Parthenopi Ralli

Climate change poses a significant threat to agricultural productivity, particularly in low-input systems where resilient cultivars are crucial. Traditional pepper (Capsicum annuum L.) landraces represent a valuable genetic reservoir for adaptation, yet their agronomic and nutritional potential remains underexplored. In this study, twenty-five Greek pepper landraces and commercial varieties were comprehensively evaluated for morphological traits, early and total yield characteristics, and key fruit quality parameters. The results revealed substantial phenotypic diversity in both vegetative and reproductive traits, as well as considerable variation in fruit nutritional composition across the tested genotypes. Notably, ‘Skopos’, ‘Mesoropi’, and ‘Lygaria’ demonstrated superior yield performance, while ‘Pogoniou’, ‘Lyra’, and ‘Kantanou’ excelled in several nutritional quality traits, including high phenolic content, vitamin C, and antioxidant capacity. Heatmap analysis further identified ‘Pogoniou’, ‘Filuria’, ‘Lyra’, ‘Lagada’, and ‘Lygaria’ as consistently ranking among the top performers across yield and quality traits. These findings highlight the dual agronomic and nutritional value of traditional pepper landraces, underscoring their importance as a genetic resource for breeding programs. Overall, the study highlights the importance of conserving and utilizing local pepper germplasm as a sustainable approach to improve productivity, nutritional quality, and resilience in the face of climate change and low-input cultivation systems.

The effect of the corm size of saffron (Crocus sativus L.) and the planting density was determined on a field study for six years. The objective of the present study was to determine the impact of the corm size and planting density on flower and stigma yields. Two corm sizes were used: corms with a diameter up to 2.5 cm and corms with a diameter greater than 2.5 cm, and five planting density: 22, 27, 33, 44 and 67 corms/m² with planting distances 30, 25, 20, 15 and 10 cm on the plant row, respectively. The results showed that the year (growing season) and the interaction of year (growing season) with corm size affected all the characteristics that were studied. Over the six-year study period, there was a gradual increase in flowering from the first to the third year, followed by a decline in the fifth and sixth years. The yield of larger corms (greater than 2.5 cm) was higher during the first three years, while smaller corms (less than 2.5 cm) produced higher yields in the fourth through sixth years. On the contrary, the planting density, did not significantly affect the characteristics studied over the six years of cultivation and therefore did not affect the stigma yield of saffron. Therefore, corm size together with the environment are important factors that can affect the productivity and the longevity of the crop and should be considered when planting a new saffron cultivation.

Crop landraces are genetically variable populations of agricultural plant species that through natural evolution and farmers’ selection and continuous cultivation have been adapted to the environment of their origin or cultivation. To be used and officially traded, there are more lax or strict registration schemes throughout the world concerning the application of distinctiveness, uniformity, stability (DUS) system. This review discusses the legislative framework of various countries worldwide and evaluates its application efficiency with a detailed focus on European Union (EU) experience. Especially in EU, landraces must be registered as conservation varieties in the European Catalogue of Varieties. A total of 313 agricultural and 173 vegetable conservation varieties were registered in the European Catalogues from 2013 to 2021. However, it is not clear how many of these registries are landraces because obsolete varieties are also included under the term conservation varieties. Moreover, our review reports the importance of landraces for the FAO (Food and Agriculture Organization of the United Nations) and EU strategies, namely ‘Farm to Fork’ and ‘Biodiversity’. Additionally, the DUS criteria were evaluated for their use when a crop landrace is registered taking into consideration the genetic structure of a landrace. Furthermore, the connection of landraces with Farmers’ Rights, their appropriateness for organic agriculture, and trade issues are discussed. Finally, the new proposal of European Commission on Plant Reproductive Material concerning landraces is critically reviewed and improvements are suggested.

The Balkan Botanic Garden of Kroussia is one of the youngest botanic gardens in Europe and includes at least 1,072 endemic and native species of the Balkan flora. The protection of plant species is a primary goal of the garden. Most plant collections have been carried out as part of funded plant conservation programs. Endangered/almost endangered species, local endemic species in the Balkans, and rare species were collected and rescued. Within the framework of the research programs, the cultivation conditions of mainly plant species with aromatic-pharmaceutical-cosmetic or even floricultural uses were studied both in research applications and in pilot fields. Furthermore, some of the research projects implemented by the garden concern the exploitation of plant ingredients derived from aromatic and medicinal plants from the cosmetics industry. The study of traditional local varieties and small fruits is also one of the research projects of the garden, and it is important that these species are collected, identified, evaluated, and utilized on a pilot basis. Some of these varieties belong to different species of the genera Pyrus, Prunus, Malus, Cydonia, Juglans, Ficus, Eriobotrya, and Punica. Thus, it has created a cluster for the utilization of Greek biodiversity and phytogenetic resources with emphasis on aromatic/medicinal plants and traditional varieties. The Greek Gene Bank aims to collect, conserve, and regenerate Greek local species. It maintains in ex situ conservation more than 15,000 plant samples that are important for agriculture and food.

Eggplant is an economically important vegetable with a potential for functional food production, mainly due to its high fruit antioxidant capacity. The goal of the present study was to investigate the main physicochemical and antioxidant parameters, and assess the bioactive profiles, of 19 eggplant genotypes of diverse origin, including Greek commercial varieties and hybrids, landraces and the related species S. macrocarpon. For that reason, the physicochemical traits (dry matter, pH, total soluble solids and total acidity) were assessed in the eggplant fruit and some important bioactive compounds (total phenols (TPC), total flavonoids (TFC), total monomeric anthocyanin (TAC), chlorogenic acid (CA) and its isomers neo- and crypto-CA) were assessed both in fruit pulp and peel. In addition, the antioxidant capacity was assessed according to ABTS^•+, DPPH^• and FRAP assays. The results revealed significant differences between the studied genotypes for all the evaluated traits, for both fruit parts. Solanum macrocarpon showed a distinct bioactive profile and was superior for most of the pulp traits (TFC, neo-CA, crypto-CA, ABTS^•+, DPPH^• and FRAP). Among the eggplant materials, the landrace ‘KD054/07’ had very high values for pH and some pulp traits (TPC, CA, ABTS^•+ and FRAP), while the commercial F₁ hybrid ‘Nilo’ was superior for dry matter and most of the peel traits (TPC, TFC, ABTS^•+ and FRAP). The Greek commercial variety ‘Langada’ performed well for TAC and peel CA, ABTS^•+ and FRAP, while ‘Tsakoniki’ had very high anthocyanin and pulp TPC content. These results constitute a source of information for a subset of the Greek eggplant germplasm and could contribute both to the promotion of Greek varieties of high bioactive and antioxidant value, as well as to the targeted selection of parents in breeding programs.

This study investigates the effect of different nitrogen fertilization levels on the agronomic traits of five Greek oregano populations. Nitrogen supply positively affected dry bio-mass production, with the highest accumulation recorded at 80 kg N ha⁻¹ (N2), which was 59% higher compared to the control plots (no additional nitrogen). In contrast, the essential oil content (mL 100 g⁻¹ DW) was reduced, with the control treatment showing a 15% higher value compared to the mean value of the nitrogen treatments. However, nitrogen supply positively affected the essential oil yield (L ha⁻¹), and the highest value was recorded at 80 kg N ha⁻¹, (N2), showing a 40% increase compared to the control. A wide phenotypic variation among the five populations was also observed. In the three-year analysis, the population with the highest dry biomass production was Papadates (92% higher), that with the highest essential oil content was Vytina (25% higher), and the highest essential oil yield was observed for Papadates and Litochoro (57% and 51% higher, respectively), compared to the least yielding population. Significant interactions were also found between nitrogen levels and populations, implying that, in all cases, nitrogen levels should be specified for each population in order to optimize oregano productivity in sustainable farming systems.

Modern intensive agricultural systems generally focus on the productivity of monocultures. They are characterized by a low diversity of crops, with uniform and symmetrical planting layouts. They largely rely on the utilization of chemical inputs. They are widely denounced for their negative environmental impacts. In this context, the ecological intensification framework proposes the exploitation of biodiversity in order to better achieve such ecosystem services and soil conservation. Intercropping, i.e., the simultaneous growth of two or more crops mixed in the same field, appears to have the potentialities to improve the productivity, resilience capacity, and ecological sustainability of agroecosystems through the intensification of such positive interactions between plants as facilitation and niche complementarity. Cereal–legume intercropping turns out to be effective in low-N agroecosystems, since legumes have the ability to fix atmospheric nitrogen via their symbiosis with rhizobia. This fixed N, in turn, benefits the cereal through various ecological processes. The objective of the project is to improve the benefit of legumes for intercropped cereals in low-input agroecosystems through the management of plant–plant and plant–microbe interactions. The nitrogen-fixing symbiosis requires phosphorus and iron to be efficient. While these nutrients are prone to be lacking in N-limited agroecosystems, as is the case in Mediterranean agroecosystems, plant–plant interactions and rhizobacteria and mycorrhiza interactions seem to play an important role in their acquisition and efficient utilization. We propose the development of a participatory research project in four Mediterranean agroecosystems. Agronomic and environmental diagnosis will be performed in the field to assess N and P biogeochemical cycles, as well as Fe availability, in combination with the plant performances and the diversity of soil microorganisms. Molecular identification of soil microorganisms from the most productive sites will be done and research of genes for tolerance to Fe- and P-deficiencies will be realized. Glasshouse experiments involving various cultivars of cereals and legumes, as well as the previously identified microorganisms, will be done in order to disentangle the various mechanisms of nutrient acquisition, sharing, and transfer between plants. Other experiments will assess the effects of cereal–legume–microbe interactions on the development and architecture of the plant root systems and root hair development. The lines of research are integrated with a strategy of functional ecology on plant–microbe–soil interactions in the agroecosystems of Gabès (Tunisia), Boumedfaa (Algeria), Beni Mellal (Morocco), and Thessaloniki (Greece). Using multidisciplinary and innovative approaches, the program will provide novel knowledge and understanding of agroecosystem management for food production.

Sideritis scardica Giseb. is a subalpine/alpine plant species endemic to the central part of the Balkan Peninsula. In this study, we combined Amplified Fragment Length Polymorphism (AFLP) and environmental data to examine the adaptive genetic variations in S. scardica natural populations sampled in contrasting environments. A total of 226 AFLP loci were genotyped in 166 individuals from nine populations. The results demonstrated low gene diversity, ranging from 0.095 to 0.133 and significant genetic differentiation ranging from 0.115 to 0.408. Seven genetic clusters were revealed by Bayesian clustering methods as well as by Discriminant Analysis of Principal Components and each population formed its respective cluster. The exception were populations P02 Mt. Shara and P07 Mt. Vermio, that were admixed between two clusters. Both landscape genetic methods Mcheza and BayeScan identified a total of seven (3.10%) markers exhibiting higher levels of genetic differentiation among populations. The spatial analysis method Samβada detected 50 individual markers (22.12%) associated with bioclimatic variables, among them seven were identified by both Mcheza and BayeScan as being under directional selection. Four bioclimatic variables associated with five out of seven outliers were related to precipitation, suggesting that this variable is the key factor affecting the adaptive variation of S. scardica.

In this study, we evaluated crop productivity and physiology during the hydroponic cultivation of medium-sized and cherry tomato crops, using two experimental greenhouses. Of the greenhouses, one used dye-sensitized solar cell (DSSC) technology for covering material, whilst the other, a conventional one (CONV), was covered using diffusion glass as a control. The effect of the colored lighting that resulted from the DSSC glass filtering on the physiological response of the crops was examined by measuring the plant transpiration rate and leaf chlorophyll content. Furthermore, we evaluated potential differences in the concentration of phytochemical compounds, such as ascorbic acid, lycopene, and quality characteristics. Tomato plants in the DSSC greenhouse presented lower early and total yields, as well as lower chlorophyll content, stomatal conductance, photosynthetic rate, and transpiration rate values, especially in the medium-sized fruits, as compared to the CONV greenhouse. The DSSC greenhouse showed significantly higher values of bioactive compounds for both the cherry and medium-sized tomato, with increases in the ascorbic acid, lycopene, β-carotene, and total carotenoids concentration, which ranged from 6% to 26%. Finally, for both the hybrids, the 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) tests showed circa 10% and 5% increase, respectively, in the DSSC greenhouse.