Cannabis sativa L. seeds have been an important source of protein, oil, and dietary fiber for human and animals. Currently, there is a growing interest in the commercial products of these seeds, which are recognized as a legitimate source of medicaments, cosmeceuticals, and nutraceuticals. The objective of this study was to investigate the nutritional, phytochemical composition, and antioxidant properties of seeds from seven hemp cultivars grown in Greece for three consecutive years. All the measured parameters strongly varied under the influence of growing year and genotype. In particular, protein, oil, and carbohydrates’ content of hemp seeds as well as fatty acids’ composition were mainly affected by genotype, whereas the growing year had a major effect on phytochemical components and antioxidant activity, which was determined by the 2,2′-azino-bis (3-ethylbenzthiazoline sulfonate) (ABTS) and ferric-reducing antioxidant power (FRAP) assays. Moreover, a predominant effect of the year was observed for phenolic profiles as determined by high-performance liquid chromatography and total carotenoids’ content. This study suggests that hemp seeds could be a promising food crop as a result of their high nutritive traits and antioxidant potential. A comparison of the studied cultivars, showed that Finola seeds had the highest oil and protein contents and, thus, appeared to be the most promising cultivar for cultivation in Greece.

Farmers’ interest in renewable raw materials such as hemp (Cannabis sativa L.) fibres has recently increased, but hemp productivity is strongly affected by genotype and environment conditions. A 3-year field experiment was conducted under Mediterranean environment in northern Greece to evaluate the productivity (regarding fibres and seeds) of six monoecious hemp varieties. The vars. Futura 75 and Bialobrzeskie provided the greatest (p < 0.01) fibre productivity (4.57 and 4.27 t ha⁻¹, respectively), which were 77.1% and 65.5%, respectively, greater than that of the least productive var. Fedora 17. However, the vars. Santhica 27, Tygra and Bialobrzeskie provided the highest (p < 0.05) seed yield (2.7, 2.9 and 2.6 t ha⁻¹, respectively), which were 28.6%, 38.1% and 23.8%, respectively, greater than that of the least productive var. Futura 75. Hemp fibre yield was strongly positively correlated with total biomass (R² = 0.8612) and stem biomass yield (R² = 0.9742), while it was inversely correlated with fibre strength (R² = 0.424). Hemp seed yield was not correlated with the hemp plant density, height, total biomass or stem biomass yield. The six hemp genotypes evaluated in the study had Δ9-tetrahydrocannabinol (THC) content lower than 0.2% satisfying the European legislation requirements for industrial hemp varieties. The results of the study indicated that, under Mediterranean conditions (northern Greece), the var. Bialobrzeskie showed high productivity, as averaged across years, for both fibres and seeds. This result is very helpful for farmers which should prefer hemp varieties of dual-purpose production (stems and inflorescences or stems and seeds) adapted best to their local environment.

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.

Cucurbita pepo contains two cultivated subspecies, each of which encompasses four fruit-shape morphotypes (cultivar groups). The Pumpkin, Vegetable Marrow, Cocozelle, and Zucchini Groups are of subsp. pepo and the Acorn, Crookneck, Scallop, and Straightneck Groups are of subsp. ovifera. Recently, a de novo assembly of the C. pepo subsp. pepo Zucchini genome was published, providing insights into its evolution. To expand our knowledge of evolutionary processes within C. pepo and to identify variants associated with particular morphotypes, we performed whole-genome resequencing of seven of these eight C. pepo morphotypes. We report for the first time whole-genome resequencing of the four subsp. pepo (Pumpkin, Vegetable Marrow, Cocozelle, green Zucchini, and yellow Zucchini) morphotypes and three of the subsp. ovifera (Acorn, Crookneck, and Scallop) morphotypes. A high-depth resequencing approach was followed, using the BGISEQ-500 platform that enables the identification of rare variants, with an average of 33.5X. Approximately 94.5% of the clean reads were mapped against the reference Zucchini genome. In total, 3,823,977 high confidence single-nucleotide polymorphisms (SNPs) were identified. Within each accession, SNPs varied from 636,918 in green Zucchini to 2,656,513 in Crookneck, and were distributed homogeneously along the chromosomes. Clear differences between subspecies pepo and ovifera in genetic variation and linkage disequilibrium are highlighted. In fact, comparison between subspecies pepo and ovifera indicated 5710 genes (22.5%) with Fst > 0.80 and 1059 genes (4.1%) with Fst = 1.00 as potential candidate genes that were fixed during the independent evolution and domestication of the two subspecies. Linkage disequilibrium was greater in subsp. ovifera than in subsp. pepo, perhaps reflective of the earlier differentiation of morphotypes within subsp. ovifera. Some morphotype-specific genes have been localized. Our results offer new clues that may provide an improved understanding of the underlying genomic regions involved in the independent evolution and domestication of the two subspecies. Comparisons among SNPs unique to particular subspecies or morphotypes may provide candidate genes responsible for traits of high economic importance.

Cotton is the most important textile plant in the world and is one of the most important crops for the production of oilseed. Because of its worldwide economic importance, new cultivars are constantly being released in the world and consequently in the Greek market, as Greece is the largest producer in Europe. We used simple sequence repeat (SSR) markers for the identification and the phylogenetic analysis of the most widely cultivated cotton cultivars in Greece. Initially, we used 12 pairs of SSR molecular markers for the analysis of 29 cultivars of Gossypium hirsutum and an interspecific hybrid (G. hirsutum x G. barbadense). Of the 12 pairs of SSR primers, 11 amplified polymorphic products, while one pair did not amplify any product. Globally, 17 polymorphic marker loci were identified. Two to four different alleles were amplified at each genomic locus, with a mean of 2.53 alleles per locus. Among the 30 genotypes that we analyzed, the polymorphism information content ranged from 0 to 0.548, with a mean of 0.293. Three main groups were formed among the 30 genotypes when a phylogenetic analysis was performed using UPGMA. Computational analysis of each molecular marker separately showed an association of SSR markers with agronomic traits such as fiber quality. To our knowledge, this is the first in-depth molecular analysis of cotton cultivars grown in Greece using SSR markers. An analysis of association of SSR markers with fiber quality traits of 29 cotton cultivars is reported for the first time.