Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Economía agraria / El dátil es una fruta conocida mundialmente, producida y comercializada hace miles de años; en Chile, en cambio, es totalmente desconocida. Estudios y experiencias anteriores en el país revelan la existencia de áreas con condiciones para la producción de dátiles en el norte del territorio, obteniéndose resultados negativos en su comercialización a nivel local y nacional, y señalando al mercado internacional como destino principal. En este contexto, es fundamental caracterizar el mercado mundial del dátil en la actualidad, y evaluar las posibilidades de inserción de Chile en el mercado mundial del producto. Para cumplir con este objetivo, se caracterizó a los mayores países productores, exportadores, importadores y consumidores de dátiles en el mundo en el periodo 2001-2009, y se identificó a los mercados importadores más prometedores, y a los exportadores más competitivos. Además se calculó el costo variable unitario de producción en Chile, usándose diversas herramientas de análisis (FODA, DELPHI y PEST), para evaluar la posibilidad de inserción en el mercado mundial de dátiles, y seleccionar la estrategia más exitosa de desarrollo para este rubro en Chile. A nivel mundial entre los años 2001 y 2009, la producción anual promedio de dátiles llegó a las 6,8 millones de toneladas, creciendo un 1,29% anualmente, siendo Egipto, Arabia Saudita, Irán y los Emiratos Árabes Unidos los productores más importantes. En el mismo periodo, las exportaciones a nivel mundial alcanzaron en promedio las 695 mil Ton/año, originándose principalmente en Túnez, Irán y Emiratos Árabes Unidos, y mostrando un valor unitario FOB promedio que llegó a los US$ 776/Ton. Las importaciones durante este periodo alcanzaron las 666 mil Ton/año en promedio, y fueron generadas mayoritariamente por India, Francia y Emiratos Árabes Unidos, promediando un valor unitario CIF de US$ 663/Ton. Tanto el valor las importaciones como las exportaciones crecieron durante el periodo de análisis, (12,75% y 14,96% respectivamente), observándose que ambas tendieron a aumentar en los últimos 5 meses de cada año, lo que se refleja en mayores valores unitarios durante esa temporada. En el periodo 2001-2007, el consumo mundial de esta fruta alcanzó los 4,8 millones de toneladas en promedio anualmente, creciendo un 1,92% al año, generándose fundamentalmente por Egipto, Arabia Saudita, e Irán. Túnez se visualiza como el exportador más competitivo, pues entre los años 2001 y 2009, el volumen y el valor unitario conseguido por los dátiles tunecinos muestran magnitudes, y tendencias crecientes en ambos ítems superiores al promedio mundial. De forma similar, Alemania se muestra como el importador más prometedor, exhibiendo un valor unitario medio de unos US$ 2.366 (CIF) /Ton. Según los requerimientos edafoclimáticos de esta especie, las condiciones presentes en Chile delimitan un gran área con potencial de cultivo, abarcando todo el litoral de las regiones I, II, III y XV, extendiéndose por los valles transversales de las regiones I y XV. Prácticamente no existe producción de dátiles en Chile. Entre los 2001 y 2009, el consumo es limitado, promediando 11 Ton/año. Las exportaciones llegan en promedio a las 10 ton/año, importándose el doble de este volumen (20 Ton/año). El costo variable unitario de producción calculado en Chile asciende a US$ 2.012 (CIF) por tonelada, observándose como los ítems más importantes los costos por mano de obra, empaque y envío (mercado europeo), dejando un margen de contribución de US$ 354 por tonelada, al acceder al mercado más atractivo (Alemania). La situación del cultivo, sus problemáticas y la realidad de la agricultura en el norte del país, llevan a sostener como estrategia de desarrollo, el establecimiento de esta especie como un cultivo borde o perimetral, para uso productivo y de protección contra el efecto del viento, al menos inicialmente.

Oil palm can accumulate up to 90% oil in its mesocarp, the highest level observed in the plant kingdom. In contrast, the closely related date palm accumulates almost exclusively sugars. To gain insight into the mechanisms that lead to such an extreme difference in carbon partitioning, the transcriptome and metabolite content of oil palm and date palm were compared during mesocarp development. Compared with date palm, the high oil content in oil palm was associated with much higher transcript levels for all fatty acid synthesis enzymes, specific plastid transporters, and key enzymes of plastidial carbon metabolism, including phosphofructokinase, pyruvate kinase, and pyruvate dehydrogenase. Transcripts representing an ortholog of the WRI1 transcription factor were 57-fold higher in oil palm relative to date palm and displayed a temporal pattern similar to its target genes. Unexpectedly, despite more than a 100-fold difference in flux to lipids, most enzymes of triacylglycerol assembly were expressed at similar levels in oil palm and date palm. Similarly, transcript levels for all but one cytosolic enzyme of glycolysis were comparable in both species. Together, these data point to synthesis of fatty acids and supply of pyruvate in the plastid, rather than acyl assembly into triacylglycerol, as a major control over the storage of oil in the mesocarp of oil palm. In addition to greatly increasing molecular resources devoted to oil palm and date palm, the combination of temporal and comparative studies illustrates how deep sequencing can provide insights into gene expression patterns of two species that lack genome sequence information.

Philosophiae Doctor - PhD / In different parts of the world, medicinal plants have demonstrated a lot of health benefits to mankind and remains an important source for the discovery of new bio-active compounds. Libya is a typical example of a country where medicinal plants are widely used. Plant extracts of five Libyan medicinal plants were used in this study to investigate their in vivo effects on spermatogenesis and steroidogenesis in male rats and on ovulation and fertility in female rats. The In vitro effects of these plant extracts were also investigated on TM3 Leydig cells and MCF 7 breast cancer cells. A phyto-chemical analysis of the five Libyan medicinal plants (flaxseed, black seeds, radish seed, date palm pollen and nutmeg) was done. The results showed that date palm pollen had a higher antioxidant activity than all of the above mentioned plants. In addition to this, Nigella sativa was observed to possess high flavonol content as well as high antioxidant activity. Male rats exposed to flaxseed, radish seeds and date palm pollen showed no significant alterations in body weight gain, whereas date palm pollen (240 mg/kg, p < 0.05) promoted an increase in body gain. This study also revealed a significant increase in the relative testicular weight of animals exposed to either flaxseed (300mg/kg) or date palm pollen (120mg/kg). In addition, the relative weights of the seminal vesicles of all treated groups showed significant increased values. The level of serum testosterone showed a significant increase after exposure to radish seed (80mg/kg) and a significant dose- dependent increase for date palm pollen when compared to control (P< 0.05). In contrast, flaxseed caused a dose-dependent significant (p <0.01) decrease in testosterone level at radish seed (300mg/Kg). All plant extracts caused a significant increase in sperm concentration. Sperm vitality significantly (p < 0.05) increased by radish seed (80mg/kg), flaxseed (300mg/kg) and date palm pollen (120, 240mg/kg) respectively. Total progressive motility improved significantly at flaxseed (300 mg/kg) (p < 0.001) as well as date palm pollen (p < 0.01). Histological examination of the cross sections of the testis showed clear presence of all stages of spermatogenesis in all the treated groups. Rat epididymides showed normal morphological appearance and their lumen were filled with spermatozoa. The diameter of seminiferous tubules in male rats exposed to date palm pollen (120 and 240 mg/kg) was significantly higher (p < 0.001). The heights of the germ cell epithelia within the eminiferous tubules were also significantly increased in all treated groups. Liver and renal functions tests showed a significant decrease in Alanine transaminase (ALT) and creatinine in all treated groups (p < 0.05), and this demonstrates the lack of cytotoxic effects of date palm pollen, radish seed and flaxseed on the rats. However, these plant extracts produced a non-significant (p > 0.05) increase in Aspartate transaminase (AST) levels. Besides this, superoxide dismutase activity (SOD) in testis was increased significantly by radish seed (160 mg/kg), flaxseed (200 mg/kg) and date palm pollen (120 mg/kg). There was also improved catalase activity in testis of male rats exposed to radish seed and date palm pollen. Regarding male sexual behavior, the time to reach the female and the mount frequency decreased significantly in male rats exposed to flaxseed (300 mg/kg) and date palm pollen (120 and 240 mg/kg; p > 0.05) thus, these plant extracts exhibit aphrodisiac properties. In addition, exposure of male rats to date palm pollen (120 mg/kg) produced a significant (p < 0.01) increase in the number of embryos in untreated female rats. In the female rats, the body weight gain was not affected (p > 0.05). However, the relative uterus weights exposed to nutmeg (200 mg/kg) and date palm pollen (120 and 240 mg/kg) were significantly decreased (p < 0.05). In addition, the relative weights of ovaries after treatment with nutmeg (400 mg/kg) and black seed (400 mg/kg) showed significantly increased values (p < 0.01). Serum FSH was significantly increased (p > 0.05 or 0.01) when the female rats have been exposed to black seed (200 mg/kg), nutmeg (200 mg/kg) or date palm pollen (120 mg/kg). The LH level significantly (p < 0.01) decreased following exposure to black seed (200 mg/kg), date palm pollen (120 mg/kg). On the other hand, serum LH concentration was significantly increased in female rats exposed nutmeg (400 mg/kg; p > 0.05). The creatinine activity in female rat serum in all treated groups was significantly decreased (p < 0.05). Whereas the higher dose of date palm pollen (240 mg/kg) caused only a non-significant decrease. ALT activity in serum of female rat exposed to either black seed (400 mg/kg) or date palm pollen (120 and 240 mg/kg) was shown to decrease significantly (p < 0.05). Histology of the reproductive organs, kidney and liver in the female rats showed no obvious alterations in any of the treated groups. In addition, the number of embryos in female rats significantly increased (p < 0.01; p < 0.001) following exposure of female rats to black seeds 400 and date palm pollen 240 mg/kg, respectively. Incubation of TM3 Leydig cells with radish seeds for 24, 48 or 72 hours caused a significant (p < 0.01) decrease in mitochondrial dehydrogenase activity. Besides that, date palm pollen and flaxseed increased the mitochondrial dehydrogenases activity of TM3 Leydig cells. In addition, higher concentration of date palm pollen, nutmeg and black seed were cytotoxic to MCF7 breast cells. In testis slices testosterone secretion in vitro was significantly increased by flaxseed (500 μg/ml; p > 0·05) and date palm pollen (500 μg/ml; p > 0·01). MCf-7 cells treated with BS 10-50 μg/ml black seed and nutmeg 10-50μg/ml significantly increased cell proliferation. However, the treatment with date palm pollen produced only a weak estrogenic effect, which resulted in a concentration dependent significant increase as observed between 50-1000 μg/ml date palm pollen. In conclusion, in this study, we observed that date palm pollen, radish seed and flaxseed increased libido as well as steroidogenesis and spermatogenesis, improved hepato and nephron-protective effects. In female rats, the plant extracts NM, BS and date palm pollen potentiated the production of gonadotropic hormones. In addition to this, at lower concentrations these medicinal plants promoted cell growth, whereas at higher concentrations they inhibited cell proliferation of MCF- 7 breast cancer cells. The anti-oxidant effects of these plant extracts have been implicated for the above mention effects.

La compréhension des mécanismes moléculaires impliqués dans la détermination du sexe chez les plantes à fleurs est primordiale d’un point de vue fondamental et appliqué. Des processus liés à la biosynthèse des hormones, tel que l’éthylène, ou la régulation de l’expression génique via des petits ARN et des facteurs de transcription ont été associés à l’unisexualisation des fleurs chez des espèces dioïques. Cependant, les déterminants contrôlant le sexe chez les plantes sont encore largement méconnus. Le palmier dattier, Phoenix dactylifera L, est une espèce dioïque dont le dimorphisme sexuel est observé très tôt au cours du développement des fleurs. Des gènes différentiellement exprimés (DEGs) ont été identifiés pendant les stades précoces du développement floral mâle et femelle. Pour cela, un transcriptome de référence rassemblant des données d’expression relatives aux deux sexes a été généré. L’analyse d'enrichissement GO des DEGs, a révélé des processus biologiques communs aux mâles et aux femelles, associés au développement reproducteur et à la réponse aux stimuli. Ce résultat indique que des mêmes processus peuvent solliciter des gènes différents au cours du développement floral précoce en fonction du sexe. Cette analyse a également mis en évidence que le développement des fleurs mâles requiert des processus biologiques spécifiques impliqués dans la régulation cellulaire et l'expression des gènes. En outre, deux DEGs femelles, une S-adenosylmethionine synthase et une Flap endonuclease et un DEG mâle, un élément transposable, ont été identifiés dans les régions non-recombinantes du génome du palmier dattier.Cette étude est la première analyse globale des processus biologiques associés à l’acquisition du dimorphisme sexuel. Elle contribue également à la compréhension de la détermination du sexe chez le palmier dattier, et plus largement à la connaissance de ces processus chez les espèces dioïques. / Unraveling molecular mechanisms involved in sex determination in flowering plants is of outstanding basic and applied interest. Several studies on dioecious species have highlighted the molecular basis of sex determination, such as cell death and ethylene biosynthesis pathway. Sex determination mechanisms in plants are, however, still largely unknown. The date palm, Phoenix dactylifera L, is a dioecious species where sexual dimorphism is observed very early in development of flowers. Differentially expressed genes (DEGs) were identified during the early stages of the male and female flower development. A reference transcriptome including male and female data was constructed to gain insight into this process in the dioecious palm Phoenix dactylifera L. Differentially expressed genes (DEG) were subsequently identified between males and females in the early flower development stages in which the first morphological gender difference occurs in date palms.Gene ontology enrichment analysis of DEG revealed biological processes shared between males and females involved in reproductive development and response to stimulus, indicating that same processes could require different genes during early flower development in date palm. This analysis also suggested that date palm triggers biological processes specifically involved in cellular regulation and gene expression to develop male flowers. Furthermore, two female DEGs related to DNA methylation S-adenosylmethionine synthase and DNA metabolism Flap endonuclease, and one male DEGs, a transposable element were found in non-recombinant date palm regions. This study provided the first insight into biological processes involved in sex determination in date palms and more widely to knowledge of this process in dioecious species.