Project description:Cultivation of hemp (Cannabis sativa L.) in tropical and subtropical regions can be challenging if the flowering behavior of a given cultivar is unknown, poorly understood, or not accurately selected for the photoperiod. Identifying cultivars adapted to local environmental conditions is key to optimizing hemp vegetative and flowering performance. We investigated the effects of varying light cycles in regulating extension growth and flowering response of 15 essential oil and 12 fiber/grain hemp cultivars both indoors and outdoors. Plants were subjected to 11 photoperiods in the controlled rooms ranging from 12 to 18 h, and natural day length in the field. The critical photoperiod threshold was identified for seven essential oil cultivars and two fiber/grain cultivars. "Cherry Wine-CC," "PUMA-3," and "PUMA-4" had the shortest critical day length between 13 h 45 min and 14 h. The flowering of essential oil cultivars was generally delayed by 1-2 days when the photoperiod exceeded 13 h compared with 12 h, and flowering was further delayed by 7-8 days when the photoperiod exceeded 14 h. In fiber/grain cultivars, flowering was generally delayed by 1-3 days when the day length exceeded 14 h. Flowering for most essential oil cultivars was delayed by 5-13 days under a 14-h photoperiod compared with 13 h 45 min, suggesting a photoperiod difference as little as 15 min can significantly influence the floral initiation of some essential oil cultivars. Cultivars represented by the same name but acquired from different sources can perform differently under the same environmental conditions, suggesting genetic variation among cultivars with the same name. Average days to flower of fiber/grain cultivars was correlated with reported cultivar origin, with faster flowering occurring among northern cultivars when compared with southern cultivars. Plant height generally increased as the day length increased in essential oil cultivars but was not affected in fiber/grain cultivars. In addition, civil twilight of ~2 μmol·m-2·s-1 was discovered to be biologically effective in regulating hemp flowering. Collectively, we conclude that most of the essential oil cultivars and some southern fiber/grain cultivars tested express suitable photoperiods for tropical and sub-tropical region cultivation.
Project description:In this study a largely available lignocellulose feedstock hemp (Cannabis sativa), obtained as an industrial waste, was used for cellulose extraction. The extraction of cellulose microfibres from hemp biomass was conducted by alkaline treatment and an acidification process. The extracted cellulose microfibres were characterised using Fourier-transformed infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The viability of the study was determined by growing human fibroblasts on the preparation which resulted in being non-toxic; indicating its potential in preparing biological scaffolds. Upon enzymatic hydrolysis of the cellulose microfibre using cellulase from Trichoderma reesei, a maximum of 909 mg/g of reducing sugars were obtained, which endorses its suitability for biofuel production.
Project description:Flowers of hemp (Cannabis sativa L.) are widely used in cosmetics, food, and in the pharmaceutical industry. The drying process plays a key role in retention of aroma and also in the quality of products. Seven variants of hemp flower drying, including convection drying (CD), vacuum-microwave drying (VMD), and combined drying consisting of convective pre-drying followed by vacuum-microwave finishing drying (CPD-VMFD) were checked in this study. For each process, we applied the two-term model. Dried material was submitted to color and chromatographical assessments. Analyses of obtained essential oil showed the presence of 93 volatile compounds, predominantly β-myrcene, limonene, and β-(E)-caryophyllene, as well as α-humulene. Application of 240 W during VMD and 50 °C during CD gave the highest retention of aroma compounds, amounting to 85 and 76%, respectively, but with huge color changes. Additionally, sensory analysis proved that drying with a microwave power of 240 W provides a product most similar to fresh material.
Project description:Cannabis sativa is a multi-use and chemically complex plant which is utilized for food, fiber, and medicine. Plants produce a class of psychoactive and medicinally important specialized metabolites referred to as phytocannabinoids (PCs). The phytohormone methyl jasmonate (MeJA) is a naturally occurring methyl ester of jasmonic acid and a product of oxylipin biosynthesis which initiates and regulates the biosynthesis of a broad range of specialized metabolites across a number of diverse plant lineages. While the effects of exogenous MeJA application on PC production has been reported, treatments have been constrained to a narrow molar range and to the targeted analysis of a small number of compounds. Using high-resolution mass spectrometry with data-dependent acquisition, we examined the global metabolomic effects of MeJA in C. sativa to explore oxylipin-mediated regulation of PC biosynthesis and accumulation. A dose-response relationship was observed, with an almost two-fold increase in PC content found in inflorescences of female clones treated with 15 mM MeJA compared to the control group. Comparison of the inflorescence metabolome across MeJA treatments coupled with targeted transcript analysis was used to elucidate key regulatory components contributing to PC production and metabolism more broadly. Revealing these biological signatures improves our understanding of the role of the oxylipin pathway in C. sativa and provides putative molecular targets for the metabolic engineering and optimization of chemical phenotype for medicinal and industrial end-uses.
Project description:Hemp (Cannabis sativa L.) is a bast-fiber crop with a great potential in the emerging bio-based economy. Yet, hemp breeding for fiber quality is restricted and that is mainly due to the limited knowledge of the genetic architecture of its fiber quality. A panel of 123 hemp accessions, with large phenotypic variability, was used to study the genetic basis of seven cell wall and bast fiber traits relevant to fiber quality. These traits showed large genetic variance components and high values of broad sense heritability in this hemp panel, as concluded from the phenotypic evaluation across three test locations with contrasting environments. The hemp panel was genotyped using restriction site associated DNA sequencing (RAD-seq). Subsequently, a large set (> 600,000) of selected genome-wide single nucleotide polymorphism (SNP) markers was used for a genome-wide association study (GWAS) approach to get insights into quantitative trait loci (QTLs) controlling fiber quality traits. In absence of a complete hemp genome sequence, identification of QTLs was based on the following characteristics: (i) association level to traits, (ii) fraction of explained trait variance, (iii) collinearity between QTLs, and (iv) detection across different environments. Using this approach, 16 QTLs were identified across locations for different fiber quality traits, including contents of glucose, glucuronic acid, mannose, xylose, lignin, and bast fiber content. Among them, six were found across the three environments. The genetic markers composing the QTLs that are common across locations are valuable tools to develop novel genotypes of hemp with improved fiber quality. Underneath the QTLs, 12 candidate genes were identified which are likely to be involved in the biosynthesis and modification of monosaccharides, polysaccharides, and lignin. These candidate genes were suggested to play an important role in determining fiber quality in hemp. This study provides new insights into the genetic architecture of fiber traits, identifies QTLs and candidate genes that form the basis for molecular breeding for high fiber quality hemp cultivars.
Project description:The growing demands for sustainable fibers have stimulated the study of genetic diversity in the quality of hemp fiber (Cannabis sativa L.). Nevertheless, the lack of high-throughput phenotyping methods that are suited for the analysis of hemp fiber, hampers the analysis of many accessions, and consequently the breeding for this complex trait. In the present report, we developed and optimized the throughput of five methods to study the diversity in hemp fiber quality including cell wall extraction, biochemical composition of cell wall polysaccharides, quantification of lignin, quantification of crystalline polysaccharides and morphology of the stems. Six hemp accessions contrasting for cell wall properties were used to assess the throughput and suitability of these methods for genetic studies. The methods presented revealed to be highly repeatable, with low coefficients of variation between technical replicates. With these methods we were able to detect significant phenotypic variation in cell wall composition and stem morphology between the six accessions. In addition, the throughput of the methods has been upgraded to a level that enables their use for phenotyping cell wall traits in breeding programs. The cell wall extraction was optimized to extract enough material for the complete characterization of the cell wall of hemp while reducing the time for the entire analysis. The throughput of the stem morphological analysis was improved by decreasing the timing of fixation, infiltration, and embedding of mature and dry hemp stems. Notwithstanding, our methods already have the potential to phenotype large number of accessions in a relatively short period of time. Our methods will enable exploration of genetic diversity of fiber quality and will contribute to the development of new hemp varieties with advanced quality of fibers.
Project description:Drought stress is the main environmental factor influencing hemp growth and yield. However, little is known about the response mechanism of hemp to drought stress. A total of 44.10 M tags and 8.91G bases were sequenced in the control hemp (CK) and drought stress hemp (DS) libraries. A total of 1292 differentially expressed genes (DEGs), including 883 up-regulated genes and 409 down-regulated genes, were identified. These results may contribute toward improving our understanding about the drought stress regulatory mechanism of hemp, and improving its drought tolerance ability.
Project description:Hemp seed (Cannabis sativa L.) contain large amounts of nutrients, e.g. protein, dietary fiber, minerals, and unsaturated fatty acids, which make them a good fortifying component in food production. The aim of the present study was to determine the effect of hemp addition on the physicochemical properties, cooking quality, texture parameters and sensory properties of durum wheat pasta. The samples were fortified with 5-40% of commercially available hemp flour or 2.5-10% of hemp cake obtained from hemp seed oil pressing. Our study showed that the addition of hemp seed raw materials led to an increase in the protein, total dietary fiber (TDF), ash and fat content in the pasta samples. Due to its lower granulation and higher nutritional value, hemp flour was found to be a better raw material for the fortification of pasta than hemp cake. Pasta enriched with hemp flour at the level of 30-40% contains 19.53-28.87% d.m. of protein and 17.02-21.49% d.m. of TDF and according to the EU, a definition can be described as a high-protein and high-fiber products. All enriched pasta samples were also characterized by safe Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) content, and their sensory properties were accepted by consumers.
Project description:To support the rapidly expanding industrial hemp industry, a commercial supply of high-quality starter plants with low genetic variability from nurseries will be key to consistent and efficient cultivation efforts. Rooting success was evaluated across four propagation medias, five rooting hormones, and eight commercially available high-cannabidiol (CBD) essential oil hemp cultivars. Cuttings were placed in a climate-controlled room and assessed for rooting success 12 days after cloning. Rooting success was determined by quantifying total root number, cumulative total root length, and total root mass. Propagation media had the greatest effect on rooting success (13-80%). Rockwool had the highest rooting success resulting in 10-fold increases in rooting traits over the next highest scoring medium (Berger BM6). Hormone applications significantly improved (15- to 18-fold) rooting success compared to no hormone application, while non-statistical differences were observed across auxin hormone concentrations and application methods. Genetic variation in rooting response was observed between cultivars with 'Cherry Wine' outperforming all other cultivars with an approximate 20% increase in rooting success over the next highest rooting cultivar, 'Wife'. Although the ideal combination was not specifically identified in this study, findings provide insight into how rooting hormone application and medium selection impact vegetative propagule rooting success of essential oil hemp.
Project description:Drought stress is the main environmental factor influencing hemp growth and yield. However, little is known about the response mechanism of hemp to drought stress. A total of 44.10 M tags and 8.91G bases were sequenced in the control hemp (CK) and drought stress hemp (DS) libraries. A total of 1292 differentially expressed genes (DEGs), including 883 up-regulated genes and 409 down-regulated genes, were identified. These results may contribute toward improving our understanding about the drought stress regulatory mechanism of hemp, and improving its drought tolerance ability. 3' tag-based DGE libraries were generated to exam the differentially expressed gene between drought-stressed and well-watered hemp