Screening for pollen tolerance to high temperatures in tomato

Among the abiotic stresses affecting plant reproduction, high temperature is one of the most prominent ones because it directly affects fruit set. So far, little attention has been paid to the investigation of the variation in high temperature tolerance among wild tomato (Solanum lycopersicum) germplasm. The objective of this study was to determine the tolerance of 17 different cultivated and wild tomato accessions to high temperature, using a pollen viability screening approach. Each of the 17 genotypes of tomato was analysed for their pollen quality under a 32 °C (day)/26 °C (night) regime. The total number of pollen per flower and the fraction of viable pollen were recorded. The number of pollen per flower varied between 35,547 and 109,490 whereas the fraction of viable pollen varied between 0.03 and 0.71. No correlation was found between these two traits. However, the combination of these traits could provide the best reproductive capability under high temperature. In this study, thermo-tolerant (LA2854, LA1478 and LA0417) as well as thermo-sensitive (LA1719, LA1580, and SWEET4) genotypes have been identified. Those genotypes can be used as novel genetic resources to get more insight into pollen thermo-tolerance mechanisms and be included in breeding programs.     

Geochemical tools for the stratigraphic correlation of floodplain deposits of the Morava River in Strážnické Pomoraví, Czech Republic from the last millennium

The floodplain of the Morava River in Strá?nické Pomoraví, south-east Moravia, Czech Republic contains a very valuable record of regional environmental change, which goes back to several thousand years. Its interpretation has been limited by poor stratigraphic correlation and dating of the sediments. We present a geochemical solution to this challenge. We studied 8 outcrops of floodplain deposits from 4 localities along a 6 km long part of the current meander belt of the Morava River in Strá?nické Pomoraví using geochemical proxy analyses, magnetic susceptibility measurements, ¹⁴C dating of wood remnants, and sediment micromorphology. The proxy methods are based on elemental analysis (EDXRF) and analysis of the cation exchange capacity of clay minerals; granulometric analyses provided the basis for lithological and facies assignment of the sediments. Our geochemical and mineralogical interpretations have further been tested by microstratigraphically studying the optical properties of the fine fraction. Horizons older than about 3 centuries were ¹⁴C dated using wood remnants and the age of deposits from the last century was determined on the base of several proxies reflecting their industrial contamination by heavy metals and magnetic particles. The mean depositional rate over the period from about 1000 to about 1900 AD ranged from 0.2 to 0.6 mm y^− 1, depending on the sedimentary facies. The coeval lithological change in the majority of the studied sections indicated a change of the meander belt structure at between ~ 1200 AD and ~ 1600 AD probably as a consequence of changes of channel structure. The alluvial deposition in the 20th century was strongly affected by the river regulation.     

The evaluation of agricultural machines field trafficking intensity for different soil tillage technologies

Fields trafficking by wheeled farm machines results often in unfavourable soil compaction. In order to monitor trafficking intensity under different soil tillage technologies, every machine was equipped with a DGPS signal receiver before the entrance into the field under conventional, minimum and zero tillage technology. Positioning data was automatically logged every 2 s and the dimensions of tyres (mainly width) and wheel spacing were marked for every machine. Trajectories of farm machines trafficking and wheel tracks covering 1 ha area are shown for different technologies evaluated during one growing season. The results document that up to 95.3% of the total field area was run-over with a machine at least once during a year, when using conventional tillage. Up to 72.8% or 55.7% of the total field area was run-over when using minimum tillage and direct seeding, respectively. It was calculated that 145.6% of covered area can be run-over repeatedly for conventional tillage, 44.8% for minimum tillage and 18.4% only for direct seeding.     

A dinuclear Ni(mu-H)Ru complex derived from H2

Models of the active site in [NiFe]hydrogenase enzymes have proven challenging to prepare. We isolated a paramagnetic dinuclear nickel-ruthenium complex with a bridging hydrido ligand from the heterolytic cleavage of H2 by a dinuclear NiRu aqua complex in water under ambient conditions (20 degrees C and 1 atmosphere pressure). The structure of the hexacoordinate Ni(mu-H)Ru complex was unequivocally determined by neutron diffraction analysis, and it comes closest to an effective analog for the core structure of the proposed active form of the enzyme.     

Mediterranean cork oak wooded grasslands: synergies and trade-offs between plant diversity,pasture production and soil carbon

Mediterranean wooded grasslands that emerge from silvopastoral activities are multifunctional systems that result in high biodiversity and offer ecosystem services such as forage production and soil carbon sequestration. During 3 years, ten grazed wooded grassland fields were studied in the Berchidda–Monti long-term observatory, located in NE Sardinia, Italy, with the aim of exploring the synergies and trade-offs between biodiversity and selected ecosystem services. Positions below and outside the canopy of three cork oak trees in each field were randomly selected to compare seasonal pasture production, pasture utilization rate by animals, botanical composition, biodiversity indicators (Shannon index and plant species richness) and soil organic carbon. In autumn, dry matter production of pasture was similar in the two positions; in two winters out of three it was greater below the trees than outside, and in spring it was greater outside than below the trees. While plant species richness and Shannon index were not significantly influenced by the position, the overall wooded grassland plant species richness was 31% higher than that outside of the tree crown. The soil organic carbon content in the 0–40-cm soil layer was also higher below the trees. Our findings highlight that if the main purpose of the wooded grasslands is to provide forage for grazing animals rather than conserving and/or enhancing plant diversity and soil fertility, the presence of trees constrains the overall forage productivity, although the greater forage availability in winter under the trees can contribute to improve the seasonal distribution of forage production.     

Preservation of land-races of cultivated plants in Czechoslovakia

Summary At present, the collection of cultivated plants comprises in Czechoslovakia 40883 cultivars of field, vegetables and fruits, vine grape and ornamental plants. The collection has been located in the Research Institute of Crop Production, Praha-Ruzyn, which also renders the central coordination, and in 17 specialized Research Institutes and Breeding Stations which are responsible for investigation, maintenance, exploration of the collections of special crops. Continual research has assumed since 1951 when former collections of different research stations (amounting only 6000 cultivars) were united.The first efforts to collect cultivars by the different research and breeding stations were started in the SSR already at the beginning of this century. A part of the then collections coming from different research and breeding stations has been conserved up to present time and represents, together with later collected cultivars, a valuable gene pool of 2000 cultivars of Czechoslovak origin. The original Czechoslovak cultivars are represented by selections, lines or clones from land-races (wheat, barley, oat, legumes, flax, hop, self-pollinated fodders and vegetables), or populations (maize, oil plants, fodders vegetables and ornamental plants). The major part of the collection is represented by Czechoslovak cultivars coming from combination crossing.The old cultivars of vine grape, fruits and ornamental plants have been maintained since the beginning of this century in old plantations of the research institutes or they are registred by them. Also cultivars of wheat (Czech red wheats, Czech alternate wheats, South-Moravian awnless and awned wheats, Slovak awned wheats) and of barley (spring malting Haná barley, Haná is territory in middle Moravia) come from the same period. The oldest native as well as foreign cultivars of other agricultural crops originate from thirties being conserved at different degree of breeding intensity at the time of their cultivation.

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Die Erhaltung der Landsorten von Kulturpflanzen in der SSR

Zusammenfassung Gegenwärtig umfaßt die Kollektion in der SSR 40883 Sorten von Feldfrüchten, Gemüse, Obst, Weinreben und Zierpflanzen. Die Kollektion befindet sich im Forschungsinstitut für Pflanzenbau Prag-Ruzyn, das für die zentrale Koordinierung zuständig ist, sowie in 17 spezialisierten Forschungsinstituten und Zuchtstationen, die für die Untersuchung und Erhaltung der Kollektionen spezieller Kulturpflanzen verantwortlich sind. Kontinuierliche wissenschaftliche Untersuchungen begannen im Jahr 1951, als die früheren Kollektionen verschiedener Forschungsstationen (nur etwa 6000 Sorten) vereinigt wurden.In der SSR bemühten sich bereits zu Beginn dieses Jahrhunderts verschiedene Forschungs- und Zuchtstationen um die Sammlung von Sorten. Ein Teil der damaligen, aus verschiedenen Forschungs- und Zuchtstationen stammenden Sammlungen wurde bis zur Gegenwart erhalten und stellt, zusammen mit später gesammelten Sorten, einen wertvollen Genpool von 2000 Sorten tschechoslowakischer Herkunft dar. Die tschechoslowakischen Originalsorten sind durch Linien oder Klone von Landsorten (Weizen, Gerste, Hafer, Leguminosen, Lein, Hopfen, selbstbefruchtende Futterpflanzen und Gemüse) oder Populationen (Mais, Ölfrüchte, Futterpflanzen, Gemüse und Zierpflanzen) vertreten. Den größten Teil der Kollektion bilden tschechoslowakische Sorten, die durch Kombinationszüchtimg entstanden sind.Die alten Sorten von Weinrebe, Obst und Zierpflanzen werden seit Beginn, dieses Jahrhunderts in alten Anpflanzungen von wissenschaftlichen Instituten erhalten und durch diese registriert. Auch Sorten von Weizen (böhmische Rotweizen, böhmische Wechselweizen, südmährische grannenlose und begrannte Weizen, slowakische begrannte Weizen) und Gerste (Sommerbraugerste Hanna; die Hanna ist ein Gebiet in Mittelmähren) stammen aus dem gleichen Zeitraum. Die ältesten einheimischen und ausländischen Sorten anderer landwirtschaftlicher Kulturpflanzen, die aus den dreißiger Jahren stammen, werden entsprechend dem Stand der Züchtung z. Z. ihres Anbaues erhalten.

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Embryo Transfer in Anovulatory Recipient Mares Treated with Estradiol Benzoate and Long-Acting Progesterone

This study aimed to prepare anovulatory mares in anestrus or in the transitional period as embryo recipients. Ninety embryo-recipient mares were divided into two groups (G). G1 (n = 45) comprised animals in anestrus or in the transitional period; these animals were treated for 3 days (D) with 5, 3, and 2 mg of estradiol benzoate (intramuscular) on D0 (day of the donor's ovulation), D1, and D2 (after ovulation), respectively, followed by weekly application of 400 mg of long-acting progesterone (intramuscular) from D3 after ovulation (donor) until the 120th day of gestation. G2 (n = 45) comprised mares with normal estrous cycles. Plasma levels of progesterone (P₄) were measured on days D1, D2, D8, and D14. Sixty percent of the animals in G1 and 71.1% in G2 (P > .05) completed the pregnancy. On D8, there was no difference in P₄ levels between G1 and G2 animals, but there was a difference in P₄ levels on D14 (P < .05). It was concluded that anovulatory mares in anestrus or in the transitional period could be used as embryo recipients. The protocol was efficient and also considered an appropriate alternative to prepare the uterine environment for embryo transfer; long-acting progesterone administration kept P₄ levels high enough to maintain pregnancy until the 120th day and provided recipients during the time of the year when fewer mares were cycling and ovulating.     

Influx and concentration of triazine pesticides in the Amaterska cave system,Moravian Karst,Czech Republic

Purpose

The aim of this study was to detect three triazine pesticides and their metabolites in the drip water and the sediment of the Amaterska cave system. Diversity of the bacterial community in the sediment was also assessed, and the potential role of bacteria in degradation of these pesticides was evaluated.

Materials and methods

Triazines and their metabolites were analyzed in the soil, drip water, and sediment of the Amaterska cave system area in seven sampling sites (S1–S7) based on the above ground cover that included forest, permanent grassland, and agriculture cropland. The bacterial community in the cave sediments (S1–S6) was also analyzed using the Illumina sequencing of the V3 and V4 regions of 16S rDNA.

Results and discussion

Triazines were present in the soil and drip water in all sites below grassland and agricultural land but not under the forest area. Only atrazine metabolites were detected in the surface soil. In contrast, atrazine was detected in all cave sediments regardless of above ground cover, and this is likely due to the occasional alluvial influx. The overall prevalence of bacteria potentially capable of atrazine degradation in the cave sediment ranged from 13.4 to 64.0% of the entire bacterial community. The concentrations of atrazine in the cave sediment were 16 to 70 times higher than in those in drip water.

Conclusions

High concentrations of atrazine in the cave sediment indicate a slow degradation rate of triazines in the cave likely due to low temperatures and absence of photolysis. The main source of atrazine in the Amaterska cave system is likely not drip water but the alluvial influx. Bacteria potentially capable of triazine degradation in the cave sediment were detected; however, their role in this process remains to be investigated.