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The Mediterranean countries face common challenges in adapting their agro-systems to climate change and demographic threats. It is on this basis that ARIMNet (Agricultural Research in the Mediterranean Network) programme was implemented by 15 Euro-Mediterranean partners to foster agricultural research and innovation with the support of two successive grants from the European Commission. Our work aims to evaluate the impact of this collaborative work of 10 years over the period (2008–2017) on the implementation of a EURO-MED Research and Innovation Area. Considering ARIMNet as the first regional experience of joint programming and co-funding, it has allowed the funding of 46 research projects in the Mediterranean region with a budget of €25 M. The carried survey with coordinators shows that ARIMNet activities have a positive effect on regional networking, mobility, scientific production, innovation and the construction of a regional common vision regarding societal challenges regarding food security and sustainable agriculture. This transnational programme has consolidated collaboration between EU-MED policymakers and impacted as well national research governance in South Mediterranean countries, as stated by the questionnaire sent to partners from these countries. The ARIMNet experience inspired the current PRIMA initiative (Partnership for Research and Innovation in the Mediterranean Area) which represents a step ahead for the reinforcement of the scientific Euro-Mediterranean collaboration in agriculture. The lessons learned from ARIMNet can benefit the Mediterranean and other regions in developing future common science and technology-based approaches to achieve Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

The article evaluates the performance of the partnership between European and non-European participating states after 2 years of implementation of the Partnership for Research and Innovation in the Mediterranean Area (PRIMA) programme. A total of 742 participating entities were involved in 83 funded projects based on two funding calls of 2018 and 2019. The results show that while extensive partnerships were established between southern and northern Mediterranean countries, there was lower project coordination by non-European states. As a result, the grant distribution was in favour of European countries which received the majority of funds. A networking analysis was performed, and it demonstrates low cooperation between Northern African countries and Eastern Mediterranean countries. Italy, France and Spain are clustered with Northern African countries; however, Germany and Portugal are more affiliated with Eastern Mediterranean countries. The private sector analysis shows an excellent participation of SMEs in Sect. 1 (funded by PRIMA) for both calls in 2018 and 2019. SMEs received 22% of EU funds — well in line with Horizon 2020 target — demonstrating the vital role that PRIMA plays for the development of SMEs. However, for Sect. 2 (funded by participating states), the participation of SMEs was low and received only 6.4% of participating state funds. The participation of SMEs from non-European countries was low and represented 30% in Sect. 1 of the total number of SMEs and only 15% in Sect. 2. [ABSTRACT FROM AUTHOR]

Recent occurrence in Tunisia of Citrus blast and black pit disease, caused by Pseudomonas syringae pv. syringae (Pss), the few available antibacterial chemicals, and the increasing resistance of Pss to copper sulfate highlighted the need for new antibacterial agents. In vitro analysis of the antagonistic activity of fifty-four native epiphytic bacterial isolates from the Citrus phyllosphere towards pathogenic Pss resulted in the selection of eight potential biocontrol strains according to their various antagonistic activities. Based on analysis of the (partial) 16S rRNA gene sequence and the rpoD housekeeping gene, five isolates were presumptively identified as Pseudomonas atacamensis (strains Y28, Y58 and Y128), P. cremoris (strain Y40), and P. lactis (strain Y21). In vivo test of these antagonistic strains showed no pathogenicity towards plant tissues. Three strains (Y28, Y128 and Y21) exhibited considerable inhibitory activities and significantly reduced disease severity in five Citrus cultivars (Cassar, Eurêka, Maltaise, Washington Navel and Pomelo) on shoots, leaves and fruits. Determination of genes coding for antibiotic production showed the presence of gacA gene in the five strains mentioned above. However, the genes prnD, pltC, pltB, phlD and phzC as well as phzD (and their homologs phzF and phzA), described earlier for Pf-5, were not detected among the tested Tunisian antagonistic Pseudomonas strains. This study presents the first description of P. atacamensis, P. cremoris, and P. lactis as potential biocontrol agents. The characterized bacterial strains may be considered as potential sources of novel bioactive metabolites as well as promising candidates to develop new biocontrol agents for sustainable control of Citrus. blast and black pit disease. [ABSTRACT FROM AUTHOR]

Verticillium dahliae is one of the most important soil pathogens, causing verticillium wilt. It is well known that the use of chemical products against this pathogen is not without side effects on the environment. In this regard, the present study was aimed to search for antagonistic rhizobacteria as an alternative of biological control against this causal agent. A total of 162 isolates were screened for their antagonistic activity according to the "double layer" and the "well diffusion" methods. Three of them (RS11, SF82 and ZO4), were subsequently selected as biological control agent (BCAs) according to their efficiency and were identified by 16S rRNA sequencing and Biolog microplate GEN III as Bacillus spp. Using 10 different lipopeptide gene primers, PCR reactions only revealed the involvement of genes responsible for iturins (ituA, ituD, ituC), bacillomycin (bmyA) and Bacilysin (bacA / B-F, bacA / B-R) biosynthesis. The Plant Growth Promoting Rhizobacteria traits [enzymatic activities, phytohormones production] of the three BCAs were also studied in vitro then on pepper plant (Capsicum annuum L.), indicating that Bacillus subtilis ZO4 was the most effective, enhancing leaf, stem and root growth comparing to the control. [ABSTRACT FROM AUTHOR]

Agrobacterium biovar 1 is responsible for crown gall disease of many plant species. However, according to the current species definition, this taxon displays too large a genomic divergence to be a single species. This is why it is considered as a complex of distinct genomic species. Members of this taxon are common inhabitants of soils and rhizospheres, with several species and strains commonly found in the same samples. Understanding factors that shape their populations is very important for ecological and epidemiological issues. In this regard, this study was aimed at assessing whether plant genotypes differentially select agrobacteria genomospecies in their root systems. To test this hypothesis, we followed the evolution of tagged Agrobacterium fabrum C58 strains co-inoculated with members of different genomospecies (G1, G4, G7 and G8), in the soil and the rhizosphere of tomato and maize seedling plants under controlled conditions. The total number of the agrobacterial population was always statistically higher in rhizospheres than in bulk soils, confirming that agrobacteria are rhizospheric bacteria. The plasmid, pTi, was found not to be necessary for either rhizosphere colonization or the multiplication of the C58 strain. The difference between proportions of co-introduced bacteria from different genomic species shows the presence of a competition between them, which can vary with the plant species. While there were no significant differences between the proportion of co-inoculated strains of G8 (J07 and C58Gmr) in either plant species, they were more abundant in tomato than maize rhizosphere. [ABSTRACT FROM AUTHOR]

Threats of desertification have been projected for the Mediterranean basin under relatively minor warming and drying scenarios. This situation raises the need for mitigation strategies and adaptation of crop production. Crop vulnerability assessment is therefore needed. In Tunisia, olive culture is a major activity. In some cases, olive is the only crop able to grow in local conditions. However, olive production may be among the more vulnerable systems to climate change since perennial crops adapt slowly. No studies have been dedicated to vulnerability evaluation of olive production. Here, the vulnerability of Tunisian olive trees to drought was assessed under extremely low precipitation levels, of 50% of normal precipitation, from 1999 to 2002. The impact of drought was quantified using a severity scale with three levels. A map of the impact of drought on olive trees was constructed for all Tunisian olive groves. We found that the number of wilting olive trees in 2002 was 7.8 millions of about 60 millions trees. A correlation was observed between olive tree affection by drought and olive orchard age. Thus, under the same drought conditions, senescent orchards were less resistant to drought than young ones. Locally, data showed that compact soils and soils containing more than 1% gypsum were not suitable for olive growth under drought. [ABSTRACT FROM AUTHOR]

Bacillus subtilis strain 14B was used to produce a novel antimicrobial peptide (bacteriocin) called Bac 14B. Pure bacteriocin was obtained after heat and acidic treatments (80°C and pH 4), precipitation by ammonium sulfate, and chromatography on Sephadex G-50 and Mono Q Sepharose columns. Based on MALDI-TOF mass spectrometry analysis, purified Bac 14B is a monomer protein with a molecular mass of 20110.13 Da. N-terminal sequencing allowed for the straightforward identification of its first 12 residues, which were of a pure bacteriocin. It also revealed that this bacteriocin contained a unique sequence, namely M-L-K-A-N-L-Q-N-P-L-N-A, suggesting the identification of a novel compound. Bac 14B was stable for 1 h at temperatures up to 80°C and pH of 4 ∼ 8. It also proved sensitive to various proteases, which demonstrated its protein nature. Bac 14B displayed a bacteriolytical mode of action and a broad range of inhibitory spectra toward Gram-positive and -negative pathogens. Interestingly, based on conventional agronomic seed vigor parameters, the application of Bac 14B (500 activity units/mL) to various crops revealed that this bacteriocin was a potent exogenous enhancer of growth that stimulated the seedling vigor of tomatoes and muskmelons. Compared to those of the control, the germination percentage, shoot weight, shoot height, and root length were all significantly enhanced in Bac 14B-treated plant seeds. Bac 14B also exhibited effective disinfectant properties against a wide range of seedborne diseases and significant effects on the control of damping off diseases, particularly at the pregermination stage. It also proved to be effective against root rot diseases caused by Alternaria solani and other bacterial seedborne pathogens such as wilt diseases. The findings indicate that Bac 14B is the first B. subtilis-produced bacteriocin ever reported to exhibit such promising biological properties. [ABSTRACT FROM AUTHOR]

Olive mill wastewater (OMW) is a rich source of antifungal agents and has a merit as alternative to synthetic fungicides. To develop disease control agents against Botrytis cinerea, a hydroxytyrosol-rich (29.27% weight:dry weight) olive mill wastewater (HROMW) and a hydroxytyrosol-rich (52.67% weight:dry weight) extract (HRE) were prepared from fresh OMW using hydrolysis and post-hydrolysis purification processes. The HROMW and HRE showed strong fungicidal activity against B. cinerea with minimal fungicidal concentrations (MFCs) of 14.36-28.72 and 28.72-57.44 mg l (dry weight), respectively. According to EN 1275: 1997 standard method, HROMW and HRE at 1.25% (dry weight:volume) showed powerful disinfectant properties resulting in a reduction in the viability of B. cinerea spores by >4 log units after 30 min of contact time. The HROMW or HRE foliar spray treatments, of the B. cinerea inoculated tomato plants, resulted in disease control percentage of 95 and 91%, respectively, whereas 70% was conferred by benomyl treatment. Although, HRE possessed a similar disease severity reduction than HROMW, it showed great advantage by fortifying plants and by improving their growth and healthy aspect. Indeed, HRE-treated plants showed significantly better: (i) plant height (146.2 and 130.5%), (ii) average stem diameter (135% and 110%), (iii) leaf number (163.6 and 128.5%), and (iv) leaf colour (chlorophyll a content) (144.4 and 103%) than benomyl-treated and non-treated plants, respectively. This study revealed that HRE offers a natural and effective extract to control grey mould. [ABSTRACT FROM AUTHOR]

The analysis of housekeeping recA gene sequences from 138 strains from 13 species or genomic species of Agrobacterium, nine being biovar 1 genomospecies, and the others Agrobacterium larrymoorei, Agrobacterium rubi, Agrobacterium sp. NCPPB 1650, and Agrobacterium vitis and one 'former' Agrobacterium species, Rhizobium rhizogenes, led to the identification of 50 different recA alleles and to a clear delineation of the 14 species or genomospecies entirely consistent with that obtained by amplified fragment length polymorphism (AFLP) analysis. The relevance of a recA sequencing approach for epidemiological analyses was next assessed on agrobacterial Tunisian isolates. All Tunisian isolates were found to belong to the Agrobacterium tumefaciens/biovar 1 species complex by both biochemical tests and rrs sequencing. recA sequence analysis further permitted their unambiguous assignment to A. tumefaciens genomospecies G4, G6, G7, and G8 in total agreement with the results of an AFLP-based analysis. At subspecific level, several Tunisian recA alleles were novel, indicating the power and accuracy of recA-based typing for studies of Agrobacterium spp. [ABSTRACT FROM AUTHOR]

Aflatoxins (AFs) are potent sources of health risks to both humans and animals. Among them, AFB1 is the most hazardously toxic and the most frequent in various food commodities, including pistachio nuts. In this survey, the effect of the storage period on AFB1 accumulation on pistachio nuts was investigated. A total of 49 samples collected during the crop year of 2005 from the most cultivated pistachio cultivars in Tunisia were rapidly screened by enzyme-linked immunosorbent assay (ELISA) combined with an immunoaffinity step. The obtained results showed that the contamination of pistachio nuts has occurred clearly after two years of storage for all the tested cultivars except the case of Mateur variety and Thyna ecotypes. In this study, the cultivar Mateur was found to be the most susceptible cultivar to contamination by AFB1. After 4 years of storage, the average contamination levels in nut samples ranged from 2.7 ± 0.3 to 12.7 ± 2.2 µg/kg for AFB1, according to the cultivar. These levels exceeded the maximum permitted limit of 2 µg/kg set by the European Commission in nuts. [ABSTRACT FROM AUTHOR]