Characterisation of the phospholipid fraction of hulled and naked tetraploid and hexaploid wheats

Phospholipid (PL) profile was determined on lipids extracted from the whole grains of 10 genotypes of tetraploid wheats (Triticum dicoccon Schrank and Triticum durum Desf.) and 10 genotypes of hexaploid wheats (Triticum spelta L. and Triticum aestivum L.) by a liquid chromatography system coupled on-line with an evaporative light scattering detector (HPLC-ELSD). Phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine were the major PL determined, accounting for more than 70% of total PL. PL represented about 10% of total lipids and were detected in naked wheats at levels of 10.1 and 10.4 g/100 g of lipids (T. durum and T. aestivum, respectively) whereas in the corresponding ancestors T. dicoccon and T. spelta PL amounts were 8.4 and 9.1 g/100 g of lipids, respectively. PL amount in naked wheats was about 17% higher than that determined on average in hulled wheats: 10.2 ± 2.8 vs. 8.7 ± 2.2 g/100 g of lipids, respectively. A hyphenated system HPLC-ELSC was revealed as a useful and more informative tool to identify different PL classes with a minimal experimental workout in comparison to the organic phosphorus assay. The identification of PL molecular species was performed by HPLC, employing as detector a mass spectrometer working in negative ASI-ES mode.     

Volatile organic compounds (VOC) as biomarkers for detection of Ceratocystis platani

Ceratocystis platani causes canker stain of plane trees, and it represents a serious disease of Platanus spp. both in the United States and Europe. Current chemical or biological controls do not effectively manage C. platani, so new preventive methods need to be developed in order to limit this pathogen spreading. In this work, we have characterized the main volatile organic compounds (VOC) emitted in vitro from pure cultures of C. platani and other common pathogenic fungal species of hosts plants growing in the same ecosystems as plane trees. We found that C. platani emitted a similar blend of VOC compared with phylogenetically similar species C. populicola. In particular, C. platani was characterized by emission of isoamyl acetate and isobutyl acetate while C. populicola by ethyl acetate and isobutyl acetate, which were not released by any of the other out‐group fungal species grown on the same medium. Moreover, following a targeted approach based on the main VOC found in vitro, we have successfully validated in vivo that VOC uniquely emitted by C. platani (i.e. isobutyl acetate along with isoamyl alcohol) were released from the bark of plane trees following C. platani inoculation. Our results highlight the possibility to exploit VOC emitted specifically by C. platani as biomarkers to recognize Platanus x acerifolia plants infected by this pathogen.     

Sponges and Their Symbionts as a Source of Valuable Compounds in Cosmeceutical Field

In the last decades, the marine environment was discovered as a huge reservoir of novel bioactive compounds, useful for medicinal treatments improving human health and well-being. Among several marine organisms exhibiting biotechnological potential, sponges were highlighted as one of the most interesting phyla according to a wide literature describing new molecules every year. Not surprisingly, the first marine drugs approved for medical purposes were isolated from a marine sponge and are now used as anti-cancer and anti-viral agents. In most cases, experimental evidence reported that very often associated and/or symbiotic communities produced these bioactive compounds for a mutual benefit. Nowadays, beauty treatments are formulated taking advantage of the beneficial properties exerted by marine novel compounds. In fact, several biological activities suitable for cosmetic treatments were recorded, such as anti-oxidant, anti-aging, skin whitening, and emulsifying activities, among others. Here, we collected and discussed several scientific contributions reporting the cosmeceutical potential of marine sponge symbionts, which were exclusively represented by fungi and bacteria. Bioactive compounds specifically indicated as products of the sponge metabolism were also included. However, the origin of sponge metabolites is dubious, and the role of the associated biota cannot be excluded, considering that the isolation of symbionts represents a hard challenge due to their uncultivable features.     

Thermographic medium-far ground-based proximal sensing for in-field wheat Stagonospora nodorum blotch detection

Journal of Plant Diseases and Protection - Thermal imaging is a potential remote sensing tool for estimating fungal wheat diseases. This study for the first time investigated the suitability of...     

Differential response of male and female Diabrotica speciosa (Coleoptera: Chrysomelidae) to bitter cucurbit-based toxic baits in relation to the treated area size

Cucurbitacin-rich extracts are phagostimulants for both male and female Luperini, but field trials reveal that males are far more attracted to them than females. The sex ratio and number of beetles killed by an application of cucurbitacin-based toxic baits was assessed at two different scales: small areas of 100 m², and a larger area of 10,000 m². The small area bait applications killed mostly males (95.2%), but the 1-ha treated plot showed a lower sexual bias (57% male). An earlier study indicated point sources (sticky traps) attracted only males. Results indicate that the distance attraction to bitter cucurbit extracts is almost exclusive to males, but the wide dispersal of a toxic bait based on them should promote encounter and control of both sexes within the treated area. No significant non-target effects were observed.     

Population structure of Phytophthora infestans collected on potato and tomato in Italy

Late blight caused by the oomycete Phytophthora infestans is a disease of potato and tomato of worldwide relevance and is widespread throughout Europe and the Mediterranean region. While pathogen populations in northern Europe have been sampled and characterized for many years, the genetic structure of populations from southern Europe, including Italy, has been less studied. Between 2018 and 2019, we collected 91 samples of P. infestans from potato and tomato crops in Italy, Algeria, and Tunisia on FTA cards and genotyped them using 12-plex microsatellites. These samples were compared to genotypes of P. infestans previously collected within the framework of the EuroBlight network and from published sources. Four clonal lineages were identified: 13_A2 (Blue 13), 2_A1, 23_A1, and 36_A2. Two other isolates collected could not be matched to any currently known clonal lineage. The 13_A2 and 36_A2 lineages were found exclusively in southern Italy and Algeria, while 2_A1 was only found in Algeria. This is the first report of the 36_A2 lineage in Italy. Two isolates from Solanum nigrum were 13_A2, suggesting this weed host could be a reservoir of inoculum. The 23_A1 lineage was found widely on infected tomato crops in Italy and is the same as the lineage US-23 that is widespread in North America. Differences in genotypes across the country suggests that there may be different sources of introduction into Italy, possibly via infected seed tubers from other countries in Europe, tubers for consumption from North Africa, or tomatoes.     

Genetic Diversity of Xylella fastidiosa Strains from Costa Rica, São Paulo, Brazil, and United States

ABSTRACT The diversity of 42 Xylella fastidiosa strains from Costa Rica, S?o Paulo, Brazil, and the United States were analyzed using the sequence of the 16S rRNA gene by variable number of tandem repeat (VNTR) fragment analysis and by restriction fragment length polymorphisms (RFLP) of a specific polymerase chain reaction (PCR)-amplification product using enzyme CfoI. Limited variability in the sequence of the 16S rRNA gene was observed and, although the separation was not absolute, most strains from Costa Rica clustered with strains from the United States and not with strains from S?o Paulo. The PCR-RFLP produced different patterns of DNA bands. The same pattern was shared by strains from Costa Rica, the United States, and two coffee strains from S?o Paulo, but a different pattern was observed in six coffee and orange strains from Brazil. In all, 32 amplification products were scored in the VNTR fragment analysis. The total variation observed among the X. fastidiosa strains had significant (P < 0.001) contributions from both geography and host origin as inferred by Nei's values of genetic diversity and WINAMOVA statistics. The strains from Costa Rica were isolated from diseased grapevines, coffee, and sweet orange and these strains grouped together and could be distinguished from strains from grapevine from the United States or from either coffee or sweet orange from S?o Paulo. The strains tested from Costa Rica are most likely of local origin, although the possibility that they have been introduced along with horticultural crops cannot be excluded. In either case, they are examples of independent selection of strains of X. fastidiosa affecting coffee and sweet orange. Greater genetic similarity was observed between strains from Costa Rica and the United States than with those from S?o Paulo.