Search

Three new homoisoflavonoids, (3R)-3,5-dihydroxy-7-methoxy-3-(4’-hydroxybenzyl)-4-chromanone, 4, and its 5-O-β-D-glucopyranoside and 5-O-β-D-gentiobiose derivatives, 5 and 6, along with the known homoisoflavonoids, (3S)-5-hydroxy-7-methoxy-3-(4-methoxybenzyl)-4-chromanone, 1, (3R)-5-hydroxy-7-methoxy-3-(4-methoxybenzyl)-4-chromanone (2) and (3S)-5-hydroxy-7-methoxy-3-(4-hydroxybenzyl)-4-chromanone, 3, were isolated from the bulbs of Ornithogalum dubium Houtt.. In addition, three known cardenolides, 3β-(O-α-L-rhamnoside)-5β,14β-dihydroxy-19-oxocardenolide 7, 3β-(O-α-L-rhamnoside)-5β,11α,14β-trihydroxy-19-oxocardenolide, 8 and 3β-(O-α-L-rhamnoside)-5β,11α,14β,19-tetrahydroxycard-20(22)-enolide, 9, were isolated from Ornithogalum ponticum ‘Sochi’. Yields of homoisoflavonoids were low (0.0002 % - 0.0003 %) so stereospecific synthetic methodology needs further refinement to produce antiangiogenic (3R)-3-benzylchromanones and (3S)-3-hydroxyhomoisoflavonoid analogues for further evaluation. This work confirms that, apart from producing cardenolides, the absolute configuration at C-3 of homoisoflavonoids produced by Ornithogalum is 3R (H-3β) for the 3-benzylchromanones and 3S (3-OH β) for the 3-hydroxy benzylchromanones, in agreement with our earlier reports.

Fragrance is a desirable characteristic for cut flowers, but is rare among commercial cultivars. To date, there are no transformed commercial flower cultivars with increased fragrance, despite the fact that genetic engineering can generate fragrance in ornamentals without compromising on other commercial traits. One of the major volatile groups responsible for fragrance of flowers such as roses, petunia, snapdragon and clarkia, are the phenylalanine-derived benzenoid phenylpropanoids (BPVs). Here we show that a variety of commercial flowers, belonging to taxonomically distant plant species have the potential of producing fragrant BPVs when treated with exogenous phenylalanine. This group of flowers includes chrysanthemums, roses, anemones, Ornithogalum dubium and gerberas. Chrysanthemums, among the five leading flowers in the cut flower industry, lack flowery fragrance. However, treatment of cut chrysanthemums with phenylalanine resulted in an increase in BPVs preexisting in the flowers, producing a flowery fragrance clearly distinguished by a sensory panel. Similarly, phenylalanine treatment of anemones, also lacking fragrance, resulted in fragrant flowers. However, unlike chrysanthemums, in anemones, in addition to increasing preexisting BPVs, phenylalanine treatment resulted in production of new BPVs, not detected in non-treated flowers. Production of novel compounds due to phenylalanine treatment suggests that concealed metabolic pathways do exist in plants, may be activated by increased substrate availability. This study presents the potential of phenylalanine treatment as a way for increasing flowery fragrance in a large variety of non-fragrant commercially important plants.

Bulbs, corms and other subterranean storage organs are commonly used as explant source material for the establishment of geophytes in vitro. The inflorescence stalk was found to be a good alternative source of explants to overcome explant contamination originating from underground storage organs. Inflorescence explants of Allium, Dichelostemma, Eucrosia, Gladiolus, Haemanthus, Hyacinthus, Narcissus, Nerine and Ornithogalum were used to establish cultures in vitro. The regeneration potential of the inflorescence was compared with regeneration from bulb twin scales or from apical buds isolated from corms. Gladiolus (Iridaceae) explants isolated from the floral stem just below the expanding florets, still enclosed in the bracts, were highly regenerative in the presence of naphthalene acetic acid (NAA) and kinetin. In the presence of 2,4-dichlorophenoxyacetic acid and benzyl aminopurine (BA) in the medium, explants isolated from the tissue at the junction between the peduncle and the pedicels of a young Nerine (Amaryllidaceae) inflorescence regenerated several buds. The scapes of young unemerged inflorescences taken from sprouting bulbs of Narcissus (Amaryllidaceae), following a 15 °C storage treatment, regenerated buds in the presence of NAA, BA, elevated phosphate and adenine sulfate in the medium. The number of buds regenerated depended on the location on the scape from which the explant was isolated, and on the duration of the 15°C treatment. In Allium (Alliaceae), capitulum tissue between the flower pedicels regenerated buds. Explants excised from the peduncle, as well as the pedicel-peduncle junction of Dichelostemma (Alliaceae), Ornithogalum, Hyacinthus (Hyacinthaceae) and Eucrosia (Amaryllidaceae) regenerated several buds in each type of explant. In the case of Haemanthus (Amaryllidaceae), pedicel-peduncle junction explants regenerated buds only when excised from inner whorl florets. Propagation protocols and the potential use of expediently isolated inflorescence explants for efficient micropropagation of geophytes are discussed.

74. Ornithogalum dubium Houtt., Nat. Hist. II(12): Aanwyz. Plaat. [2], 309, tab. 82, fig. 3. 1780. Lectotypus (designated here by Wijnands): SOUTH AFRICA: Auge s.n. [?] (G-PREL [G00818064]!). Notes. ��� Original material is present in the Cape herbarium. It is designated here as the lectotype. There is no obvious corresponding collection in UPS-THUNB., Published as part of Wijnands, Dirk Onno, Heniger, Johannes, Veldkamp, Jan Frederik, Fumeaux, Nicolas & Callmander, Martin W., 2017, The botanical legacy of Martinus Houttuyn (1720 - 1798) in Geneva, pp. 155-198 in Candollea 72 (1) on page 182, DOI: 10.15553/c2017v721a11, http://zenodo.org/record/5721887

Benzothiadiazole (BTH) is a structural analogue of salicylic acid (SA) which is widely recognized for its role in elicitation of systemic acquired resistance in a broad range of plant species. Here, BTH was applied to cell cultures of the bulbous ornamental plants Ornithogalum dubium and O. thyrsoides, showing a strong effect on rates of differentiation and morphogenesis. Morphogenic cell clusters in liquid Murashige and Skoog (MS) medium containing 1-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) were used for all treatments. The calluses were washed thoroughly and activated with increasing concentrations of BTH. Following the induction, calli were grown on a solid MS medium without growth regulators (MS) or on a comparable media with NAA and BAP (M-206). The calli treated with BTH displayed a dose dependent increase in formation of meristematic centres followed by enhanced shoot formation compared to controls. Microscopic analyses revealed increased differentiation to cell organelles and a strengthening of the cell wall. A stronger response to BTH was observed in MS than in M-206 medium. A similar effect on calli differentiation was obtained by three weeks darkness followed by light exposure. The dark/light positive effect on differentiation was further augmented by BTH in a synergistic fashion. It is suggested that BTH enhances the rates of morphogenesis in Ornithogalum cultures by triggering a plant regulator-like activity.

Aims: Ornithogalum dubium is a natural host of the soft rot pathogen Pectobacterium carotovorum ssp. carotovorum (Pcc). The present study was aimed to develop a quantification system for Pcc expressing a gfp reporter gene, using fluorescent activated cell sorter (FACS) in planta. Methods and Results: Several calibration steps were required to distinctly gate the GFP-labelled bacteria at FL1 mode and count the bacteria. To validate the bacterial counts obtained by FACS analysis, an internal standard of polystyrene green fluorescent microsphere beads was employed, resulting in high correlation with serial dilutions and plate counting. This allowed quantification of the bacteria, with no further need to culture, dilute or plate the cells. Micropropagation tools were developed to produce uniform plantlets of O. dubium, which were either inoculated with increasing concentrations of Pcc or elicited for resistance towards Pcc using methyl jasmonate. The rapid counting procedure allowed recovering, gating and counting the bacterial population in planta, separately from the plant cells background and from the microsphere beads. Conclusions: The FACS based quantification approach of Pcc was found accurate, reproducible and time saving, thus useful for counting bacteria in planta. Significance and Impact of the Study: The combination of time- and cost-saving approach for Pcc quantification with efficient screening tools during early stages of micropropagation may facilitate the preliminary process of selection for resistant cultivars.

Genetic transformation mediated by bombardment with microscopic metal particles carrying target genes is the preferred method for the introduction of foreign genes into monocotyledonous plants. The fact that most flower bulbs are monocotyle-donous and that almost all commercial cultivars are propagated vegetatively makes them good candidates for molecular breeding through microprojectile bombard-ment. We report here on a development of a reliable method for an efficient genetic transformation of both Lilium longiflorum and Ornithogalum dubium using a particle inflow gun to deliver gene constructs into the target plant tissue, followed by a prolonged selection in the dark in liquid medium supplemented with kanamycin. The system was first optimized for Lilium longiflorum 'Snow Queen'. Based on the level of transient GUS expression, liquidgrown cell clumps are more competent than leaves. Large cell clusters (2-10mm) maintain their organogenic potential while smaller clusters (

SummaryOrnithogalum dubium hybrid 327 clone 2 (‘327-2’) bulbs were stored dry at 10°, 16°, 22°, 28°, and 35°C for six weeks after harvest. After storage, bulbs were evaluated by nuclear magnetic resonance imaging (MRI) to obtain the spin-lattice relaxation time (T1) profile across the transverse section of intact bulbs, by scanning electron microscopy (SEM) to observe inflorescence development, and by forcing in a 18.5°/18°C greenhouse to observe growth and flowering responses. Bulbs treated at 10°C had the shortest T1 (0.33 ms) through the bulb which is largely composed of scales. Leaf emergence from bulbs treated at 10°C was delayed, and plants failed to flower. This indicated that bulbs were dormant and dormancy was not broken, thus delaying initiation of floral organs. Bulbs treated at 22°C and 28°C formed the primary inflorescence with several florets. At the base of the primary scape of bulbs treated at 22°C, a vegetative apex was observed by both MRI and SEM. In the centre of bulbs where both leave...

Ornithogalum dubium is a frost-tender bulbous plant native to South Africa. It is mainly grown for cut flower and flowering pot-plant production. It generally produces 10-25 cm-long flowering-stems, bearing 5-25 yellow to orange flowers with a dark green/brown center. It is in great demand in Europe and North America as a cut flower and a flowering-house pot plant. O. dubium was introduced as a new cut-flower crop less than a decade ago and is still only grown on a small scale due to its variable flower quality. The main objective of the present study was to improve flowering-stem length. A three week preplanting temperarture treatment of 13C resulted in significantly longer flowering-stems than treatments at 2, 9 or 25C. Controlled growth-temperature and day length experiments indicated that warm day/night tempertures of 27/22C induce early anthesis. Under this temperature combination, earliest flowering occurred under long day conditions. Stem length was maximal at moderately-low production temperatures, and long days further increased length. The number of florets per inflorescence depended on temperature. Under the two lower temperature regimes, many flowers developed per inflorescence and, again, long days enhanced this number. However under the highest temperature regime tried, this effect was reversed. Bulbs of different size were planted and even the smallest, flowered during the first year. Leaf production was proportional to planted bulb size. The rate of growth, time to flowering and total yield of daughter bulbs also depended on size of the planted bulb. Gibberellin, applied either as a preplanting dip or as foliar sprays, moderate shading (20%), as well as, a 24-h pre-planting exposure of bulbs to 10 ppm ethylene all increased flowering-stem length. INTRODUCTION Ornithogalum (Family Hyacinthaceae, formerly Liliaceae), a genus of some 150 species of bulbous plants mainly found in the Mediterranean (and also in the temperate) regions of Africa, Asia and Europe (Bryan, 1993). Ornithogalum dubium Houtt. is native to South Africa. It is a frost tender plant grown mainly for cut flower and flowering pot-plant production. The inflorescence is generally a 10-25 cm long raceme, bearing 5-25 yellow to orange flowers with a dark green/brown center (Du Plesis and Duncan 1989). These flowering-stems are in great demand in Europe and North America as cut flowers. The plants are also gaining popularity as a potted flowering-plant. O. dubium was introduced as a new cut-flower crop less than a decade ago and it is still grown on a small scale due to several limitations. Some of these are related to the availability of high-quality planting material. Propagation from seed introduces wide genetic variability, whereas propagation from bulbs is more expensive and results in fast accumulation of virus disease. The main problem however is the often poor flower quality characterized by short flower stems which are unacceptable on the cut flower market. Proc. 8th Int. Symp. on Flowerbulbs Eds. G. Littlejohn et al. Acta Hort. 570, ISHS 2002 114 Growth and flowering of all commercially grown geophytes are significantly affected by environmental conditions at all stages of their development. These can be manipulated for controlled and predictable production (De Hertogh and Le Nard, 1993). Bulb storage, forcing treatments, temperature, daylength and light intensity during growth, as well as, the use of plant growth regulators and shading, have all been used to improve flower quality which also includes elongation of the floral stem (De Hertogh and Le Nard 1993, Halevy 1990). Since little has so far been published for O. dubium (De Hertogh and Gillitano 1997), the objective of the present study was to examine the effects of production temperature, daylength and light intensity, gibberellin and ethylene treatments, as well as bulb size, on growth and flowering of O. dubium. The work was conducted over 4 years. MATERIALS AND METHODS All bulbs used in the following experiments were lifted in July after one season's growth from seed. They were stored in a well ventilated shed for 150 days, under ambient conditions with a daily average temperatures ranging between 25 and 30°C. Bulbs were planted in early November. 1. Precooling Temperature. Bulbs sized 2-3 cm in circumference, were precooled for three weeks at 2, 9, 13 or 25°C. Twenty five bulbs per treatment replicated four times were planted in sandy loam, in unraised beds in an unheated, plastic clad greenhouse. Flowering-stem length was measured at anthesis of the first floret. 2. Precooling duration. In the following year, the effect of precooling duration, ranging from 0 to 8 weeks, was tested at 13°C, as above. 3. Effect of Growth Temperature. Bulbs stored for 150 days and precooled at 13°C were used for this experiment which was conducted in The Hebrew University Phytotron at Rehovot. The temperatures in the different units were:32/27, 27/22, 22/17 and 17/12C (day/night) with a deviation of up to 0.5°C. Light conditions in the units were either 8 h of daylight (short day) or 8 h of daylight plus 8 h of incandescent light at 5 mmol m s (long day). Twenty bulbs (2-3 cm in circumference) were planted individually in 15 cm pots for each treatment. Days to flowering, floweringstem length and the number of florets per stem were recorded. Growth Regulator Treatments 1.Gibberellin and Shading. Stored and precooled bulbs were planted in a greenhouse as described above. The treatments were:a 20 min preplanting bulb dip in a 100 ppm GA3 solution, a single canopy spray with a 100 or 200 ppm GA3 solution when plants were either at the rosette stage (~30 days after planting), or, when the flowering-stem had reached a length of 5 cm (~ 60 days after planting). Shading treatments to reduce natural light intensity by 20 to 40% were combined with the GA treatments. Twenty bulbs were replicated four times per treatment. 2.Ethylene. Twenty bulbs weighing 2g each which were stored for 150 days were held in the presence of 10 ppm ethylene for 24 h at room temperature prior to planting. Sprouting date, leaf length at flowering and flowering stem length were recorded. 3. Effect of Bulb Size on Growth and Flowering. Eighty stored and precooled bulbs were weighed individually and planted at random in a large polystyrene box placed in an unheated greenhouse.To facilitate recording of data, each bulb position in the box was marked. The number of leaves per plant 65 days after planting, days to flowering, and the total weight of daughter bulblets per plant, were recorded at lifting. RESULTS Following 150 days of storage and a three week dry, precooling treatment at 2, 9, 13 or 25°C, all planted bulbs flowered well. Stem length varied with temperature, the 13°C treatment resulting in significantly longer flower stems than in all other temperatures tried (Table 1). The duration of precooling at 13°C did not affect the time from planting to flowering which was 20 ± 1 weeks. However, just a short two week precooling treatment resulted in. significantly longer flowering-stems over those produced by uncooled bulbs. Maximum stem lengths were obtained

Bacterial soft rot caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) is one of the most devastating diseases of Ornithogalum species. No effective control measures are currently available to use against this pathogen; thus, introduction of resistant genes via genetic transformation into this crop is a promising approach. Tachyplesin I, an antimicrobial peptide, has been shown to effectively control numerous pathogenic bacteria, including Pcc. In this study, liquid-grown cell clusters of Ornithogalum dubium and Ornithogalum thyrsoides were bombarded with a pCAMBIA2301 vector containing a cel I leader sequence fused to a gene encoding tachyplesin I, a neomycin phosphotransferase ( npt II) gene that served as a selectable marker and a β-glucuronidase (GUS) gene that served as a reporter. Selection was carried out in the dark in liquid medium containing 80 mg/L kanamycin. Regeneration was executed in the light after 6–14 months depending on the cultivar. Hundreds of transgenic plantlets were produced and their identity was confirmed through GUS activity assays. PCR and RT-PCR were used to confirm the presence of the target, reporter and selection genes in the divergent lines of plantlets. The resistance of the O. dubium plants to Pcc was evaluated in vitro, following infection with a highly virulent isolate from calla lily. Although control plantlets were completely macerated within a week, 87 putative transgenic subclones displayed varying levels of disease resistance. During three growing seasons in the greenhouse, the transgenic O. dubium lines grew poorly, whereas the transgenic O. thyrsoides plants grew similarly to non-transgenic plants.

Additional index words. embryo rescue, breeding, pot-plant, carotenoids Abstract. Embryo rescue was successfully applied to develop hybrids between Ornithogalum dubium Houtt. (short inflorescence with orange flowers) and O. thyrsoides Jacq. (tall inflorescences with white flowers). Meiosis in these hybrids showed abnormalities such as univalents, laggards, and bridges. The F, hybrids were partially fertile, and F 2 and BC1 progeny were produced. The backcross hybrids segregated for flower color and, inflorescence traits and introgressed seedlings with orange pigmented flowers on tall inflorescences were obtained in the population. Several Ornithogalum species produce long lasting cut flowers and are commercially grown in the United States and Europe. The most commonly grown species is O. thyrsoides, characterized by a tall 20 to 90 cm long raceme with a tight cluster (short pedicels) of between 10 to 70 flowers, 3 to 5 cm in diameter. The perianth is yellow-white to white with a dark greenish or brown center that fades with age (Obermeyer, 1978; R.D. Pienaar, personal commu- nication). Another species, O. dubium, is noted for its bright yellow to deep orange-pigmented flowers. There is also a form with white flowers. The colored form of O. dubium produces a short 10 to 25 cm long raceme with a loose cluster (long pedicels) of between 5 and 25 flowers, 2 to 3 cm in diameter. The white form of O. dubium (formerly known as O. alticolum) is taller (up to 70 cm) and often confused with O. thyrsoides (Obermeyer, 1978; R.D. Pienaar, personal communication). Our goal was to extend the color spectrum of the commercial cut-flower types and to develop new pot-plant forms through interspecific hybridization of O. dubium and O. thyrsoides. The initial crosses were consistent with those of Pienaar (1963) and Van Niekerk and Pienaar (1968) who found that the interspecific crosses between most of these two species did not produce mature viable seed. This paper describes the use of in vitro, ovule-rescue in obtaining interspecific hybrids and the carotenoid analysis of their flowers. Materials and Methods

In 1982 the new crops research program was initiated in the Florist and Nursery Crops Laboratory to increase the diversity of florist crop germplasm in the United States. Anigozanthos, Chamelaucium, Correa, a dwarf form of Eustoma grandiflorum ‘Little Blue Belle’, Chamelaucium, Cupressus, and other crops have been introduced to the industry with information that describes propagation, culture, and controlled flowering. Rooting of cutting or in vitro tissue culture propagation of new crops had included Achimenantha, Chamelaucium uncinatum, ‘Purple Pride’, and Eustoma grandiflorum, ‘Little Belle Blue’, Ornithogalum dubium, Lachenalia aloides, and Lilium. In addition, a new production technology using bulbils as propagules was developed for Lilium elegans, Asiatic hybrid lily. This production technology is discussed.

Techniques are described to determine whether embryos are formed in ovules of incompatible crosses between Ornithogalum (L.) plants, and to rescue embryos in cases where the development of embryos is halted following fertilization. By using Herr's clearing liquid, it can be ascertained within 5 hours whether hybrid embryos have been formed. Such embryos can be rescued by culturing them in ovulo on basal medium containing 70 g sucrose/liter and no added growth regulators. The embryos' requirement for sucrose changes as they develop; therefore, cultured ovules are transferred after 14 days to a medium containing 10 g sucrose/liter, where germination occurs.

The ovule of Ornithogalum dubium is anatropic, bitegmic and crassinucellate. The integuments are biseriate. Starch grains occur in the outer integument, the funicule and in the intercellular space surrounding the embryo-sac. The embryo-sac development is of the Polygonum type. The synergids are conspicuous and contain a large filiform apparatus. Fertilization is porogamic and occurs 24 h after pollination. The pollen tube enters the egg apparatus in the region of an intercellular space between the micropylar ends of the synergids. Sperm cells in the pollen tube appear to be released through small protuberances of the pollen tube. Migration of the sperm cell to the egg cell is possibly through a gap in the wall between the egg cell and the receptive synergid. Changes in the synergids occur only after a pollen tube has entered the receptive synergid. Changes occurring in the persistent synergid suggest that this cell may be involved in the nutrition of the pro-embryo up to the eight-cell pro-embryo stage. Syngamy is of the post-mitotic type. The first division of the zygote is transverse. The basal cell gives rise to the multicellular suspensor, and the terminal cell to the embryo. The endosperm is of the Helobial type.