Gaillardia Pulchella Research Articles

The effect of combined Azospirillum inoculation and nitrogen fertilizer on plant growth promotion and yield response of the blanket flower Gaillardia pulchella

The investigation was carried out to examine the performance of Azospirillum isolates on growth and N uptake of Gaillardia pulchella with two nitrogen levels. Azospirillum strain OAD-2 inoculation significantly increased plant height, number of leaves per plant, branches per plant and total dry mass accumulation in G. pulchella than other inoculations and/or uninoculated control. The application of 150 kg N ha −1 further enhanced the above plant growth parameters significantly over application of 112 kg N ha −1. The N uptake of G. pulchella was enhanced due to Azospirillum strain OAD-2 inoculation, which was further augmented in the presence of nitrogen. The combination of Azospirillum strain OAD-2 and 150 kg N ha −1 showed the highest N uptake at 120 DAT. Plant growth and yield parameters also increased when inoculated with the non-diazotrophic, but efficient IAA producing, Azospirillum strain OAD-57. From this investigation, it can be concluded that Azospirillum strains OAD-2 and OAD-11 can play an important role in the N nutrition of G. pulchella.

Tolerance of Native Wildflower Seedlings to Imazapic

Abstract Plateau (imazapic) at 0.0175 kg ai/ha (0.0156 lb ai/A) to 0.14 kg ai/ha (0.125 lb ai/A) was applied the day after seed of annual phlox (Phlox drummondii), black-eyed susan (Rudbeckia hirta), blanketflower (Gaillardia pulchella), lanceleaf coreopsis (Coreopsis lanceolata), scarlet sage (Salvia coccinea), standing cypress (Ipomopsis rubra), and sundial lupine (Lupinus perennis), were sown on a commercial potting medium or a sandy field soil in plastic pots. All seed were from one commercial source, with additional seed of black-eyed susan, lanceleaf coreopsis, and blanketflower from a second source (Florida ecotype). At 28 days after treatment, slight stand thinning was observed on scarlet sage, blanketflower, and black-eyed susan but the major effect of Plateau was stunting on all species. Annual phlox was the most tolerant of Plateau, with only occasional slight stunting and no stand thinning even at the highest rate. Lanceleaf coreopsis and sundial lupine were slightly less tolerant, with scarlet sage, blanketflower, and black-eyed susan being the most susceptible. Planting medium frequently affected Plateau activity, with stunting usually greater in the commercial medium than in a sandy field soil. For the species in which there were two seed sources, seed source affected tolerance of black-eyed susan and lanceleaf coreopsis. The Florida ecotype of lanceleaf coreopsis was more sensitive to Plateau than the commercial source. For black-eyed susan, sensitivity to Plateau depended on the medium in which seedlings were growing. Results for blanketflower were inconclusive.

Growth and Nutrient Content of Herbaceous Seedlings Associated with Biological Soil Crusts

Biological soil crusts of arid and semiarid lands contribute significantly to ecosystem stability by means of soil stabilization, nitrogen fixation, and improved growth and establishment of vascular plant species. In this study, we examined growth and nutrient content of Bromus tectorum, Elymus elymoides, Gaillardia pulchella, and Sphaeralcea munroana grown in soil amended with one of three levels of biological soil crust material: (1) a low-fertility sand collected near Moab, Utah; (2) sand amended with a 1-cm top layer of excised soil crust; and (3) crushed crust material. In addition, all plants were inoculated with spores of the arbuscular mycorrhizal fungus, Glomus intraradices. Plants were harvested after 10 weeks growth, dried, weighed, and leaves were ground for nutrient analysis. Three aspects of root architecture were also quantified. Soil crust additions significantly affected nearly all variables examined. Both above- and below-ground vegetative biomass were significantly increased in the presence of crust material. Similarly, reproductive tissue of the three species that flowered was greatest in the crushed-crust medium. The effect of soil crust additions is likely due to the increased nitrogen content of the crusts. Nitrogen tissue content of all four species was greatly enhanced in crusted soils. All species showed a decline in root/shoot ratio and specific root length with crust additions, indicating a shift in plant allocation pattern in response to improved soil fertility. These data support other studies suggesting that soil crusts have a positive effect on the establishment and growth of associated vascular plant species.

Growth and Nutrient Content of Herbaceous Seedlings Associated with Biological Soil Crusts

Biological soil crusts of arid and semiarid lands contribute significantly to ecosystem stability by means of soil stabilization, nitrogen fixation, and improved growth and establishment of vascular plant species. In this study, we examined growth and nutrient content of Bromus tectorum, Elymus elymoides, Gaillardia pulchella, and Sphaeralcea munroana grown in soil amended with one of three levels of biological soil crust material: (1) a low-fertility sand collected near Moab, Utah; (2) sand amended with a 1-cm top layer of excised soil crust; and (3) crushed crust material. In addition, all plants were inoculated with spores of the arbuscular mycorrhizal fungus, Glomus intraradices. Plants were harvested after 10 weeks growth, dried, weighed, and leaves were ground for nutrient analysis. Three aspects of root architecture were also quantified. Soil crust additions significantly affected nearly all variables examined. Both above- and below-ground vegetative biomass were significantly increased in the presence of crust material. Similarly, reproductive tissue of the three species that flowered was greatest in the crushed-crust medium. The effect of soil crust additions is likely due to the increased nitrogen content of the crusts. Nitrogen tissue content of all four species was greatly enhanced in crusted soils. All species showed a decline in root/shoot ratio and specific root length with crust additions, indicating a shift in plant allocation pattern in response to improved soil fertility. These data support other studies suggesting that soil crusts have a positive effect on the establishment and growth of associated vascular plant species.

Wilson Knight's Wheel of Fire

Wilson Knight's Wheel of Fire

Effect of Harvest Method on Seed Yield of Coreopsis lanceolata L. and Gaillardia pulchella Foug.

Abstract Seed of north Florida ecotypes of lanceleaf coreopsis (Coreopsis lanceolata L.) and blanketflower (Gaillardia pulchella Foug.) were sown in February 1998 and harvested manually or mechanically (portable seed stripper) at two different times during the growing season. Mechanical harvesting of both species was more efficient based on the length of harvesting time relative to the yield of clean seed but hand harvesting yielded substantially more clean seed. Date of harvest (mid-July or early October) had several significant effects on blanketflower yield and quality. The July harvest resulted in 67% higher clean seed yield, 45% higher clean seed yield rate (a measure of harvesting efficiency), 9% greater seed mass, and 95% greater germination rate than the October harvest. Date of harvesting for lanceleaf coreopsis (late June and late August) had minimal effects on clean seed yield or quality.

John H. Dippel, Bound Upon a Wheel of Fire: Why So Many German Jews Made the Tragic Decision to Remain in Nazi Germany. New York: Basic Books, 1996. 353 pp.

John H. Dippel, Bound Upon a Wheel of Fire: Why So Many German Jews Made the Tragic Decision to Remain in Nazi Germany. New York: Basic Books, 1996. 353 pp.

Wildflower Seed Source Affects Performance of Six Wildflower Species

Field plantings of six native wildflower species were established at five sites in 1997 from seeds derived from local native populations (local ecotype) and from seeds purchased from commercial sources outside of Florida (nonlocal ecotype). The species were Cassia fasciculata (partridge-pea), Coreopsis lanceolata (lance-leaf coreopsis), Gaillardia pulchella (blanketflower), Ipomopsis rubra (standing cypress), Rudbeckia hirta (black-eyed susan), and Salvia lyrata (lyre-leaf sage; cancer weed). They were evaluated once per month from June to Oct. 1997. Plantings were maintained as follows: no supplemental fertilization; irrigation as needed up until early April to ensure germination; no pesticides except to control fireants and weeds on the perimeter of the plantings; plots were handweeded as necessary. It was clearly evident from these evaluations that the local ecotypes generally were better adapted to north Florida conditions than were the nonlocal ecotypes. The most noteworthy differences were as follows: 1) the local ecotypes of Rudbeckia and Gaillardia had longer flowering periods than their nonlocal counterparts, 2) the local ecotype of Coreopsis flowered profusely while flowering of the nonlocal ecotype was sparse, and 3) the local ecotypes of Coreopsis and Salvia had less disease incidence than their nonlocal counterparts.

Bound upon a wheel of fire: why so many German Jews made the tragic decision to remain in Nazi Germany

Introduction Antecedents Setting the Trap The Gathering Storm Facing the Unthinkable Now We Are All Jews Suffering the Slings and Arrows Testing the New Jews Second-Class Citizens Tightening the Noose Rushing for the Exits The Night of Broken Glass Epilogue.

Germination response patterns to temperature during afterripening of achenes of four Texas winter annual Asteraceae

Patterns of change in temperature requirements for germination of achenes of four Texas winter annual Asteraceae were investigated as they afterripened at simulated summer habitat temperatures. In addition, temperature requirements for after-ripening were determined. In Gaillardia pulchella, Krigia gracilis, and Pyrrhopappus multicaulis, the maximum temperature for germination increased during afterripening (type 1 response pattern). This is the first report of a type 1 pattern in the Asteraceae. In Hymenoxys linearifolia, the maximum and minimum temperatures for germination increased and decreased, respectively, increasing to two the number of winter annuals with a type 3 response pattern. As in winter annuals in other plant families, achenes of the four species required exposure to moderately high temperatures (25:15, 30:15 °C) to gain the ability to germinate to high percentages at autumn temperatures in autumn. Of the 32 species of Asteraceae whose afterripening pattern has been investigated, 3 have type 1, 22 have type 2, and 7 have type 3. Evidence suggests that types 1 and 3 and types 2 and 3 are more closely related physiologically than are types 1 and 2. Key words: winter annuals, Asteraceae, achenes, seed germination, afterripening.

EXAMINATION OF JUVENILITY IN GAILLARDIA PULCHELLA

Gaillardia pulchella is an annual wildflower with ornamental potential native to the South and Southern West part of the U. S. This experiment attempted to further describe the long day (LD) flowering requirement, approximate the length of the juvenility phase, and characterize apical events during floral initiation. Plants were transferred from short day to LD at various leaf numbers and the time to first flower was recorded from the onset of LD. A quadratic response described the data and indicated that a minimum of 19-20 expanded leaves were needed to flower most rapidly (49 days) once placed in LD. Histological results characterizing apical events will also be discussed.

Structure-Activity Relationships of Pseudoguaianolides Isolated from Gaillardia pulchella and Their Derivatives

Three new pseudoguaianolides, 4-epipulchellin, 4-epineopulchellin and pulchelloid D, were isolated from Gaillardia pulchella together with other eleven pseudoguaianolides and three guaianolides. Fifteen natural sesquiterpene lactones and their thirty one derivatives were tested for cytotoxic activity against KB cell line. Among them, twenty seven compounds were shown to be active (ED 50 < 4 μg/ml). The structure-activity relationships of these sesquiterpene lactones are discussed.

In vitro regeneration of Gaillardia pulchella Foug.

Young leaf and internodal stem segments of Gaillardia pulchella, collected from wild species re-established in the greenhouse, were used to initiate callus on Murashige & Skoog medium supplemented with NAA (2.0 mgl−1) and BA (0.4 mgl−1). Callus formed after 10 to 14 days in the dark. Cultures were transferred to fresh medium and placed under lighted conditions where shoot formation occurred approximately 14 to 30 days after initiation. Callus sub-cultured at 14 to 21-day intervals continued to produce primordia for several weeks. Flowers were produced by regenerated shoots maintained on MS medium, but roots did not develop until the plantlets were transferred to soil conditions.

CLINAL VARIATION ASSOCIATED WITH EDAPHIC ECOTONES IN HYBRID POPULATIONS OF GAILLARDIA PULCHELLA.

The variety pulchella of the outcrossing annual plant species Gaillardia pulchella consists of two edaphic races in central Texas which are divergent for one morphological and four electrophoretic characters. Reduced pollen stainability in F1 hybrids suggests the races are also divergent in chromosome structure. The recent proliferation of this species on roadsides and in pastures has led to hybridization between these races. An analysis of character variation in three hybrid populations revealed significant clinal variation associated with edaphic ecotones, and the width of these clines was found to vary among characters in a consistent pattern. It is argued that this pattern is the result of different characters experiencing different effective selection regimes, with narrower clines reflecting greater differentials in effective selection. Several mechanisms are discussed by which selection may impede the transgression of alleles across the ecotones in these populations. The results of this study are compared to the results of parallel studies on the autogamous annual species Avena barbata in California, and it is suggested that the difference between these two species in the width of clines separating edaphic ecotypes may be accounted for by their different breeding systems.

ASSOCIATIONS BETWEEN ALLOZYME FREQUENCIES AND SOIL CHARACTERISTICS IN GAILLARDIA PULCHELLA (COMPOSITAE).

Selection favoring different alleles in different environments frequently has been suggested as an explanation for allozyme variation within and among populations. This hypothesis predicts that allozyme frequencies will be correlated with environmental variables. Previous studies on allozyme frequency-environment covariation in plants often have relied on qualitative assessments of the environment and have emphasized highly autogamous species. We have examined allozyme frequency-soil associations in Gaillardia pulchella, an obligately outcrossed annual plant, by regressing the frequencies of 15 common allozymes representing six polymorphic enzyme loci on principal components from a set of 20 quantitative soil variables. Fifty-one populations, representing four taxonomic varieties, were included in the analysis. Among the 26 populations representing the var. pulchella, allozymes Adh-2f and Pgm-1c were significantly associated with a block of highly inter-correlated soil characteristics which serve to discriminate between soils derived from calcareous vs. non-calcareous rock types. This geographically complex pattern of allozyme frequency-soil covariation is not likely to be spurious and, thus, indicates the presence of adaptively differentiated soil races, or ecotypes. However, these results are not sufficient to conclude that the allozyme frequency divergence between ecotypes was mediated by selection, either directly or through genetic hitchhiking. The pattern of allozyme frequency-soil covariation within var. pulchella was not found among the other taxonomic varieties. Patterns of genotype-environment covariation often may be recognizable only within geographically or environmentally restricted groups of populations because of the confounding influences of other environmental variables.

Allozyme Variation in Gaillardia pulchella and G. amblyodon (Compositae): Relation to Morphological and Chromosomal Variation and to Geographical Isolation

Gaillardia pulchella and G. amblyodon are obligately outcrossed, diploid annuals that occur sympatrically in Texas. Gaillardia pulchella consists of three parapatric varieties and at least four chromosomally differentiated races. Six of thirteen allozyme loci assayed (46%) are polymor- phic in both species. Mean expected heterozygosities are 0.188 for G. pulchella and 0.125 for G. amblyodon. No significant linkage disequilibria were observed between pairs of polymorphic loci, and no deviations from Hardy-Weinberg expectations were detected. Nei's coefficient of gene differentiation (GST) was 0.160 between convarietal populations, 0.021 between varieties of G. pul- chella, 0.146 between populations of G. amblyodon, and 0.144 between the two species. Mean values of Nei's genetic distance (D) were 0.035 among local populations, 0.059 among varieties, and 0.285 between species. There is little allozyme differentiation among varieties of G. pulchella. Clustering (UPGMA) of populations by genetic distance failed to discern either morphological varieties or chromosomal races within this species. Genetic distances are significantly correlated with geograph- ic distances within G. pulchella, suggesting gene flow may be an important deterrent to differentia- tion. Data from other outcrossing plant taxa are consistent with the contention that strong barriers to gene flow are a prerequisite for allozyme differentiation. It is suggested that allozyme variation within species will often show little concordance with variation in other characters and may there- fore be of limited use for delimiting infraspecific taxa.

Studies on non-sesquiterpenoid constituents of Gaillardia pulchella. II. Less lipophilic substances, methyl caffeate as an antitumor catecholic.

A less lipophilic non-sesquiterpenoid antitumor constituent, methyl caffeate, along with D-fructose, was isolated from the aqueous methanol extract of the dried whole plant of Gaillardia pulchella. Among forty-three synthetic catechol analogues related to methyl caffeate tested for antitumor activity against Sarcoma 180 in mice, acetates of methyl catecholylpropionoid type showed stronger activity than the corresponding catechuic acid and catechualdehyde derivatives as well as simple benzaldehyde (so-called vidrol). None of the catecholic and related compounds tested showed significant antimicrobial activity in vitro.

Sesquiterpene lactones as taxonomic characters in the asteraceae

The Asteraceae is characterized by structurally diverse sesquiterpene lactones and furanosesquiterpenes. In this review the tribal, subtribal and generic distribution of sesquiterpene lactones is examined and the compounds’ utility as taxonomic characters discussed. Sesquiterpene lactones fulfill the major requirements for good analytic and synthetic characters. Studies of infraspecific sesquiterpene lactone variation indicate that different elements within complex taxa are often defined by distinct chemistries, termed chemotypes. Chemotypes have been identified within many of the thoroughly investigated taxa:Ambrosia camphorata, A. chamissonis, A. confertiflora, theA. cumanensis-A. psilostachya-A. artemisiifolia complex,A. dumosa, Artemisia tridentata, Gaillardia pulchella andMelampodium leucanthum. Such an analytic usage is mostly restricted to the infraspecific level. Synthetic usage at the interspecific level and above profits from the application of a biogenetically based methodology for sorting out the complex molecules’ carbon-skeletal and substitutional features into unit characters. Cladistics or Hennigian phylogenetic systematics provides a useful framework for such an analysis. Preliminary surveys indicate that sesquiterpene lactones are especially good characters for differentiating subtribes within several major tribes: the Vernonieae, Heliantheae and Mutisieae. As yet, too few data are available for other tribes to discern such patterns. Species surveys inVernonia, Ambrosia, Iva, Parthenium,Tetragonotheca andArtemisia demonstrate that sesquiterpene lactones are useful in discerning infrageneric groups. The biogenetic cladistic analysis of the interspecific sesquiterpene lactone variation inIva shows the efficacy of this analytical methodology. At present, such biogenetically based approaches are impeded by limited biosynthetic evidence and the erratic distribution of sesquiterpene lactones within the family. Instances of apparent displacement of sesquiterpene lactones by other terpenoids (i.e. sesquiterpene furans, alcohols and acids, diterpenes, diterpene acids, etc.) at various taxonomic levels suggest that ultimately sesquiterpene lactones must be interpreted as taxonomic characters in the context of the family’s total terpene chemistry. All taxa from which sesquiterpene lactones have been reported are listed together with the compound names, major structural features and the literature cited. A less-complete listing is provided for taxa producing furanosesquiterpenes. Structures for all reported compounds are included. Two appendices listing alphabetically taxa and compounds and relevant text page numbers permit cross-indexing of plants and compounds.

Sesquiterpene lactones as taxonomic characters in the asteraceae

The Asteraceae is characterized by structurally diverse sesquiterpene lactones and furanosesquiterpenes. In this review the tribal, subtribal and generic distribution of sesquiterpene lactones is examined and the compounds’ utility as taxonomic characters discussed. Sesquiterpene lactones fulfill the major requirements for good analytic and synthetic characters. Studies of infraspecific sesquiterpene lactone variation indicate that different elements within complex taxa are often defined by distinct chemistries, termed chemotypes. Chemotypes have been identified within many of the thoroughly investigated taxa:Ambrosia camphorata, A. chamissonis, A. confertiflora, theA. cumanensis-A. psilostachya-A. artemisiifolia complex,A. dumosa, Artemisia tridentata, Gaillardia pulchella andMelampodium leucanthum. Such an analytic usage is mostly restricted to the infraspecific level. Synthetic usage at the interspecific level and above profits from the application of a biogenetically based methodology for sorting out the complex molecules’ carbon-skeletal and substitutional features into unit characters. Cladistics or Hennigian phylogenetic systematics provides a useful framework for such an analysis. Preliminary surveys indicate that sesquiterpene lactones are especially good characters for differentiating subtribes within several major tribes: the Vernonieae, Heliantheae and Mutisieae. As yet, too few data are available for other tribes to discern such patterns. Species surveys inVernonia, Ambrosia, Iva, Parthenium,Tetragonotheca andArtemisia demonstrate that sesquiterpene lactones are useful in discerning infrageneric groups. The biogenetic cladistic analysis of the interspecific sesquiterpene lactone variation inIva shows the efficacy of this analytical methodology. At present, such biogenetically based approaches are impeded by limited biosynthetic evidence and the erratic distribution of sesquiterpene lactones within the family. Instances of apparent displacement of sesquiterpene lactones by other terpenoids (i.e. sesquiterpene furans, alcohols and acids, diterpenes, diterpene acids, etc.) at various taxonomic levels suggest that ultimately sesquiterpene lactones must be interpreted as taxonomic characters in the context of the family’s total terpene chemistry. All taxa from which sesquiterpene lactones have been reported are listed together with the compound names, major structural features and the literature cited. A less-complete listing is provided for taxa producing furanosesquiterpenes. Structures for all reported compounds are included. Two appendices listing alphabetically taxa and compounds and relevant text page numbers permit cross-indexing of plants and compounds.

Chromosome Races of Gaillardia pulchella (Asteraceae)

Gaillardia pulchella Foug. is subdivided into partially interfertile cytotypes which are in some cases morphologically recognizable. The greatest morphological and cytological variation occurs in the southern and eastern portions of the species range. The evolutionary history of the species cannot be determined from the cytological information presented here although paleoclimatic information suggests the species or its ancestral form would have occupied areas to the south or west of the present distribution during the late Pleistocene-Recent climatic shifts.