Flower age and pollenizer could affect fruit set in late-blooming self-compatible almond cultivars under warm climatic conditions

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Kernel quality in a local walnut (Juglans regia) population grown under different ecological conditions in Morocco

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Evaluation de la tolérance des fleurs d’amandier à la gelée par fluorescence de la chlorophylle

Most almond cultivars are susceptible to negative temperatures, a limiting factor for almond expansion to regions with risks of spring frosts. Flower and fruitlet tolerance to frosts has only been studied so far by observing the morphological damages produced by low temperatures. Thus, our objective was the evaluation of chlorophyll fluorescence (CF) to estimate the tolerance of 12 commercial almond cultivars of different origin to low temperatures. Flowers were maintained for 24 hours at different temperatures (0º, -1º, -2º and -3ºC), after which CF was measured. In general, the variable fluorescence (Fv) and the ratio Fv/Fm decreased with time in all genotypes, although the rate of decrease depended on the genotype. The decrease of these parameters was slower in the cultivars tolerant to low temperatures, whereas the decrease was linear or/and sigmoid in the susceptible cultivars. In general, the classification of genotypes with this technique according to their frost tolerance level agreed with the published references. These results point out that chlorophyll fluorescence is a promising technique (fast, quantitative, easy and non-destructive) to ascertain the tolerance of almond genotypes to frosts independently of their blooming timeLa plupart des variétés d'amandier sont sensibles aux gelées, ce qui constitue un facteur déterminant dans la propagation et l'expansion de sa culture aux régions à haut risque de gelées printanières. De nos jours, la tolérance des fleurs et des petits fruits aux gelées a été évaluée en observant visuellement les dégâts morphologiques causés par les gelées. Notre objectif est l'évaluation de l'usage de la fluorescence de la chlorophylle (CF) pour estimer la tolérance de 12 cultivars commerciaux d'amandier de différentes provenances aux faibles températures. Avant de procéder aux mesures de CF, les fleurs ont été soumises pendant 24 h à différentes températures (0º, -1º, -2º y -3ºC). En général la fluorescence variable (Fv) et le ratio Fv/Fm ont diminué avec la température chez tous les génotypes, malgré que la vitesse de réduction était variable en fonction du génotype. Le taux de réduction de ces paramètres est plus lent chez les cultivars qui tolèrent les basses températures, alors que la réduction est quadratique ou linéaire chez les génotypes sensibles. En général, la classification des génotypes avec cette technique en fonction de leur tolérance aux gelées est en concordance avec les résultats publiés. Ces résultats indiquent que la fluorescence de la chlorophylle est une technique prometteuse (rapide, quantitative, facile et non destructive) pour évaluer la tolérance des génotypes d'amandier aux gelées printanières indépendamment de leur époque de floraiso

Commercial and industrial implication of the variability of oil and protein content and of the nut and kernel physical traits of almond in Mediterranean climates

Se determinaron los caracteres físicos y la composición química de los frutos de 11 cultivares de almendro cultivados en dos zonas distintas, Zaragoza (España) y Meknès (Marruecos). Independientemente de la variabilidad entre cultivares para todos los parámetros medidos, el efecto del año fue significativo para todos los parámetros físicos, excepto para el espesor de la pepita. Igualmente fue significativo el efecto de la localidad para todos los parámetros físicos, excepto para la longitud y el índice de esfericidad del fruto, la longitud y la anchura de la pepita, y el rendimiento en pepita. La calidad física de las pepitas producidas en Zaragoza fue mayor que las producidas en Meknès, probablemente por el diferente sistema de cultivo y las condiciones ambientales que fueron más extremas en Meknès. Estos resultados muestran que las condiciones de cultivo adecuadas favorecen el aumento de los caracteres conducentes a una mayor calidad física del fruto y de la pepita. En cuanto al contenido en aceite y en proteína, se encontraron diferencias significativas entre los genotipos y las localidades. Las condiciones ambientales y de cultivo de Zaragoza favorecieron la acumulación de aceite en la pepita, mientras que las de Meknès favorecieron la acumulación de proteína. Ello apunta a que la utilización industrial de los distintos cultivares estudiados no sólo depende del propio cultivar, sino también de las condiciones ambientales y de cultivo, lo que debe tenerse muy en cuenta para la valorización de la producción en las distintas zonas de cultivo del almendroThe fruit physical traits and the chemical composition were determined for 11 almond cultivars grown in two different regions: Zaragoza (Spain) and Meknès (Morocco). Independently of the variability among cultivars for all traits measured, the year effect was significant for all physical traits except for kernel thickness. The location effect was significant for all physical traits except for fruit length and sphericity, kernel length and width, and kernel percentage. The physical quality of the kernels produced in Zaragoza was higher than that of the kernels produced in Meknès, probably because of the different growing system and the environmental conditions, more extreme in Meknès. These results show that adequate growing conditions favour the increase of traits leading to increased physical quality of nuts and kernels. The cultivar and the location effects were significant for the contents of oil and protein. The environmental and growing conditions of Zaragoza led to a higher oil accumulation, whereas those of Meknès to a higher protein accumulation. These results indicate that the industrial utilization of the different almond cultivars does not only depend on the cultivar, but also on the environmental and growing conditions, a fact to be considered when marketing the production of the different growing region

La calidad de la almendra en función del tipo de polinización en almendros auto-compatibles

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Phytosterol variability in almond germplasm

Phytosterols are important dietary components that contribute to reducing serum cholesterol levels. The objective of this research was to assess genetic diversity for total content and profile of free and esterified phytosterols in a world germplasm collection of almond [Prunus amygdalus Batsch; syn. P. dulcis (Mill.) D.A. Webb]. Steryl glycosides and acylated steryl glycosides were not measured. Fruit from 160 almond accessions were collected in 2009 and 2010. Kernel phytosterol content ranged from 1126 to 2769 mgkgL1 in 2009 and from 1191 to 2777 mgkgL1 in 2010. The phytosterol fraction was mainly made up of b-sitosterol (from 59.1% to 84.1% in 2009 and from 55.9% to 84.6% in 2010) and D5 -avenasterol (from 8.9% to 25.4% in 2009 and from 8.5% to 28.2% in 2010). Significant genotypic effects were observed for kernel phytosterol content and concentration of major phytosterols. Kernel oil content was positively correlated with kernel phytosterol content in both years. The results suggested that almond germplasm contains genetic variability for both phytosterol content and profile that can be used for developing cultivars with increased levels of phytosterols and contrasting phytosterol profiles. Positive correlation between kernel phytosterol content and kernel oil content suggests the feasibility of simultaneous selection for both traits.Publishe

Flowering and pollination time affect fruit set of foreign almond cultivars in Morocco

The associations ‘Marcona’-‘Fournat de Brézenaud’ and ‘Ferragnès’-‘Ferraduel’ are the cultivar combinations mostly planted in commercial almond orchards in Morocco. The blooming times and effective pollination period (EPP) were determined for these associations to determine the effect of blooming and pollination times on the irregular yields observed in Morocco with these cultivars. ‘Marcona’ bloom was earlier than that of ‘Fournat de Brézenaud’, but ‘Ferragnès and ‘Ferraduel’ coincided. Fruit set and percentage of pistils with pollen grains was maximized when pollination occurred at day 2 after emasculation. Fruit set and stigmatic receptivity decreased drastically by day 4 after emasculation. Fruit set in the open pollination treatment was lower than that obtained after hand pollination at days 0 and 2 after emasculation, especially in ‘Marcona’. These results emphasize the importance of early pollination and the selection of new cultivars with the same flowering period as ‘Marcona’ to improve almond yields in Morocco.Peer ReviewedPrunus amygdalusbloomeffective pollination periodstigmatic receptivityfruit setPublishe

Organic acids, sugars, vitamin C content and some pomological characteristics of eleven hawthorn species (Crataegus spp.) from Turkey

Background: The Hawthorn (Crateagus sp.) mostly occurs around the temperate region of the world with a high number of species, producing a fruit with numerous beneficial effects for human health. The aim of the study was to determine organic acid and sugar contents in the fruit of a number of hawthorn species grown in Erzincan province of Turkey. Results: Citric acid was the predominant organic acid in all hawthorn species and C. pseudoheterophylla had the highest citric acid content (23.688 g/100 g). There were not statistically significant differences among hawthorn species (except C. atrosanguinea Pojark) in terms of fumaric acid content. C.pontica C.Koch had a higher content of vitamin C (9.418 mg/100 g) compared to other species. Fructose was the predominant sugar component in all species and C. monogyna subsp. monogyna Joiq had the highest fructose content (18.378 g/100 g). Conclusions: The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source. The study revealed that there were differences in terms of fruit characteristics among hawthorn species and thus better quality hawthorn genotypes can be selected within the species. Hence, this study is considered to be a valuable reference for forthcoming studies. The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source