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Tagetes erecta L., Gaillardia grandiflora Hort. e×Van Houtte. and Dahlia pinnata Cav. belong to the family Asteraceae, Matthiola incana (L.) R.Br. and Erysimum cheiri (L.) Crantz. are in the family...

Gaillardia grandiflora, or blanket flower, is a perennial, herbaceous composite used as an ornamental plant. Following a series of rains in January, 1997, landscape plantings of G. grandiflora in Monterey County, CA, exhibited symptoms of a previously undescribed disease. Affected stems turned gray to tan and became dry and brittle. Large branches often developed cracks. Attached leaves and flowers wilted and turned tan. Infections on the smaller stems and branches sometimes spread to the main stem and crown of the plant, resulting in plant death. White mycelia and large, irregular, black sclerotia (3 to 6 mm in diameter) were occasionally observed on external surfaces of infected stems and crowns. However, the internal pith cavity of diseased stems often contained abundant mycelia and sclerotia. Isolations from symptomatic stems, mycelia, and sclerotia produced colonies of Sclerotinia sclerotiorum. Pathogenicity was confirmed by culturing representative isolates on potato dextrose agar and allowing the fungus to colonize sterilized toothpicks placed on the surface of the agar (1). The pointed tips of the toothpicks were inserted approximately 3 mm deep into stems of potted G. grandiflora cv. Goblin plants, which were incubated in plastic bags for 48 h and then kept in a greenhouse. After 10 to 14 days, symptoms and mycelia similar to those originally observed developed on inoculated plants and S. sclerotiorum was reisolated. Stems on plants left for 21 or more days contained abundant sclerotia. Plants inoculated with sterile, uncolonized toothpicks did not develop disease. This pathogenicity test was repeated and the results were similar. This is the first report of G. grandiflora as a host of S. sclerotiorum. Reference: (1) Y. Yanar et al. Plant Dis. 80:342, 1996.

Disease samples of Gaillardia × grandiflora cvs. Goblin and Baby Cole were received at the Hampton Roads Agricultural Research and Extension Center in Virginia Beach in early April 2002. Samples were from a nursery in eastern Virginia, and most diseased plants had several to more than a dozen, round, flat, white to tan spots with indistinct margins up to 1 cm in diameter on their leaves. The spots later turned brown and necrotic, followed by necrosis of the entire leaf. Leaves of ‘Baby Cole’ were beginning to wilt and were more spotted than those of ‘Goblin’. Fungal fruiting bodies were not observed on the surface of diseased leaves. However, microscopic examination of internal leaf tissues revealed masses of round, double-walled, pale green-to-yellow spores approximately 12 μm in diameter and typical of the ustilospores of Entyloma polysporum (2,3). Inoculum for pathogenicity tests was prepared by blending 10 diseased leaves in 200 ml of sterile distilled water (SDW) for 2 min in a blender at low speed. The spore suspension was adjusted to 5 × 105 spores per ml with SDW. Healthy ‘Goblin’ gaillardia plants were obtained from a nursery where smut symptoms had never been seen. Four plants in one-gallon containers were inoculated by spraying them to runoff with the spore suspension. Four control plants were sprayed with SDW only. All plants were maintained in a greenhouse (15 to 35°C) and covered with a clean polyethylene plastic sheet overnight (14 h) to maintain high humidity and separated to avoid potential cross contamination. Inoculated and uninoculated plants were hand-watered separately, with application of water to the foliage to enhance spread of the disease. Typical white smut symptoms were observed on inoculated plants 2 weeks after inoculation, and numerous spores of E. polysporum were observed in the diseased tissues. No disease symptoms were seen on control plants. White smut has been reported on gaillardia in a few other states (1), but to our knowledge, this is the first report of the disease on gaillardia in Virginia. Growers at the affected nursery reported observing white smut symptoms on gaillardia in previous years, but in the spring of 2002, almost the entire gaillardia crop was destroyed. The disease has not been seen on gaillardia in any other nurseries, but it could have significant impact on production if it spreads. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) W. Fischer. Manual of the North American Smut Fungi. Ronald Press, New York, 1953. (3) D. B. O. Savile. Can. J. Res. 25(C):109,1947.

In situ phytoremediation of dyes from textile wastewater was carried out in a high rate transpiration system ridges (91.4 m × 1.0 m) cultivated independently with Tagetes patula, Aster amellus, Portulaca grandiflora and Gaillardia grandiflora which reduced American Dye Manufacturers Institute color value by 59, 50, 46 and 73%, respectively within 30 d compared to dye accumulated in unplanted ridges. Significant increase in microbial count and electric conductivity of soil was observed during phytoremediation. Reduction in the contents of macro (N, P, K and C), micro (B, Cu, Fe and Mn) elements and heavy metals (Cd, As, Pb and Cr) was observed in the soil from planted ridges due to phyto-treatment. Root tissues of these plants showed significant increase in the specific activities of oxido-reductive enzymes such as lignin peroxidase, laccase, veratryl alcohol oxidase, tyrosinase and azo reductase during decolorization of textile dyes from soil. Anatomical studies of plants roots revealed the occurrence of textile dyes in tissues and subsequent degradation. A minor decrease in plant growth was also observed. Overall surveillance suggests that the use of garden ornamental plants on the ridges of constructed wetland for the treatment of dyes from wastewater along with the consortia of soil microbial flora is a wise and aesthetically pleasant strategy.

In vitro grown Petunia grandiflora and Gaillardia grandiflora plantlets showed 76 percent and 62 percent American Dye Manufacturers Institute value (color) removal from a simulated dyes mixture within 36 h respectively whereas their consortium gave 94 percent decolorization. P. grandiflora, G. grandiflora and their consortium could reduce BOD by 44 percent, 31 percent and, 69 percent and COD by 58 percent, 37 percent and 73 percent respectively. Individually, root cells of P. grandiflora showed 74 and 24 percent induction in the activities of veratryl alcohol oxidase and laccase respectively; whereas G. grandiflora root cells showed 379 percent, 142 percent and 77 percent induction in the activities of tyrosinase, riboflavin reductase and lignin peroxidase respectively. In the consortium set, entirely a different enzymatic pattern was observed, where P. grandiflora root cells showed 231 percent, 12 percent and 65 percent induction in the activities of veratryl alcohol oxidase, laccase and 2, 6-dichlorophenol-indophenol reductase respectively, while G. grandiflora root cells gave 300 percent, 160 percent, 79 percent and 55 percent inductions in the activities of lignin peroxidase, riboflavin reductase, tyrosinase and laccase respectively. Because of the synergistic effect of the enzymes from both the plants, the consortium was found to be more effective for the degradation of dyes from the mixture. Preferential dye removal was confirmed by analyzing metabolites of treated dye mixture using UV–vis spectroscopy, FTIR and biotransformation was visualized using HPTLC. Metabolites formed after the degradation of dyes revealed the reduced cytogenotoxicity on Allium cepa roots cells when compared with untreated dye mixture solution. Phytotoxicity study exhibited the less toxic nature of the metabolites.

During a survey, in Shiraz area (Southern Iran), leaf samples from sweet william (Dianthus barbatus), blanket flower (Gaillardia grandiflora), oat (Avena sativa) and clover (Trifolium repens) showing characteristic symptoms of viral infection were investigated by Indirect-ELISA and RT-PCR and sequencing. Direct sequencing of coat protein (CP) gene confirmed the presence of Pelargonium leaf curl virus (PLCV) and Moroccan pepper virus (MPV) in samples. To our knowledge this is the first report of PLCV and MPV in these plants.

Centaurea maculosa Lam. is a noxious weed in western North America that produces a phytotoxin, (±)-catechin, which is thought to contribute to its invasiveness. Areas invaded by C. maculosa often result in monocultures of the weed, however; in some areas, North American natives stand their ground against C. maculosa and show varying degrees of resistance to its phytotoxin. Two of these resistant native species, Lupinus sericeus Pursh and Gaillardia grandiflora Van Houtte, were found to secrete increased amounts of oxalate in response to catechin exposure. Mechanistically, we found that oxalate works exogenously by blocking generation of reactive oxygen species in susceptible plants and reducing oxidative damage generated in response to catechin. Furthermore, field experiments show that L. sericeus indirectly facilitates native grasses in grasslands invaded by C. maculosa, and this facilitation can be correlated with the presence of oxalate in soil. Addition of exogenous oxalate to native grasses and Arabidopsis thaliana (L.) Heynh grown in vitro alleviated the phytotoxic effects of catechin, supporting the field experiments and suggesting that root-secreted oxalate may also act as a chemical facilitator for plant species that do not secrete the compound.

Scheduling crops to flower on specific dates requires a knowledge of the relationship between temperature and time to flower. Our objective was to quantify the effect of temperature on time to flower and plant appearance of four herbaceous perennials. Field-grown, bare-root Coreopsis grandiflora (Hogg ex Sweet.) `Sunray', Gaillardia ×grandiflora (Van Houtte) `Goblin', and Rudbeckia fulgida (Ait.) `Goldsturm', and tissue culture—propagated Leucanthemum ×superbum (Bergman ex J. Ingram) `Snowcap' plants were exposed to 5 °C for 10 weeks and then grown in greenhouse sections set at 15, 18, 21, 24, or 27 °C under 4-hour night-interruption lighting until plants reached anthesis. Days to visible bud (VB), days to anthesis (FLW), and days from VB to FLW decreased as temperature increased. The rate of progress toward FLW increased linearly with temperature, and base temperatures and degree-days of each developmental stage were calculated. For Coreopsis, Leucanthemum, and Rudbeckia, flower size, flower-bud number, and plant height decreased as temperature increased from 15 to 26 °C.

The juvenile phase of Coreopsis grandiflora `Sunray', Gaillardia×grandiflora `Goblin', Heuchera sanguinea `Bressingham', and Rudbeckia fulgida `Goldsturm' was characterized by exposing plants with 0 to 20 nodes to cold treatments at 5°C. After 0, 10, or 15 weeks cold treatment, plants were grown at constant 20° C under a 9 h photoperiod with 4 h night-interruption lighting (22:00 to 02:00 h; long days) or under a 9 h photoperiod (short days). Based on flowering percentage and time to flower, we concluded that the juvenile phase of Coreopsis, Gaillardia, Heuchera, and Rudbeckia ended when they had approximately 8, 16, 19, and 10 nodes, respectively. Coreopsis required cold treatments to flower. A cold treatment was not required for flowering of Gaillardia and Rudbeckia; however, such treatment improved their flowering percentage and greatly accelerated flowering. Increasing cold duration from 10 to 15 weeks did not influence time to flower of Coreopsis, Gaillardia, and Rudbeckia; however, the increase enhanced flowering percentage of Coreopsis and Gaillardia and hastened flowering of Heuchera. Heuchera was a day-neutral plant after ten weeks cold treatment, Rudbeckia was an obligate long-day plant, and Gaillardia and Coreopsis were quantitative long-day plants.

Background: Gaillardia grandiflora Hort. ex Van Houte and Gaillardia pulchella Foug are flowering plants widely cultivated in Egypt for their ornamental value. Previous reports demonstrated that sesquiterpene derivatives represent the major compounds in both species. Moreover, only few flavones were identified from genus Gaillardia and few studies on the cytotoxicity of G. pulchella were found. Aim of the Study: Investigation of the phenolic constituents of the aerial parts of both species and evaluation of their anti-inflammatory and hepatoprotective activities. Materials and Methods: The 80% aqueous methanol extracts (AME) were prepared for both plants and evaluated for their biological activities. Phytochemical investigation of both extracts resulted in isolation of twelve compounds, which have been identified on the basis of ultraviolet, 1D and 2D nuclear magnetic resonance spectroscopy and negative ESI-MS. Results: The new 8-hydroxyapigenin 6-O-β-D-apiofuranosyl-(1’’’→6’’)-C-β-D-4C1-glucopyranoside was isolated from G. grandiflora for the first time in nature, along with schaftoside, luteolin 6-C-β-D-4C1-glucopyranoside 8-methyl ether, apigenin 6-C-β-D-4C1-glucopyranoside 8-methyl ether, isoorientin, isovitexin, 6-methoxyluteolin and hispidulin, as well as vicenin-2, vitexin, luteolin and apigenin, which were isolated from G. pulchella together with 6-methoxyluteolin. Furthermore, the AME of both species were found to be nontoxic to mice and exhibited significant anti-inflammatory and hepatoprotective activities in dose dependent manner. Conclusion: Current results shed light on the phenolic constituents of G. grandiflora and G. pulchella aerial parts and the safety of the AME of both species, in addition to their significant anti-inflammatory and hepatoprotective activities. Both plant species may be promising candidates for natural anti-inflammatory and hepatoprotective drugs. SUMMARY Phytochemical investigation of Gaillardia grandiflora and Gaillardia pulchella 80% aqueous methanol extracts of the aerial parts led to the isolation of twelve compoundsThe new compound 8-hydroxyapigenin 6-O-β-D-apiofuranosyl-(1’’’’→6’’)-C-β-D-4C1-glucopyranoside was isolated from G. grandiflora for the first time in natureSchaftoside, luteolin 6-C-β-D-4C1-glucopyranoside 8-methyl ether, apigenin 6-C-β-D-4C1-glucopyranoside 8-methyl ether, isoorientin, isovitexin, 6-methoxyluteolin and hispidulin were isolated from G. grandifloraVicenin-2, vitexin, luteolin, apigenin and 6-methoxyluteolin were isolated from G. pulchellaThe extracts of both species were nontoxic to mice up to 5 g/kg body weightBoth extracts exhibited significant anti-inflammatory and hepatoprotective activities in dose dependent manner Abbreviations used: ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AME: The 80% aqueous methanol extract of G. grandiflora or G. pulchella aerial parts; AST: Aspartate aminotransferase; br d: Broad doublet; Comp-PC: Comparative paper chromatography; d: Doublet; 2D-PC: Two-dimensional paper chromatography; DMSO-d6: Deuterated dimethyl sulfoxide; G.: Gaillardia; GPx: Glutathione peroxidase; GRd: Glutathione reductase; GSH: glutathione; GST: Glutathione-S-transferase; J: Nuclear spin-spin coupling constant; m: Multiplet; [M-H]−: Molecular ion peak; MDA: Malondialdehyde; m/z: Mass/charge ratio; NO: Nitric oxide; p: Probability; PC: Paper chromatography; Rf: Retention flow; rpm: Rotation per minute; s: Singlet; SDE: The ethanol extract of Scoparia dulcis; SE: Standard error; SOD: Superoxide dismutase; TMS: Tetramethylsilane; λmax: Maximum fluorescence emission wavelength.

In the summer of 2009, a leaf spot disease occurred on 100% of Gaillardia × grandiflora cv. Goblin in a commercial nursery in coastal Monterey Co., CA. Nearly all of the affected plants were unsalable. The causal agent was determined to be Entyloma gaillardianum based on morphological features, host, and ITS region. This species has not been reported previously from this host in North America. Accepted for publication 16 March 2010. Published 28 April 2010.

During recent surveys of fieldgrown Gaillardia × grandiflora (Blanket flower) in Yakima Co., WA, a powdery mildew disease was observed on the cv. ‘Baby Cole.’ This report documents the occurrence of the powdery mildew fungus in question (Leveillula taurica (Lév.) G. Arnaud) on Gaillardia × grandiflora and provides information on disease symptomatology as well as features distinguishing this fungus from other powdery mildew pathogens of Gaillardia in North America. Accepted for publication 8 December 2005. Published 12 January 2006.

Field-grown plants of Alcea rosea (L.) Cav. (hollyhock), Asparagus officinalis L., Coreopsis grandiflora Hogg ex Sweet `Sunray', Dicentra spectabilis (L.) Lem. (bleeding heart), Gaillardia ×grandiflora Van Houtte `Baby Cole', Lupinus polyphyllus Lindl. `Russell Hybrids', and Phlox subulata L. `Emerald Pink' harvested as bare-root crowns in late fall were packaged in polyethylene-lined crates and stored for 6 months. There were no significant differences in the regrowth performance of any of the perennials following storage at 0 or -2C. The amount of surface covered by fungal hyphae (surface mold) increased more than 2-fold between 4 and 6 months of storage at 0 or -2C on all species. Dicentra spectabilis and Alcea rosea were most susceptible to mold growth during storage. Alcea rosea and Coreopsis grandiflora stored poorly at all storage temperatures. In a second experiment, the regrowth performance of Artemisia schmidtiana Maxim `Silver Mound', Asclepias tuberosa L., Aster novae-angliae L., Centranthus ruber (L.) DC., Chrysanthemum superbum Bergmans ex. J. Ingram, Dicentra eximia (Ker-Gawl.) Torr., Dicentra spectabilis, Geum quellon Sweet `Mrs. Bradshaw', Hosta `Honeybells', and Lupinus polyphyllus was tested following 6 months of storage at temperatures between -10 and +5C. Regrowth performance was generally similar at -2, 0, and 5C for most species. The results indicated, however, that Centranthus ruber and Chrysanthemum ×superbum should not be stored at temperatures of -2C or below. Sufficient etiolated growth developed for most species when stored at 2C or above to cause problems during shipping, handling, and potting. In general, mold growth on crowns during storage did not reduce regrowth performance of the species tested.

Chopped newspaper at 3.5 and 7.0 kg.m-2 enclosed in white polyethylene sheeting or enclosed in nylon netting at 3.5 kg.m-2 was compared with two layers of 0.64-cm microfoam as winter covering of four taxa of container-grown nursery plants. White polyethylene-enclosed newspaper moderated winter temperatures more than net-enclosed newspaper or two layers of microfoam under white polyethylene. All coverings provided protection against winter injury, as evidenced by container temperature, but net-enclosed newspaper at 3.5 kg.m-2 resulted in a minimal percentage of Daphne burkwoodii `Carol Mackie' plants with three or more shoots longer than 2 cm in the spring. Gaillardia grandiflora, covered by newspaper during winter, had less spring growth than plants covered by microfoam, but all coverings provided protection for Juniperus horizontalis `Prince of Wales' and Physostegia virginiana.

Coreopsis and Gaillardia were exposed to supra-optimal temperatures of 35 °C for a 6-week period beginning at flower initiation. Photosynthesis measurements were recorded at 1100 hr, 1300 hr, and 1500 hr for 3 days each week and carbohydrate partitioning was determined once per week. Results indicate that the time of day the measurements were taken made little difference on rate of photosynthesis and that there was a similar trend in photosynthetic rate over the 6-week period. Photosynthesis decreased as the plants began to flower and then increased until the onset of flower senescence. The patterns of carbohydrate partitioning were similar to those observed for photosynthesis. The plants grown at supra-optimal and optimal conditions had a similar trend and rate of photosynthesis throughout the 6-week period. Plant growth and total carbohydrates significantly decreased as the duration of high temperature increased for both species, however Gaillardia was more heat tolerant than Coreopsis.

Scheduling crops to flower for specific dates requires a knowledge of the relationship between temperature and time to flower. Our objective was to determine the relationship between temperature and time to flower of four herbaceous perennials. Field-grown, bare-root Coreopsis grandiflora `Sunray', Gaillardia grandiflora `Goblin', Rudbeckia fulgida `Goldsturm', and tissue culture-propagated Chrysanthemum superbum `Snow Cap' were exposed to 5C for 10 weeks. They were grown at 15, 18, 21, 24 or 27C under 4-h night interruption lighting. Time to visible bud (VB) and first flower (FLW) were recorded. Days to VB, days to FLW, and days from VB to FLW decreased as temperature increased. Time to flower at 15C was 70, 64, 96, and 54 days and 24, 39, 48, and 36 days at 27C for Coreopsis, Gaillardia, Rudbeckia, and Chrysanthemum, respectively. The 27C temperature apparently caused devernalization on Coreopsis because only 40% of the plants flowered. The effects of temperature on flower size, flower bud number, and plant height also are presented.

Most plants have a postgermination juvenile phase in which flower induction will not occur. Some species require a cold period for flower induction and will not respond to the cold treatments during the juvenile phase. We determined juvenile phases of Coreopsis grandiflora `Sunray', Gaillardia grandiflora `Goblin', Heuchera sanguinea `Bressingham', and Rudbeckia fulgida `Goldsturm'. Plants were exposed to 5C for 0, 10, or 15 weeks when Coreopsis had 0, 2, 4, 6, 8, or 10 leaves (>1 cm); Gallardia, 4, 8, 12, or 16 leaves; Heuchera, 8, 12, 16, or 20 leaves; Rudbeckia, 5, 10, 15, or 20 leaves. Plants were grown under a 4-h night interruption lighting (LD) or under a 9-h photoperiod (SD) after cold treatments. Based on time to flower and final leaf count, the juvenility of Coreopsis, Gaillardia, Heuchera, and Rudbeckia ended when they had about 6, 10, 12, and 15 leaves, respectively. Cold treatments were necessary for flower induction of Coreopsis and Heuchera and they increased the flowering percentage of Gaillardia and Rudbeckia. Heuhera was a day-neutral plant, Rudbeckia was on obligate LD plant, and Gaillardia and Coreopsis were quantitative LD plants.

Style and stigma elongation and stigma unfolding, and the roles of plant hormones in these processes in Gaillardia grandiflora Van Houtte were investigated. Style and stigma elongation in vivo began just after anthesis, and style elongation was accompanied by epidermal cell elongation (greatest near the stigma) and a fresh weight increase, but not by cell division or a dry weight increase. The stigma unfolded after the style and stigma elongated. Style-stigma units excised from young disc flowers of this composite were measured as they responded to plant growth regulators applied singly, as well as in sequential and simultaneous combinations, in vitro. Style elongation was promoted by auxin, was inhibited by gibberellins and ethylene, and was unaffected by other growth regulators. Stigma elongation followed a similar pattern of response. Endogenous auxin levels and ethylene production showed parallel variation and endogenous gibberellin levels showed inverse variation with style and stigma elongation. Stigma unfolding was more sensitive to auxin applications and was promoted by applied ethylene. Ethylene production showed parallel variation and endogenous auxin levels showed inverse variation with stigma unfolding. AVG and Co2+ applications decreased auxin-induced style elongation and fusicoccin promoted all of the growth responses of style-stigma units in vitro. A gibberellin-auxin-ethylene-acid growth interaction mode of control is proposed for these three

Corolla elongation and the roles of plant hormones in this process in GailZardia grandiMlora Van Houtte ray flowers were examined. The sterile ray flowers elongated during a 2-day period, and corolla growth was accompanied by fresh and dry weight increases and epidermal cell elongation (greatest near the base of the corolla) but not by cell division. Corollas excised from young ray flowers were measured during treatment in vitro with solutions of plant growth regulators. They elongated in response to gibberellins and fusicoccin but did not respond to auxins, cytokinins, abscisic acid, ethylene, or inhibitors of ethylene biosynthesis. Sequential and simultaneous hormone applications indicated no additive or synergistic effiects between hormones, but auxin did reduce gibberellin-promoted growth. Analyses of endogenous auxins showed no significant variation, and ethylene production decreased prior to elongation, while a 20-fold increase in endogenous gibberellin activity was observed just prior to rapid corolla elongation. It appears that corolla growth in Gaillardia is accomplished by an increase in gibberellin activity alone, that multiple hormone interactions are not important in the control of corolla growth, and that part of the mode of action of gibberellin is acid-induced growth. THE FLOWERING PROCESS has at least five sequential phases of development: flower induction, flower primordia differentiation, flower opening, anthesis and pollination, and flower senescence. The process of flower opening is in turn a sequence of several elongation and expansion processes which varies from species to species. In the Asteraceae, the inflorescence is usually composed of two flower types: the disc flowers (which are perfect and have a greatly reduced corolla), and the ray flowers (which are sterile and have a much larger corolla). The roles of plant hormones in the flower-opening processes of Gaillardia disc flowers have been described previously (Koning, 1 983a, b). The present work extends the study of the Gaillardia inflorescence by examining the roles of plant hormones in the growth of the corolla of the ray flower. The role of plant hormones in corolla ex' Received for publication 10 September 1982; revision accepted 27 June 1983. 2 Present address: Department of Biological SciencesBotany, Rutgers University, P.O. Box 1059, Piscataway, NJ 08854. This work is part of a doctoral thesis submitted to the Rackham School of Graduate Studies, University of Michigan, Ann Arbor. The author is greatly indebted to Dr. Peter B. Kaufman (University of Michigan, Ann Arbor) for help with the manuscript and for equipment supplied through his NASA Grant NAGW-34. Dr. Jan Zeevaart, Dr. Robert Bandurski, and Dr. Jerry Cohen (Michigan State University, East Lansing) provided valuable advice for the endogenous hormone analyses. pansion has been partially demonstrated for several genera. In the most complete studies of this involvement, gibberellins seem to be important(Blake, 1969;deJongandBruinsma 1974; Jeffcoat, Scott and Harris, 1969; Plack, 1958; Rao and Mohan Ram, 1979; Zieslin Biran and Halevy, 1974), but the other hormones (auxins, cytokinins, ethylene, and abscisic acid) may also be implicated especially when hormone interactions are considered (deJong and Bruinsma, 1974). The effects of applied hormones, hormone synthesis, and hormone-action inhibitors have been used to help demonstrate regulatory roles for these hormones (deJong and Bruinsma, 1974Rao and Mohan Ram, 1979). Studies showing parallel or inverse variation of endogenous hormone levels and corolla elongation add further support to the roles for the plant hormones in this growth process. Such correlations have been made for flower opening processes and auxin (Hatcher, 1945; Ilahi, 1979; Janardhan Raju and Gopal, 1977), gibberellins (Alpi et al., 1976; Einert, Staby and DeHertogh, 1972 Leshem and Ophir, 1977; Murakami, 1973 1975), cytokinins (Mayak and Halevy, 1970 Watanabe, Yokota and Takahashi, 1978), and ethylene (Beyer and Sundin, 1978Blumenfeld, 1975) in various species. All ofthese studies have been done with plants having perfect flowers, where interactions between flower parts are important. In the present work, the roles of plant hormones have been elucidated by

The molecular structure of spathulin (1a), a highly oxygenated pseudoguaianolide isolated from Gaillardia grandiflora has been established by a three dimensional X-ray crystallographic analysis of diacetylspathulin (1b). The space group of the crystal of 1b is P212121 and the dimensions of the cell with z=4 are a=9.6976 (3), b=26.968 (2), c=8.9288 (3) A. The structure of the crystal was refined to R=0.05. The conformation of spathulin (1a) was estimated to be similar to that of pulchellin (2a), namely bis-deacetoxyspathulin except some differences particularly at C (6) and C (9), when the conformation of the pseudoguaianolide skeleton in 1b is compared with that in 11, 13-dibromopulchellin (2b).

Filament elongation and the role of auxin in this process in Gaillardia grandiflora was investigated. Filament elongation in vivo occurred just prior to anthesis and was accompanied by cell elongation and fresh weight increase. Filaments isolated and exposed to auxin in vitro grew more rapidly than controls and their growth was comparable to that of filaments in vivo. Furthermore, the natural auxin content of disc flowers (determined by double-standard isotope dilution analyses) increased just prior to anthesis and filament elongation. These results imply that auxin cont-rols filament elongation. Applied ethylene slightly promoted filament elongation in vitro, and ethylene production of the flowers (determined by gas chromatography) slightly increased prior to filament growth. Fusicoccin and acidic buffers also stimulated elongation of isolated filaments. Thus, the role of auxin in controlling filament elongation in Gaillardia may involve stimulation of ethylene biosynthesis and acid growth. THE REGULATION of the flowering process of plants has been studied in several phases of flower development. The induction of flowering (Tompsett and Schwabe, 1974; Zeevaart, 1976; Chailakhyan, 1979) and the development of flower primordia (Heslop-Harrison, 1959; Bose and Nitsch, 1970; Bilderback, 1972; Berghoef and Bruinsma, 1979) seem to be environmentally and hormonally influenced. After the differentiation of the primordia, the flower buds develop slowly until the time when the flower opens. During flower opening, several rapid growth responses occur in an organized sequence. The corolla opens by means of rapid elongation and expansion of the petals and subsequently the filaments and style rapidly elongate. The role of auxin in filament elongation has been studied in several plants (Lang, 1961). The results of recent studies show that filaments of some plants respond to cytokinins (Pool, 1975; Raman and Greyson, 1978), others to gibberellins (Schaeverbeke, 1960; Grey

The aerial parts of Gaillardia grandiflora afforded two new pseudoguaianolides,9- O -desacetylspathulin-2- O -angelate 9- O -desacetylspathulin-2- O -isovalerate. The structures were elucidated by 1 H NMR spectroscopic investigations by some chemical transformations.

A new pseudoguaianolide named 11βH-dihydro-4-epineopulcehllin (1a) was isolated from the methanol extract of Gaillardia grandiflora. The stereostructure was determined on the basis of spectral evidence, especially proton nuclear magnetic resonance (including the 1H-1H correlation spectroscopy technique), and was confirmed by the transformation from neopulchellin (2a).