Determining the Optimum Night Length for Flower Development in a Modern Poinsettia Cultivar

The effect of night length (NL) on the flower development of poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) ‘Prestige Red’ was evaluated. Flower initiation occurred by subjecting plants to a 14-hour NL for 10 or 17 days, termed short-day (SD) treatments, and then transferring the plants to each of four NL treatments (11, 12, 13, or 14 hours) to observe the effects of NL on flower development. The plants grown continuously with the 14-h NL treatment were the control group. The timing of first color, visible bud, and anthesis were recorded during flower development, and bract and leaf data were collected at anthesis. Leaf number was unaffected by the SD or NL treatments, suggesting that flower initiation occurred during the 10-day SD treatment before the start of NL treatments; thus, the NL treatments only affected flower development. The timing of first color and visible bud were significantly delayed with the 10-day SD × 11-hour NL treatment relative to the 14-hour NL control; however, first color and visible bud were not delayed with the 17-day SD × 11-hour NL treatment. The 11-hour NL treatment resulted in fewer plants reaching anthesis, and these plants had fewer stem bracts and less bract color development compared with the 12-hour, 13-hour, and 14-hour NL treatments. Therefore, an 11-hour NL is suboptimal for flower development; nonetheless, significant development did occur. The 12-hour NL resulted in less color development than the 13-hour and 14-hour NL treatments in the lowest stem bract positions, but the plants had a commercially acceptable appearance. These results demonstrate that minimal differences in flower development occur with NL ≥12 hours, but that optimal development required NL ≥13 hours.

La nochebuena (Euphorbia pulcherrima), el tesoro mexica

Desde culturas prehispánicas, coloniales y actuales se ha utilizado la nochebuena, flor de pascua, cuetlaxochitl, sijoyo, Euphorbia pulcherrima, poinsettia, entre otros nombres con que se conoce esta planta nativa de México y parte de Sudamérica. Presenta una característica que la hacedistintiva de otras, la presencia de hojas modificadas. En este artículo mencionaremos características de la nochebuena, algunos usos comunes comerciales como medicinales que se le da a esta planta tanto. Se mencionan los estados de la República Mexicana que más la producen ya que forma parte de nuestra biocultura.

Identificación de híbridos F1 de nochebuena mediante RAPDS

México es el centro de origen de la nochebuena Euphorbia pulcherrima Willd. ex Klotzsch, es originaria del estado de Morelos. La identificación molecular de híbridos determina las relaciones filogenéticas entre ellos. El objetivo de la presente investigación fue identificar los híbridos F1 de E. pulcherrima mediante el uso de marcadores moleculares RAPD. Se utilizaron 39 plantas F1 provenientes de los cruzamientos de tres variedades de nochebuenas de sol (Amanecer navideño, Belén y Juan Pablo) con tres variedades de sombra (Festival red, Ice Punch y Burgundy). Los análisis de agrupamiento se realizaron sobre la relación de matrices con el método de ligamiento promedio aritmético de grupos de pares no ponderados (UPGMA) siglas en inglés. El iniciador OPA-07 es el que permitió identificar el origen híbrido de siete plantas F1 de la cruza Juan Pablo x Ice punch. De la progenie de las cruzas de Amanecer navideño x Ice punch y Amanecer navideño x Festival red, el iniciador OPA identificó a ocho plantas como híbridas. Los iniciadores RAPDs utilizados en las cruzas obtenidas de Belén x Ice punch, Belén x Burgundy y Belén x Festival red, no lograron identificar a los progenitores con la progenie híbrida, los fragmentos no mostraron diferencias incluso entre los mismos progenitores.

Efficacy of Selected Insecticides as Replacement for Neonicotinoids in Managing Sweetpotato Whitefly on Poinsettia

Management of sweetpotato whitefly (Bemisia tabaci), one of the most economically important pests of poinsettia (Euphorbia pulcherrima), relies heavily on neonicotinoid insecticides. Growers are seeking insecticide alternatives to neonicotinoids due to market demands. Although several systemic and translaminar insecticides have been suggested as alternatives to neonicotinoids, no published study has simultaneously compared their efficacies against sweetpotato whiteflies. This study compared the efficacies of 10 systemic and translaminar alternative insecticides with those of two systemic neonicotinoids, when all products were applied as foliar spray (twice at 14 d) or substrate drench (once) against sweetpotato whiteflies on poinsettia plants. Sweetpotato whitefly nymph and adult densities were examined 2 weeks before the first application (pretreatment), and weekly after the application for 8 weeks. Results showed that insecticides varied greatly in their efficacy, particularly against adults, and that spray application provided more effective suppression of nymphs than drench application. Spray and drench applications of imidacloprid and dinotefuran were consistently the most effective against sweetpotato whitefly nymphs and adults. Among the neonicotinoid alternatives, cyantraniliprole was the most effective insecticide in reducing sweetpotato whitefly nymph densities by both spray and drench application methods, with efficacy comparable to those of imidacloprid and dinotefuran. Although less effective than cyantraniliprole, foliar sprays of afidopyropen, chloratraniliprole, cyclaniliprole, flonicamid, flupyradifurone, pyrifluquinazon, spirotetramat, and sulfoxaflor + spinetoram were also effective against nymphs and could serve as partners in an insecticide rotation program.

Unravelling the Role of Temperature and Photoperiod on Poinsettia Heat Delay

The effects of day temperature (DT), night temperature (NT), and night length (NL) were evaluated on the flowering responses of heat-tolerant and heat-sensitive poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) cultivars Orion Red and Prestige Red, respectively. Plants were placed under 60 DT × NT × NL treatments that consisted of three DT (20, 24, 28 °C), four NT (16, 20, 24, 28 °C), and five NL (10, 11, 12, 13, 14 hours) for the first 17 days of the experiment. After 17 days, all plants were consolidated to one greenhouse with an inductive environment (14-hour NL, 24 ± 2.0 °C DT and 21.2 ± 1.4 °C NT), and the timing of first color, visible bud, and anthesis were recorded. ‘Orion Red’ reached anthesis 8 to 10 days faster than ‘Prestige Red’ across all NLs; however, in both cultivars, days to anthesis decreased in a sigmoidal pattern as NL increased. The relative rate of progress to anthesis (1/days to anthesis) under a 12-hour NL was approximately half that of plants grown at a 13- or 14-hour NL. At a 12-hour NL, the relative rate of progress to anthesis decreased linearly as DT increased for both cultivars. At 13- to 14-hour NL, DT had relatively little effect on the relative rate of progress to anthesis. Thus, high DT delayed flowering of both heat-tolerant and heat-sensitive cultivars when flower initiation occurred under NL, typical of naturally occurring NLs in September and early October (i.e., 12-hour NL), whereas high DT did not delay flowering for either cultivar under a 14-hour NL, which is typically provided under black cloth systems. In contrast, the flowering responses to NT were quite different for the two cultivars. The heat-tolerant cultivar showed relatively little change in the relative rate of progress to anthesis as NT increased from 16 to 28 °C within each NL treatment; however, the heat-sensitive cultivar displayed a large decrease in the relative rate progress to anthesis as NT increased from 20 to 28 °C within each NL treatment. Although the delayed flowering that occurred at 28 °C and 14-hour NL was significant, the relative rate of progress to anthesis at this treatment was significantly higher than the 28 °C and 12-hour NL treatment. This suggests that artificially shortening NL to 14 hours with a black cloth system does not prevent heat delay of poinsettia, but it allows for more rapid flowering than if flower initiation took place under natural NL (≈12 hours). To summarize, high DT affected flowering when flower initiation took place at 12-hour NL for heat-tolerant and heat-sensitive poinsettia cultivars, whereas high NT uniquely delayed flowering of the heat-sensitive cultivar at NL from 12 to 14 hours.

First genome edited poinsettias: targeted mutagenesis of flavonoid 3′-hydroxylase using CRISPR/Cas9 results in a colour shift

The CRISPR/Cas9 system is a remarkably promising tool for targeted gene mutagenesis, and becoming ever more popular for modification of ornamental plants. In this study we performed the knockout of flavonoid 3′-hydroxylase (F3′H) with application of CRISPR/Cas9 in the red flowering poinsettia (Euphorbia pulcherrima) cultivar ‘Christmas Eve’, in order to obtain plants with orange bract colour, which accumulate prevalently pelargonidin. F3′H is an enzyme that is necessary for formation of cyanidin type anthocyanins, which are responsible for the red colour of poinsettia bracts. Even though F3′H was not completely inactivated, the bract colour of transgenic plants changed from vivid red (RHS 45B) to vivid reddish orange (RHS 33A), and cyanidin levels decreased significantly compared with the wild type. In the genetically modified plants, an increased ratio of pelargonidin to cyanidin was observed. By cloning and expression of mutated proteins, the lack of F3′H activity was confirmed. This confirms that a loss of function mutation in the poinsettia F3′H gene is sufficient for obtaining poinsettia with orange bract colour. This is the first report of successful use of CRISPR/Cas9 for genome editing in poinsettia.

Skrining fitokimia pada tanaman penyembuh luka di Lombok Timur

The ethnomedicinal study which conducted in East Lombok revealed 5 potentially plants that have wound healing properties (Jatropha multifida L., Stachytarpheta jamaicensis (L.) Vahl, Centella asiatica (L.) Urban, Euphorbia pulcherrima Willd, and Angelica keiskei). The five plants have been no further research related to the presence of compounds that have activity in wound healing. This study aims to screen the plants secondary metabolites from above plants. The sample was maserated with 96% solvent methanol. The viscous extract was determined by physical characterization including consistency and color as well as chemical characterization, namely the phytochemical screening test. The results showed that the five plants contained flavonoids, phenolics, saponins, and steroids, except for Stachytarpheta jamaicensis (L.) Vahl showed negative results for saponins and Angelica keiskei showed negative results for steroid compounds. Keywords: phytochemical screening, total phenolic content, wound healing herbs, East Lombok

A highly mutable GST is essential for bract colouration in Euphorbia pulcherrima Willd. Ex Klotsch

BackgroundMutation breeding is an extraordinary tool in plant breeding to increase the genetic variability, where mutations in anthocyanin biosynthesis are targets to generate distinctive phenotypes in ornamental species. In poinsettia, ionizing radiation is routinely applied in breeding programs to obtaining a range of colours, with nearly all pink and white varieties being obtained after γ- or X-ray mutagenesis of red varieties. In the present study we performed a thorough characterization of a potential mutagenesis target gene as the main responsible for the ‘white paradox’ in poinsettia.ResultsWe identified aGSTgene in poinsettia (Bract1) as an essential factor for the expression of anthocyanin-based red colouration of bracts, which presents a high phylogenetic similarity to known anthocyanin-related GSTs. Red poinsettia varieties and white mutants generated from these varieties by X-ray were analysed for polymorphisms related to the ‘white paradox’ in the species. A 4 bp mutation in a short repeat within the coding region ofBract1is most likely responsible for the appearance of white phenotypes upon irradiation treatment. The polymorphism between wild-type and mutant alleles co-segregates with the phenotype in progeny from heterozygous red and white parents. Moreover, overexpression ofBract1wild-type allele in Arabidopsistt19mutants restored the anthocyanin phenotype, while theBract1mutated allele showed to be non-functional.ConclusionsThe identified repeat seems to be highly unstable, since mutated plants can be easily detected among fewer than 200 shoots derived from 10 mutated plants. Our data indicate that particular short repeat sequences, similar to microsatellite sequences or so-called dynamic mutations, might be hot spots for genetic variability. Moreover, the identification of theBract1mutation fills a gap on the understanding on the molecular mechanism of colour formation in poinsettia.

Potential Extract of Poinsettia (Euphorbia pulcherrima) as a sunscreen against UV exposure

Exposure to UV (Ultraviolet) rays for a certain period can cause erythema, sunburn,photoallergies, and forms ROS (Reactive Oxygen Species) which leads to gene mutations,premature aging, and skin cancer. Skin cancer in Indonesia ranks third after cervical cancer andbreast cancer. Sunscreens can protect skin from UV exposure, although many sunscreens usechemicals that can cause contact dermatitis and other allergies. Various studies have shown thatplants with antioxidants can protect the skin from exposure to UV rays. Poinsettia (Euphorbiapulcherrima) is an ornamental plant with antioxidant properties. This literature review aims to examine the potential of the poinsettia as a sunscreen against UV rays. The extract of thepoinsettia leaf has the potential to be sunscreen against UV exposure because the antioxidantcontent of flavonoids and other photo protectors, inhibits ROS, thereby preventing mutations andthe process of ordering skin cancer. Antioxidants in poinsettia help heal burns and stimulatefibroblast to prevent premature photoaging due to excessive UV exposure. Conclusion, Kastubaleaf extract (Euphorbia Pulcherrima) has the potential as a sunscreen against UV exposure Keywords: Poinsettia; Ultraviolet (UV); Antioxidant; Reactive Oxygen Species (ROS)