Quantitative analysis of cell organization in the external region of the olive fruit

Definitions of the cells that constitute the exocarp or exterior tissue of fleshy fruits are often vague, sometimes providing contradictory descriptions of the epidermis plus none or varying numbers of underlying cell layers for the same species. This study uses a morphometric approach to investigate how cell dimensions, cell number, and their relation with genetically based fruit size differences can contribute to a characterization of tissue organization in the external fruit region, using the olive drupe as an example.We determined cell area, radial and tangential widths, and cell number in the epidermis and 20 subepidermal cell layers of mature fruits of four olive cultivars that range in fruit size. Variation of these measurements among cell layers and the implied cellular contributions to fruit expansion revealed two different subepidermal regions, but with constant widths and layer numbers for all cultivars: (1) the first four cell layers (1-4), which have similar behavior to the epidermis; and (2) the following five cell layers (5-9), which are more similar to the mesocarp. The results provide new insights about cell patterns in the external region of the olive fruit and suggest that layers 1-4 together with the epidermis may act as a multiseriate exocarp and layers 5-9 may act as an outer mesocarp. © 2012 by The University of Chicago. All rights reserved.The study was funded by the Ministry of Science and Innovation of Spain and European Research and Development Funds (grant AGL2009-07248).Peer Reviewe

The floral biology of the olive: effect of flower number, type and distribution on fruitset

10 pages, 1 figure, 5 tables, 15 references.The effect of flower number and distribution on the fruiting behavior of various olive cultivars was studied over a period of 10 years. The number of staminate flowers within each cultivar had no significant effect on fruitset. Pre-bloom removal of up to 50% of the flowers did not affect fruitset. Variation in prebloom flower-removal position resulted in similar fruitset per inflorescence, whether flowers were removed along the inflorescence axis or from the distal half of each inflorescence. Removal of half of the inflorescences resulted in doubling the fruit set on the remaining ones, except in cv. Koronaiki which normally sets more than one fruit on most of its inflorescences. The distal fruitful inflorescence set more than one fruit (mostly two) on 70–80% of the shoots of various cultivars. In cv. Santa Caterina a clear increase in fruitset per shoot was observed when 80% of the flowers per inflorescence were removed. In this cultivar the lateral flowers were significantly more fruitful than the king flower. This however, was not the case with cv. Manzanillo.Peer reviewe

Histological characterization of table olive fruit bruising cv. Manzanilla de Sevilla

Sin paginarActualmente el sector del olivar en España incluye dos subsectores claramente diferenciados por su aprovechamiento: el olivar de almazara y el de mesa o verdeo, cada uno con unas particularidades específicas que los diferencian, tales como variedades empleada s y técnicas de cultivo como la poda o la recolección. En los últimos años, la necesidad de optimizar los costes de producción ha generalizado la recolección mecanizada mediante brazos vibradores o máquinas cabalgadoras en explotaciones de olivar de aceite. Sin embargo, no se ha extendido de igual manera en plantaciones de aceituna de mesa, debido a los altos porcentajes de frutos dañados por los golpes que se producen durante la recolección mecanizada. El molestado, manchas oscuras en la parte externa del exocarpo de los frutos, hace referencia a los daños provocados en los frutos por los golpes durante la recolección, más notables en la recolección mecánica. Estas manchas deprecian el fruto a nivel comercial con el consecuente rechazo del consumidor. No todos los cultivares presentan la misma susceptibilidad al molestado. ‘Manzanilla de Sevilla’, variedad por excelencia de aceituna de mesa, es considerada sensible al molestado lo que dificulta su recolección por medios mecánicos. El Departamento de Ciencias Agroforestales de la Un iversidad de Sevilla empezó a trabajar en el año 2003 en un programa de mejora genética de olivo para mesa. Una de las líneas de trabajo dentro de este proyecto ha consistido en estudiar diferentes parámetros de calidad, entre los que se encuentra el molestado. En colaboración con el Instituto de Agricultura Sostenible-CSIC, se ha desarrollado una metodología para evaluar el mismo en aceituna de mesa. En este trabajo se describe anatómicamente el molestado en frutos frescos de ‘Manzanilla de Sevilla’, después de un golpe inducido, a los 30 minutos y 24 horas del impacto y fijados posteriormente con FAE (formalina, ácido acético, etanol del 95% y agua destilada (10:5:50:3 5 v/v/v/v)). Se han evaluado histológicamente los cambios (rupturas celulares y pérdida de grosor en paredes celulares) que se producen en el mesocarpo de las zonas dañadas. Las observaciones histológicas han revelad o diferencias en los daños para los dos momentos evaluados. La presencia de rupturas celulares y la pérdida de grosor de las paredes celulares, en las zonas dañadas, han sido más evidentes a las 24 horas tras el golpe.Currently olive growing in Spain includes two main industries: olive oil and table olives, each of which has its own peculiarities, such as different varieties and specific performance of cultivation techniques like pruning or harvesting. In recent years, due to the need of reducing production costs, mechanical harvesting using trunk shakers or straddle harvesters has become widespread in olive oil orchards. However, that is not the case in table olive plantations, due to the high percentage of fruit damaged by the impacts that take place during mechanical harvesting. The term fruit bruising, dark spots on the outside of the fruit exocarp, refers to the fruit damage caused by impacts during collection, most notably in mechanical harvesting. These spots decreases commercial fruit value, being rejected by the consumer. Not all cultivars have the same fruit bruise susceptibility. Manzanilla de Sevilla, Spanish leading table olive cultivar, is considered to be sensitive to bruising being therefore difficult to harvest by mechanical devices Researchers from the Departamento de Ciencias Agroforestales at the University of Seville, Spain, are working since 2003 on a table olive breeding program. One of the research lines within the program has been to study. different table olive quality parameters, including fruit bruising. An evaluation methodology is being developed to asses this phenomenon in collaboration with the Instituto de Agricultura Sostenible-CSIC. This paper describes anatomical changes related to fruit bruising in 'Manzanilla de Sevilla' fresh fruits after an induced impact. Bruised fruits were chemically fixed in FAE (formalin, acetic acid, 95% ethanol and distilled water (10:5:50:35 v/v/v/v)) 30 minutes and 24 hours after the impact. Histological changes (cell breakage, loss of cell wall thickness and higher colour intensity) produced in the mesocarp of the damaged areas have been evaluated. Histological observations revealed differences between the evaluated times. The presence of cell ruptures and the loss of thickness in the cell walls, in the damaged areas, has been most evident at 24 hours after the impact.Ministerio de Ciencia e Innovación y fondos FEDER, proyectos AGL2007-65184-C02-02 y AGL2009-0724

The Regulation of Ion Homeostasis, Growth, and Biomass Allocation in Date Palm Ex Vitro Plants Depends on the Level of Water Salinity

The date palm, a central plant in the fragile oasis ecosystem, is considered one of the fruit species most tolerant to salt stress. However, the tolerance mechanisms involved are yet to be addressed and their evaluation until now was mainly based on heterogenous plant material such as seedlings or limited to in vitro experiment conditions. For these reasons, we propose to deepen our knowledge of the morphological and physiological responses to salt stress using acclimated ex vitro plants resulting from the propagation of a single genotype. The plants were irrigated with 0, 150, 300, or 450 mM NaCl solutions for four months. Our results showed that the influence of water salinity on growth and ion-homeostasis regulation was very dependent on stress levels. The 150 mM NaCl concentration was found to improve dry biomass by about 35%, but at higher salt concentrations (300 and 450 mM) it decreased by 40–65%. The shoot:root dry mass ratio decreased significantly at the 150 mM NaCl water concentration and then increased with increasing water salt concentration. The leaf:root ratio for Na+ and Cl− decreased significantly with increasing water salinity up to a concentration of 300 mM NaCl, and then stabilized with similar values for 300 mM and 450 mM NaCl. In contrast to Na+ and Cl−, leaf K+ content was significantly higher in the leaf than in the root for all salt treatments. Unlike Na+ and K+, Cl− was expelled to the surface of leaves in response to increased water salinity. Overall, date palm plants appear to be more capable of excluding Cl− than Na+ and of changing biomass allocation according to salt-stress level, and their leaves and roots both appear to play an important role in this tolerance strategy.All authors are funded through the Small Research group project from the Deanship of Scientific Research at King Khalid University under research grant number (R.G.P.1/295/43).Peer reviewe

A more sustainable and efficient definition of Regulated Deficit Irrigation phases in olive (Olea europaea L.)

Resumen del trabajo presentado en 20th EGU General Assembly, clelebrada en Viena (Austria) del 04 al 13 de abril de 2018.Water is a limited but highly essential resource, with large quantities required for agriculture. Regulated Deficit Irrigation (RDI) is an agricultural technique with great relevance for water savings worldwide, in which water stress is imposed by irrigation withholding based on fruit growth phases. The objective of this method is to identify phases where water stress has little or no effect on yield. RDI in olive has been demonstrated as an efficient tool to save water without negatively affecting yield. In olive trees, the mid-summer “pit hardening” is recognized as the most drought-resistant phenological stage, and has been used successfully for RDI water savings even though neither the description, boundaries, nor length of the period have been cleared reported. Many studies merely utilize a constant reference date for pit hardening, providing no explanation regarding how it was estimated or measured, while a few cases report the resistant to a knife-cut as the proper method to identify hardening, but leave unclear whether it represents its onset or completion. Recent studies have addressed these uncertainties, better showing the nature and duration of olive pit hardening, to which RDI can now be fitted. The objective of this current work was to determine if a RDI strategy more precisely fitted to pit hardening influences yield. In Ciudad Real (Spain) in 2016 and 2017, four irrigation treatments were applied in an ‘Arbequina’ olive orchard planted at 7 x 4.75 m in 1999. Treatment T1 consisted in water stress during pit hardening, aiming to maintain stem water potential (SWP) of -2 MPa during this phase. Treatment T2 was severely water stressed, aimed at maintaining -3 MPa during the same phase. In the rest of the season, before and after pit hardening, both treatments were irrigated to prevent water stress. Additionally, a highly deficit treatment was established (T3), irrigated only after pit hardening was completed. A control treatment (T0), irrigated following FAO methodology, was established to determine potential yield. Irrigation water savings with respect to T0 were approximately 45%, 57%, and 77% for T1, T2, and T3, respectively. There were no significant yield differences among treatments, although 2017 was nearly significant (P = 0.06), as when both years were considered together, due to the low yield of T3. Average yields from the two years were 25, 24, 23 and 21 kg tree-1 in T0, T1, T2 and T3, respectively. In conclusion, basing RDI on a new, more precise definition of the pit hardening phase produces similar yields with higher water savings, with the consequent environmental, economic and energetic benefits.Peer reviewe

Genotype, environment and their interaction on olive

Resumen del trabajo presentado en la 6th International Conference on the Olive Tree and Olive Products, celebrada en Sevilla (España) del 15 al 19 de octubre de 2018.The wide olive genetic patrimony has revealed high variability for most of the agronomic and oil quality traits of interest in olive growing. Few studies, however, have addressed the interaction of this variability with the environment, a subject of particular interest considering the natural high instability of the Mediterranean climate and the challenge of the predicted climate change. The current work presents results on the interaction between genotype and environment from multi-environment trials of olive cultivars and breeding selections, planted in different edaphoclimatic conditions of Andalusia, Southern Peninsular Spain and Canary Islands. For most of the agronomic and oil quality characters evaluated (flowering phenology, flower quality, pattern of oil accumulation, fatty acid composition and phenol content and composition), significant genotype and environment effects have been observed. For example, olive cultivars grown in Tenerife under much milder winter temperatures than in the Iberian Peninsula showed substantially earlierflowering and oil accumulation. Only in the case of flowering phenology was no significant genotype effect found. Furthermore, a strong genotype x environment effect was highly consistent in all characters considered. Regarding resistance to disease, such as Verticillium wilt, the variability of results from both natural and artificial inoculations also tends to indicate a considerable environmental effect and the need for careful testing of disease evolution. All this information strongly suggests the necessity of comparative trials of olive cultivars for both adequate choice of cultivar and final selection in breeding programs

Calendar of olivebud differentiation and development

Trabajo presentado en el Workshop Olive cultivar adaptation and climatic change, celebrado en Baeza el 2 y 3 de noviembre de 2017.N

Bases Biológicas del Crecimiento de la Aceituna: Desarrollo de los Tejidos y Células

Trabajo presentado en el I Congreso Iberico de Olivicultura, celebrado en Badajoz del 13 al 15 de abril de 2016.El crecimiento y desarrollo del fruto, de cuyo conocimiento depende la optimización de la producción, se basa en los procesos morfogenéticos de sus células y tejidos - división celular. expansión celular, diferenciación y almacenamiento. Estudios que llevamos a cabo utilizando microscopia y análisis de Imagen proporcionan Información más completa sobre su papel, cuándo ocurren, las interacciones entre ellos, y los factores que les influyen. la aceituna es un fruto de tipo drupa, compuesta por exocarpo o piel, mesocarpo o carne, y endocarpo o hueso. Cada uno de estos tejidos, y la semilla en su interior, tiene diferentes requisitos, pautas e implicaciones en el crecimiento global del fruto y todos actúan en determinar sus características finales. El tamaño y número de células en el momento de floración están relacionados con el tamaño en maduración de cada cultivar. La tasa más alta de división celular en el mesocarpo ocurre en el período postfloracíón, como es conocido en drupas en general, pero la división celular continúa a lo largo del crecimiento del fruto, aunque con una tasa bastante menor. El número celular del mesocarpo determina las diferencias princípales en tamaño entre cultivares, pero por el contrario el estado hidrlco tiende a Impactar más sobre tamaño celular que sobre el número. A diferencia de la gran expansión celular y la diferenciación metabólica para el almacenamiento de aceite que experimentan las células del mesocarpo, el desarrollo del endocarpo consiste en la esclerifícación, un proceso de deposición de una pared celular secundaria muy gruesa y con alta composición de lignína, produciendo la durela de este tej ido. la esclerificaclón del endoarpo está afectada por el estado hfdrico y la disponibilidad de asimilados, y parece Impulsar el fin de la expansión de este tejido. La pautas morfogenéticas de los diferentes tejidos del fruto y las necesidades de substrato asociadas a ellas nos proporcionan Información importante en la interpretación y manejo del crecimiento de la aceituna, así como para la elección de criterios de selección y mejora de cultivares.N

Olive fruit cellular processes: implications for growth, quality and management

Resumen del trabajo presentado en la 6th International Conference on the Olive Tree and Olive Products, celebrada en Sevilla (España) del 15 al 19 de octubre de 2018.Fruit developmental depends on the cellular processes in the fruit tissues - cell division, expansion, and differentiation. Studies to better define and quantify these processes provide a more comprehensive view of their role, timing, interaction, and the factors which influence them, sometimes contrasting with traditional perceptions. While the highest rate and amount of mesocarp cell division is confirmed to occur immediately following bloom, increase in cell number continues throughout much of fruit development, although at a reduced rate. Cell number forms the basis of cultivar differences in fruit size, water status tends to impact cell size rather than number, and crop load, closely linked to substrate interactions, appears to affect cell number to a greater degree than cell size. Olive mesocarp oil metabolism may be less linked to cell division and expansion than previously hypothesized. Pit hardening entails the initiation and completion of individual cell sclerification, events which respond to different factors and vary among cells, and are coordinated with endocarp expansive growth. Endocarp sclerification is affected by both water and assimilate status, and appears to drive the end of endocarp expansion rather than vice versa. The developmental patterns of the different fruit tissues, and their associated substrate demands, provide new information for interpreting and thus optimizing olive fruit growth by crop management practices