Increasing the content in bioactive phenolics in the eggplant (Solanum melongena) fruit is of interest, but may result in enhanced browning. We evaluated six varieties of S. melongena, 22 accessions of wild related species and 42 interspecific hybrids between cultivated eggplant and wild relatives for phenolics content, fruit flesh colour, polyphenol oxidase (PPO) activity, and fruit flesh browning. Wild relatives generally had a higher content in phenolics and a broader range of variation than cultivated eggplant. Chlorogenic acid was the predominant (>65.0%) phenolic acid in cultivated eggplant and its primary genepool wild ancestor S. insanum, while for the other wild species on average represented <50% of the chromatogram peak area. Fruit flesh colour was lighter in S. melongena than in the wild species, while PPO activity and browning was much higher in wild species of the secondary and tertiary genepools. Interspecific hybrids between S. melongena and S. insanum were intermediate in their characteristics, while those with secondary and tertiary genepool species were more similar to the wild species. No significant correlations were found between total phenolics or chlorogenic acid contents and fruit flesh browning, but PPO activity was correlated to both the degree of browning (r=0.404) and colour difference (r=0.458). The results indicate that wild species can contribute to improving the bioactive properties of eggplant without affecting negatively fruit flesh colour and browning.
The Mediterranean agro-food systems need to be properly managed. A promising pathway is the transition towards more sustainable food systems through agroecology, which represents the ecology of food systems. In this paper, the state-of-the-art of agroecology is described for three representative euro-Mediterranean countries: Italy, Greece, and Spain. The analysis has been partly based on results of a dedicated literature search and partly on grey literature and expert knowledge. After an overview of the history of agroecology, targeted research and education, collective action (political and social), and some agroecological practices in the three countries are presented. These countries share a rather similar use of the term “agroecology”, but they differ regarding (i) the existence/extent of strong civil and social movements; (ii) the type of study/educational programmes, and the relative importance of different scientific disciplines and their evolution; (iii) the development of political support and legal frameworks; and (iv) the elaboration of concepts to rediscover traditional practices and apply new ones, often taken from the organic agriculture sector. Agroecology is an emerging concept for the Mediterranean agricultural sector, with huge potential due to the peculiar socio-cultural, bio-physical, and political-economic features of the region. To boost agroecology in Mediterranean Europe, better networking and engagement of different actors within a coherent institutional framework supporting the transition is strongly needed.
Climate change and its detrimental effects on agricultural production, freshwater availability and biodiversity accentuated the need for more stress-tolerant varieties of crops. This requires unraveling the underlying pathways that convey tolerance to abiotic stress in wild relatives of food crops, industrial crops and ornamentals, whose tolerance was not eroded by crop cycles. In this work we try to demonstrate the feasibility of such strategy applying and investigating the effects of saline stress in different species and cultivars of Portulaca. We attempted to unravel the main mechanisms of stress tolerance in this genus and to identify genotypes with higher tolerance, a procedure that could be used as an early detection method for other ornamental and minor crops. To investigate these mechanisms, six-week-old seedlings were subjected to saline stress for 5 weeks with increasing salt concentrations (up to 400 mM NaCl). Several growth parameters and biochemical stress markers were determined in treated and control plants, such as photosynthetic pigments, monovalent ions (Na+, K+ and Cl−), different osmolytes (proline and soluble sugars), oxidative stress markers (malondialdehyde—a by-product of membrane lipid peroxidation—MDA) and non-enzymatic antioxidants (total phenolic compounds and total flavonoids). The applied salt stress inhibited plant growth, degraded photosynthetic pigments, increased concentrations of specific osmolytes in both leaves and roots, but did not induce significant oxidative stress, as demonstrated by only small fluctuations in MDA levels. All Portulaca genotypes analyzed were found to be Na+ and Cl− includers, accumulating high amounts of these ions under saline stress conditions, but P. grandiflora proved to be more salt tolerant, showing only a small reduction under growth stress, an increased flower production and the lowest reduction in K+/Na+ rate in its leaves.
Wild edible plants are an important source of healthy food and have played an important role in traditional Mediterranean diets. In this paper, quality characteristics were typified in Portulaca oleracea L. and Porophyllum ruderale (Jacq.) Cass, undervalued plants inherent to the spring-summer season in the Valencian coastal region. Nutritional composition and bioactive compounds were analyzed and compared between plants in wild and organic cultivation conditions. Proximate analysis was carried out according to Association of Official Analytical Chemists methods. Total antioxidants were measured as 2.2-diphenyl-1-picrylhydrazyl hydrate and total polyphenols content via the Folin–Ciocalteu procedure. The HS-SPME technique was used to characterize the volatiles profile, and the polyphenol profile was evaluated by HPLC. The most important microelement was iron. Total antioxidants ranged from 4392.16 to 7315.00 μmol Trolox·equivalents 100 g−1 fw, and total phenolic content ranged from 99.09 to 391.18 mg gallic acid equivalents·100 g−1 fw. Results show that the content of antioxidants and phenols was higher in wild species than in cultivated ones. The volatiles profile revealed that P. ruderale was rich in monoterpenoids (48.65–55.82%), and fatty alcohols were characteristic in P. oleracea species (16.21–54.18%). The results suggest that both plants could be healthy foods and could have new sustainable agro-ecological potential for the local commercial sector.
The wild species Solanum incanum has been used as a donor parent for the development of a set of eggplant introgression lines (ILs), which are of interest for breeding for stress tolerances and relevant morpho-agronomic traits but could also be useful for breeding for fruit quality, due to the generally higher content in health-promoting compounds of S. incanum. The use of eggplant ILs with introgressions from S. incanum requires ensuring that glycoalkaloids levels are below safety limits. We evaluated 25 fruit composition traits, including proximate composition, sugars, acids, phenolics, glycoalkaloids, and minerals in a set of 16 eggplant ILs with S. incanum, both parents and the F1, grown under two environments (open field and screenhouse). The results demonstrated that the parents were significantly different regarding most fruit composition traits. Large variation was found among the 16 ILs for all traits analyzed and a strong influence of the environment accounted for the variation of 17 out of the 25 traits evaluated. Although the S. incanum parent produced fruits with high levels of glycoalkaloids, the 16 ILs showed mean values of total glycoalkaloids below the currently accepted safety limit for human consumption (200 mg kg−1 fresh weight). Overall, the ILs produced fruits that are safe for consumption, with nutritional and functional quality similar to the recipient parent. Furthermore, six putative QTLs were detected spread over chromosomes 3 for crude protein, 5 for malic and total acids, and 7 for chlorogenic acid and solamargine, and potential candidate genes were spotted for most of them, which provide new relevant information for eggplant breeding.