Euphorbia Pulcherrima Willd Research Articles

Standardization of Specific and Non-Specific Parameters of Methanol Extract from Poinsettia Red Leaves (Euphorbia pulcherrima Willd.)

The poinsettia red leaves (Euphorbia pulcherrima Willd.) have the potential as antibacterial and antioxidant agents and are widely utilized by the community for wound healing purposes. This research aims to determine the specific and non-specific parameter values of methanol extract from poinsettia red leaves. Samples of poinsettia red leaves were processed into extracts using the maceration method with 96% methanol as the solvent. The extract was standardized by determining specific and non-specific parameters. The test result data were analyzed descriptively in both qualitative and quantitative manners. The standardization results of specific parameters showed the identity of the extract as methanol extract of poinsettia red leaves, with organoleptic properties of a thick greenish-black extract, distinctive poinsettia aroma, and bitter taste. The water-soluble compound content was 51,47% ± 0,437 and ethanol-soluble 61,22% ± 0,117. Results for non-specific parameters indicated drying loss of 12,50% ± 0,419, moisture content of 12,62% ± 0,173, total ash content of 5,25% ± 0,538, acid-insoluble ash of 0,34% ± 0,048, residual solvent 0,00% ± 0,000, total plate count was TFTC (Too Few To Count), and mold and yeast count was 1,5 x 104 colonies/g sample. This research can serve as a reference for determining specific and non-specific parameters of methanol extract from poinsettia red leaves.

Effects of different explant and growth regulator combinations on in vitro propagation of Poinsettia (Euphorbia pulcherrima Willd.)

The aim of the research is to develop a suitable micropropagation protocol for the Poinsettia (Euphorbia pulcherrima Willd.) plant, which is used as an ornamental plant. In the sterilization step, mercuric chloride together with sodium hypochlorite is approved as the best option. Thus, contamination of explants is eliminated. At the shoot propagation stage, BA is absolutely necessary as all doses of BA increased shoot propagation compared to the control. The highest number of shoots per explant (2.62 shoots/explant) and the longest shoots (2.16 cm) were obtained from 1.0 mg.L-1 BA medium. The highest number of leaves (20.41 leaves/explant) was obtained from 2.0 mg.L-1 BA medium. Kinetin was also effective when adding different concentrations to the culture medium compared to the control. In general, BA is more effective than Kinetin in these parameters. Kinetin, on the other hand, performed much better than BA in terms of shoot number. On the other hand, the highest rooting percentage (58.2%) was obtained from the addition of 0.3 mg.L-1 NAA. The highest root number (5.10 roots/explant) was obtained by adding 0.1 mg.L-1 NAA. Good performance was found in the acclimatization phase with plantlets transferred to the soil with a high survival rate reaching 100%. Most of the plantlets started growing well. The plantlets grew well and did not show morphological abnormalities. In addition, a successful plant regeneration was achieved by adding 1.0 mg.L-1 BA and 0.5 mg.L-1 NAA on the callus produced in leaf disc explants and a very good organogenesis was determined in terms of roots and shoots.

Free-Radical Scavenging Activity and Total Phenolic Compounds of Red and Green Poinsettia Leaves (Euphorbia pulcherrima Willd.) from Lombok Island

Free-Radical Scavenging Activity and Total Phenolic Compounds of Red and Green Poinsettia Leaves (Euphorbia pulcherrima Willd.) from Lombok Island

Identifying the Temporal Sensitivity of Poinsettia Flowering to High Temperatures

The objective of this study was to identify the specific weeks and night lengths when poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) flowering is most sensitive to high temperatures. One experiment was conducted in greenhouses under natural daylength (ND) conditions at lat. 34.7°N starting on 4 Sep, and a second experiment was conducted in growth chambers with an initial night length (NL) of 11 hours 01 minutes that was increased by 2 min/d to simulate ND conditions through September and October. Each week, one group of plants was moved from a moderate-temperature environment [22 °C average daily temperature (ADT)] to a high-temperature environment 28 °C ADT. Each group of plants spent 1 week in the high-temperature environment before returning to the moderate-temperature environment. The temperature treatments lasted for 7 or 8 weeks for the growth chamber and greenhouse studies, respectively. Additional groups of plants were kept in either the moderate- or high-temperature environment for the entire treatment period as controls. Four cultivars were used in the greenhouse study: Advent Red, Freedom Red, Prestige Red, and Tikal Red; only Prestige Red was used in the growth chamber study. Advent Red was identified as the most heat-tolerant cultivar followed by Tikal Red, Freedom Red, and Prestige Red. ‘Advent Red’s’ period of sensitivity to high temperatures ranged from 4 Sep to 1 Oct. ‘Tikal Red’s’ period of sensitivity to high temperature ranged from 11 Sep to 8 Oct. ‘Freedom Red’ had a longer period of high-temperature sensitivity: from 11 Sep to 22 Oct. ‘Prestige Red’ had the longest period of sensitivity to high temperatures encompassing 4 Sep to 29 Oct, and 11 hours 01 minute to 12 hours 37 minutes NL for the greenhouse and growth chamber studies, respectively. Within periods of sensitivity to high temperatures, time to visible bud and anthesis were most affected by high temperatures in earlier weeks, and final bract color development and time to first bract color were more affected by high temperatures during the latter weeks. As cultivars varied in their duration of sensitivity to high temperatures, duration, as well as magnitude of response to high temperature, should be considered in future breeding projects.

Anthocyanin metabolic engineering of Euphorbia pulcherrima: advances and perspectives.

The range of floral colors is determined by the type of plant pigment accumulated by the plant. Anthocyanins are the most common flavonoid pigments in angiosperms; they provide a wide range of visible colors from red-magenta to blue-purple, products of cyanidin and delphinidin biosynthesis, respectively. For the floriculture industry, floral color is one of the most important ornamental characteristics for the development of new commercial varieties; however, most plant species are restricted to a certain color spectrum, limited by their own genetics. In fact, many ornamental crops lack bluish varieties due to the lack of activity of essential biosynthetic enzymes for the accumulation of delphinidin. An example is the poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch), the ornamental plant symbol of Christmas and native to Mexico. Its popularity is the result of the variety of colors displayed by its bracts, a kind of modified leaves that accumulate reddish pigments based mainly on cyanidin and, to a lesser extent, on pelargonidin. The commercial success of this plant lies in the development of new varieties and, although consumers like the typical red color, they are also looking for poinsettias with new and innovative colors. Previous research has demonstrated the possibility of manipulating flower color through metabolic engineering of the anthocyanin biosynthesis pathway and plant tissue culture in different ornamental plant species. For example, transgenic cultivars of flowers such as roses, carnations or chrysanthemums owe their attractive bluish colors to a high and exclusive accumulation of delphinidin. Here, we discuss the possibilities of genetic engineering of the anthocyanin biosynthetic pathway in E. pulcherrima through the introduction of one or more foreign delphinidin biosynthetic genes under the transcriptional control of a pathway-specific promoter, and the genome editing possibilities as an alternative tool to modify the color of the bracts. In addition, some other approaches such as the appropriate selection of the cultivars that presented the most suitable intracellular conditions to accumulate delphinidin, as well as the incorporation of genes encoding anthocyanin-modifying enzymes or transcription factors to favor the bluish pigmentation of the flowers are also revised.

Anti-Stapylococcus Epidermidis of Methanolic Extracts from Some East Lombok Medicinal Plants

Wounds are structural and functional disruptions of the skin that occur as a result of an injury. Wound healing is a complex tissue repair or remodelling process in response to the injury. The most common factor that causes wounds not properly heal is infection. An infection develops when microorganisms enter the body, multiply, and trigger an immune reaction in the body. This study aims to determine the activity of Jatropha multifida L., Stachytarpheta jamaicensis (L.) Vahl, Centella asiatica (L.) Urb., Euphorbia pulcherrima Willd. ex Klotzsch, and Angelica keiskei (miq.) Koidz has long been used to treat and manage wounds in East Lombok. The plants were dried and macerated with methanol; excessed solvent was evaporated. Disc diffusions were used to determine the antibacterial activity of the plant extracts. All extracts were tested against Staphylococcus epidermidis, a common cause of wound infection. Statistically, the activity of Jatropha multifida (5;10 mg/mL), Stachytarpheta jamaicensis (10 mg/mL), Centella asiatica (10 mg/mL), Euphorbia pulcherrima (M) (5, 10 mg/mL), and Angelica keiskei (2,5; 5; 10 mg/mL) extracts were comparable with positive control. However, Angelica keiskei has a wider inhibition zone than other extracts. This discovery could be served as a basis for using plants to aid wound healing, especially to combat the interference bacteria. However, further research is needed to discover the active phytochemicals involved in the antibacterial and wound healing process.

Paula Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) indoor variety

Objective: To evaluate the behavior of the Paula poinsettia variety (Euphorbia pulcherrima Willd. ex Klotzsch) and to describe its characteristics, based on the guidelines established by the International Union for the Protection of New Varieties of Plants (UPOV). Design/Methodology/Approach: The genetic improvement included hybridization and selection techniques. To promote compaction and greater branching, it was grafted on a commercial variety. The cuttings obtained gave rise to the Paula variety (Euphorbia pulcherrima Willd. ex Klotzsch), which was described in 2020, based on the Guidelines for the Conduct of Tests for Distinctness, Uniformity and Stability of the International Union for the Protection of New Varieties of Plants. A completely randomized experimental design with 10 replications was used. Vegetative and bract characteristics were recorded and an analysis of variance was applied, as well as a Tukey’s mean comparison test (P≤ 0.05). Results: The Paula variety is medium-sized and has a wide breadth and medium branching. It is pale green in the middle third of the stem. It has oval-shaped, long, and broad leaves of the same medium-intensity color, and a wedge-shaped base. It has a long petiole with a pale green upper side. This variety also has many elliptical red bracts of medium length and narrow width. Compared to other INIFAP varieties, the vegetative and bract characteristics of Paula presented statistical differences. Study Limitations/Implications: The commercial production of poinsettia is carried out through asexual propagation. The mother plant is kept in a vegetative state, through comprehensive and intensive management, preventing its flowering and obtaining a continuum of propagation material. Findings/Conclusions: Paula has an intermediate cycle, with quality and competitive size, branching, and color of the bract (red). It can satisfy the taste and preference of consumers in the domestic and even foreign markets

First Report of Root-Knot Nematode Meloidogyne enterolobii on Poinsettia 'Luv U Pink' in Taiwan.

Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch.), originated in southern Mexico and northern Guatemala, is the most valuable potted flowering plant in the spurge family (Euphorbiaceae). The European Union and the United States are two biggest poinsettia markets (Taylor et al. 2011), with a wholesale value of $153 million in the United States in 2019. Root knot galls of poinsettia 'Luv U Pink' were collected from a production greenhouse located in Nantou County, Taiwan in March 2021. No aboveground symptoms were observed. A nematode population was established from a single female and used for identification and the Koch's postulate. The perineal patterns of randomly picked 5 females are round or ovoid with moderate to high dorsal arches, but no distinct lateral lines, ventral striae are fine and smooth. The Morphometric characters of second-stage juvenile include: a vermiform body shape, tail narrow and tapering with rounded tail tips, and a distinct hyaline tail end. Measurements of 20 J2 are as follows: body length, 430 (398 - 473) μm; body width, 15.4 (13.4 - 17.8) μm; stylet length,13.4 (13.0 - 14.0) μm; dorsal esophageal gland orifice to basal knob, 3.4 (2.8 - 3.9) μm; tail length, 52.9 (47.6 - 62.2) μm. All morphometric data were consistent with the original description of Meloidogyne enterolobii (Yang and Eisenback 1983). Nematode DNA was extracted using GeneMark Tissue & Cell Genomic DNA Purification Kit (GeneMark, Taiwan) from approximately 1500 J2 and used for amplification of 18S rRNA gene, a D2-D3 region of 28S rRNA gene, and a mtDNA COII region with primer sets 1A/MelR, D2A/D3B, and C2F3/1108, respectively (Power and Harris 1993, Subbotin et al. 2006, Tigano et al. 2005). The sequence of 18S rRNA gene (accession no. MZ948800 haplotype 1 and MZ955998 haplotype 2), haplotype 1 shared 100% identity with that of M. enterolobii from the United States (KP901058) and China (MN832688); haplotype 2 shared 99.8% identity with that of KP901058 and MN832688. The sequence of the D2-D3 region (MZ955995) shared 99% identity with that M. enterolobii from the United States (KP901079). Sequence of the COII region (MZ964625) also shared 99% identity with that of M. enterolobii from the United States (AY446975) and China (MN840970). Phylogenetic trees of the three gene sequences plotted as described by Ye et al. (2021) revealed that the newly described nematode was grouped with M. enterolobii. Sequence analysis of two fragments: 236 bp and 520 bp amplified with gene specific primers Me-F/R and MK7F/R, respectively (Long et al. 2006, Tigano et al. 2010) also confirmed the identity of M. enterolobii. To measure the reproductive factor (Rf), the Poinsettia 'Luv U Pink' seedlings with eight true leaves were transplanted into three 12-cm diameter pots each containing 6000 eggs or water (mock control). Forty-five days after inoculation, the average Rf value of three inoculated plants was 6, and no galls were observed on mock control plant roots, confirming that poinsettia is the host of M. enterolobii. M. enterolobii has been reported in several Euphorbia species, including E. heterophylla, E. prostrata, E. punicea and E. tirucalli (Han et al. 2012, Rich et al. 2009). To the best of our knowledge, this is the first report of M. enterolobii infecting E. pulcherrima 'Luv U Pink'. .

Whole-Plant Tissue Nitrogen Content Measurement Using Image Analyses in Floriculture Crops

AbstractResearch on image analysis techniques for estimating plant N status in floriculture is limited. We subjected poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) cultivars to five nitrogen concentration treatments for 45 days and captured grayscale images of plants briefly exposed to 450, 625, 660, and 870 nm of light using a multispectral image station. Images were processed to calculate normalized reflectance ratios, including R870/450, R870/625, and R870/660. Dried shoots were analyzed in a laboratory for whole-plant tissue N content (mg·g−1). Results indicated that whole-plant N content ranged from 21 to 44 mg·g−1 in different N treatments. Among the reflectance ratios, R870/625 showed higher correlation with whole-plant N content in different cultivars of poinsettia (0.72< r2 <0.78) compared to R870/450 and R870/660. Based on these results, we custom-built a low-cost image sensor that can be remotely controlled to capture red (625 nm) and near infrared (870 nm) images of plants and transfer images to a cloud storage for processing. The normalized reflectance ratio measured by the image sensor was linearly related to the whole-plant N content (r2=0.84) and more accurate than soil plant analysis development (SPAD) measurements at predicting plant N status. These results indicate that image analysis in general and images captured by low-cost image sensors can be used for estimation of plant N status in floriculture.Index words: Chlorophyll, poinsettia, red light reflectance, plant segmentation.Chemicals used in this study: Water soluble 15-5-15 Cal Mg.Species used in this study: Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch, cultivars ‘Christmas Beauty Marble', ‘Christmas Tradition', ‘Christmas Glory White', and ‘Wintersun White').

The Effects of Spray Volume on the Management of Bemisia tabaci (Hemiptera: Aleyrodidae) in the Greenhouse

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a major insect pest of poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch; Family: Euphorbiaceae) in the greenhouse. Currently, neonicotinoids are widely used for B.tabaci management in the greenhouse, which is less favored by the consumers because of the potential nontarget effects of these insecticides on beneficial insects. Little is known on how the high spray volumes of spinetoram (20%) + sulfoxaflor (20%) (XXpire®) affect the B.tabaci population in the greenhouse. The objective of the study was to determine the efficacy of spinetoram + sulfoxaflor and dinotefuran (Zylam®) applied as foliar-spray volumes (high, referred to as spench, and low, referred to as foliar) and soil drench against B.tabaci. The high foliar-spray volume application (spench) of both insecticides reduced the B.tabaci immature densities, compared with low foliar-spray volume (foliar) and soil drench applications. The soil drench application did not provide adequate B.tabaci control regardless of insecticide type. Spinetoram + sulfoxaflor applied as a high-spray volume treatment was moderately effective in controlling B.tabaci nymphs relative to nontreated control.

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.

Euphorbia pulcherrima (poinsettia)

Starch grain morphology in laticifer amyloplasts of Euphorbia pulcherrima Willd. (poinsettia) was examined for evidence of starch metabolism in vegetative and flowering plants. Laticifer starch grains in vegetative plants were rod shaped with lengths ranging from 3 to 60 ,um. Average grain size was significantly larger in stems than leaves, and in older than younger tissues. Starch grain length frequency was unimodal and approximated a normal probability distribution in stems, but was skewed positively toward smaller grains in leaves. Frequency distributions were shifted toward larger grains in older tissues. Under short-day photoperiod (flowering) conditions, round starch grains formed in latex of stems, and the average length of rod-shaped grains decreased in latex of stems and leaves. Round grains did not occur in laticifers of leaves or bracts. Round starch grains often occurred in aggregates of two or more subunits. Changes in size and shape of latex starch grains indicate that amyloplasts in fully differentiated laticifers metabolize starch. Identification of metabolically active amyloplasts in differentiated laticifers suggests that the function of these organelles may involve starch mobilization under certain physiological conditions. STARCH GRAINS IN amyloplasts of the nonarticulated laticifer of Euphorbia differ from those in other cells in their complex and varied morphologies, unusual structural properties, and apparent nonutilization (Mahlberg, 1975; Biesboer and Mahlberg, 1978, 1981; Spilatro and Mahlberg, 1985). Laticifer starch increases in quantity in leaves throughout their expansionary phase of growth, and then remains stable in mature leaves (Spilatro and Mahlberg, 1986). Although amylase activity was detected in latex of several Euphorbia species, laticifer starch was not mobilized in plants subjected to an extended dark period or during repro

Biological Cycle of the Fungus Gnat Bradysia sp.1 in a Lily (Lilium spp.) Crop

Bradysia sp. Frey, 1948 (Diptera: Sciaridae) damages mostly ornamentals, vegetables, and Agave spp. in greenhouses and nurseries. In Mexico, study has been infrequent, and only the identity of species of fungus gnats associated with crops of poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) and forest nurseries has been reported. To contribute to knowledge of the species, an experiment was done at 24.7 ± 1.4°C, 53.9 ± 3.2% relative humidity, and photoperiod of 18:6 light:dark hours in a laboratory to determine the length of the biological cycle of the fungus gnat. The life cycle from egg to adult emergence was 25 ± 2.65 days. Eggs hatched 3.63 ± 0.5 days after oviposition. The larval stage lasted 17.19 ± 3.02 days, while the pupal stage was 2.19 ± 0.4 days. The adult stage was 2 days. This is the first report of the biology of the fungus gnat associated with lilies (Lilium L.) and its presence in the State of Oaxaca.

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.

Evaluating Fungicide Selections to Manage Pythium Root Rot on Poinsettia Cultivars with Varying Levels of Partial Resistance.

Pythium aphanidermatum is the predominant species causing Pythium root rot of commercially grown poinsettia (Euphorbia pulcherrima Willd. ex Kotzch) in North Carolina. Pythium root rot is managed primarily through a combination of sanitation practices and preventative fungicide applications of mefenoxam or etridiazole. Insensitivity to mefenoxam is common but growers continue to rely on it from lack of inexpensive and efficacious alternatives. This research was conducted to identify alternative fungicides for Pythium root rot control and to evaluate their efficacy on poinsettia cultivars with varying levels of partial resistance. Greenhouse studies were conducted to assess efficacy of fungicide treatments in seven poinsettia cultivars inoculated with a mefenoxam-sensitive isolate of P. aphanidermatum. One study examined control with a single fungicide drench made at transplant and a second study examined repeat fungicide applications made throughout the experiment. Treatments containing etridiazole, mefenoxam, fenamidone, and cyazofamid provided control of Pythium root rot across all cultivars in both experiments whereas Fosetyl-al, potassium phosphite, and Trichoderma spp. failed to offer satisfactory control. Azoxystrobin, pyraclostrobin, and propamocarb reduced disease on some cultivars but failed to control Pythium root rot on highly susceptible cultivars. Four isolates of P. aphanidermatum cultured from plants growing in commercial greenhouses were evaluated for in vitro sensitivity to fungicides labeled for Pythium root rot control at four rates. Etridiazole, fosetyl-al, and potassium phosphite completely inhibited mycelial growth, whereas isolates varied in response to mefenoxam, cyazofamid, propamocarb, fenamidone, azoxystrobin, and pyraclostrobin in vitro. Twenty-one additional isolates then were evaluated at label rates of these fungicides. Seven isolates were insensitive to label rates of all three quinone outside inhibitors and one isolate was insensitive to the quinone outside inhibitors and mefenoxam. These results provide guidelines for selecting fungicides to maximize control of Pythium root rot on poinsettia cultivars.

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

Adding a Natural Enemy to Respond to Pest Immigration and Delayed Natural Enemy Releases in Augmentative Biological Control.

Whether increased natural enemy density or adding a second natural enemy species will provide superior pest suppression in greenhouse augmentative biological control is unknown for many commercially available natural enemy species. In this study, we use sweetpotato whiteflies, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on poinsettias, Euphorbia pulcherrima Willd. ex Klotzsch (Malpighiales: Euphorbiaceae), to determine whether adding Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) to Eretmocerus eremicus Rose and Zolnerowich (Hymenoptera: Aphelinidae) is better for B. tabaci suppression compared with either natural enemy alone, both with and without challenges with whitefly immigration or delayed natural enemy releases. The number of whiteflies on caged poinsettias treated with different natural enemy release rates (single or double rate), natural enemy species (one or two species), natural enemy delayed release (weeks 4 and 8), and whitefly immigration treatments (introduced at week 4 or week 8) was censused biweekly for 16 wk. Both species used in combination provided similar or better suppression of whiteflies compared with either natural enemy alone. Both species combined also provided superior suppression of whiteflies when challenged with whitefly immigration or delays in natural enemy releases compared with E. eremicus alone. Whitefly immigration or delays in E. eremicus releases did not increase whitefly populations, suggesting that suppression of whiteflies by E. eremicus alone is relatively robust. This study found no evidence for negative interactions between E. eremicus and A. swirskii for suppressing B. tabaci.

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 a GST gene 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 of Bract1 is 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 of Bract1 wild-type allele in Arabidopsis tt19 mutants restored the anthocyanin phenotype, while the Bract1 mutated 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 the Bract1 mutation fills a gap on the understanding on the molecular mechanism of colour formation in poinsettia.

Using Multiple Natural Enemies to Manage Sweetpotato Whiteflies (Hemiptera: Aleyrodidae) in Commercial Poinsettia (Malpighiales: Euphorbiaceae) Production

Abstract In this case study, we investigate the efficacy and economics of using two natural enemies in an integrated pest management (IPM) program to manage sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in commercial poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) production. Two similar greenhouses at each of three different grower locations were designated as either the IPM or the conventional insecticide greenhouses in southeastern United States. In the IPM greenhouses, we released Eretmocerus eremicus (Rose & Zolnerowich) (Hymenoptera: Aphelinidae) weekly and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) every 4 wk, and selective insecticides were used to treat high whitefly densities as needed. In the conventional greenhouses, growers were autonomous in their insecticide application decisions. All whitefly stages were counted weekly on a maximum of 20 leaves per 50 randomly sampled poinsettias and 50 flagged (i.e., revisited) poinsettias in every greenhouse. Whitefly densities were consistently similar or higher in the IPM greenhouses compared to their conventionally managed counterparts for the duration of the trial. The cost of inputs and labor for whitefly management in the IPM greenhouses was between 0.57- and 3.0-fold the cost of conventional management. Our study supports that releasing E. eremicus and A. swirskii can reduce insecticide applications by 25–78% and may be considered a feasible strategy to manage B. tabaci in commercial poinsettia production in place of conventional insecticidal control in southeastern United States.

Predation Capacity of Phytoseius crinitus Swirski Et Schebter on Each Stage of Tetranychus urticae and Alternative Food for Laboratory Mass Rearing

Providing a sensible breeding stock of predatory mites for a biological control system is important. For this purpose, the predatory mites need high feeding capacity on every stage of pest mites and high survival rates on alternative food. This research aimed at testing the predation capacity of P. crinitus on each stage of development of pest mites T. urticae, and investigating appropriate alternative food for laboratory rearing of predatory mites P. crinitus. Completely Randomized Design (CRD) was used in this research. For investigating the predation capacity of P. crinitus, we performed 20 experiments consisted of treatments with eggs, larvae, nymphs, and adults of T. urticae, with five replicates. The variable for these experiments was the number of individuals of each stage of T. urticae consumed by P. crinitus during the period of 24. For investigating the proper alternative food for predatory mites, P. crinitus were given a free choice between pollen of Euphorbia pulcherrima Willd and pollen of Hibiscus rosa-sinensis L, with six replicates. The variables of survival rate, facundity, duration of oviposition, and the length of the life cycle of P. crinitus were recorded for each alternative food. All experiments were conducted in room temperatures (-) and rH (-). The data were analyzed using the F test and followed by Least Significant Difference (LSD) with error levels of 5% and 1%. The results indicated that predatory mites P. crinitus consumed eggs more than other developmental stages of T. urticae. In terms of alternative food, the pollen of Euphorbia pulcherrima was more suitable for laboratory mass rearing of P. crinitus.