Tulip Research Articles

Trichoderma polysporum as possible weak pathogen of tulip bulbs and roots

In the spring 2000, on tulip plantations in south-eastern Poland, spots of died-off plants were observed. The inhibited growth, wilting of leaves and yellowish necrosis on roots and scales surface occurred especially in low-lying areas. Mycological analysis indicated the presence of Trichoderma polysporum (Link ex Pers.) Rifai on the bulbs and roots of all tested plant samples. Pathogenicity test of 7 T. polysporum isolates was carried out on forced tulips cv. Merry Christmas in flower pots. After flowering, brownish necrosis (covering 5–30% of the surface) on the bulbs and roots were observed, as well as white-yellowish mycelium heaps of T. polysporum. Typical Trichoderma symptoms on above-ground plant parts like light-gray leaves tips were not observed.

First Report of Tulip band breaking virus in Mosaic Diseased Tulip in Japan.

Tulip (Tulipa spp.) is an ornamental plant of major economic importance in Japan. Regions in Toyama Prefecture are some of the most productive for producing tulip bulbs, shipping approximately 50 million bulbs annually. However, mosaic diseases caused by viruses such as Tulip breaking virus (TBV) currently limit bulb production in these areas. Only the potyviruses TBV and Lily mottle virus (LMoV) have been reported infecting tulip in Japan. A virus isolate from tulip with flower-breaking symptom in Toyama Prefecture was tentatively named OE4 and was presumed to be LMoV after detection by LMoV-specific reverse transcription-polymerase chain reaction (RT-PCR) (4). When OE4 was mechanically inoculated on test plants (13 species from six families), RT-PCR confirmed that it infected plants in the Liliaceae (Tulipa spp., Lilium formosanum, and L. concolor) with mosaic symptoms but did not induce any symptoms in Chenopodium quinoa, Tetragonia tetragonoides, and Nicotiana benthamiana. According to Dekker et al. (2) LMoV and Tulip band breaking virus (TBBV) infected Tulipa spp. and TBBV did not infect C. quinoa, T. tetragonoides, N. clevelandii, and N. benthamiana, species that were local or systemic hosts for LMoV. To analyze the genomic sequence of OE4, a primer set was designed for amplifying the coat protein (CP) gene of LMoV, with 5' -GCAAATGAGACACTCAATG-3' as a forward primer and 5'-TTACATAGAAATTCCAAGTAAG-3' as a reverse primer. The fragment obtained was cloned and sequenced (DDBJ/EMBL/GenBank Accession No. AB078007). The CP gene of OE4 consisted of 825 nucleotides and had 86.5% identity (90.6% identity in deduced amino acid sequence) with the CP gene of LMoV-Netherlands (S44147) (3). When it was compared with partial sequences (277 nucleotides) of LMoV (S60810) and TBBV (S60805) (2), the nucleotide sequence identities were 89.9 and 96.4%, respectively. Multiple alignment and a phylogenetic tree based on the 277 nt of the tulip potyviruses, including OE4, showed the close relationship between OE4 and TBBV. These results indicated that OE4 was an isolate of TBBV. However, the CP amino acid sequence identity between TBBV and LMoV was more than 80%, and it seemed logical that TBBV be assigned to a strain of LMoV, according to potyvirus species demarcating criteria (1). Another screening using RT-PCR based detection, and an inoculation test for 55 flower-breaking tulips collected from fields in Toyama Prefecture revealed that four tulip plants were infected with TBBV and 54 with TBV. This suggests that TBV is more prevalent than TBBV, and we need to produce an attenuated virus of TBV, which will be effective for managing tulip breaking disease in the prefecture.

Bud abortion in tulip bulbs studied by magnetic resonance imaging.

After storage and subsequent planting of flower bulbs, the flower bud frequently appears to be aborted. This physiological aberration is probably caused by a change in the water status of the bulb and may be initiated during storage. The development of bud abortion in tulip bulbs was studied during long-term dry storage of the bulbs at 5 degrees C. The anatomy of individual tulip bulbs was followed non-invasively with T2-weighted NMR imaging, which allowed the monitoring of the growth of the shoot and daughter bulbs. Quantitative maps of T1 and T2 relaxation times of individual bulbs were used to assess regional changes in the water status of different tissues. Parallel to the NMR measurements, bulbs were planted to assess the ultimate flower quality. Moreover, water content, osmolality of tissue sap and ion leakage of excised shoot and scale tissues were determined to obtain information about the water status and viability of the bulbs. Significant decreases during long-term storage were found in T1 and T2 relaxation times in the shoot and particularly in the stamens. An increase in the osmolality of tissue sap and the decrease in relaxation times in the shoot below a certain threshold value attained after 24 weeks of storage, could be indicative for the emergence of bud abortion in tulips.

The ‘tulip sign’: a sonographic clue for in‐utero diagnosis of severe hypospadias

AbstractObjectiveTo describe a unique sonographic sign for prenatal detection of severe penoscrotal hypospadias.MethodsUltrasound findings of hypospadias diagnosed in the second trimester of pregnancy in seven patients were compared with postnatal clinical features. All patients were recruited from routine sonographic examinations performed for various obstetric indications.ResultsIn six of the seven cases with hypospadias, a severe form of peno‐scrotal hypospadias was found. In all six cases, a unique ultrasound feature was observed represented by extreme ventral angulation of the penis, with or without chordee, in a form resembling a tulip flower. This ‘tulip’ is formed by the ventrally bent penis located between the two scrotal folds. In all six patients, the postnatal pictures of the newborns' genitalia corresponded perfectly to the prenatal sonograms. Associated anomalies occurred in two cases, with Nager syndrome in one case and mild renal hydronephrosis in the other case.ConclusionsThe ‘tulip sign’ is a specific ultrasonic finding of severe hypospadias. The recognition of this may help to distinguish between severe hypospadias and other genital abnormalities (e.g. ambiguous genitalia). Copyright © 2002 ISUOG

Carbon dioxide and ethylene interactions in tulip bulbs.

The effect of CO2 on ethylene-induced gummosis (secretion of polysaccharides), weight loss and respiration in tulip bulbs (Tulipa gesneriana L.) was investigated. A pretreatment with 1-MCP prevented these ethylene-induced effects, indicating that ethylene action must have been directed via the ethylene receptor. Treatment with 0.3 Pa ethylene for 2 days caused gummosis on 50% of the total number of bulbs of cultivar Apeldoorn, known to be sensitive for gummosis. Addition of CO2 (10 kPa) reduced the ethylene-induced gummosis to 18%. In a second experiment the influence of ethylene and CO2 on respiration and FW loss of bulbs of the cultivar Leen van der Mark was studied. A range of ethylene partial pressures (0.003-0.3 Pa) was applied continuously for 29 days. Ethylene caused a transient peak in O2 consumption rate during the first days after the start of application. The relation between O2 consumption rate and ethylene partial pressure could be described by Michaelis-Menten kinetics. Respiratory peaks were reduced by CO2. This inhibition by CO2 could not totally be due to competition with ethylene at the receptor binding-site, as was indicated by the use of an O2 consumption model. Pre-treatment of bulbs with 1-MCP and subsequent exposure to CO2 showed that CO2 could influence respiration irrespective of any interaction with ethylene. Ethylene and CO2 both stimulated weight loss. The effect of combined treatments of ethylene and CO2 on weight loss was at least as strong as the sum of the separate effects, which implies that competition between ethylene and CO2 at the receptor binding-site was unlikely.

DEFINING SAFE ETHYLENE LEVELS FOR LONG TERM STORAGE OF TULIP BULBS

The maximum ethylene level that can be permitted in storage rooms, without causing damage to tulip bulbs, is not exactly known. Therefore, a zero-tolerance for the presence of ethylene during storage of tulip bulbs is common practice. This results in excessive ventilation and coherent large energy costs. It is questioned whether this is always necessary. In different phases of the storage period the critical levels of ethylene were determined. Bulbs of eight economically important cultivars (‘Apeldoorn’, ‘Christmas Marvel’, ‘Leen van der Mark’, ‘Monte Carlo’, ‘Negrita’, ‘Prominence’, ‘White Dream’ and ‘Yokohama’) were exposed to various ethylene levels. In the first experiment bulbs were exposed to ethylene for two days shortly after harvest. Only in the cultivar ‘Apeldoorn’ this resulted in gummosis. In two subsequent experiments later during storage, bulbs were exposed to various ethylene levels during five weeks. Bulbs were investigated on visible internal damage, flower quality and bulb production. Damage depended on applied ethylene level, cultivar and period of storage. Research will be continued to define tolerable ethylene levels, taking into account the cultivar and the developmental stage of the bulb.

A GREENHOUSE SCREENING ASSAY FOR BOTRYTIS TULIPAE RESISTANCE IN TULIPS

As a leaf pathogen, Botrytis tulipae severely affects tulip bulb production. Chemical control is not desired for environmental reasons. Thus, resistant cultivars can play an important role in the control of this disease. To select genotypes resistant to B. tulipae, a reliable screening assay is needed. A greenhouse test was developed to establish resistance at clonal level. Removal of the wax layer by soft rubbing of the leaves was essential to obtain a homogeneous distribution of the spore suspension on the leaves. Small lesions were found within 24 hr after inoculation. Continuous leaf wetness was obtained by regular water evaporation. This was essential to obtain rapidly spreading lesions. After eight days, leaves of susceptible genotypes were completely destroyed. Large differences in resistance were found within tulip genotypes. Feeding additions to the inoculum suspension enhanced the infection process, but were unnecessary. Plants inoculated before flowering were less sensitive to B. tulipae than plants inoculated at flowering. Plants inoculated after flowering were most sensitive to infection. Ranking of resistance for the tested genotypes before or after flowering however remained nearly the same. The influence of factors involved in the screening test and the implications for resistance breeding are discussed.

CONTROL OF SPREAD OF AUGUSTA DISEASE CAUSED BY TOBACCO NECROSIS VIRUS IN TULIP BY COMPOSTING RESIDUAL WASTE OF SMALL BULBS, TUNICS, ROOTS AND SOIL DEBRIS

ISHS VIII International Symposium on Flowerbulbs CONTROL OF SPREAD OF AUGUSTA DISEASE CAUSED BY TOBACCO NECROSIS VIRUS IN TULIP BY COMPOSTING RESIDUAL WASTE OF SMALL BULBS, TUNICS, ROOTS AND SOIL DEBRIS

Windbreaks in southern Patagonia, Argentia : A review of research on growth models, windspeed reduction, and effects on crops

In Patagonia, where strong winds are a constraint to agricultural production, live windbreaks are often planted in agricultural fields to protect crops, livestock, and soils from wind hazards. The major factors that determine the efficacy of windbreaks are height, porosity, orientation, length, and location in the landscape. A review of the research on the effect of live windbreaks during 1993 through 2000 is presented in the paper. Porosity and distance from windbreak were found to have major effects on relative windspeed reduction. The greatest degree of protection was for dense windbreaks (windspeed reduction of 85%) at 1H (1H = a distance of one tree height, leeward of the windbreak). Different crops showed a differential yield response to wind stress. The production of garlic (Allium sativum) was not significantly affected by wind. Tulip (Tulipa sp.) bulb yield decreased on average by 25% between 2H and 17H. The production of lucerne (Medicago sativa) at 1H was 40% higher than lucerne grown in open conditions. In contrast, strawberry (Fragaria sp.)and cherry (Prunus avium) were more sensitive to the effect of the wind. Dendrometric models (diameter, site index, volume and crown dynamics) were developed to define the wood potential productivity that could be expected from different site qualities. The prediction of height growth as a function of age, allows the estimation of the area protected by the windbreak. An economic assessment based on realistic estimates of shelter benefits is required to encourage the development of windbreak systems that could also offer other benefits, including erosion control and timber production.

Changes in the Distribution of Tulip Bulb Cultivation in the Kurobe Alluvial Fan

Changes in the Distribution of Tulip Bulb Cultivation in the Kurobe Alluvial Fan

Karyotypic study in some Iranian species and populations of Tulipa L. (Liliaceae)

Karyotypic studies were performed on 12 species/ populations of Iran- ian tulips for the first time. The species/ populations possessed 2n = 2x = 24 chro- mosome number but varied in details of karyotype including type of chromo- somes, karyotype symmetry and number of SAT-chromosomes and differed sig- nificantly in total chromatin length as well as length of chromosome arms. A pair of heteromorph chromosomes occurred in T. humilis. The use of karyotypic da- ta in taxonomy of the genus Tulipa L. is discussed.

The botany of desire: a plant's eye view of the world

A farmer cultivates genetically modified potatoes so that a customer at McDonald's half a world away can enjoy a long, golden french fry. A gardener plants tulip bulbs in the autumn and in the spring has a riotous patch of colour to admire. Two simple examples of how humans act on nature to get what we want. Or are they? What if those potatoes and tulips have evolved to gratify certain human desires so that humans will help them multiply? What if, in other words, these plants are using us just as we use them? In blending history, memoir and superb science writing, Pollan tells the story of four domesticated species - the apple, the tulip, marijuana and the potato. All four plants are integral to our everyday lives and Pollan demonstrates how each has thrived by satisfying one of humankind's most basic desires. Weaving fascinating anecdote and accessible science, Pollan takes the reader on an absorbing journey through the landscape of botany and desire. It is a journey that will change the way we think about our place in nature

Magnetization transfer and double-quantum filtered imaging as probes for motional restricted water in tulip bulbs

Parameter sensitive MRI experiments were performed on tulip bulbs before and after storage at two different temperatures, 4°C (chilled), and 20°C (non-chilled). Quantitative measurements of the amount of magnetization transfer (MT) in the storage scales of the bulbs, were compared to the average values of the relaxation rates R1 and R2, and the apparent normalized spin density (NSD). At the end of the storage period, bulbs were also scanned using 1H double quantum (DQ) filtered imaging. Both MT and DQ filtered imaging revealed significant differences between chilled and non-chilled bulbs, which were consistent with the differences observed in the average values of NSD, R1, and R2. The results indicated a smaller fraction of solid protons (e.g., starch, sugars, and possibly bound water), or less contact between these solid protons and (free) water in the storage scales of the chilled bulbs, after 8 weeks of storage at low temperature.

Possible mechanisms influencing the dynamics of rhizoctonia disease of tulips

looseness-1In two observation fields, where six sites were artificially infested with Rhizoctonia solani AG 2-t, bare patches developed. These patches did not re-occur at the site of infestation in three successive years. In fields with and without artificial infestation, natural infection of tulip bulbs by Rhizoctonia spp. occurred. The spatial distribution of infected tulip bulbs was visualised in maps after kriging. The influence of sampling intensity was evaluated by stepwise reduction obtained in the observed data set of the first year. Omnidirectional semivariogram characteristics did not change when sampling intensity was reduced down to 10%. The average maximum prediction error was minimised at sampling intensities varying from 7% to 25%. Naturally occurring bare patches slowly vanished during successive cropping of flower bulbs and did not re-appear in the fourth growing season. A high frequency of isolation of R. solani AG 2-t in one field (Lisse-2) in the fourth consecutive crop did not result in bare patches in that year. It is hypothesised that a reduction in aggressiveness may account for this observation. In contrast, bulb rot due to Rhizoctonia spp. increased during the observation period. R. solani AG 5 isolates were seldom isolated before the bulbs flowered, but were the dominant isolate from bulbs at harvest. In a growth chamber experiment, it was demonstrated that AG 5 did not account for replacement of AG 2-t. However, it was demonstrated that competition may partially explain replacement of AG 2-t isolates during the growing season. At 18 °C, but not at 9 °C, an AG 4 isolate prevented AG 2-t colonising and infecting iris bulbs when both isolates were introduced together to soil. Rhizoctonia populations develop in relation to soil temperature and plant development. It is hypothesised that a ‘temporal niche differentiation’ may be one of the mechanisms affecting the dynamics of rhizoctonia bare patch of tulips.

The lipoxygenase pathway in tulip (Tulipa gesneriana): detection of the ketol route

The in vitro metabolism of [1-14C]linoleate, [1-14C]linolenate and their 9(S)-hydroperoxides was studied in cell-free preparations from tulip (Tulipa gesneriana) bulbs, leaves and flowers. Linoleate and its 9-hydroperoxide were converted by bulb and leaf preparations into three ketols: (12Z)-9-hydroxy-10-oxo-12-octadecadienoic acid (α-ketol), (11E)-10-oxo-13-hydroxy-11-octadecadienoic acid (γ-ketol) and a novel compound, (12Z)-10-oxo-11-hydroxy-12-octadecadienoic acid (10,11-ketol), in the approximate molar proportions of 10:3:1. The corresponding 15,16-dehydro α- and γ-ketols were the main metabolites of [1-14C]linolenate and its 9-hydroperoxide. Thus bulbs and leaves possessed 9-lipoxygenase and allene oxide synthase activities. Incubations with flower preparations gave α-ketol hydro(pero)xides as predominant metabolites. Bulb and leaf preparations possessed a novel enzyme activity, γ-ketol reductase, which reduces γ-ketol to 10-oxo-13-hydroxyoctadecanoic acid (dihydro-γ-ketol) in the presence of NADH. Exogenous linolenate 13(S)-hydroperoxide was converted mostly into chiral (9S,13S)-12-oxo-10-phytodienoate (99.5% optical purity) by bulb preparations, while [1-14C]linolenate was a precursor for ketols only. Thus tulip bulbs possess abundant allene oxide cyclase activity, the substrate for which is linolenate 13(S)-hydroperoxide, even though 13(S)-lipoxygenase products were not detectable in the bulbs. The majority of the cyclase activity was found in the microsomes (105g pellet). Cyclase activity was not found in the other tissues examined, but only in the bulbs. The ketol route of the lipoxygenase pathway, mediated by 9-lipoxygenase and allene oxide synthase activities, has not been detected previously in the vegetative organs of any plant species.

The lipoxygenase pathway in tulip (Tulipa gesneriana): detection of the ketol route

The in vitro metabolism of [1-(14)C]linoleate, [1-(14)C]linolenate and their 9(S)-hydroperoxides was studied in cell-free preparations from tulip (Tulipa gesneriana) bulbs, leaves and flowers. Linoleate and its 9-hydroperoxide were converted by bulb and leaf preparations into three ketols: (12Z)-9-hydroxy-10-oxo-12-octadecadienoic acid (alpha-ketol), (11E)-10-oxo-13-hydroxy-11-octadecadienoic acid (gamma-ketol) and a novel compound, (12Z)-10-oxo-11-hydroxy-12-octadecadienoic acid (10,11-ketol), in the approximate molar proportions of 10:3:1. The corresponding 15, 16-dehydro alpha- and gamma-ketols were the main metabolites of [1-(14)C]linolenate and its 9-hydroperoxide. Thus bulbs and leaves possessed 9-lipoxygenase and allene oxide synthase activities. Incubations with flower preparations gave alpha-ketol hydro(pero)xides as predominant metabolites. Bulb and leaf preparations possessed a novel enzyme activity, gamma-ketol reductase, which reduces gamma-ketol to 10-oxo-13-hydroxyoctadecanoic acid (dihydro-gamma-ketol) in the presence of NADH. Exogenous linolenate 13(S)-hydroperoxide was converted mostly into chiral (9S,13S)-12-oxo-10-phytodienoate (99.5% optical purity) by bulb preparations, while [1-(14)C]linolenate was a precursor for ketols only. Thus tulip bulbs possess abundant allene oxide cyclase activity, the substrate for which is linolenate 13(S)-hydroperoxide, even though 13(S)-lipoxygenase products were not detectable in the bulbs. The majority of the cyclase activity was found in the microsomes (10(5) g pellet). Cyclase activity was not found in the other tissues examined, but only in the bulbs. The ketol route of the lipoxygenase pathway, mediated by 9-lipoxygenase and allene oxide synthase activities, has not been detected previously in the vegetative organs of any plant species.

Evaluation of algorithms for analysis of NMR relaxation decay curves

Quantitative processing of NMR relaxation images depends on the characteristics of the used fitting algorithm. Therefore several common fitting algorithms are compared for decay curves with low signal-to-noise ratios. The use of magnitude data yields a non-zero base line, and is shown to result in an overestimation of the decay time. A simple base line correction is no solution since this yields an equally large underestimation due to overcorrection of the first part of the curve. The use of squared data does yield reliable results, but only in the case of monoexponential decays. The best fitting algorithm under all experimentally occurring conditions turns out to be using real data after phase correction. A phase correction scheme is proposed, which applies to all imaging experiments for which the phase of the pixels is constant over the echo train. This scheme is validated for a phantom and for a tulip bulb.

Developmental changes and water status in tulip bulbs during storage: visualization by NMR imaging.

Magnetic Resonance Imaging (MRI) and light and scanning electron microscopy (SEM) were used to follow time-dependent morphological changes and changes in water status of tulip bulbs (Tulipa gesneriana L., cv. 'Apeldoorn') during bulb storage for 12 weeks at 20 degrees C (non-chilled) or 4 degrees C (chilled) and after planting. MR images reflecting the water content, the relaxation times T1 and T2 (or their reciprocal values, the relaxation rates R1 and R2), and the apparent self-diffusion coefficient of water molecules (ADC), were obtained for intact bulbs. After planting, scape elongation and flowering occurred only in chilled bulbs, while elongation in non-chilled bulbs was retarded. Microscopic observations showed different structural components and high heterogeneity of the bulb tissues. MRI revealed the elongation of the flower bud during storage, which was significantly faster in the chilled bulbs. In addition, MRI demonstrated a redistribution of water between different bulb organs, as well as significant differences in the pattern of this redistribution between the chilled and non-chilled bulbs. Generally, R2 relaxation rates became faster in all bulb organs during storage. At the same time, ADC values remained constant in the chilled bulbs, while exhibiting a significant increase in the non-chilled bulbs.

Developmental changes and water status in tulip bulbs during storage: visualization by NMR imaging

Magnetic Resonance Imaging (MRI) and light and scanning electron microscopy (SEM) were used to follow time‐dependent morphological changes and changes in water status of tulip bulbs (Tulipa gesneriana L., cv. ‘Apeldoorn’) during bulb storage for 12 weeks at 20 °C (non‐chilled) or 4 °C (chilled) and after planting. MR images reflecting the water content, the relaxation times T1 and T2 (or their reciprocal values, the relaxation rates R1 and R2), and the apparent self‐diffusion coefficient of water molecules (ADC), were obtained for intact bulbs. After planting, scape elongation and flowering occurred only in chilled bulbs, while elongation in non‐chilled bulbs was retarded. Microscopic observations showed different structural components and high heterogeneity of the bulb tissues. MRI revealed the elongation of the flower bud during storage, which was significantly faster in the chilled bulbs. In addition, MRI demonstrated a redistribution of water between different bulb organs, as well as significant differences in the pattern of this redistribution between the chilled and non‐chilled bulbs. Generally, R2 relaxation rates became faster in all bulb organs during storage. At the same time, ADC values remained constant in the chilled bulbs, while exhibiting a significant increase in the non‐chilled bulbs.

Oxidation of xenobiotics by plant microsomes, a reconstituted cytochrome P450 system and peroxidase: a comparative study

The microsomal fraction from tulip bulbs ( Tulipa fosteriana, L.) contains cytochrome P450 (CYP 3, EC 1.14.14.1) and peroxidase (EC 1.11.1.7.) enzymes catalyzing the NADPH — and hydrogen peroxide — dependent oxidation of the xenobiotic substrates, N-nitrosodimethylamine (NDMA), N-nitrosomethylaniline (NMA), aminopyrine and 1-phenylazo 2-hydroxynaphthalene (Sudan I), respectively. Oxidation of these model xenobiotics has also been assessed in a reconstituted electron-transport chain with a partially purified CYP fraction, phospholipid and isolated tulip NADPH:CYP reductase (EC 1.6.2.4.). Peroxidase isolated from tulip bulbs (isoenzyme C) oxidizes these xenobiotics, too. Values of kinetic parameters ( K m, V max), requirements for cofactors (NADPH, hydrogen peroxide), the effect of inhibitors and identification of products formed from the xenobiotics by the microsomal fraction, partially purified CYP and peroxidase C were determined. These data were used to estimate the participation of the CYP preparation and peroxidase C in oxidation of two out of the four studied xenobiotics (NMA, Sudan I) in tulip microsomes. Using such detailed study, we found that the CYP-dependent enzyme system is responsible for the oxidation of these xenobiotics in the microsomal fraction of tulip bulbs. The results demonstrate the progress in resolving the role of plant CYP and peroxidase enzymes in oxidation of xenobiotics.