Fine structure and functional morphology of the mouthparts of a male Veigaia sp (Gamasida: Veigaiidae) with remarks on the spermatodactyl and related sensory structures

Mites of the genus Veigaia are common gamasid inhabitants of forest litter. They engage in the peculiar reproductive strategy of podospermy which, along with other morphological and behavioral adaptations, involves modification of the chelicerae of the relatively rare males into gonopods. Each movable digit is provided with an appendage (spermatodactyl) that is involved in sperm transfer. We describe the gross anatomy, fine structure, and functional morphology of the mouthparts of a male Veigaia species and give ultrastructural details for the corniculi, laciniae, preoral cavity, labrum, pharynx, and movable and fixed digits. The fine structure of the spermatodactyl is illustrated here for the first time in detail. A semischematic reconstruction of the gnathosoma and spermatodactyl is provided. The spermatodactyl is totally fused with the movable digit and a sperm transfer duct runs along its entire length. This duct starts at the adaxial base of the movable digit, continues inside the digit into the tube of the spermatodactyl, and finally opens at the distal abaxial surface of the spermatodactyl. Several sensory structures associated with the spermatodactyl probably provide the male with mechanical and chemical clues

Benefits of Bacillus subtilis QST 713 treatment in tomato plant productivity and defence

World population is projected to reach 9 billion by 2050. In this context, in addition to challenges, such as education equity and environmental resources consumption, poverty and malnutrition will be addressed first of all. To ensure correct nutrition, respecting the environmental conditions, application of biocontrol agents (BCAs) represents a good solution. BCAs can be used to provide systemic resistance against plant pathogens, thus allowing increased productivity and quality of crop. Yield loss and plant death represent the last stage of disease caused by Cucumber mosaic virus Fny (CMV) in tomato host. Among BCAs, Bacillus spp. are typical plant growth promoting rhizobacteria (PGPR). To investigate the effects of BCA in healthy and inoculated with CMV tomato plant, on fruit characteristics and against CMV infection, Bacillus subtilis QST 713 was chosen. Productive and qualitative parameters as quantity, weight and diameter as well as lutein and beta-carotene contents in tomato fruits were estimated. Obtained outcomes show that plants treated with Bacillus subtilis QST 713, though inoculated with CMV, produced more, heavier and bigger fruits than untreated plants. Furthermore, the contents of lutein and beta-carotene are highest in the same fruits. Moreover, ELISA results indicate that the viral load is controlled by bacterial strain used. Chromatographic analyses of nutraceuticals such as polyphenols and vitamins are in progress. To conclude, application of Bacillus subtilis QST 713 as biocontrol agent performs a powerful approach to increase food availability providing also antioxidants-rich fruits in response to growing population, protecting the natural resources and preserving the environmental sustainability

Chitosan-elicited defense responses in Cucumber mosaic virus (CMV)-infected tomato plants

The control of plant diseases by inducing plant resistance responses represents an interesting solution to avoid yield losses and protect the natural environment. Hence, the intertwined relationships between host, pathogen and inducer are increasingly subject of investigations. Here, we report the efficacy of chitosan-elicited defense responses in Solanum lycopersicum var. cerasiforme plants against Cucumber mosaic virus (CMV). Chitosan was applied via foliar spray before the CMV inoculation to verify its effectiveness as a preventive treatment against the viral infection. Virus accumulation, photosynthetic performance, as well as genes encoding for proteins affecting resistance responses and biosynthetic pathways, were investigated. It was observed a significant reduction of CMV accumulation in chitosan-treated plants that were successively infected with CMV, compared to only CMV-infected ones (up to 100%). Similarly, a positive effect of chitosan on gas exchange dynamics was revealed. The analysis of gene expression (CEVI-1, NPR1, PSY2 and PAL5) suggested the occurrence of chitosan-induced, systemic acquired resistance-related responses associated with a readjustment of the plant’s oxidative status. In addition, the absence of deleterious symptoms in chitosan-treated successively CMV-infected plants, confirmed that chitosan can be used as a powerful control agent. Our data indicate that chitosan, when preventively applied, is able to elicit defense responses in tomato to control CMV infection. Such finding may be recommended to protect the tomato fruit yields as well as other crops

Influence of chitosan on the antioxidant status of tomato plants infected by cucumber mosaic virus

Fruit quantity and quality loss represents a huge problem for farmers and more generally for human nutritional needs. Viruses are dangerous phytopathogens, that cannot be faced using agrochemicals. Hence, they are responsible for severe crop and quality losses. In such a scenario, chitosan is an interesting eco-friendly solution. The strong decrease of the load of cucumber mosaic virus strain Fny (CMV-Fny) in Solanum lycopersicum plants, treated with the combination of Trichoderma harzianum T-22 and chitosan, has been previously reported. The present research was aimed to investigate the influence of chitosan on the antioxidant status of CMV-inoculated tomato plants. The transcript amounts of the genes encoding peroxidase, phenylalanine ammonia lyase (PAL) and phytoene synthase 2 (PSY2), were analyzed in leaves. Lutein, lycopene, β-carotene, vitamin C and polyphenols as rutin and naringenin, were determinated in ripe fruits. Results show that chitosan treatment, both before CMV and alone, downregulated peroxidase- and PSY2-related transcripts, while upregulated PAL-related transcripts, compared to only infected plants. Fruits harvested from plants treated with chitosan alone had the highest lutein, lycopene and β-carotene contents. The same fruits also contained more caffeoyl glucoside and less naringenin chalcone, compared to the fruits of control plants. Furthermore, the fruits of control plants had the lowest vitamin C level. In conclusion, chitosan was able to enrich fruits with nutraceuticals, as carotenoids, and it controlled CMV infection likely through phenylalanine-derived products, such as salicylic acid, by affecting the plant antioxidant status

STUDI PRELIMINARI SUL “FLUSSO SCHIUMOSO DEGLI AGRUMI” IN BASILICATA

PRELIMINARY STUDIES ON “CITRUS FOAMY FLUX” IN BASILICATA, ITALY In the Autumn of 2018 and 2019, during surveys to verify the phytosanitary status of citrus orchards located in the countryside of Scanzano Ionico (Basilicata, Italy), on trunks and branches of 5-years-old sweet orange cv. Fukomoto grafted on Carrizo citrange, located in the countryside of Scanzano Jonico, copious whitish foamy exudates were observed. Alongside the flows the bark appeared cracked. The percentage of symptomatic plants was around 5-10%. Trees with the described symptoms were declining and with poor production. In order to identify the possible causes, specific investigations were conducted. In particular, phytopathological and chemical analyses of symptomatic plants were carried out. The results of chemical analyses showed that the nutritional levels were normal; also, virological analyses resulted negative. A yeast (and occasionally a bacterium), was constantly isolated from the symptomatic tissues and exudates, which were identified molecularly by PCR and subsequent gene analysis. The obtained PCR amplicons were sequenced and compared with those already present in the databases (NCBI) showing high similarity with those of Torulaspora delbrueckii and Zymobacter palmae. Further studies must be conducted to fulfill Koch's postulates, in order to verify the role played by T. delbrueckii and/or Z. palmae in determining the observed symptoms, and also to check if other factors, biotic or abiotic, are involved