Wheat Landraces Are Better Qualified as Potential Gene Pools at Ultraspaced rather than Densely Grown Conditions

The negative relationship between the yield potential of a genotype and its competitive ability may constitute an obstacle to recognize outstanding genotypes within heterogeneous populations. This issue was investigated by growing six heterogeneous wheat landraces along with a pure-line commercial cultivar under both dense and widely spaced conditions. The performance of two landraces showed a perfect match to the above relationship. Although they lagged behind the cultivar by 64 and 38% at the dense stand, the reverse was true with spaced plants where they succeeded in out-yielding the cultivar by 58 and 73%, respectively. It was concluded that dense stand might undervalue a landrace as potential gene pool in order to apply single-plant selection targeting pure-line cultivars, attributable to inability of plants representing high yielding genotypes to exhibit their capacity due to competitive disadvantage. On the other side, the yield expression of individuals is optimized when density is low enough to preclude interplant competition. Therefore, the latter condition appears ideal to identify the most promising landrace for breeding and subsequently recognize the individuals representing the most outstanding genotypes

Phenotypic diversity of Greek dill (Anethum graveolens L.) landraces

Dill has multiple culinary and medicinal purposes and the use of their landraces into a plant breeding program, requires the analysis of their phenotypic diversity. In this study, 33 Greek dill landraces collected from diverse areas were evaluated using traits based on UPOV descriptor list. Phenotypic diversity was assessed using Shannon-Weaver diversity index (H΄) and non-linear principal component analysis. Grouping of landraces was further performed through hierarchical cluster analysis. The H' index ranged from 0.32 (stem waxiness) to 0.98 (density of foliage) with a mean value of 0.68 indicating a high level of phenotypic diversity. High H' values were recorded for the foliage width, stem color and anthocyanin coloration. Multivariate analysis revealed three common genetic groups: 1) North mainland Greece, 2) Aegean islands and 3) Central mainland Greece. The landraces’ heterogeneity was attributed to various traits linked to specific geographic origin, such as early time of flowering and high stem waxiness allied with the landraces originated from the Aegean islands. Greek dill landraces revealed useful variation on yield component traits related to fresh herb weight and to seed production, such as high number of leaves/plant and large diameter of main umbel that can be promptly exploited in breeding programs

CROSYMED Project: Enhancing Nutrient Use Efficiency through Legumes in Agroecosystems of the Mediterranean Basin

International audienceModern 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 Gabes (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

Assessing Physicochemical Parameters, Bioactive Profile and Antioxidant Status of Different Fruit Parts of Greek Eggplant Germplasm

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

Assessing Physicochemical Parameters, Bioactive Profile and Antioxidant Status of Different Fruit Parts of Greek Eggplant Germplasm

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

Performance and Hydroponic Tomato Crop Quality Characteristics in a Novel Greenhouse Using Dye-Sensitized Solar Cell Technology for Covering Material

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

Nitrogen Effects on the Essential Oil and Biomass Production of Field Grown Greek Oregano (Origanum vulgare subsp. hirtum) Populations

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

Morphological and molecular characterisation of Longidorus pauli (Nematoda: Longidoridae), first report from Greece

Sampling for needle nematodes was carried out in a grapevine area in Thessaloniki, North Greece and two nematode species of Longidorus (L. pauli and L. pisi) were collected. Nematodes were extracted from 500 cm3 of soil by modified sieving and decanting method, processed to glycerol and mounted on permanent slides, and subsequently identified morphologically and molecularly. Nematode DNA was extracted from single individuals and PCR assays were conducted to amplify D2-D3 expansion segments of 28S rRNA, ITS1 rRNA, and partial mitochondrial coxI regions. Morphology and morphometry data obtained from these populations were consistent with L. pauli and L. pisi identifications. To our knowledge, this is the first report of L. pauli for Greece, and the second world report after the original description from Idleb, Syria, extending the geographical distribution of this species in the Mediterranean Basin.Spanish authors acknowledge grant 201740E042, ‘Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos’ from Spanish National Research Council (CSIC)