ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Variedades de albaricoquero y melocotonero obtenidas en los programas de mejora genética del IVIA
Get PDFSe describen las principales características de 7 variedades de albaricoquero y 5 de
melocotonero ya registradas, o en vías de registro, obtenidas en los programas de mejora
genética del IVIA
Citrus rootstock responses to water stress
No full textTolerance to drought-stress (DS) of the citrus rootstock Forner-Alcaide no. 5 (FA-5) was tested and compared with that of its parents, Cleopatra mandarin (CM) and Poncirus trifoliata (PT). Nine-month-old seedlings of CM, PT and FA-5 and 15-month-old grafted trees of 'Valencia' orange scions on these three rootstocks were cultivated in sand under glasshouse conditions and irrigated with a nutrient solution. Plants were drought-stressed by withholding irrigation until leaves were fully wilted. Survival time of both seedlings and grafted trees under DS was linked to the water extraction rate from the soil, which depended mainly on leaf biomass and on transpiration rate. Seedling responses to DS affecting leaf water relationships and gas exchange parameters varied among genotypes. FA-5 seedlings survived longer than the other seedlings, maintaining the highest levels of water potential, stomatal conductance, transpiration rate and net CO(2) assimilation towards the end of the experiment, when water stress was most severe. Thus, FA-5 was more resistant to DS than its parents (CM and PT). Moreover, rootstock affected the performance of grafted trees under water stress conditions. The higher drought tolerance induced by FA-5 rootstock could be related to the greater osmotic adjustment (OA), which was reflected by smaller reductions in leaf relative water content (RWC) and in higher turgor potentials and leaf gas exchange than the other rootstocks
Proyecto integral del granado: resultados en fertirrigación
Get PDFEste artículo muestra las actividades que se desarrollan dentro del Proyecto Integral del Granado financiado por la Consellería de Agricultura de la Generalitat Valenciana en materia de fertirrigación. El objetivo principal es optimizar el uso de agua y fertilizantes en este cultivo. Se pretende pues determinar los balances hídricos y nutricionales óptimos a fin de realizar una recomendación de riego y abonado basada en criterios de sostenibilidad. Se está evaluando además la eficacia del riego deficitario controlado como técnica a emplear en caso de escasez de recursos hídricos. La efectividad de las recomendaciones de riego y abonado se fundamentan, no sólo sobre la respuesta productiva del cultivo, sino también sobre aspectos relacionados con la calidad de la granada tanto en el momento de la recolección como después de un periodo de almacenamiento en frío
Predation of 'Zodarion'sp. (Araneae: Zodariidae) upon the invasive ant 'Linepithema humile' (Mayr)
No full text
"Garbi" Mandarin: A New Late-maturing Triploid Hybrid
Get PDFCitrus is the most extensively produced
fruit tree crop in the world (FAO, Food and
Agriculture Organization, 2009). There are
two clearly differentiated markets: fresh fruit
and processed juice. In 2007, the main citrus
fruit-producing countries were China (17.9%),
Brazil (17.8%), the Mediterranean countries
(17.1%), and the United States (8.5%) (FAO,
Food and Agriculture Organization, 2009).
These areas account for more of two-thirds
of the total production of citrus fruits. In the
Mediterranean area, citrus fruits are primarily
produced for the fresh fruit market. Spain is
the principal producer in the area with a total
planted area of 330,000 ha and a production
6.3 million tons.
Seedlessness is one of the most important
characteristics for mandarin on the fresh fruit
market, because consumers do not accept
seeded fruits. Parthenocarpy is an essential
trait for seedless fruit production, and this
characteristic is present in citrus germplasm.
Triploidy gives rise to seedless commercial
cultivars. However, triploid plants have very
low fertility, are generally sterile, and do not
induce seeds in other cultivars by crosspollination
(Frost and Soost, 1968). Several
methods have been developed to obtain
triploid citrus (Navarro et al., 2002; Ollitrault
et al., 2008). One exploits natural events of
polyploidization such as 2n gametes using
embryo rescue and flow cytometry to select
triploids in 2x · 2x crosses. Second meiotic
division restitution has been proposed for
diploid megagametophyte development in
clementine (Luro et al., 2004), whereas Chen
et al. (2008) proposed first meiotic division
restitution in sweet oranges.
In Spain, the structure of mandarin cultivars
poses several problems. Mandarins include
satsumas, clementines, and mandarin
hybrids. Satsumas are harvested from the
beginning of September until the beginning
of November. They are cultivars with a high
degree of parthenocarpy and have sterile
pollen and ovules. Clementines are the most
representative cultivars of mandarin in Spain.
They are picked from mid-September until
mid-February. They are self-incompatible,
but pollen and ovules are viable, being able
to pollinate and to be pollinated by other
cultivars. Mandarin hybrids, like ‘Nova’ [C.
clementina · (C. paradisi · C. tangerina)],
‘Fortune’ (C. clementina · C. tangerina), and
‘Ortanique’ tangor (natural hybrid between
mandarin and C. sinensis), were introduced
in the Spanish citriculture to cover the demand
of late-season mandarins by international
markets. They enable the harvesting
period to be extended until May. These hybrids
are also self-incompatible, but pollen
and ovules are viable and cross-pollinate with
clementines, producing fruits with seeds in
both groups of cultivars.
A triploid breeding program has been
carried out in Spain since 1996 based on
sexual hybridization, embryo rescue, and
ploidy analysis by flow cytometry (Navarro
et al., 2002). The objective is to produce new
high–quality, late-season and seedless triploid
mandarin hybrids. In this article, we describe
‘Garbı´’ mandarin, a new triploid hybrid developed
within this program characterized by
its high-quality, late-season ripening and
seedless fruits
Tissue-specific transcriptome profiling of the citrus fruit epidermis and subepidermis using laser capture microdissection
Get PDFMost studies of the biochemical and regulatory pathways that are associated with, and control, fruit expansion and ripening are based on homogenized bulk tissues, and do not take into consideration the multiplicity of different cell types from which the analytes, be they transcripts, proteins or metabolites, are extracted. Consequently, potentially valuable spatial information is lost and the lower abundance cellular components that are expressed only in certain cell types can be diluted below the level of detection. In this study, laser microdissection (LMD) was used to isolate epidermal and subepidermal cells from green, expanding Citrus clementina fruit and their transcriptomes were compared using a 20k citrus cDNA microarray and quantitative real-time PCR. The results show striking differences in gene expression profiles between the two cell types, revealing specific metabolic pathways that can be related to their respective organelle composition and cell wall specialization. Microscopy provided additional evidence of tissue specialization that could be associated with the transcript profiles with distinct differences in organelle and metabolite accumulation. Subepidermis predominant genes are primarily involved in photosynthesis- and energy-related processes, as well as cell wall biosynthesis and restructuring. By contrast, the most epidermis predominant genes are related to the biosynthesis of the cuticle, flavonoids, and defence responses. Furthermore, the epidermis transcript profile showed a high proportion of genes with no known function, supporting the original hypothesis that analysis at the tissue/cell specific levels can promote gene discovery and lead to a better understanding of the specialized contribution of each tissue to fruit physiology
Abonado de los cultivos hortícolas
Get PDFLos cultivos hortícolas comprenden un gran número de especies botánicas con exigencias de suelo y clima muy variables. Algunos de estos cultivos son típicos de los meses más fríos, como el caso de la alcachofa o la coliflor, mientras que otros se cultivan en los meses más cálidos, como el melón, la sandía o el tomate. La producción y calidad de los cultivos hortícolas están influidos por los niveles de disponibilidad de los macro y micronutrientes en el suelo, sobre todo cuando estos niveles están fuera del rango de suficiencia. El nitrógeno es el nutriente que más frecuentemente limita la producción, aunque en otros casos el factor limitante puede ser la disponibilidad de fósforo y potasio, o bien de algún micronutriente. La influencia que cada nutriente puede tener sobre la calidad del producto hortícola, depende mucho de cada cultivo. Por ejemplo, un exceso de nitrógeno eleva el contenido de nitrato en la lechuga y la espinaca y este aumento puede afectar a su valor comercial
Occurrence of Monosporascus cannonballus in Watermelon Fields in Tunisia and Factors Associated with Ascospore Density in Soil
No full textSurveys of 11 watermelon fields throughout production areas of this crop in southern and central regions in Tunisia were conducted in 2007 to determine the aetiology and distribution of watermelon vine decline. Monosporascus cannonballus was isolated from diseased roots in all surveyed fields. All the isolates were identified according to morphological features and confirmed by amplification of a fragment of the ITS region with specific primers. Ascospores of M. cannonballus were recovered from soil in all watermelon fields surveyed and the average population densities ranged from 3.65 to 10.14 ascospores per g of soil. Multiple linear regression analysis revealed that only four of the crop and soil factors evaluated had a significant correlation with ascospore density at the end of the growing season: vertisol vs. other soils, disease incidence, percentage of clay and pH. The pH of the soil showed a strong significant negative linear relationship with ascospore density, while the other three factors correlated positively