Hippeastrum Hybridum Research Articles

Assessment of genetic diversity and identification of core germplasm in single-flowered amaryllis (Hippeastrum hybridum) using SRAP markers

Selection for new single-flowered amaryllis with cultivated wild species or hybrids has continued for more than 200 years. However, our basic knowledge of the extent of genetic variation within the single-flowered amaryllis is still not sufficient, which is very important for the ongoing improvement of the double-flower type in China. In this study, a total of 23 screened sequence-related amplified polymorphism (SRAP) markers were used to assess the genetic diversity and population structure of 82 cultivated accessions. It produced 244 clearly amplified fragments, of which 242 (99.2%) were polymorphic. A higher level of genetic diversity was observed, with estimates of Nei’s diversity index (H) and the Shannon information index (I) of 0.344 and 0.513, respectively. Genetic distance- and structure-based analyses mainly clustered all accessions into two or five subgroups, indicating the complexity of the hybrid pedigree of single-flowered amaryllis. To effectively explore and preserve the novel variation in these 82 genetic resources, we further established an initial core collection with 15 accessions with the goal of maximizing the SRAP alleles. This preliminary core set retained 100% of the SRAP variation with greater genetic diversity and heterogeneity (H = 0.355, and I = 0.529). Our research provided insight into the genetic structure of modern hybrids of single-flowered amaryllis, from which an easily manageable amaryllis core collection was identified, facilitating future breeding progress for double-flowered amaryllis.

The influence of seaweed extract and irrigation interval on growth and quality production of Hippeastrum hybridum, Hort

The influence of seaweed extract and irrigation interval on growth and quality production of Hippeastrum hybridum, Hort

Revealing the complex genetic structure of cultivated amaryllis (Hippeastrum hybridum) using transcriptome-derived microsatellite markers

Although amaryllis (Hippeastrum hybridum) plants are commonly used in physiological and ecological research, the extent of their genomic and genetic resources remains limited. The development of molecular markers is therefore of great importance to accelerate genetic improvements in Hippeastrum species. In this study, a total of 269 unique genes were defined that might regulate the flower spathe development of amaryllis. In addition, 2000 simple sequence repeats (SSRs) were detected based on 171,462 de novo assembled unigenes from transcriptome data, and 66,4091 single nucleotide polymorphisms (SNPs) were also detected as putative molecular markers. Twenty-one SSR markers were screened to evaluate the genetic diversity and population structure of 104 amaryllis accessions. A total of 98 SSR loci were amplified for all accessions. The results reveal that Nei’s gene diversity (H) values of these markers ranged between 0.055 and 0.394, whereas the average values of Shannon’s Information index (I) ranged between 0.172 and 0.567. Genetic tree analysis further demonstrates that all accessions can be grouped into three main clusters, which can be further divided into two subgroups. STRUCTURE-based analysis revealed that the highest ΔK values were observed when K = 5, K = 6, K = 7 and K = 8. The results of this study enable large-scale transcriptomics and classification of Hippeastrum genetic polymorphisms and will be useful in the future for resource conservation and production.

The Influence of Bulb Storage Regimes on the Growth and Flowering of Hippeastrum (Hippeastrum hybridum Hort.)

Hippeastrum hybridum cultivar ‘Cam Tu’ bulbs were subjected to ten different treatment regimens to evaluate the effect of temperature (4°C or 25°C), duration (4, 6, or 8 weeks), and wrapping materials (coir fiber or newspaper) on their growth and flowering. The data revealed that the storage treatments had significant effects on several growth and flowering characteristics of H. hybridum cv. ‘Cam Tu’. In terms of vegetative characteristics, bulbs stored at 4°C with coir fiber wrapping for 6 weeks (T9) had the largest leaf size (a length of 39.46 cm, a width of 4.39 cm), the longest flower scape (48.64 cm in length), and the longest pedicel (4.75 cm in length). Bulbs of the T9 treatment also showed the shortest time to flower bud emergence (62.24 days) and first flower opening (80.43 days), and the date of 70% first flower fully opening was January 19, 2018. Both of the two thermal treatment regimens shortened flowering time (80.43-103.16 days) compared to the control (132.46 days). However, the number of bulblets per plant, number of leaves per plant, number of florets per scape, floret diameter, longevity of a flower, and longevity of a flower scape were not statistically impacted by the treatments.

The Hippeastrum hybridum PepR1 gene (HpPepR1) encodes a functional guanylyl cyclase and is involved in early response to fungal infection

It is generally known that cyclic GMP widespread in prokaryotic and eukaryotic cells, is involved in essential cellular processes and stress signal transduction. However, in contrast to animals the knowledge about plant guanylyl cyclases (GCs) which catalyze the formation of cGMP from GTP is still quite obscure. Recent studies of plant GCs are focused on identification and functional analysis of a new family of membrane proteins called “moonlighting kinases with GC activity” with guanylyl cyclase catalytic center encapsulated within intracellular kinase domain. Here we report identification and characterization of plasma membrane receptor of peptide signaling molecules – HpPepR1 in Hippeastrum hybridum. Both bioinformatic analysis of amimo acid sequence and in vitro studies revealed that the protein can act as guanylyl cyclase. The predicted amino acid sequence contains highly conserved 14 aa-long search motif in the catalytic center of GCs from lower and higher eukaryotes. Here, we provide experimental evidence to show that the intracellular domain of HpPepR1 can generate cGMP in vitro.Moreover, it was shown that the accumulation of HpPepR1 transcript was sharply increased after Peyronellaea curtisii (=Phoma narcissi) fungal infection, whereas mechanical wounding has no influence on expression profile of studied gene. These results may indicate the participation of cGMP-dependent pathway in rapid, alarm plant reactions induced by pathogen infection.

FIRST RECORD OF Xanthopastis timais IN AMARYLLIS AND EFFECT OF SOURSOP EXTRACT ON LARVAL MORTALITY

ABSTRACT The aim of this study was to report the occurrence of Xanthopastis timais (Cramer, 1780) (Lepidoptera: Noctuidae) in amaryllis (Hippeastrum hybridum Hort., Amaryllidaceae), as well as estimating lethal concentrations (LC50 and LC99) of soursop seed extract, Annona muricata L. (Annonaceae), against its larvae. The experiment was carried out at the Laboratory of Entomology of the Research Center for Agricultural Sciences, Federal University of Alagoas, in Rio Largo-AL, Brazil. First, we collected caterpillars from amaryllis plants that were reared until pupal and adult stages (parental generation). Next, part of the adults was used for species identification, and the rest were bred to produce next generation (F1), being after that applied in a laboratory bioassay. The lab trial was performed in a completely randomized design, with six treatments and five replications containing three second-instar caterpillars. These larvae were fed pieces of amaryllis leaf (4 x 4 cm), which were previously soaked in treatments for 30 seconds and, air -dried on absorbent papers for one hour. Each treatment consisted of one concentration of ethanol extract of soursop seeds (0.0, 1.0, 0.5, 0.25, 0.125 and 0.0625% w/ v) with distilled water and DMSO at 1% (v/ v), for solutions. We noted that the lethal concentrations LC50 and LC99 were 0.29% (w/ v) and 2.27% (w/ v), respectively. In view of our results, we can state that larval stage of X. timais were influenced by extract application in terms of survival, mortality, larvae weight and larval stage length. Besides of that, it was the first time this species was recorded in Alagoas state.

<i>Hippeastrum hybridum</i> anthocyanins as indicators of endpoint in acid – base titrations

Anthocyanins from Hippeastrum hybridum (Amaryllis) were investigated as indicators of endpoint in acid- base titrations. Extraction of the anthocyanins was done using distilled water, methanol and methanol containing 0.5% acetic acid. The extracts were used in determination of endpoint in titrations between strong acid/strong base, strong acid / weak base, weak acid / strong base and weak acid / weak base at concentration levels of 0.1 M, 0.5 M and 1.0 M. The titres were compared to those obtained using phenolphthalein, methyl orange and mixed indicator. The shelf life of anthocyanin extracts kept in amber bottles at room temperature (16.8 0C – 29.1 0C) was also investigated. The plant extracts gave accurate and precise results in titration of strong acids with strong bases and weak acids against strong bases at all concentrations investigated (0.1, 0.5 and 1.0 M) that were very comparable to the values obtained using phenolphthalein, methyl orange and mixed indicator. In titration of weak acids against weak bases, the plant extracts gave accurate results when concentration was 0.1 M but failed for 0.5 M and 1.0 M. On average the anthocyanins from Hippeastrum hybridum could be used in the titration of strong acid versus strong base, weak acid versus strong base and weak acid versus weak base. The anthocyanins from Hippeastrum hybridum had a good shelf life of 90 days when kept at room temperature. The extracts can thus be used in any place including those that have no access to refrigeration facilities since they can be kept at room temperature for some time before they undergo degradation.© 2016 International Formulae Group. All rights reserved.Keywords: Hippeastrum hybridum, anthocyanins, pH indicators, acid-base titrations, shelf life

STUDY THE EFFECT OF CYTOKININS AND AUXINS IN THE COMPOSITION AND PRODUCTION OF IN VITRO PLANTLETS HIPPEASTRUM HYBRIDUM

The First Part of this study was conducted in the Plant Tissue Culture Lab at the College of Science, University of Nahrain from October 2014 to February,2015. The experiment was then completed in the Plant Tissue Culture Lab at the College of Agriculture, University of Baghdad From February 2015 to September 2015. Examine the possibility of using the tissue culture technique in the propagation of Hippeastrum hybridum. Explants (Bulbs, Leaves) had been sterilized using four different NaOCL concentrations: % 4.0, 2.0, 1.0, 0.0. After sterilization, explants were cultured on MS media supplemented with BA at four concentrations (2.0, 1.0, 0.5, 0.0 mg.liter-1) and NAA at four concentrations (0.5, 0.3, 0.1, 0. 0 mg.liter-1) to obtain plantlets. Afterwards, plantlets were moved to new MS media supplemented with BA (2.0, 1.0, 0.5, 0.0 mg.liter-1) and with or without four concentrations of NAA (0.5, 0.3, 0.1, 0.0 mg.liter-1) to enhance shoot proliferation. The resulted shoots from the best proliferation-enhance media were divided into two parts the first part was transferred to root-promoting media which also included two experiments where the first experiment was by transferring the shoots to MS media (half and full strength) supplemented with NAA at four concentrations (0.5, 0.3, 0.1, and 0.0 mg.liter-1). The second experiment included the best resulted shoots from the first experiment in addition to (0 and 2 mg.liter-1) actived charcoal to increase root percentage, root count, and root length.The resulted plants were acclimatized using peatmoss/soli mixture at the ratio of 1:1, 2:1, and 1:2 to obtain high surviving ratio. Results showed that the best explant(Bulbs, Leaves) was soaking in 3% NaOCl for 10 min. the results also showed that the leaves gave best response 90% when using MS media supplemented with 1.0 mg.liter-1 BA and 0.3 mg.liter-1 NAA when compared with the bulbs that showed low response profile. Furthermore, the best shoot proliferation media was MS supplemented with 1.0 mg.liter-1 BA and 0.3 mg.liter-1 NAA which resulted in 8.30 shoots.plant-1. The best rooting percentage was obtained when culturing the shoots in half strength MS media supplemented with 0.5 mg.liter-1 NAA with the existence of activated charcoal. The surviving percentage reached 95% when using the previously mentionedpeatmoss-soil/mixtures.

Effect of Potting Media on Growth, Flowering and Bulb Production of Hippeastrum (Hippeastrum hybridum Hort.)

A pot experiment was conducted at the Horticulture Research Farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur-1706, during the period from March, 2008 to May, 2009 to investigate the suitable potting media for flower and bulb production of hippeastrum. The potting media containing a mixture of rice husk and cowdung at the ratio of 1:1 supplemented with 10 g per pot (30 cm) each of TSP and MP was found to be the best for bigger size of flower (14.20 x 13.70 cm) and flower scape (44.40 x 27.30 cm), the highest number (7.4) and weight (252.5 g) of bulblets, the maximum diameter (76.0 mm) and weight (218.4 g) of mother bulb and total bulb yield (470.9 g) of hippeastrum. But the maximum number (3.8) of flower per scape and the longest flowering duration (11.60 days) were obtained from the potting media containing a mixture of soil, rice husk, cowdung and coirdust in 1:1:1:1 ratio supplemented with 10 g each of TSP and MP. Int J Appl Sci Biotechnol, Vol 4(3): 259-271

Influence of sucrose and aluminium sulphate vase life of cut Hippeastrum flower (Hippeastrum hybridum Hort.) as influenced

An experiment with Hippeastrum flower (Hippeastrum hybridum Hort.) cv. ‘Apple Blossom’ comprising three sucrose concentrations viz. 0 (control), 2 and 4 % and five aluminium sulphate concentrations viz. 0 (control), 0.25, 0.50, 0.75 and 1.0 mM at the Horticulture Laboratory of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh during the period from April 01 to April 30, 2009. The experiment was laid out in a Completely Randomized Design (CRD) with three replications. Sucrose, aluminium sulphate and their combinations had significant influence on most of the parameters studied. Transpiration loss and water uptake ratio decreased significantly with the increased sugar levels and aluminium sulphate upto 0.75 mM beyond which they were increased. Transpiration loss and water uptake ratio was found minimum in the vase solution containing 4% sucrose (0.78) and 0.75 mM aluminium sulphate (0.80), which ultimately resulted in an enhanced vase life (9.2 days for sucrose and 9.11 days for aluminium sulphate) of cut Hippeastrum flower. A linear relationship between water uptake and vase life of flowers was found (y = 0.056x + 5.791). Sucrose 4% and aluminium sulphate 0.75 mM in combination gave maximum total water uptake, maximum days to onset of deterioration, the highest average fresh weight of single scape at 6th and 10th day after setting the trial. Transpiration loss and solution uptake ratio was found maximum in the combination of 4% sucrose and 0.75 mM aluminium sulphate (0.48) with the longest vase life of 10.33 days of cut Hippeastrum flower cv. ‘Apple Blossom’.Bangladesh J. Agril. Res. 41(2): 221-234, June 2016

Characterization of a New Tomato Spotted Wilt Virus Isolates Found in Hippeastrum hybridum (Hort.) Plants in Poland

Abstract Two Tomato spotted wilt virus (TSWV) isolates H1 and H2 found in Hippeastrum hybridum plants were characterized based on biological, serological, and molecular properties. Virus isolates showed differences in symptom expression – H1 isolate displayed severe necrotic spots and patterns, whereas mild mosaic symptoms were observed on H2-infected H. hybridum plants. Both TSWV isolates showed comparable reactivity with TSWV-specific antibodies and they induced similar symptoms on herbaceous indicator plants, but some differences between these isolates were detected at the nucleotide sequence level of genomic S and M ssRNAs segment fragments. The nucleotide sequences encoding nucleocapsid (N) and nonstructural (NSs and NSm) proteins showed 98.2%, 97.5%, and 96.5% identity, respectively. Phylogenetic analysis of N and NSs sequences conducted for tested isolates and 31 TSWV isolates included for comparison revealed that H1 and H2 isolates fell into the same cluster and they were grouped together with isolates found previously in different vegetables, ornamentals, and weeds. When NSm ORF was analyzed, the tested isolates formed a separate cluster: H1 isolate showed the highest affinity with TSWV isolates infecting chrysanthemum and pepper plants, whereas H2 isolate was most closely related to other virus isolates found in sweet pepper and tomatoes. These results indicate that both isolates were reassortants between different virus isolates, and represented two novel genetic patterns of TSWV.

Response of N, P and K on the growth and flowering of hippeastrum (Hippeastrum hybridum Hort.)

An experiment was conducted at the Horticultural Research Field of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Salna, Gazipur during September 2008 to May 2009 to determine the response of hippeastrum (cu. ‘Apple Blassom) to different combinations of nitrogen, phosphorus and potassium levels. There were 14 treatment combinations comprising four levels of nitrogen viz. 0, 100, 200, and 300 kgha-1; five levels of phosphorus viz. 0, 200,300, 400 and 500 kgha-1 and five levels of potassium viz. 0, 100, 200, 300 and 400 kgha-1 with an exclusively Cowdung treatment at the rate of 10 tha-1 . The experiment was laid out in a Randomized Complete Block Design with three replications. The growth and flowering parameter of hippeastrum were significantly influenced by combined application of N, P & K.The highest values in respect of leaves per plant (8.6), leaf breadth (5.4 cm), number of plants per bulb (3.07), flower scape per plant (2.07), flowers per scape (4.2), length and diameter of flower (14 cm x 13.83 cm), flower scape (43.33 cm x 29.37 cm) and flowering duration (10.7 days) were observed with N200P400K300. The same treatment showed earliness in days to flower scape emergence (172.3 days), days to flower bud appearance (185.3 days) and days to first flower open (189.3 days). The biggest flower (14.00 cm x 13.83 cm), longest flower scape (43.33 cm), maximum number of flowers per scape (4.20), and maximum flowering duration (11.5 days) were also exhibited by the treatment N200P400K300 .The control treatment (N0P0K0) recorded the lowest values except days to first leaf emergence, days to flower scape emergence, days to flower bud appearance and days to first flower open.Bangladesh J. Agril. Res. 41(1): 91-101, March 2016

Effect of plant growth regulators on flower and bulb production of hippeastrum (Hippeastrum hybridum Hort.)

The experiment was conducted at the Horticultural research field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur during October 2008 to July 2009 to investigate the effect of plant growth regulators on flower and bulb production of Hippeastrum. There were ten treatments comprising of three concentrations of three growth regulators viz., IAA (20, 60 and 100 ppm), ethrel (100, 300 and 500 ppm) and GA3 (100, 300 and 500 ppm) along with control (soaked in water). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Flower and bulb characteristics of Hippeastrum were influenced significantly by different levels of growth regulators. Application of IAA at 60 and 100 ppm and GA3 at 100, 300 or 500 ppm twice as foliar spray at an interval of 30 days promoted the number of bulblets on the treated plants. Ethrel at a concentration of 100 ppm increased the number of flowers per scape (4) and showed earliness in days to flower scape emergence (72.33 days) and first flower open (88.67 days). On the other hand, the biggest size of flower (15.14 cm x 12.44 cm) and flower scape (40.28 cm x 21.95cm) at harvest and the maximum days for flowering (11.50 days) were evident from plants treated with 500 ppm GA3. The highest number of bulblets per plot (40.00), bulbs weight per plot (4056 g) along with bulb yield (40.56 t/ha) were also obtained in GA3 at 500 ppm.Bangladesh J. Agril. Res. 40(4): 591-600, December 2015

Identification of a Hippeastrum hybridum guanylyl cyclase responsive to wounding and pathogen infection

Guanosine 3′,5′-cyclic monophosphate (cGMP) is a critical component of many (patho)physiological processes in plants whilst guanylyl cyclases (GCs) which catalyse the formation of cGMP from GTP have remained somewhat elusive. Consequently, the two major aims are the discovery of novel guanylyl cyclases and the identification of GC/cGMP mediated processes.To identify a novel GC from Hippeastrum hybridum plant and facilitate the preparation of guanylyl cyclase in an amount sufficient for further crystallographic studies, we have constructed an overproduction system for this enzyme. This gene encodes a protein of 256 amino acids, with a calculated molecular mass of 28kD. The predicted amino acid sequence contains all the typical features and shows a high identity to other plant GCs. The GST-HpGC1 was catalytically active in Escherichia coli cells and the purified, recombinant HpGC1 was able to convert GTP to cGMP in the presence of divalent cations. The used overexpression system yields a guanylyl cyclase as 6% of the bacterial cytosolic protein. Besides the identification of HpGC1 as a guanylyl cyclase, the study has shown that the level of HpCG1 mRNA changed during stress conditions. Both mechanical damage and a Peyronellaea curtisii (=Phoma narcissi) fungi infection led to an initial decrease in the HpGC1 transcript level, followed by a substantial increase during the remainder of the 48-h test cycle. Moreover, significant changes in cyclic GMP level were observed, taking the form of oscillations.In conclusion, our data unequivocally identified the product of the HpGC1 gene as a guanylyl cyclase and demonstrates that such an overproduction system can be successfully used in enzyme synthesis. Furthermore, they indicate a link between the causing stimulus (wounding, infection) and guanylyl cyclase expression and the increase in cGMP amplitude. Therefore, it is concluded that appearance of cyclic GMP as a mediator in defense and wound-healing mechanisms provides a clue to the regulation of these processes.

Nitrogen Fertilization as Ammonium or Nitrate-N on <i>Hippeastrum hybridum</i> Bulb Growth

Hippeastrum (Hippeastrum hybridum), a native of Central and South America, is a bulbous ornamental flowering plant in the Amaryllidaceae family. However, the correct balance of NH4 to NO3-nitrogen in a fertilizer mix for Hippeastrum plants is largely unknown. Nitrogen was applied 2x weekly following irrigation at either 0.6 g (high), 0.3 g (medium) or 0.15 g (low) total N every four months. Nitrogen was supplied in different combinations of NO3 and/or NH4. Nitrate:NH4-N ratios were either 100% NO3:0% NH4 (100NO3), 70% NO3:30% NH4 (70NO3), 50% NO3:50% NH4 (50NO3) (second group only), 30%NO3:70%NH4 (30NO3), or 0% NO3/100% NH4 (100NH4). Growth in bulb diameter after one year of fertilizer treatments not only increased from 0.15 to 0.6 g N (low to high level), but also differed with the form of N supplied to the plant. The largest diameter bulbs were produced in the 70NO3 and 50NO3 high N treatments. Within any NO3/NH4-N ratio grouping, fertilization at the high N rate resulted in larger diameter bulbs. No significant differences existed between treatments in the number of bulbs produced. Bulb growth was greater with a portion of N supplied as NO3 than with NH4-N alone. These results indicate that application of N as a mixture of NH4 and NO3 at 0.6 g per 4 months produces the largest increase in bulb diameter.

Sequence analysis and genetic diversity of five new Indian isolates of cucumber mosaic virus.

Cucumber mosaic virus (CMV) is an important virus since it causes severe losses to many economically important crops worldwide. Five new isolates of CMV were isolated from naturally infected Hippeastrum hybridum, Dahlia pinnata, Hemerocallis fulva, Acorus calamus and Typhonium trilobatum plants, all exhibiting severe leaf mosaic symptoms. For molecular identification and sequence analyses, the complete coat protein (CP) gene of these isolates was amplified by RT-PCR. The resulting amplicons were cloned and sequenced and isolates were designated as HH (KP698590), DP (JF682239), HF (KP698589), AC (KP698588) and TT (JX570732). For study of genetic diversity among these isolates, the sequence data were analysed by BLASTn, multiple alignment and generating phylogenetic trees along with the respective sequences of other CMV isolates available in GenBank Database were done. The isolates under study showed 82-99% sequence diversity among them at nucleotide and amino acid levels; however they showed close relationships with CMV isolates of subgroup IB. In alignment analysis of amino acid sequences of HH and AC isolates, we have found fifteen and twelve unique substitutions, compared to HF, DP and TT isolates, suggesting the cause of high genetic diversity.

Bioactivity of Exogenous Cytoskeleton Proteins: Regulation of Development of Plant Microspores as Biosensors

Bioactivity of the cytoskeleton proteins such as actin, myosin and titin that have been extracted from the rabbit muscle was analyzed on plant misrospores as unicellular biosensors. The fibrillar forms of the proteins stimulated the germination of vegetative microspores from horsetail Equisetum arvense and generative (pollen) microspores from knight’s star Hippeastrum hybridum. In special experiments the proteins tested were able to reverse the blockade of ion channels by drugs d-tubocurarine and α-bungarotoxin, acting on cholinoreceptors, or verapamil, regulating Ca2+-channels. Keywords: Actin, biosensors, Equisetum arvense, germination, Hippeastrum hybridum, ion channels’ blockers, myosin, pollen, titin.

Allelopathic effects of Eucalyptus citriodora on amaryllis and associated grassy weed

A Petri dish assay was carried out for screening different concentrations of aqueous extracts of fresh and dry leaves of Eucalyptus citriodora on germination and seedling growth of wild oat weed (Avena fatua). Seed germination, root and shoot length of wild oat exhibited different degrees of inhibition according to the concentration of the aqueous extract. Maximum inhibitions of germination percentage, root and shoot length were recorded when using 25% fresh leaf extract. Based on this preliminary work (Petri dish assay), studies were conducted under greenhouse conditions at the National Research Center, Egypt, in the two winter seasons of 2006/2007 and 2007/2008 to evaluate the effects of foliar and soil treatments of aqueous extracts of Eucalyptus citriodora fresh and dry leaves on wild oat weed as well as on the growth and flowering of amaryllis (Hippeastrum hybridum), compared with the recommended dose of the herbicide tralkoxydim. Amaryllis fresh and dry weights as well as flowering increased significantly when treated with the previous extracts, especially the fresh leaf extract. However, the fresh and dry weights of wild oat were significantly reduced by the aqueous extracts, either fresh or dry, indicating phytotoxic effects. Tralkoxydim caused complete inhibition of wild oat as compared with the control. The studies involved estimation of the endogenous contents of total phenols in weed. With all the treatments, the inhibitory effects on weeds were correlated with accumulation of the internal contents of total phenols, compared to their respective controls. The amount of phenols correlated well with the weed's growth performance. This study establishes the effect of the aqueous extracts on the weed wild oat, associated with amaryllis, which may serve as a tool in establishing their herbicidal potential.

First Report of Capsicum chlorosis virus Infecting Amaryllis and Blood Lily in Taiwan.

Capsicum chlorosis virus (CaCV), a thrips-transmitted, tentative species in the genus Tospovirus, family Bunyaviridae, was first identified in solanaceous crops, but also infects several ornamental crops such as orchid (4), gloxinia (3), and calla lily (1). From 2005 to 2007, virus-like yellow ringspots were observed on the leaves of amaryllis (Hippeastrum hybridum Hort.) and blood lily (Haemanthus multiflorus Martyn.) plants cultured in screenhouses and a private garden, respectively. Three of several hundred amaryllis plants in screenhouses from two places were observed as showing yellow ringspot symptoms and one of six blood lily plants was observed as showing similar yellow ringspot symptoms. Sap extracts from symptomatic leaves were inoculated to Chenopodium quinoa Willd. and the resulting local lesions were passaged three successive times to C. quinoa for virus isolation. Using the tospovirus genus-specific primers gL3637 and gL4435c designed from the conserved region in the L RNA (2), DNA fragments of the expected size of 800 bp were amplified by reverse transcription (RT)-PCR from field samples and local lesions from C. quinoa. Extracts from the diseased plants and local lesions of C. quinoa reacted strongly with antiserum against the nucleocapsid (N) protein of CaCV in ELISA and western blotting. To confirm the identity of this virus, we amplified the N gene from three amaryllis and one blood lily source using primer pair WN2328 and WN3534 designed from the S RNA of Watermelon silver mottle virus (1), and these products were cloned and sequenced. The sequence from each virus isolate was determined from three independent clones. The nucleotide and deduced amino acid sequences of N genes for the blood lily isolate (GenBank Accession No. EF101344) and three amaryllis isolates (GenBank Accession Nos. EF101343, EF137177, and FJ185170) had identities greater than 97% with that of a CaCV isolate infecting Capsicum spp. found in Australia (GenBank Accession No. AY036057). Phylogenetic analysis using maximum parsimony showed that these sequences clustered with CaCV. These results show that the virus identified from amaryllis and blood lily that were expressing yellow ringspot symptoms are isolates of CaCV. To our knowledge, this is the first report of CaCV naturally infecting amaryllis and blood lily and it could become an important threat to ornamental production in Taiwan.

First molecular detection and identification of a potyvirus associated with severe mosaic disease of amaryllis (Hippeastrum hybridum Hort.) in India

A potyvirus associated with mosaic disease of amaryllis was detected and identified by reverse-transcription and polymerase chain reaction using degenerate primers specific to the core region of coat protein gene of potyviruses followed by cloning and sequencing. The sequence shared highest (98–95%) amino acid identities with Amaryllis potyvirus that is not yet recognised by the International Committee on Taxonomy of Viruses, Amazon lily mosaic virus (tentative potyvirus) and Hippeastrum mosaic virus (recognised potyvirus). Screening bulbs of elite amaryllis cultivars for potyvirus infection would be useful to establish virus-free propagating material for the floriculture industry in India.