BACKGROUND: Goji berries, traditionally used in Chinese medicine, are nowadays gaining popularity in the Western world. The efforts are made to establish their cultivation in Europe. Goji berries might derive from two closely related species: Lycium barbarum and Lycium chinense, however, plant species is rarely stated by commercial suppliers. OBJECTIVE: The aim of this study was to evaluate the antioxidant activity and the bioactive compounds profile of fruits from six goji berries cultivars cultivated in Switzerland and to provide their genetic characterisation. METHODS: Goji fruits were cultivated at the experimental field of the Agroscope Research Center in Wallis, Switzerland. The genetic characterization was carried out by amplifying and sequencing two nuclear genes and one chloroplastic gene. The comparison with L. barbarum and L. chinense obtained from the Conservatory and Botanical Garden of Geneva (CBGG) was made. The profile of carotenoids and polyphenols was analysed using an HPLC-DAD. The antioxidant capacity was determined by ORAC and TEAC assays. RESULTS: DNA sequencing and phylogenetics confirmed that all the cultivars belonged to the Lycium genus. 'Tibet', 'Red Life', 'Sweet Lifeberry', 'Big Lifeberry' seemed to be closely related to a L. barbarum, whereas 'Number One' segregated closer to L. chinense. The individual Saxon, appeared genetically different from all other cultivars and the L. barbarum and L. chinense individuals from CBGG. Zeaxanthin esters were the predominant carotenoid in all six cultivars. 'Number One' had the highest content of phenolic compounds such as rutin and ferulic, chlorogenic, caffeic and p-coumaric acid. CONCLUSIONS:The study confirmed the importance of combining the quantification of bioactive compounds with genetic characterisation in the analysis of goji species. The dissimilarity of 'Number One' and Saxon from four remaining cultivars investigated in this study was evident from the DNA sequencing and Principal Component Analysis of chemical results.

Fungi were isolated in pure cultures from decaying giant sequoias in Geneva (Switzerland). Isolates were genetically identified by ITS rDNA sequencing. Young giant sequoia trees were artificially infected with a pure culture of Botryosphaeria parva. Henle-Koch’s Postulates demonstrated that Botryosphaeria parva was pathogenic to Sequoiadendron giganteum. When analysing the microorganisms associated to canker and dieback symptoms in a giant sequoias (Sequoiadendron giganteum) in Geneva, the fungus Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, teleomorph Botryosphaeria parva (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, was isolated, whereas such symptoms are commonly associated to Fusicoccum aesculi (teleomorph Botryosphaeria dothidea). These two fungal species belong to the same genus Botryosphaeria of the Botryosphaeriaceae family. Because Neofusicoccum parvum was causing cankers and diebacks in other woody species around the world, we extended the analysis to other trees displaying sequoia dieback symptoms in order to evaluate the involvement of Neofusicoccum parvum in such increasing symptoms in sequoias in Geneva. Dried twigs, trunk, and branch cankers from diseased trees were sampled on several distinct sites. From all samples, isolated fungi in pure cultures showed a phenotype typical of Botryosphaeriaceae species. Isolates were then genetically identified at the species level. Subsequently Neofusicoccum parvum was inoculated to young giant sequoia trees, re-isolated in pure culture from provoked symptoms, and re-identified to fulfil Henle-Koch’s postulates. The identification confirmed that Neofusicoccum parvum was present on all sites, while Fusicoccum aesculi was retrieved only once alone. The inoculation of Neofusicoccum parvum isolates on young sequoias demonstrated for the first time that this fungus was able to develop cankers in Sequoiadendron gigantean. Neofusicoccum parvum could, therefore, be the major cause for dying of giant sequoias in the Geneva Lake area.

In Switzerland, chestnut forests cover about 27100 ha, plus some 6800 ha of mixed stands.Due to environmental and historical reasons, most of these still existing forests are located in the Swiss Southern Alps, whereas in the northern parts of the country the chestnut cultivation and the related knowledge strongly regressed since the Little Ice Age period.Nevertheless, Switzerland still hosts valuable genetic resources of the sweet chestnut tree.The present genetic study bases on a nationwide inventory, identification and precise localisation of old and/or grafted chestnut trees for conservation purposes. The main objectives were 1) to evaluate the genetic diversity and the genetic structure of Castanea sativa Mill. in Switzerland, and 2) to define a program of conservation including the proposal of a defined core collection. We genetically analysed a pre-selection of 962 accessions (out of 14165 inventoried trees throughout Switzerland), profiling them with 24 microsatellites. We identified 675 different genotypes out of 962 accessions with a 29.8% of repetitiveness due to clonality. A structural analysis based on a Bayesian method allowed to identify two main clusters, one mostly related to the genetic group from southern Europe (Reconstructed Panmictic Population RPP1) and a second one (RPP2) which revealed to be independent and genetically different from other European groups of chestnut cultivars. The Swiss RPP2 represents a new genetic group, and consequently a complement to genetic resources of chestnut tree in Europe. Genetic analysis allowed defining a core collection of 46 genotypes, which should be used in priority for the Swiss conservation program.

Plant-growth-promoting rhizobacteria (PGPR) are soil bacteria colonizing the rhizosphere and the rhizoplane which have an effect on plant growth through multiple chemical compounds. Rhizobacteria with beneficial effects for plants could therefore be used to reduce the dependence on synthetic chemical fertilizers in conventional agriculture. Within this study, 67 endophytic fungi and 49 bacteria were isolated from root samples from 3 different commercial productions: an off-ground tomato production in a greenhouse, an organic production and a conventional production, both in a soil tunnel. Following morphological selection, 12 fungal and 33 bacterial isolates were genetically identified. Thirteen bacterial isolates belonging to nine potential PGPR species were then applied to tomato seedlings established in sterile substrate. The ability of these bacteria to produce indole acetic acid (IAA) and solubilize phosphate was also evaluated. They all were IAA producers and solubilized phosphate. The most interesting strains for growth promotion were found to be the isolates Pseudomonas palleroniana B10, Bacillus subtilis B25, Bacillus aryabhattai B29 and Pseudomonas fluorescens B17. The isolates P. fluorescens B17, B. aryabhattai B29, B. subtilis B18 and Pseudomonas moraviensis B6 also increased root growth. This study proposed a quick protocol for isolating and testing potential endophytic PGPR that should be characterized further for the direct and indirect mechanisms of growth promotion.