Phenotypic characterization and quality traits of Greek garlic (Allium sativum L.) germplasm cultivated at two different locations

In the present study, we examined the phenotypic diversity of Greek garlic (Allium sativum L.) genotypes using morphological descriptors derived from IPGRI and UPOV. Thirty-four garlic genotypes were cultivated at two different locations: (a) Velestino, Magnesia, Region of Thessaly, and (b) Kavasila, Ilia, Region of Western Greece. The garlic genotypes were characterized using twenty-seven morphological descriptors and four quantitative characters, namely bulb dry matter, chlorophyll content in the leaf, yield and total soluble solids (°Brix) of plants and raw bulbs. The Shannon–Weaver (H′) phenotypic diversity index varied among the genotypes, although identical mean values (0.79) were recorded for both fields. Traits, such as flowering stem length, bulb skin color, skin color of the clove presented low (H′) values indicating a high coefficient of heritability and less environmental effect. Principal component analysis based on morphological characters showed that the first seven axes could explain 71.49% and 75.86% of total variation for Kavasila and Velestino fields respectively. Significant differences were also observed among the garlic genotypes for the quantitative characters studied. Furthermore, significant statistical correlations were recorded for specific characters between the two cultivation sites e.g. yield with weight of cloves (r = 0.55 and r = 0.62) and number of cloves per bulb with weight of cloves (r = −0.51 and r = −0.55), which could be exploited further in future breeding programs. In conclusion, the high phenotypic diversity observed among the garlic genotypes could be attributed to various factors such as the genotype, the cultivation practices and the environmental conditions. © 2019, Springer Nature B.V

Variability in bulb organosulfur compounds, sugars, phenolics, and pyruvate among greek garlic genotypes: Association with antioxidant properties

In order to assess the diversity of Greek garlic (Allium sativum L.) landraces, 34 genotypes including commercial ones were grown in the same field and their content in organosulfur compounds, pyruvate, total sugars, and total phenolics, alongside antioxidant capacity, was determined. The organosulfur compounds were studied by Gas Chromatography–Mass Spectrometry (GC–MS) after ultrasound‐assisted extraction in ethyl acetate, identifying 2‐vinyl‐4H‐ 1,3‐dithiin and 3‐vinyl‐4H‐1,2‐dithiin as the predominant compounds, albeit in different ratios among genotypes. The bioactivity and the polar metabolites were determined in hydromethanolic extracts. A great variability was revealed, and nearly one‐third of landraces had higher concentration of compounds determining bioactivity and organoleptic traits than the imported ones. We recorded strong correlations between pyruvate and total organosulfur compounds, and between antioxidant capacity and phenolics. In conclusion, chemical characterization revealed great genotype‐dependent variation in the antioxidant properties and the chemical characters, identifying specific landraces with superior traits and nutritional and pharmaceutical value. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Impact of organic practices on growth, yield, and greenhouse gas emissions by pea landraces

Legume crops constitute an essential component of rotations in organic farming systems due to their ability to provide plant available nitrogen to agricultural ecosystems arising from symbiotic N2 fixation. However, there is a general need to increase grain legume protein production in Europe so as to meet the increasing demand while reducing resource utilization, thereby contributing to mitigation of global climate change. Taking this need into consideration, a field-based experiment with pea (Pisum sativum L.) was carried out in a field certified for organic agriculture from November 2014 to June 2015. The experiment was laid out in a split-plot design with two main treatments (conventional and organic farming system) and four subplots per main plot corresponding to four different pea genotypes, particularly one commercial cultivar ('Onward'), and three local landraces ('Amorgos', 'Andros' and 'Schinousa'). Standard inorganic fertilizer (11-15-15, N:P2O5:K2O) and sheep manure were used as base dressings in the conventional and the organically-treated plots, respectively. The aim of the experiment was to test the performance of each pea genotype in organic farming crops as compared to conventional cropping, in terms of: green seed yield, and greenhouse gas (GHG) emissions. The results of this study indicate that 'Andros' increased significantly the above-ground biomass and the fresh green seed production on the harvesting date when compared with all the other genotypes. In addition, there were significant differences in cumulative N2O fluxes between the pea cultivars with 'Schinousa' producing the highest N2O amounts and 'Andros' the lowest. In conclusion, the pea genotype seems to have a strong influence on both GHG emissions and production and therefore, appropriate selection of cultivars is imperative for efficient use of this legume in organic cropping systems

Cereal landraces for sustainable agriculture. A review

Modern agriculture and conventional breeding and the liberal use of high inputs has resulted in the loss of genetic diversity and the stagnation of yields in cereals in less favourable areas. Increasingly landraces are being replaced by modern cultivars which are less resilient to pests, diseases and abiotic stresses and thereby losing a valuable source of germplasm for meeting the future needs of sustainable agriculture in the context of climate change. Where landraces persist there is concern that their potential is not fully realised. Much effort has gone into collecting, organising, studying and analysing landraces recently and we review the current status and potential for their improved deployment and exploitation, and incorporation of their positive qualities into new cultivars or populations for more sustainable agricultural production. In particular their potential as sources of novel disease and abiotic stress resistance genes or combination of genes if deployed appropriately, of phytonutrients accompanied with optimal micronutrient concentrations which can help alleviate aging-related and chronic diseases, and of nutrient use efficiency traits. We discuss the place of landraces in the origin of modern cereal crops and breeding of elite cereal cultivars, the importance of on-farm and ex situ diversity conservation; how modern genotyping approaches can help both conservation and exploitation; the importance of different phenotyping approaches; and whether legal issues associated with landrace marketing and utilisation need addressing. In this review of the current status and prospects for landraces of cereals in the context of sustainable agriculture, the major points are the following: (1) Landraces have very rich and complex ancestry representing variation in response to many diverse stresses and are vast resources for the development of future crops deriving many sustainable traits from their heritage. (2) There are many germplasm collections of landraces of the major cereals worldwide exhibiting much variation in valuable morphological, agronomic and biochemical traits. The germplasm has been characterised to variable degrees and in many different ways including molecular markers which can assist selection. (3) Much of this germplasm is being maintained both in long-term storage and on farm where it continues to evolve, both of which have their merits and problems. There is much concern about loss of variation, identification, description and accessibility of accessions despite international strategies for addressing these issues. (4) Developments in genotyping technologies are making the variation available in landraces ever more accessible. However, high quality, extensive and detailed, relevant and appropriate phenotyping needs to be associated with the genotyping to enable it to be exploited successfully. We also need to understand the complexity of the genetics of these desirable traits in order to develop new germplasm. (5) Nutrient use efficiency is a very important criterion for sustainability. Landrace material offers a potential source for crop improvement although these traits are highly interactive with their environment, particularly developmental stage, soil conditions and other organisms affecting roots and their environment. (6) Landraces are also a potential source of traits for improved nutrition of cereal crops, particularly antioxidants, phenolics in general, carotenoids and tocol in particular. They also have the potential to improve mineral content, particularly iron and zinc, if these traits can be successfully transferred to improved varieties. (7) Landraces have been shown to be valuable sources of resistance to pathogens and there is more to be gained from such sources. There is also potential, largely unrealised, for disease tolerance and resistance or tolerance of pest and various abiotic stresses too including to toxic environments. (8) Single gene traits are generally easily transferred from landrace germplasm to modern cultivars, but most of the desirable traits characteristic of landraces are complex and difficult to express in different genetic backgrounds.Maintaining these characteristics in heterogeneous landraces is also problematic. Breeding, selection and deployment methods appropriate to these objectives should be used rather than those used for high input intensive agriculture plant breeding. (9) Participatory plant breeding and variety selection has proven more successful than the approach used in high input breeding programmes for landrace improvement in stress-prone environments where sustainable approaches are a high priority. Despite being more complex to carry out, it not only delivers improved germplasm, but also aids uptake and communication between farmers, researchers and advisors for the benefit of all. (10) Previous seed trade legislation was designed primarily to protect trade and return royalty income to modern plant breeders with expensive programmes to fund. As the desirability of using landraces becomes more apparent to achieve greater sustainability, legislation changes are being made to facilitate this trade too. However, more changes are needed to promote the exploitation of diversity in landraces and encourage their use