth in the last 5 years, thanks to the high demand of this product in the world, which has been achieved through promotion mechanisms organized by the government and by the peruvian producers. Peruvian producers have been able to adapt their offer, and thus Peruvian avocado has been gaining a name in the world, it has had a very good acceptance by consumers and has posicionated as a high-quality product. In the framework of the Pacific Alliance, even though Chile is Hass avocado producer, it has become in the main importer of Hass avocado from Peru, because the peruvian offer is not a direct competition, it works as a complementary offer. Chile has a per capita consumption of 7 to 8 kilos per year, it is the second largest consumer in the world, this is stated by the director of the Department of Agricultural Production of the Faculty of Agronomic Sciences of the University of Chile, Thomas Fichet. The Chilean market it represents an attractive market in terms of volume; however, as they are producers and exporters, they know the product very well and have very demanding requirements regarding quality, in addition to this, the try to safeguard their local production, not only in terms of final product but also talking about plants, for example saving their crops of some plague, that is why there are "complicated protocols" (qualified in this way by Peruvian exporters interviewed). These protocols have many requirements that often make exporting to this country a very difficult challenge. Requirements of labeling, sampling and checking on the production line, separate environments in the cold rooms, are some of the demanding requirements that the Chile raises in order to allow the entry of peruvian avocado, all of these detailed in the Export Protocol. That is why this research aims to analyze whether non-tariff barriers affect peruvian avocado Hass exports to Chile in the last 5 years within the framework of the Pacific Alliance. / Tesis

A variety of plants synthesize and store oil in the form of triacylglycerols (TAG) in their seed and nonseed tissues that are commonly used as vegetable oils. In seed tissues, an acyl CoA-dependent diacylglycerol (DAG) acyltransferase (DGAT) and/or -independent phospholipid:DGAT (PDAT) catalyze the conversion of DAG to TAG. In avocado fruit, which stores up to 70% oil by dry weight in mesocarp, it is hypothesized that both DGAT and PDAT are likely involved in TAG synthesis. To investigate, TAG content and composition and transcript levels for the acyltransferases in avocado fruit were quantified by gas chromatography and real-time polymerase chain reaction, respectively. Temporal, tissue-specific and phenotypic comparisons revealed that while DGAT1 gene expression was specifically associated with TAG accumulation, PDAT also correlated with higher levels of polyunsaturated fatty acid; DGAT2 was barely detectable. These studies suggest that TAG biosynthesis in nonseed tissues of avocado involves acyl CoA-dependent and -independent reactions.

Plants synthesize and store oil mostly as triacylglycerols (TAG) in seeds that is transcriptionally controlled by WRINKLED 1 (WRI1), an APETALA2 (AP2) transcription factor. In contrast, avocado (Persea americana) mesocarp, which accumulates ~70% lipids by dry weight showed high expression of WRI2, along with WRI1 and WRI3. Among the four Arabidopsis WRI paralogs, WRI2 is nonfunctional, while the others are expressed in a tissue-specific manner. Through in silico analysis, we identified that PaWRI2 has a single intact AP2 DNA-binding domain and lacks a C-terminal intrinsically disordered region (IDR3) and PEST motif, which likely results in a relatively stable protein, compared to its Arabidopsis ortholog. We further demonstrated that avocado WRI2 is functional, unlike Arabidopsis WRI2, and accumulates TAG when transiently expressed in Nicotiana benthamiana leaves. Additionally, co-infiltration of PaWRI2 with PaWRI1 and genes encoding for terminal step in TAG assembly, acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) and/or phospholipid:diacylglycerol acyltransferase 1 (PDAT1) also led to further increase in the lipid content and oleic acid levels in ‘benth’ leaves. Quantitative real-time PCR (qPCR) analyses of > 40 fatty acid biosynthetic pathway genes revealed that several were distinctly up or down regulated by the expression of PaWRI2 and PaWRI1. In conclusion, avocado WRI2 is capable of transactivation of fatty acid biosynthesis genes and TAG accumulation, synergistically with DGAT1 and PDAT1, in nonseed tissues. This study provides a functional role for WRI2 in a basal angiosperm species that is likely lost in modern angiosperms and thus provides basis for mechanistic differences in the transcriptional regulation of lipid biosynthesis among different plant species and between seed and nonseed tissues.

Fresh produce may be contaminated by bacterial pathogens including Listeria monocytogenes during harvesting, packaging, or transporting. Consumers may be at risk of foodborne illness if produce become contaminated. In this project, a cavitation process (formation of bubbles in water) was studied to determine the efficacy of microbubbles at inactivating the pathogen L. monocytogenes on stainless steel and the surface of fresh cucumber and avocado. Stainless steel coupons (1"×2''), cucumber, and avocado surfaces were inoculated with L. monocytogenes (LCDC strain). After 1, 24 or 48 h, loosely attached cells were washed off, and inoculated areas were targeted by microbubbles (~0.5 mm dia.) through an air stone (1.0 L air/min) for 1, 2, 5, or 10 min. After treatment, samples were transferred to sterile containers and serial diluted in peptone water and plated on Oxford agar. Plates were incubated for 48 h at 35℃. For stainless steel, the mean log reduction of L. monocytogenes (48 h drying) peaked at 2.95 after 10 min of microbubbles when compared to a no bubble treatment. After 48 h pathogen drying, cucumbers treated for 10 min resulted in a 1.78 mean log reduction of L. monocytogenes. For avocados, the mean log reduction of L. monocytogenes (24 hr drying) peaked at 1.65 after 10 min of microbubbles. This cavitation treatment (10 mins) reduced over 95% of L. monocytogenes on the surface of stainless steel, cucumber, and avocado. Microbubble applications may be an effective, economical, and environmental-friendly way to remove L. monocytogenes and possibly other bacterial pathogens from food impact surfaces and the surface of whole, intact fresh produce. / Master of Science in Life Sciences / Fresh produce may be contaminated by bacterial pathogens like Listeria monocytogenes during the process of harvesting, packaging, or transport. Consuming contaminated fresh produce without enough and proper decontaminated measures, consumers are in risk of being infected with foodborne illness. A cavitation process (formation of bubbles in water) was conducted to determine the efficacy of microbubbles at inactivating the pathogen Listeria monocytogenes on the impact surface of fresh produce (stainless steel), fresh cucumber, and fresh avocado. Stainless steel coupons (1"×2''), fresh cucumbers, and fresh avocados were inoculated respectively with Listeria monocytogenes (LCDC strain). After removing loosely attached pathogen cells on the surface of inoculated steel coupons, cucumbers, and avocados, their inoculated areas were targeted by microbubbles (~0.5 mm dia.) for 1, 2, or 10 minutes, with a constant air flow rate of 1.0 L/min through an air stone. The L. monocytogenes on stainless steel and cucumber, and avocado surfaces was reduced by 95% to 99%. This study suggests that microbubbles may remove, and possibly inactivate, L. monocytogenes effectively from the surface of fresh produce and their impact surfaces. Microbubbles thus could be an effective, economical, and environmental-friendly tool for minimizing produce contamination.

The primary objective of the research was to study the physiological and biochemical changes in Hass avocado fruit stored in different combination of oxygen and carbon dioxide concentrations at both 0 degrees and 5 degrees Centigrade (C), and to determine whether storage in controlled atmosphere (CA) can decrease the incidence of chilling injury (CI). A secondary objective was to identify possible correlations between CA, the incidence of CI, the activity of some ripening related enzymes and changes in proteins during ripening at 20 degrees C following storage at low temperatures. Fruit suffered no CI and ripened normally following CA storage for 3 weeks at both 0 degrees and 5 degrees C, then transferred to air for 6 days at 20 degrees C. CI symptoms did develop after CA storage for 6 and 9 weeks at 0 degrees C. Changes in proteins during ripening were analysed by 2D-PAGE. Some polypeptides were detected in unripe fruit but decreased with ripening. Polypeptides of 16.5, 25, 36 and 56 kD (kilo Dalton) were present early in ripening and their levels further increased during ripening. The appearance of three ripening related polypeptides with estimated molecular weights 80 kD (pI 3.6), 36 kD (pI 5.8) and 16.5 kD (pI 5.7) was observed in fruit at the climacteric stage. Three polypeptides with estimated molecular weights of 41 kD (pI7.8), 36 kD (pI 5.8) and 33 kD (pI 5.1) were found in air stored fruit but were not detected in fruit stored in CA. This research showed that CA did not ameliorate CI at 0 degrees C, instead storage at 0 degrees C caused a premature increase in ethylene production when the fruit were returned to air at 20 degrees C. In contrast, CA storage at 5 degrees C retarded ethylene production and ripening in fruit after it was returned to air at 20 degrees C. / Doctor of Philosophy (PhD)

The role of agriculture in rural development is widely documented in literature. Many analysts regard agriculture, specifically small-scale agriculture, as the cornerstone for viable and sustainable economic growth. Furthermore, the agricultural sector is seen as an effective instrument for poverty reduction, particularly in rural communities of developing countries where a large amount of poor people are concentrated. Indeed, analysts now agree that developing the agricultural sector is perhaps one of the most effective ways to address high levels of poverty evident in the developing world, and call on the world leaders to commit themselves to direct more investment into this sector. Using the avocado industry in Giheta-Burundi, this dissertation argues that some emerging crops (such as avocados) present enormous opportunities to income generation for small-scale farmers with the potentiality of diversifying cash crop farming in Burundi, an area currently dominated by coffee, tea and cotton. This study further suggests that avocado farming presents the economic, market and health potentiality to contribute to a viable and sustainable rural economy in Giheta Burundi, thereby reducing levels of poverty in this area. The main research question is as follows: “To what extent does the production of avocados benefit the income and wellbeing of small-scale farming households in Giheta?” Accordingly, the main policy concern is that if avocados are playing a crucial role for income generation, wellbeing and diet of the small-scale farmers in Giheta, the avocado sector needs to be substantially supported by both the private and public sectors in order to increase the capacity of avocado production in this area and subsequently enable small-scale farmers to gain greater income from this sector. All of which will contribute significantly to reducing levels of poverty in Giheta. This dissertation is 42 266 words in length excluding references and appendices. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2011.

Thesis (Ph.D.) -- University of Western Sydney, 2002. / "A thesis submitted in fulfilment of the requirement for the degree of Doctor of Philosophy" Bibliography: leaves 161-189.

Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-08Bitstream added on 2014-06-13T20:25:29Z : No. of bitstreams: 1 oliveira_ivm_dr_jabo.pdf: 1019049 bytes, checksum: 205fb28114ff3cf08f1d526343964c4e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esse trabalho teve por objetivo fornecer informações sobre aspectos morfológicos da semente; determinar a possibilidade de clonagem da variedade Duke 7 por alporquia; avaliar influência da época no pegamento da enxertia em abacateiro das variedades 'Hass' e 'Fortuna' e caracterizar, por estudos anatômicos e morfológicos, mudanças na gema vegetativa à florífera, para duas variedades de abacate 'Hass' e 'Fortuna'. As sementes são monoembriônicas e exalbuminosas, de germinação hipógea e a emergência das plântulas ocorreu 33 dias após a semeadura; a raiz primária é longa e de coloração branca e as raízes secundárias são curtas e filiformes; os cotilédones são maciços e de coloração rosada sendo que foi possível observar a presença de múltiplos caulículos na semente de abacate, originados do colo; os frutos são do tipo baga; as sementes apresentam policaulia; o início da estabilização da emergência de plântulas ocorre na oitava semana. Não houve enraizamento dos alporques; o período mais indicado para o sucesso da enxertia, é de modo geral, compreendido entre os meses de novembro e dezembro para ambas as variedades 'Hass' e 'Fortuna'. A transição entre a fase vegetativa e a reprodutiva ocorre no mês de maio, quando há diminuição da temperatura; a evocação floral ocorre um mês após, caracterizado pelo formato arredondado das gemas; a iniciação da inflorescência ocorre dois meses após a transição, no mês de julho. / This work aimed to study morphological aspects of seeds; determine the cloning possibility of Duke 7 cultivar by air layering; evaluate the influence of the season on grafting of Hass and Fortuna avocado cultivars and to characterize by anatomical and morphological studies the modifications on vegetative to flowering bud. The seeds are monoembryonic, the germination is hypogea and the emergence of seedlings occurred 33 days after planting; the main root is long, white and the secondary roots are short; the cotiledons are hard and pink; the seeds presented polystems it was observed the presence of many small stems on avocado seed; the fruit is a berry. The stabilization of seed emergency occurred with eight weeks. There was no rooting in the air-Iayerings; the season more indicated for grafting is between November and December for both cultivars. The change from vegetative to reproductive phase was in May, when there is lower temperatures; the floral evocation occurs one month after, characterized by the rounded format of buds; the initiation of the inflorescence occurs after two months of the transition, in July.