Optimal photoperiod for indoor cultivation of leafy vegetables and herbs

In Vertical Farms with Artificial Lighting (VFALs), optimal light management is a crucial determinant of both economic and environmental viability. Applications of LED technologies to plant cultivation are still recent, and research has to date mainly targeted the definition of optimal spectral and light intensity features. On the other hand, despite the relevant implications on production costs, literature on optimal photoperiod management is to date limited. Indeed, the number of hours per day correlates with the total light supplied to the crop \u2013 expressed as Daily Light Integral (DLI) \u2013 and the associated energetic costs. The present study aims at defining how photoperiods of 16 h d-1 (DLI= 14.4 mol m-2 d-1), 20 h d-1 (DLI= 18 mol m-2 d-1) and 24 h d-1 (DLI= 21.6 mol m-2 d-1)of light affect growth performances and resource use efficiency in leafy vegetables and herbs, represented by lettuce (Lactuca sativa L.), basil (Ocimum basilicum L.), rocket (Eruca sativa Mill.), and chicory (Cichorium intybus L.). Plants were cultivated indoor under a red (R) and blue (B) LED light (RB=3, photosynthetic photon flux density (PPFD)= 250 mmol m-2 s-1). Photoperiod variations\u2019 effects differed according to the considered plant species. In lettuce and chicory, the adoption of a DLI of 14.4 mol m-2 d-1 at 16 h d-1 photoperiod resulted in a greater plants fresh biomass and leaf area, which also contributed to generally obtain higher energy use efficiency (fresh biomass per unit of electricity input), light use efficiency (dry biomass per unit of light input) and, in chicory, also water use efficiency (fresh biomass per liter of water consumed). Contrarily, although photoperiod variations did not affect basil and rocket growth parameters (e.g., fresh biomass and leaf area) and the plant capacity to transform resources (e.g., water use efficiency and light use efficiency), energy use efficiency in basil also presented a downward trend in response to growing DLI. Accordingly, the adoption of a DLI of 14.4 mol m-2 d-1 at 16 h d-1 photoperiod resulted to be the optimal option among the ones tested in the presented research

Combined effect of salinity and led lights on the yield and quality of purslane (Portulaca oleracea l.) microgreens

The present work aims to explore the potential to improve quality of purslane microgreens by combining water salinity and LED lighting during their cultivation. Purslane plants were grown in a growth chamber with light insulated compartments, under different lighting sources on a 16 h d-1 photoperiod\u2014fluorescent lamps (FL) and two LED treatments, including a red and blue (RB)) spectrum and a red, blue and far red (RB+IR) LED lights spectrum\u2014while providing all of them a light intensity of 150 umol m-2 s-1. Plants were exposed to two salinity treatments, by adding 0 or 80 mM NaCl. Biomass, cation and anions, total phenolics (TPC) and flavonoids content (TFC), total antioxidant capacity (TAC), total chlorophylls (Chl) and carotenoids content (Car) and fatty acids were determined. The results showed that yield was increased by 21% both in RB and RB+FR lights compared to FL and in salinity compared to non-salinity conditions. The nitrate content was reduced by 81% and 91% when microgreens were grown under RB and RB+FR, respectively, as compared to FL light, and by 9.5% under saline conditions as compared with non-salinity conditions. The lowest oxalate contents were obtained with the combinations of RB or RB+FR lighting and salinity. The content of Cl and Na in the leaves were also reduced when microgreens were grown under RB and RB+FR lights under saline conditions. Microgreens grown under RB light reached the highest TPC, while salinity reduced TFC, Chl and Car. Finally, the fatty acid content was not affected by light or salinity, but these factors slightly influenced their composition. It is concluded that the use of RB and RB+FR lights in saline conditions is of potential use in purslane microgreens production, since it improves the yield and quality of the product, reducing the content of anti-nutritional compounds

Landscape genomics and biased FST approaches reveal single nucleotide polymorphisms under selection in goat breeds of North-East Mediterranean

<p>Abstract</p> <p>Background</p> <p>In this study we compare outlier loci detected using a <it>F<smcaps>ST </smcaps></it>based method with those identified by a recently described method based on spatial analysis (SAM). We tested a panel of single nucleotide polymorphisms (SNPs) previously genotyped in individuals of goat breeds of southern areas of the Mediterranean basin (Italy, Greece and Albania). We evaluate how the SAM method performs with SNPs, which are increasingly employed due to their high number, low cost and easy of scoring.</p> <p>Results</p> <p>The combined use of the two outlier detection approaches, never tested before using SNP polymorphisms, resulted in the identification of the same three loci involved in milk and meat quality data by using the two methods, while the <it>F<smcaps>ST </smcaps></it>based method identified 3 more loci as under selection sweep in the breeds examined.</p> <p>Conclusion</p> <p>Data appear congruent by using the two methods for <it>F<smcaps>ST </smcaps></it>values exceeding the 99% confidence limits. The methods of <it>F<smcaps>ST </smcaps></it>and SAM can independently detect signatures of selection and therefore can reduce the probability of finding false positives if employed together. The outlier loci identified in this study could indicate adaptive variation in the analysed species, characterized by a large range of climatic conditions in the rearing areas and by a history of intense trade, that implies plasticity in adapting to new environments.</p

Postharvest LED lighting: effect of red, blue and far red on quality of minimally processed broccoli sprouts

BACKGROUND: The main objective of this study was to evaluate physiological and quality changes of minimally processed broccoli sprouts illuminated during postharvest storage under blue, red and far-red LED lighting as compared to darkness or illumination with fluorescent light, as control treatments. RESULTS: Morphological and microbiological changes were determined during 15 days at 5 \ub0C. In addition, total antioxidant activity and bioactive compound changes throughout the shelf life were also monitored. Results showed that far-red LED lighting increased hypocotyl and sprout length, decreased microbial growth and improved the total antioxidant and scavenging activities, compared to darkness and fluorescent lighting treatments. However, it did not stimulate the biosynthesis of phenolic acids. In contrast, blue LED light reduced by 50% the total antioxidant capacity of broccoli sprouts compared to far-red treatment, as well as morphological development. In addition, total scavenging activity was increased under far-red LED light compared with the other treatments by 12\u201310% (darkness and fluorescence) and 33\u201331% (blue and red LEDs). CONCLUSIONS: Our results suggest that minimally processed sprouts may benefit from LED lighting during shelf life in terms of quality, although further experiments should be conducted to optimize a proper exposure cycle and intensity aiming for use in the distribution chain. The results also open the way for further development towards the integration of this technology in the food distribution chain

Postharvest yellow LED lighting affects phenolics and glucosinolates biosynthesis in broccoli sprouts

Nowadays, literature is still limited on the effects that LEDs may trigger during postharvest. The present study aimed to investigate the effect of continuous monochromatic Yellow or Green light on total and individual phenolic and glucosinolate content of 9-day broccoli sprouts stored up to 15 days at 5 \ub0C as a ready-to-eat product. In addition, a broad-spectrum White LED light, a Fluorescent light and storage in Darkness were used as treatments. An improvement in the total phenolic content (TPC) of 15 % and 13 % was observed under Yellow and White LED lighting, respectively, throughout the shelf-life as compared to Darkness. While Green LEDs did not affect the TPC, an increase of 34.5 % on the total glucosinolate content (TGC) was associated to this treatment on day 4. The highest increase of the TGC was observed under Yellow lighting (77 %, compared to Darkness). In contrast, Fluorescent and Darkness did not affect the TPC, but reduced the TGC (69 and 62 % compared to values at harvest, respectively). Our study demonstrates that a postharvest Yellow LED lighting stimulates the TPC and the TGC accumulation, opening the way for its further applications along the shelf life of other horticultural commodities

Optimal light intensity for sustainable water and energy use in indoor cultivation of lettuce and basil under red and blue LEDs

Indoor plant cultivation systems are gaining increasing popularity because of their ability to meet the needs of producing food in unfavourable climatic contexts and in urban environments, allowing high yield, high quality, and great efficiency in the use of resources such as water and nutrients. While light is one of the most important environmental factors affecting plant development and morphology, electricity costs can limit the widespread adoption of indoor plant cultivation systems at a commercial scale. LED lighting technologies for plant cultivation are also rapidly evolving, and lamps for indoor cultivation are often designed to optimize their light emissions in the photosynthetically active spectrum (i.e. red and blue), in order to reduce energetic requirements for satisfactory yield. Under these light regimens, however, little information is available in literature about minimum photosynthetic photon flux density (PPFD) for indoor production of leafy vegetables and herbs, while existing literature often adopts light intensities from 100 to 300 \u3bcmol m-2 s-1. This study aims at defining the optimal PPFD for indoor cultivation of basil (Ocimum basilicum L.) and lettuce (Lactuca sativa L.), by linking resource use efficiency to physiological responses and biomass production under different light intensities. Basil and lettuce plants were cultivated at 24 \ub0C and 450 \u3bcmol mol-1 CO2 under red and blue light (with red:blue ratio of 3) and a photoperiod of 16 h d-1 of light in growth chambers using five PPFD (100, 150, 200, 250 and 300 \u3bcmol m-2 s-1, resulting in daily light integrals, DLI, of 5.8, 8.6, 11.5, 14.4 and 17.3 mol m-2 d-1, respectively). A progressive increase of biomass production for both lettuce and basil up to a PPFD of 250 \u3bcmol m-2 s-1 was observed, whereas no further yield increases were associated with higher PPFD (300 \u3bcmol m-2 s-1). Despite the highest stomatal conductance associated to a PPFD of 250 \u3bcmol m-2 s-1 in lettuce and to a PPFD 65 200 \u3bcmol m-2 s-1 in basil, water use efficiency was maximized under a PPFD 65 200 \u3bcmol m-2 s-1 in lettuce and PPFD 65 250 \u3bcmol m-2 s-1 in basil. Energy and light use efficiencies were increased under a PPFD of 200 and 250 \u3bcmol m-2 s-1 in lettuce and under a PPFD of 250 \u3bcmol m-2 s-1 in basil. Furthermore, in lettuce grown under 250 \u3bcmol m-2 s-1 antioxidant capacity, phenolics and flavonoids were higher as compared with plants supplied with PPFD 64 150 \u3bcmol m-2 s-1. Accordingly, a PPFD of 250 \u3bcmol m-2 s-1 seems suitable for optimizing yield and resource use efficiency in red and blue LED lighting for indoor cultivation of lettuce and basil under the prevailing conditions of the used indoor farming set-up

Variabilit\ue0 genetica di Bos taurus e Bos indicus misurata con marcatori molecolari AFLP

Bos taurus e Bos indicus discendono da un antenato comune l\u2019uro, Bos primigenius, e rappresentano la maggioranza delle popolazioni di bovini domestici nel mondo. Bench\ue9 differiscano morfologicamente per alcuni caratteri distintivi e siano classificate come specie differenti, B. taurus e B. indicus sono interfertili. Nonostante l\u2019ampia diffusione mondiale di queste due specie domestiche, il rischio di estinzione delle loro popolazioni locali \ue8 cresciuto esponenzialmente negli ultimi anni: 209 razze sono ormai scomparse e pi\uf9 di 200 potrebbero estinguersi in tempi brevi (censimento FAO 2007). Le cause di questo fenomeno sono da ricercarsi essenzialmente nell\u2019abbandono delle aree marginali, spesso culla di razze locali, nella sostituzione di queste ultime con razze cosmopolite ad alta produttivit\ue0 o negli incroci indiscriminati. La salvaguardia della biodiversit\ue0 \ue8 tuttavia il prerequisito essenziale per rispondere alle future esigenze del mercato e ai cambiamenti climatici, e un\u2019approfondita conoscenza delle variabilit\ue0 genetica entro razza e delle relazioni genetiche esistenti tra razze \ue8 fondamentale per la messa a punto di un efficiente programma di conservazione delle risorse genetiche. Integrando i dati prodotti nell\u2019ambito del progetto europeo Resgen (http://www.eaap.org/content/resgen.htm) con altri ottenuti grazie a collaborazioni internazionali, e stato possibile costruire un dataset di dati AFLP (Ampliefied Fragment Length Polymorphism) comprendente 1833 bovini appartenenti a 71 razze distribuite tra Europa, Africa, India e Brasile. Il calcolo delle statistiche descrittive ha evidenziato valori di eterozigosi compresi tra 0,14 e 0,28 in Guinea N\u2019dama (Africa) e Hariana (India), rispettivamente, e un numero di marcatori polimorfici compreso tra 36 in Guinea N\u2019dama (Africa) e 95 in Sokoto Gudali (Africa). Le tecniche di analisi multivariata - Analisi Fattoriale delle Corrispondenze (AFC) e visualizzazione tramite Multidimensional scaling della matrice delle distanza genetiche di Reynolds \u2013 hanno fornito risultati concordanti. I primi tre fattori dell\u2019AFC spiegano complessivamente il 48,11% della varianza; sul Segreteria organizzativa [email protected] Segreteria tecnico-scientifica [email protected] Sito web: www.biod.irealp.it primo asse appare chiara la suddivisione tra B. taurus e B. indicus. Quando si considera il contributo del secondo asse, si nota chiaramente come gli zeb\uf9 risultino a loro volta suddivisi in due gruppi, africani e indiani allevati in Brasile, con gli africani localizzati in posizione intermedia. Ci\uf2 potrebbe indicare un flusso genico pi\uf9 recente o pi\uf9 marcato tra le razze taurine europee e le razze di zeb\uf9 africane e/o un effetto di isolamento delle razze brasiliane che ne aumenta la divergenza genetica. Interessante \ue8 anche la posizione di alcune razze taurine - Guinea N\u2019dama, le razze turche Anatolian Black e Turk Graues Steppenrind, Modicana - che si collocano in posizione intermedia tra le nuvole di punti di B. taurus e B. indicus e sembrerebbero pertanto possedere una componente genomica derivante dallo zeb\uf9 superiore alla medi