Comparative characteristics of oat doubled haploids and oat × maize addition lines: Anatomical features of the leaves, chlorophyll a fluorescence and yield parameters.

As a result of oat (Avena sativa L.) × maize (Zea mays L.) crossing, maize chromosomes may not be completely eliminated at the early stages of embryogenesis, leading to the oat × maize addition (OMA) lines development. Introgression of maize chromosomes into oat genome can cause morphological and physiological modifications. The aim of the research was to evaluate the leaves' anatomy, chlorophyll a fluorescence, and yield parameter of oat doubled haploid (DH) and OMA lines obtained by oat × maize crossing. The present study examined two DH and two disomic OMA lines and revealed that they differ significantly in the majority of studied traits, apart from: the number of cells of the outer bundle sheath; light energy absorption; excitation energy trapped in PSII reaction centers; and energy dissipated from PSII. The OMA II line was characterized by larger size of single cells in the outer bundle sheath and greater number of seeds per plant among tested lines.

An Insight into an Olive Scab on the "Istrska Belica" Variety: Host-Pathogen Interactions and Phyllosphere Mycobiome.

The olive tree is one of the most important agricultural plants, affected by several pests and diseases that cause a severe decline in health status leading to crop losses. Olive leaf spot disease caused by the fungus Venturia oleaginea can result in complete tree defoliation and consequently lower yield. The aim of the study was to obtain new knowledge related to plant-pathogen interaction, reveal mechanisms of plant defense against the pathogen, and characterize fungal phyllosphere communities on infected and symptomless leaves that could contribute to the development of new plant breeding strategies and identification of novel biocontrol agents. The highly susceptible olive variety "Istrska Belica"' was selected for a detailed evaluation. Microscopy analyses led to the observation of raphides in the mesophyll and parenchyma cells of infected leaves and gave new insight into the complex V. oleaginea pathogenesis. Culturable and total phyllosphere mycobiota, obtained via metabarcoding approach, highlighted Didymella, Aureobasidium, Cladosporium, and Alternaria species as overlapping between infected and symptomless leaves. Only Venturia and Erythrobasidium in infected and Cladosporium in symptomless samples with higher abundance showed statistically significant differences. Based on the ecological role of identified taxa, it can be suggested that Cladosporium species might have potential antagonistic effects on V. oleaginea.

Genetic analysis of water loss of excised leaves associated with drought tolerance in wheat.

BACKGROUND: Wheat is widely affected by drought. Low excised-leaf water loss (ELWL) has frequently been associated with improved grain yield under drought. This study dissected the genetic control of ELWL in wheat, associated physiological, morphological and anatomical leaf traits, and compared these with yield QTLs. METHODS: Ninety-four hexaploid wheat (Triticum aestivum L.) doubled haploids, mapped with over 700 markers, were tested for three years for ELWL from detached leaf 4 of glasshouse-grown plants. In one experiment, stomata per unit area and leaf thickness parameters from leaf cross-sections were measured. QTLs were identified using QTLCartographer. RESULTS: ELWL was significantly negatively correlated with leaf length, width, area and thickness. Major QTLs for ELWL during 0-3 h and 3-6 h were coincident across trials on 3A, 3B, 4B, 5B, 5D, 6B, 7A, 7B, 7D and frequently coincident (inversely) with leaf size QTLs. Yield in other trials was sometimes associated with ELWL and leaf size phenotypically and genotypically, but more frequently under non-droughted than droughted conditions. QTL coincidence showed only ELWL to be associated with drought/control yield ratio. DISCUSSION: Our results demonstrated that measures of ELWL and leaf size were equally effective predictors of yield, and both were more useful for selecting under favourable than stressed conditions.

Fatal cocaine intoxication in a body packer.

INTRODUCTION: 'Body packer' syndrome with severe intoxication or sudden death may happen in persons who smuggle drugs in their body cavities. In case of lethal outcome when carrying cocaine, it is important, but sometimes difficult to determine whether death was due to intoxication or due to other causes. Therefore, it is necessary not only to quantify cocaine and its metabolites in biological material, but also based on their distribution in body fluids and tissues to conclude whether it is acute intoxication. We described a well-documented case of fatal poisoning in a body packer and post mortem distribution of the drug in biological samples. CASE REPORT: A 26-year-old man was brought to hospital with no vital signs. Resuscitation measures started at once, but with no success. Autopsy revealed 66 packets of cocaine in his digestive tract, one of which was ruptured. Hyperemia of the most of all internal organs and pulmonary and brain edema were found. High concentrations of cocaine, its metabolites benzoylecgonine and ecgonine methyl ester, as well as cocaine adulteration levamisole were proven in the post mortem blood and tissues by liquid chromatography-mass spectrometry (LC-MC) method with selective-ion monitoring. CONCLUSION: The ratio of cocaine and its metabolites concentrations in the brain and blood obtained by LC-MS method can be used for forensic confirmation of acute intoxication with cocaine.

The application of various anatomical techniques for studying the hydraulic network in tomato fruit pedicels.

The abscission zone in fruit pedicels plays an important role in affecting not only water uptake in the developing fruit, but also in the transport of chemical signals from root to shoot. In order to characterize the hydraulic network of tomato fruit pedicels, we applied various techniques, including light, fluorescence microscopy, electron microscopy, maceration, tissue clearing, and X-ray computed tomography. Because of significant changes in xylem anatomy, the abscission zone in tomato fruit pedicels is illustrated to show a clear reduction in hydraulic conductance. Based on anatomical measurements, the theoretical axial xylem conductance was calculated via the Hagen-Poiseuille law, suggesting that the hydraulic resistance of the abscission zone increases at least two orders of magnitude compared to the pedicel zone near the stem. The advantages and shortcomings of the microscope techniques applied are discussed.

Anatomical injury induced by the eriophyid mite Aceria anthocoptes on the leaves of Cirsium arvense.

Anatomical injury of the leaves of the invasive species, Cirsium arvense (L.) Scop., caused by the eriophyid mite Aceria anthocoptes (Nal.), which is the only eriophyid mite that has been recorded on C. arvense worldwide, is described. The injury induced by the mite feeding on the leaves of C. arvense results in visible russeting and bronzing of the leaves. Other conspicuous deformations are folding and distortion of the leaf blade and curling of leaf edge, as well as gradual drying of leaves. The anatomical injury of the mature leaves of field-collected plants was limited to the epidermis of the lower leaf surface. However, on young leaves of experimentally infested plants, rust mite injuries extend to epidermal cells on both leaf surfaces and to those of deeper mesophyll layers. On these leaves, lesions on the lower leaf surface even affected the phloem of the vascular bundles. Leaf damage induced by A. anthocoptes is discussed with regard to the mite's potential as a biological control agent of C. arvense.