Contents lists available at ScienceDirect Postharvest Biology and Technology journal homepage: www.elsevier.com/locate/postharvbio The impact of light on vase life in (Anthurium andraeanum Hort.) cut flowers Sarah Evelyn a , Aidan D. Farrell a , Winston Elibox a , Kathryn De Abreu a , Pathmanathan Umaharan a a Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies, St. Augustine Campus, College Road, The Republic of Trinidad and Tobago 1. Introduction Anthurium (Anthurium andraeanum Hort.), a herbaceous perennial, is one of the most important ornamental crops in the global cut flower market. It produces a cut flower, which comprises a modified bract (spathe) and a stalk-like inflorescence (spadix), supported on a ped- uncle (Dufour and Guérin, 2003). Horticulturally mature cut flowers of some cultivars have exceptionally long vase lives (> 40 days), while many other varieties have short vase lives (< 15 days) despite posses- sing other desirable market characteristics (e.g. brightly coloured, large or showy spathes) (Elibox and Umaharan, 2010). Although the me- chanism governing the variation in vase life in anthurium is unknown, several studies have linked vase life with water relations (Mujaffar and Sankat, 2003; Elibox and Umaharan, 2008, 2010; Farrell et al., 2012; Aghdam et al., 2016a, 2016b) interaction with holding solutions (Fukui et al., 2005; Hettiarachchi and Balas, 2005; Agampodi, 2007) and spathe pigment content (Elibox and Umaharan, 2010, 2014). Farrell et al. (2012) found that cut flowers of V long were able to retain water in their bulk tissue for longer than short lived cultivars, i.e. V long maintained a higher spathe relative water content than some cultivars, despite having similar rates of stomatal conductance. This suggests that longer vase life is mediated by metabolically controlled factors, such as carbohydrate availability and the maintenance of solute potential (van Doorn, 1997), and that the conditions under which the cut flowers are held, including the light regime, could have significant impacts on their longevity. The optimum light intensity for growing anthurium is 15,000–20,000 Lux (Ravinath, 2007), which equates to 285–380 μmol m −2 s −1 , while light intensity experienced by the cut flower will typically be a fraction of this. The role of light in vase life experiments involving cut flowers has not been well studied (Heo et al., 2004). The response of cut flowers to light is influenced by pigment com- position. Depending on cultivar, anthurium spathes contain one or more of the following pigments: chlorophyll, carotenoids, and coloured flavonoids (anthocyanins). In anthurium, flavones, a subgroup of an- thocyanin, absorb light in the UV region and are responsible for white to pale-yellow spathe colour (Williams et al., 1981; Elibox and Umaharan, 2008; Séquin, 2012). Another anthocyanin, pelargonidin 3- rutinoside, is responsible for the orange to coral spathe colours, or in combination with cyanidin 3-rutinoside for the red to pink spathe col- ours (Iwata et al., 1979). Chlorophyll causes spathes to look green (Collette et al., 2004; Elibox and Umaharan, 2008) with light absorp- tion occurring at 400–500 nm and 600–700 nm (Séquin, 2012). Some spathes (obake types) can be co-pigmented with both anthocyanin and chlorophyll (Elibox and Umaharan, 2008). Anthocyanins are located in vacuoles of the hyperdomal cells whilst chlorophyll exist in chloroplasts throughout the mesophyll but mainly in the palisade layer (Higaki et al., 1984). The placement of these pigments combined with the thickness and structural properties of the tissue determine the overall reflected colour (van der Kooi et al., 2016). Elibox and Umaharan (2008) reported that vase life in anthurium was strongly correlated with colour and abaxial stomata density. Cultivars with low abaxial stomata density and green or white spathes had the longest vase life. Furthermore, it was observed that high pH levels, which promote long vase life, were associated with green and white spathe colours (Avila- Rostant et al., 2010). The reflectance properties of pigments can be investigated using reflectance spectral indices (Miyazak et al., 2006; Iriel and Lagorio, 2009; Manjunath et al., 2016); mathematical expressions derived from raw reflectance data that are used to estimate pigment content. Typi- cally, two specific wavelength bands are utilised: one wavelength serves as a reference where the pigment of interest does not absorb incident radiation, whereas the other highlights the region where pigment ac- tivity is seen (Sims and Gamon, 2002). Examples of these indices in- clude Simple Ratio (NIR/Red) and NDVI (NIR-Red)/(NIR + Red) used for chlorophyll estimation (Gamon et al., 1995), PRI (R 531 –R 570 /R 531 +R 570 ) for xanthophyll pigment conversions (Penuelas et al., 1996; Gamon et al., 1997) and R red :R green ratio for anthocyanin estimation (Gamon and Surfus, 1999). The exact target wavelengths are usually determined empirically since they are heavily influenced by pigment spectral activity, species differences, and internal leaf structure char- acteristics (Gamon and Surfus, 1999; Richardson et al., 2002;Blackburn and Ferwerda, 2008). The relationship between reflectance indices and vase life has not been studied in anthurium. Here we compare the physiological responses of cut flowers under fluorescent light and under different intensity LEDs, to investigate the role of light quality and quantity in regulating vase life. The relation- ship between light source, water status and vase life are explored over https://doi.org/10.1016/j.postharvbio.2019.110984 Received 2 May 2019; Received in revised form 11 August 2019; Accepted 11 August 2019 E-mail address: aidan.farrell@sta.uwi.edu (A.D. Farrell).