Characterization and selection of globe artichoke and cardoon germplasm for biomass, food and biocompound production

Globe artichoke and cardoon, belonging to the Asteraceae (Compositae) family, are herbaceous perennial plants native to the Mediterranean area, which are traditionally grown as vegetables for the heads and the fleshy petiole leaves, respectively. Italy is the richest reserve of globe artichoke autochthonous germplasm, which is vegetatively propagated and well adapted to the different pedoclimatic conditions of the Country. In Central Italian environments, the Romanesco type is widespread. In the last years, the development of in vitro technologies allowed the propagation of Romanesco globe artichoke type and its rapid expansion. As a result, the micropropagated Romanesco clone C3 has replaced many landraces traditionally grown in the Latium Region and has led either to a significant erosion of local genetic resources. As regards Italian cultivated cardoon germplasm, there are few studies on its genetic characterization and identification and there is a lack of information about the genetic variability existing within and among accessions. For the wild cardoon, no specialized crop is present and it represents mainly a weed in Italian environments. The great variability existing in Cynara spp. has not been described, the nomenclature of Italian germplasm is not always very clear since there are many cases of homonyms. In addition, Italian globe artichoke sector is facing a crisis due principally to the appearance on the market of foreign products and to the high labor cost required for crop cultivation and harvesting. In order to overcome this crisis several possible industrial uses were considered for the species. Considering these preliminary remarks, a strategy for valorizing Italian germplasm using biomass and biocompound production has been carried out during the three years of PhD program. The first objective of PhD work consisted in (i) characterizing agro-morphologically Italian germplasm using UPOV descriptors, (ii) assessing the genetic variability existing within and among landraces/clones and (iii) identifying and preserving genetic resources for the development of future plant breeding programs. As a result of this characterization, three genotypes have been selected and registered under the names of Michelangelo, Donatello and Raffaello. In order to analyze Italian Cynara spp. germplasm also from a biomass point of view, different traits explaining plant vigor and dry matter production have been considered. The aerial biomass yield resulted very high underlining the possibility of using this crop as raw industrial material. A focal point of PhD program was to set up biocompound extraction methods and analysis techniques to optimize polyphenol recovery from biomass of Cynara spp at a laboratory scale. In particular, ASE was found as the best extraction technique which allows to reduce extraction time and solvent consumption, increase nutraceutical yield and improvement of extract quality. Moreover, the kinetics of biomass and bio-compound production has been evaluated and the optimal physiological stage to collect plant material grown in open field has been identified. Biochemical characterization has been performed using the methods set up and collecting plant material in the optimal physiological stage identified in order to distinguish which genotypes were more suitable for bio-compound production purpose. The last focal point of PhD program was the development of an alternative technique for biomass and biocompound production in greenhouse grown conditions. Results obtained in the three PhD years, highlighted the possibility of using successfully some Cynara spp. genotypes for biomass and bio-compound production, in particular in open field condition. Also the real prospect of using some globe artichoke genotypes for food and non-food dual-production (biomass for biocompound extraction and heads for human food) has been underlined.