On the Path towards a "Greener" EU: A Mini Review on Flax (Linum usitatissimum L.) as a Case Study

Variation in Linseed Oil Composition: Impact of Cultivar, Cultivation System, and Year of Cultivation

Linseed oil quality depends on cultivar and agriculture practice/conditions. In this study, we analyzed the effect of the main variable, which was continuous cropping system vs. crop rotation system. The aim of this study was to compare the oil content and composition (fatty acid composition and sterol, tocochromanol, carotenoid, and phenolic contents) of two fiber-type linseed cultivars (Modran and Nike). All measurements were performed according to standard chromatographic/spectrophotometric procedures typical for oil analysis. The factors that affected the crop yield and oil quality of the tested cultivars included the cultivation system (crop rotation or continuous cropping), plant protection level (herbicide application or no herbicide application), and year of cultivation (2018 and 2019). The cultivars exhibited high oil content (35.4-42.7%) with substantial omega-3 fatty acid (α-linolenic acid) content (53.6-62.2% of total fatty acids). The primary bioactive components in all the oils were sterols (dominated by β-sitosterol), with their content reaching 5079 mg/kg, and tocochromanols, with their content reaching 679 mg/kg (dominated by γ-tocopherol), which was influenced by all of the studied factors. In contrast, carotenoids and phenolic compounds constituted a smaller fraction of the oils (up to 17 and 159 mg/kg, respectively), but their content was the most variable and was strongly dependent on the cultivation year and cultivation system (CV 21 and 37%, respectively). In summary, the results of the current study showed that continuous linseed cropping resulted in increased levels of carotenoids, phenolic compounds, and γ-tocopherol in oil. Our findings indicated that the oil content was mostly affected by the cultivar and cultivation year, while the α-linolenic acid content in the oil was also affected by plant protection practices. These findings may be helpful in predicting the composition of obtained linseed oil and applying proper cultivation technology, depending on the purpose of oil usage.

Utilizing Flaxseed as an Antimicrobial Alternative in Chickens: Integrative Review for Salmonella enterica and Eimeria

This review provides an integrative framework for understanding flaxseed (Linum utassitissimum) as an antimicrobial alternative for poultry production. We begin by familiarizing the reader with the global legislation of antibiotics in animal husbandry; highlighting gaps and current issues for Salmonella enterica (S. enterica) and Eimeria (coccidiosis-inducing). We then discuss the natural, symbiotic characteristics of the Galliformes order (chicken-like birds) and Linum (the flaxes). The key immunological themes in this review include: (i) flaxseed's regulation of innate and adaptive immunity in chickens, (ii) flaxseed's ability to accelerate chicken recovery from infection with S. enterica and Eimeria, and (iii) flaxseed's strengthening of immunity via vitamin B6 antagonism. Research indicates that whole flaxseed increases adaptive immune capacity by augmenting cecal Bacteroides and short-chain fatty acids while also attenuating the heterophil to lymphocyte ratio in chickens. Moreover, flaxseed accelerates chicken recovery from infection with Salmonella Enteritidis or Eimeria tenella; however, future work is needed to better understand (i) defatted flaxseed's superior performance against Eimeria species and (ii) Eimeria maxima's resilience against whole flaxseed. In the context of vitamin B6 antagonism, we propose that 15% whole flaxseed overcomes S. enterica's insult to estrogen synthesis by sustaining the activity of phosphatidylethanolamine methyltransferase (PEMT) in liver. We also propose that 10% defatted flaxseed (as a metformin homologue) strengthens chicken immunity by safeguarding gonadal physiology and by increasing plasma thymidine bioavailability. The concepts in this review can be used as a template for conducting advanced immunological studies in poultry science.

Local climate and vernalization sensitivity predict the latitudinal patterns of flowering onset in the crop wild relative Linum bienne Mill

BACKGROUND AND AIMS

The timing of flowering onset is often correlated with latitude, indicative of climatic gradients. Flowering onset in temperate species commonly requires exposure to cold temperatures, known as vernalization. Hence, population differentiation of flowering onset with latitude might reflect adaptation to the local climatic conditions experienced by populations.

METHODS

Within its western range, seeds from Linum bienne populations (the wild relative of cultivated Linum usitatissimum) were used to describe the latitudinal differentiation of flowering onset to determine its association with the local climate of the population. A vernalization experiment including different crop cultivars was used to determine how vernalization accelerates flowering onset, in addition to the vernalization sensitivity response among populations and cultivars. Additionally, genetic differentiation of L. bienne populations along the latitudinal range was scrutinized using microsatellite markers.

KEY RESULTS

Flowering onset varied with latitude of origin, with southern populations flowering earlier than their northern counterparts. Vernalization reduced the number of days to flowering onset, but vernalization sensitivity was greater in northern populations compared with southern ones. Conversely, vernalization delayed flowering onset in the crop, exhibiting less variation in sensitivity. In L. bienne, both flowering onset and vernalization sensitivity were better predicted by the local climate of the population than by latitude itself. Microsatellite data unveiled genetic differentiation of populations, forming two groups geographically partitioned along latitude.

CONCLUSIONS

The consistent finding of latitudinal variation across experiments suggests that both flowering onset and vernalization sensitivity in L. bienne populations are under genetic regulation and might depend on climatic cues at the place of origin. The association with climatic gradients along latitude suggests that the climate experienced locally drives population differentiation of the flowering onset and vernalization sensitivity patterns. The genetic population structure suggests that past population history could have influenced the flowering initiation patterns detected, which deserves further work.

Phytoremediation Potential of Flax Grown on Multimetal Contaminated Soils: A Field Experiment

The aim of this study was to assess the phytoremediation potential of fiber flax (Linum usitatissimatum L., var. Calista) cultivated in a soil contaminated with multiple metals, under real field conditions. A two-year (2022 and 2023) field experiment was conducted in a site contaminated with elevated concentrations of Cd, Ni, Cu, Pb, and Zn due to mining and metallurgical activities. Three different nitrogen fertilization levels were tested (N0: 0 kg N ha-1, N1: 30 kg N ha-1, N2: 60 kg N ha-1), and both spring and winter sowings were conducted. At full maturity, growth parameters and yields were measured. The phytoremediation potential of flax was assessed in terms of the metal concentrations in the above-ground biomass and of the metal uptake (i.e., the potential removal of the soil metals in g ha-1 and per year). Flax demonstrated a shorter growth cycle, with shorter and thicker plants and higher yields when sown in spring compared to winter sowing. Plant growth and productivity were not evidently influenced by additional nitrogen fertilization during plant growth. The cadmium bioaccumulation factor was 1.06, indicating that flax accumulates this metal. For Ni, Cu, Pb, and Zn, the corresponding values were 0.0, 0.04, 0.004, and 0.02, suggesting that this crop excludes these metals. The order of the higher uptake in plant tissues was as follows: Zn > Pb > Cd > Cu > Ni. In conclusion, flax demonstrated tolerance to heavy metals in the soil, effectively supporting soil restoration through cultivation. Additionally, flax showed potential as a cadmium accumulator while excluding nickel, copper, lead, and zinc.

Molecular Advances to Combat Different Biotic and Abiotic Stresses in Linseed (Linum usitatissimum L.): A Comprehensive Review

Flax, or linseed, is considered a "superfood", which means that it is a food with diverse health benefits and potentially useful bioactive ingredients. It is a multi-purpose crop that is prized for its seed oil, fibre, nutraceutical, and probiotic qualities. It is suited to various habitats and agro-ecological conditions. Numerous abiotic and biotic stressors that can either have a direct or indirect impact on plant health are experienced by flax plants as a result of changing environmental circumstances. Research on the impact of various stresses and their possible ameliorators is prompted by such expectations. By inducing the loss of specific alleles and using a limited number of selected varieties, modern breeding techniques have decreased the overall genetic variability required for climate-smart agriculture. However, gene banks have well-managed collectionns of landraces, wild linseed accessions, and auxiliary Linum species that serve as an important source of novel alleles. In the past, flax-breeding techniques were prioritised, preserving high yield with other essential traits. Applications of molecular markers in modern breeding have made it easy to identify quantitative trait loci (QTLs) for various agronomic characteristics. The genetic diversity of linseed species and the evaluation of their tolerance to abiotic stresses, including drought, salinity, heavy metal tolerance, and temperature, as well as resistance to biotic stress factors, viz., rust, wilt, powdery mildew, and alternaria blight, despite addressing various morphotypes and the value of linseed as a supplement, are the primary topics of this review.