The influence of early yield on the accumulation of major taste and health-related compounds in black and red currant cultivars (Ribes spp.)

The focus of our study was to investigate the effect of crop load on the accumulation and composition of primary metabolites (sugars and organic acids), selected groups of flavonoids (anthocyanins and flavonols), and total phenolics in two subsequent years in four black currant cultivars ('Titania', 'Triton', 'Tsema', and 'Cacanska crna') and three red currant cultivars ('Junifer', 'Rolan', and 'Stanza'). For the determination and quantification of compounds, high-performance liquid chromatography-photodiode array with a mass spectrometer was used. Significant differences among cultivars were detected in all analyzed compounds. Anthocyanins were the predominant phenolic group and were more abundant in black currant cultivars as compared to red ones. Similar amounts of sugars and organic acids were measured in both Ribes species; however, vitamin C was 3-fold higher in black currants. A larger crop load in the second year had a negative effect on the sugar content of berries and promoted a higher degree of acids, with the exception of vitamin C, which was higher in the year with a lower crop load. On the other hand, the content of anthocyanins and flavonols was higher in the year with a larger crop load, while there were no differences in total phenolic content.     

Response of the phenylpropanoid pathway to Venturia inaequalis infection in maturing fruit of ‘Braeburn’ apple

Summary

This study investigated the activities of key enzymes in the phenylpropanoid pathway and the accumulation of phenolic products in apple peel in response to infection with Venturia inaequalis [(Cooke) G. Wint.]. We compared healthy apple peel with apple peel showing symptomatic scab lesions, and with peel tissue from 1 – 2 mm around the scab lesions in fruit 1 month before maturity [140 d after full bloom (DAFB)] and at physiological maturity (175 DAFB). Infection with V. inaequalis enhanced the synthesis of some phenolic compounds. Compared to healthy peel, scab lesion tissue had ≤ 3.1-times higher hydroxycinnamic acid content, ≤ 1.3-times higher dihydrochalcone content, and ≤ 3.9-times higher flavan-3-ol content. Scab lesions showed slightly higher phenylalanine ammonia-lyase, chalcone synthase, chalcone isomerase, flavonol synthase, and dihydroflavonol 4-reductase activities. The total amount of phenolics remained relatively stable between the two sampling dates, except for epicatechin and caffeic acid which decreased in amount toward fruit maturity, and levels of catechin which increased in more mature fruit. During fruit maturation, only chalcone synthase and chalcone isomerase activities decreased in all tissues examined. This study showed that the phenylpropanoid pathway in apple fruit peel changed significantly following infection with the apple scab pathogen.     

Ophiostomatoid fungi associated with three spruce-infesting bark beetles in Slovenia

Context

Ophiostomatoid fungi can severely affect the health and economic value of Norway spruce trees (Picea abies). Although the diversity of ophiostomatoid species and their associations with insects have been well-investigated in central and northern Europe, little is known about the conditions in south-eastern Europe.

Aim

This study aims to study the assemblages of ophiostomatoid fungi associated with three bark beetle species (Ips typographus, Ips amitinus, and Pityogenes chalcographus) that infect Norway spruce in Slovenia.

Methods

Bark beetles were sampled in four phytogeographic regions in Slovenia. The fungi found on the bark beetles were identified based on morphology, DNA sequence comparisons of ITS regions and phylogenetic analysis. The species compositions of the fungal associates of the three insect species were compared and the pairwise associations of the occurrence of the fungal species were analysed.

Results

Thirteen different species were found. The most commonly encountered fungal associates of the beetles were Ophiostoma bicolor, Ophiostoma brunneo-ciliatum, Grosmannia piceiperda, Ophiostoma ainoae, Ceratocystiopsis minuta, and Grosmannia penicillata. The composition of the fungal associates differed among the bark beetle species, but not among the phytogeographic regions.

Conclusions

This study confirms that ophiostomatoid species are common associates of the investigated bark beetle species. Many ophiostomatoid species have strong host associations. I. typographus and P. chalcographus can act as effective vectors for O. bicolor, O. ainoae, G. piceiperda and O. brunneo-ciliatum, whereas I. amitinus often carries G. piceiperda and C. minuta in Slovenian forests.     

Development of a yield monitoring system for citrus mechanical harvesting machines

A load cell based yield monitoring system was developed for the Oxbo citrus mechanical harvesting machines. The yield monitoring system consisted of a GPS receiver, a mass flow sensor and data processing and storage units. The mass flow sensor consisted of four load cells attached to a carbon-fiber plate which sensed the impact force created by the oranges hitting the plate. A mathematical model was developed to relate the impact force to fruit mass. Laboratory tests were conducted on a test rig that replicated the flow of oranges to measure the accuracy of the system under a controlled environment. The system performed very well under laboratory conditions (R ² = 0.99 and an average error of 3.3%). In addition, a field test was conducted in a citrus orchard in Florida to evaluate the performance of the system under field conditions. Of the 72 rows used in the field test, the first 10 rows were used to calibrate the computed weight. A correlation of R ² = 0.97 between the actual weight and the computed weight was found from the field data with an average error of 7.81%.     

The introduction of oil palm in Northeast Thailand: A new cash crop for smallholders?

As part of the Thai Government's objective to increase energy security through biodiesel, oil palm was introduced to Northeast Thailand in 2005. Nong Khai Province was selected as a pilot project because of its suitable environmental conditions. This study assesses the acceptance of policy interventions and socio‐economic conditions by adopters and non‐adopters. We found that total farmland size was significantly higher among oil palm producers than among non‐producers. Nevertheless, the area under oil palm cultivation did not increase in accordance with land size in the way rubber did. Oil palm and non‐oil palm farmers had almost equal amounts of rice area thereby providing household food security. Oil palm did not replace food crops. Farmers investing in oil palm tend to base their livelihood around on‐farm production, whereas non‐adopters tend to diversify with off‐farm income sources. Oil palm was found to be one component of a diversified farming system and an additional income source, albeit not the primary one. In conclusion, oil palm was a crop that had been tried by (wealthier) farmers with sufficient capital, and an aim to further diversify on‐farm household income. Oil palm is certainly not (yet) contributing substantially to household income in Thailand's Northeast.     

The Content of As and Heavy Metals in TSP and PM<Subscript>10</Subscript> Near Copper Smelter in Bor,Serbia

The content of As and heavy metals (Pb, Cd, Ni, and Cu) in total suspended particulate (TSP) and PM₁₀ at 3 locations (Park, Institute, and Jugopetrol) near the copper smelter in Bor (Serbia) has been analyzed within the period 2004 to 2015 with the aim of investigating the seasonal and spatial changes of those pollutants in the suspended particles. The content of As in TSP and PM₁₀ was over the annual EU limit value at all measuring points during the entire period of observation, while contents of Cd and Pb were periodically above the annual EU limits. There were no statistically significant seasonal changes between mean levels of the observed elements in the cold (October–March) and warm (April–September) periods during the year. A strong and moderate positive correlation was detected between the concentrations of each particular element (except Ni) at all measuring points. Additionally, Cd was the most enriched element followed by Pb, As, and Cu, while Ni was low-enriched. The constant air pollution with As particles, sometimes in concentrations even 20 times higher than the permitted annual value, requires urgent undertaking of concrete actions in order to reduce anthropogenic emission of suspended particles in Bor.     

Genetic analysis of Newcastle disease virus strains isolated in Bosnia-Herzegovina,Croatia, Slovenia and Yugoslavia,reveals the presence of only a single genotype,V, between 1979 and 2002

Newcastle disease (ND) epizootics in some European countries after the World War II were caused by ND virus (NDV) of multiple genotypes (IV-VIIa) occurring sequentially and/or simultaneously. This study was carried out to characterise the genetic composition of NDV strains during the outbreaks in the territory of the former Yugoslavia in order to enhance our understanding of the relationships of past epizootics in Europe. Sixty-eight NDV strains isolated between 1979 and 2002 were analysed by restriction enzyme digestion and partial sequencing of the fusion protein gene. All isolates were placed in genotype V, an exotic type, that was introduced to western Europe in 1970. Residue substitution analysis has allowed the recognition of four genetic variants, Vb1-Vb4, and the tracing of their movements. Vb1, a dominant variant in Bulgaria from the late 1970s, was also wide spread in the former Yugoslavia throughout the period under investigation. Vb2, a variant occurring in the neighbouring countries in the early 1970s could be the founder of the epidemic in Yugoslavia and it was present up to the late 1980s. Variants Vb3 and Vb4 could be found only after 1987. In conclusion, the ND outbreaks in Yugoslavia were part of the epizootic wave due to genotype V viruses that started in western Europe in 1970 and became endemic in the region. Inter-country transmission occurred for all variants, and Vb3 and Vb4 might have evolved during the endemic period.     

Hat niedrigere Dosierung der Insektizide in der Schädlingsbekämpfung bedeutenderen praktischen Wert?

Zusammenfassung Aus den hier dargelegten Untersuchungsergebnissen über die Wirkung niedriger Dosen von DDT-Präparaten lassen sich für die Forschung und Praxis folgende Schlüsse ziehen:1. Nicht nur gegen Schwammspinner- und andere Raupen, welchen eine starke Veranlagung für Virosen und andere Krankheiten eigen ist, sondern auch gegen viele andere Insekten könnte man mit niedrigerer Dosierung erfolgreich vorgehen.2. Mit niedrigeren Dosen von DDT kann man 100%ige Mortalität der Raupen herbeiführen, gleichzeitig aber die Sterblichkeit der nützlichen Insekten auf ein Zehntel gegenüber Normaldosierung senken.3. Überall dort, wo wir auf ausreichende Wirkung subletaler Dosen rechnen können, sollten zur Schonung der Biocönose schwächere Konzentrationen angewendet werden.4. Die Befürchtung eine nachträglichen Resistenz ist vorläufig unbegründet, da sich die subletalen Dosen als Auslöser latenter Erkrankungen erwiesen haben.5. Die Wirkung niedriger Dosen auf jene Insekten mit hoher DDT-Empfindlichkeit, die nicht zu den latent-virotischen Arten zählen, müßte genauer untersucht werden, um über die praktische Bedeutung dieser Erscheinung Sicherheit zu gewinnen.6. Die Anwendung subletaler und kleinerer Insektiziddosen wird in Zukunft große Bedeutung erlangen, da sie die Biocönosen viel weniger stört und die biologische Schädlingsbekämpfung unterstützt, also einen Weg zur integrierten Schädlingsbekämpfung darstellt.