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1.
Abstract: Generally, lycophytes are not well represented in Anisian floras. Nonetheless, four different genera, each with one species, have been distinguished in the Anisian flora from Kühwiesenkopf (Monte Prà della Vacca), Italy. They were well preserved and yielded leaf cuticles in all four taxa and in situ spores in two of them. Lycopia dezanchei gen. et sp. nov. is the most common form; it is characterized by a dichotomising creeping prostrate rhizome (representing the primary shoot axis) from which arise aerial axes, apically bifurcated and covered with bundles of long leaves. This taxon cannot be attributed to any of the lycophyte orders, but most resembles Lycopodiales. Two representatives of the Isoetales have been found, of which Isoetites brandneri sp. nov. is abundant. This species is characterized by a short stem, which is unusual for this genus. In situ immature microspores and megaspores were found in some specimens. Lepacyclotes bechstaedtii sp. nov. has a quadrilobe corm with fertile scales inserted in whorls or slightly helicoidally. Short sterile leaves arise distally from the corm in some specimens. Selaginellales are very rare in the flora; Selaginellites leonardii sp. nov. is represented by a strobilus that yielded both micro‐ and megaspores. Some sterile fragments have been found associated, but never in organic connection.  相似文献   

2.
Barinophyton citrulliforme is definitely proven to be a tracheophyte. The vascular cylinder of the main axis is an exarch protostele composed of tracheids having a continuous secondary wall folded into protrusions into the cell lumen. These protrusions delineate the position of annular thickenings which were deposited earlier than the continuous secondary wall. Between successive protrusions, the later-deposited secondary wall is interrupted by minute pitlike structures. It is suggested that the secondary walls of the tracheids were laid down in a two-phase depositional sequence. The fertile system of B. citrulliforme consists of a main axis bearing spirally arranged strobili. The strobilus consists of an axis that bears two alternate rows of sporangiferous appendages. The sporangiferous appendages are borne laterally along the strobilar axis and recurve abaxially around the axis. The sporangia are attached along the inside curve of the appendages, one sporangium per appendage, each containing both microspores and megaspores. This species thus exhibits sporangial heterospory which is considered to be an adaptation to an aquatic habit and the sporangia are considered to be functional analogs of the sporocarps of Marsilea. The interpretation of the strobilus is morphologically identical to Ananiev's interpretation of the strobilus of Pectinophyton bipectinatum; consequently P. bipectinatum is here transferred to Barinophyton as B. robustius comb. nov.  相似文献   

3.
Fukui M 《Planta》2003,218(1):37-41
Two-year old saplings grown from cuttings of Cryptomeria japonica D. Don initiate strobilus development following treatment with gibberellic acid under long-day photoperiods. At 25 °C with a 14-h photoperiod in a phytotron, male strobili initiated normally; however, they remained green and fell from the saplings prematurely. To examine the change in male strobilus development at the molecular level, three genes expressed specifically in male strobili were analyzed. Two were MADS box genes homologous to the B-function genes in angiosperms, CjMADS1 and CjMADS2, and the third was Cry j I, which encodes an allergen protein, and this gene is expressed mainly in microspores. Under phytotron growing conditions, the homeotic genes were expressed constantly, which reflected the extended early developmental stage of male strobili. On the other hand, Cry j I expression was detected after a long delay just before strobilus development ceased. These results indicate that the expression of the genes related to male reproductive development in C. japonica is regulated by a factor(s) that is sensitive to environmental signals.Abbreviation GA3 gibberellic acid  相似文献   

4.
Taber D. Allison 《Oecologia》1990,83(4):523-529
Summary Canada yew (Taxus canadensis) populations currently browsed by white-tailed deer (Odocoileus virginianus) or browsed by deer in the past had significantly lower production of male strobili, female strobili, and seeds than unbrowsed yew populations. Exclosure studies showed that protected yews produced significantly more male and female strobili than unprotected yews, but only after several years of protection. Seed production did not respond as readily to protection from deer perhaps because of reduced pollination levels in browsed yew populations. Previously unbrowsed yews were clipped at different levels of removal of available browse (control (no removal), 25%, 50%, 75%, and 100% removal) to simulate deer browsing. Reduction in male strobilus production was linearly related to clipping intensity in three years of observation. Female strobilus production was significantly reduced only at the 100% level of removal. Intermediate levels of clipping may have even stimulated production of female strobili. Analysis of covariance, with previous year's branch production as the covariate, showed no significant effect of clipping on male strobilus production except in the 100% removal group. Female strobilus production showed no such covariance with branch production. Effects of clipping on seed production could not be reliably assessed in 1984 and 1985 due to low seed production. Seed production in 1986 was significantly reduced only in the 100% removal group. Field observations of deer browsing of Canada yew indicate that 100% levels of removal are typical of natural levels of browsing.  相似文献   

5.
Clevelandodendron ohioensis Chitaley & Pigg gen. et sp. nov. is an almost entire lycopsid plant known from a single compressed specimen from the Cleveland Shale member of the Upper Devonian Ohio Shale. This unique specimen is 125 cm long, consisting of an unbranched, slender, monopodial axis with a partially preserved plant base bearing thick appendages at one end, and a compact, terminal ovoid bisporangiate strobilus at the other. The stem is 2 cm wide for most of its length. Visible on the decorticated stem surface are helically arranged, elongate leaf traces and laterally compressed, slender leaves along the stem margin. The plant base bears 4-6 thick appendages. The terminal strobilus is compact, ovoid, 9 cm long and up to 6 cm wide, morphologically similar to those of some Lepidodendrales, and bears helically arranged sporophyll/sporangium complexes with narrow bases and distal laminae up to 18 mm long, turned upward. Megaspores are 320-360 μm, trilete and laevigate, lacking a gula; microspores are 30-42 μm, trilete, indistinctly punctate and possibly assignable to Calamospora or Punctatisporites. Clevelandodendron demonstrates that slender unbranched lycopsids with an isoetalean plant habit similar to the Carboniferous genera Chaloneria and Sporangiostrobus and Triassic Pleuromeia-like forms were present as early as the Late Devonian. The early occurrence of this unique habit suggests that diversification within the isoetalean clade sensu Rothwell and Erwin (including both Isoetales and Lepidodendrales) was well established prior to the Carboniferous.  相似文献   

6.
Taber D. Allison 《Oecologia》1992,89(2):223-228
Summary Browsed Canada yew (Taxus canadensis) populations have a higher proportion of males and a lower proportion of monoecious plants than unbrowsed yew populations. The proportion of monoecious plants increases with time following protection from browsing suggesting that deer browsing causes male-biased sex expression in Canada yew. In contrast, results from comparing browsed and unbrowsed populations, exclosure studies, and browse simulation experiments indicate that strobilus ratios and phenotypic gender of browsed yews may be female-biased. In part, these results correspond to the influence of size on sex expression in Canada yew; small yews tend to be male, but if monoecious, have female-biased strobilus ratios. Large yews are monoecious, but have male-biased strobilus ratios. There is, however, no consistent relationship between size and gender in Canada yew, suggesting that in some circumstances, yews shift allocation to female function in response to browsing.  相似文献   

7.
Flowering was significantly promoted in 4-year-old grafts of mature coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) clones by exogenous gibberellins (GAs) A4 and A7 (as a mixture) applied alone and in combination with A5 and A9. Biweekly applications of 400 μg GA4/7 per branch between late March and late June gave a 5-fold increase in ovulate and 3-fold increase in staminate strobilus production over untreated controls. 6N-benzyladenine and 2,3,5-triiodobenzoic acid applied in combination with GAs had no consistent effect on strobilus production. Non-destructive branch girdling, ineffective by itself as a cultural treatment, enhanced the GA benefit to flowering. Exogenous application of GA4/7 is effective and appears to be a practical method for promotion of early and enhanced flowering in grafted Douglas-fir seed orchards.  相似文献   

8.
Xylaria magnoliae forms abundant conidial and sexual fruiting structures on the fallen strobili of Magnolia spp. throughout the southeastern United States. Populations of X. magnoliae may be identified as isolates originating from a single strobilus, among different strobili from different host trees, and different host tree localities. We examined the stratified structure of X. magnoliae populations by analysis of their ribosomal DNA restriction patterns. A sample of 48 single-conidial isolates was obtained from strobili of both Magnolia grandiflora and M. fraseri in the piedmont and mountains of North Carolina and Georgia. Southern blotting experiments revealed considerable variation in rDNA lengths between and within different isolates. Although a single rDNA phenotype usually dominates within a particular collecting locality, different phenotypes were also observed within a locality and even between isolates obtained from a single strobilus. Some rDNA restriction phenotypes are distributed over localities separated by up to 400 km. These results suggest a fine-grained population structure for X. magnoliae, together with the potential for genetic exchange and dispersal between widely separated localities.  相似文献   

9.
The Conservation Reserve Program (CRP) is a primary tool for restoring grassland in the United States, in part as wildlife habitat, which has benefited declining grassland bird populations. Among potential mid-contract management practices used to maintain early-successional CRP grasslands, cattle grazing had been prohibited and is currently disincentivized during the primary nesting season for birds (much of the growing season), despite the important role that large herbivores historically played in structuring grassland ecosystems. Conservative grazing of CRP grasslands could increase spatial heterogeneity in vegetation structure and plant diversity, potentially supporting higher densities of some grassland bird species and higher bird diversity. Our objective was to determine the effect of experimental cattle grazing on species-specific relative abundance and occupancy, species diversity, and community dissimilarity of grassland birds on CRP grasslands across the longitudinal extent of Kansas, USA (a 63.5-cm precipitation gradient) during the 2017–2019 avian breeding seasons. Fifty-three of 108 fields were grazed by cattle during the growing seasons of 2017 and 2018 and all fields were rested from grazing in 2019. For all analyses, we examined separate model sets for semiarid western versus more mesic eastern Kansas. Using data from line transect surveys, we modeled relative abundances of 5 songbird species: grasshopper sparrow (Ammodramus savannarum), dickcissel (Spiza americana), eastern meadowlark (Sturnella magna), western meadowlark (Sturnella neglecta), and brown-headed cowbird (Molothrus ater). Grazing had delayed yet positive effects on abundances of grasshopper sparrow in western Kansas, and eastern meadowlark in eastern Kansas, but negative effects on dickcissel abundance in western Kansas and especially on burned fields in eastern Kansas. Somewhat counterintuitively, brown-headed cowbirds in western Kansas were more abundant on ungrazed versus grazed fields in the years after grazing began. In addition, we modeled multi-season occupancy of 3 gamebird species (ring-necked pheasant [Phasianus colcicus], northern bobwhite [Colinus virginianus], mourning dove [Zenaida macroura]) and Henslow's sparrow (Centronyx henslowii); grazing did not affect occupancy of these species. In eastern Kansas, species diversity was highest in grazed, unburned fields. In western Kansas, bird communities in grazed and ungrazed fields were dissimilar, as determined from multivariate analysis. Though regionally variable, conservative stocking of cattle on CRP grasslands during the nesting season as a mid-contract management tool might increase bird species diversity by restructuring habitat that accommodates a greater variety of species and decreasing abundances of species associated with taller, denser stands of vegetation.  相似文献   

10.
It has become increasingly important to understand the factors controlling the abundance of male strobili in Cryptomeria japonica since allergic reactions to the species?? pollen have become prevalent in Japan. There is considerable inter-annual variation in the abundance of male strobili, so it is important to investigate and validate quantitative trait loci (QTL) for strobili abundance across different years. Data on third generation families derived from an individual that produces abundant male strobili were studied using Kruskal?CWallis tests and Bayesian regression analysis, resulting in the detection of a single major QTL that was observed over multiple years. This QTL explained between 10.4 and 26.5?% of the phenotypic variation in male strobilus abundance. The consistency and significance of this QTL??s effects suggest that it has a major role in male strobilus production in C. japonica, although we also detected other QTLs, indicating that strobilus production is subject to complex and multifactorial regulation. These QTL may also affect precocity because we were unable to separate their effects from the genetic variability in male strobilus production. The major QTL that we detected occurs in a region homologous to a QTL detected in a previous study examining trees with a different genetic heritage following artificial induction of male strobilus production. This result further supports the importance of the QTL detected in the present study. Identifying the important genes in this QTL will therefore significantly increase our understanding of the genetic mechanisms of pollen production in C. japonica.  相似文献   

11.
Summary Mitochondrial DNA from four paired (fertile and male-sterile) lines and six isocytoplasmic strains of sorghum (Sorghum bicolor (L.) Moench) were fragmented by endonucleases and their electrophoretic patterns were examined. Cytoplasmic male sterile lines differed from their male-fertile counterparts consistently. Among the isocytoplasmic strains, KS 36A (S. verticilli-florum cytoplasm), KS 38A (S. conspicum cytoplasm), and KS 39A (S. niloticum cytoplasm) showed minor differences from the other strains. Results suggest that restriction endonuclease patterns are useful in detecting differences in mitochondrial genomes.This study was supported by a research grant from Kansas Grain Sorghum Commission, Kansas Board of Agriculture. Contribution 89-28-J from the Kansas Agricultural Experiment Station.  相似文献   

12.
The survival of the wheat curl mite (WCM), Aceria tosichilla Keifer, on five sources of resistant wheat (Triticum aestivum L.) was determined for collections of mites from Kansas (including a strain adapted to TAM 107), South Dakota and Texas, USA and Alberta, Canada. Sources of resistance to Aegilops squarrosa L. and Agropyron elongatum (Host) were resistant to WCMs from South Dakota and Alberta, but susceptible to WCMs from Kansas and Texas. Two wheats with resistance to rye (Secale cereale L.), PI 475772 and TAM 107, were resistant to all WCM collections except the strain from Kansas that was selected for adaptation to TAM 107. A common wheat (PI 222655) was resistant to all WCM collections except the one from Alberta, Canada. Because WCMs have overcome the resistance of TAM 107 in Kansas, the only resistance now available in commercial cultivars may be lost. Results indicate that PI222655 is the best source of resistance to replace TAM 107 in the USA but it may not be effective in Canada. Resistance to Ae. squarrosa and A. elongatum could be deployed against WCMs in Alberta and South Dakota but these sources may not be effective in Kansas and Texas. However, one WCM collection from each location may not represent the general mite population of an area. Therefore, any new sources of resistance should be evaluated fully against WCMs from areas where they are likely to be used in commercial cultivars.  相似文献   

13.
Cridland , Arthur A., and John E. Morris . (Kansas U., Lawrence.) Spermopteris, a new genus of pteridosperms from the Upper Pennsylvanian Series of Kansas. Amer. Jour. Bot. 47(10) : 855–859. Illus. 1960.— Spermopteris gen. nov., based upon seed-bearing specimens of the formgenus Taeniopteris, is described from the Lawrence Shale, Pennsylvanian System, of Kansas. The single species S. coriacea (Göppert) comb. nov. is known. Comparison is made with other fertile and supposedly fertile Paleozoic specimens of Taeniopteris and with specimens of T. spatulata from the Rhaetic of Tonkin.  相似文献   

14.
Understanding the causes of interannual variability in atmospheric pollen concentration is an important but elusive goal for public health and environmental change. We analyzed long-term daily records of pollen counts from urban Kansas City, Missouri, USA collected from 1997 to 2009 for three pollen groups: Ambrosia, Poaceae, and a third group which is mostly composed of arboreal pollen types. The annual pollen index varied from 8,368 to 80,822 over the thirteen-year period. Although Ambrosia pollen is often thought to be associated with droughts and disturbance, years with high Ambrosia pollen were associated with high summer precipitation to the south of Kansas City. Years with high Poaceae pollen were associated with high spring precipitation to the south of the city. In support of the southern influence to Kansas City pollen, Ambrosia and Poaceae pollen mostly arrived on southern winds. In contrast to the other two pollen groups, the arboreal pollen was most associated with growing season precipitation to the east of Kansas City, although it was still highest on days with southern winds. Based on the correlations with climate, the severity of an upcoming allergy season may be predicted with early-season precipitation data, while short-term severity can be forecast from local weather patterns.  相似文献   

15.
Summary A survey of 84 dust samples from 42 air-conditioners and controls was conducted at Kansas State University, Manhattan. Isolations ofC. neoformans andH. capsulatum were attemped using various mycological procedures. H. capsulatum was not recovered in this survey. One isolate ofC. neoformans was obtained. The contaminated air-conditioner yielding the organism contained considerable bird feces, feathers, and dust.Contribution No. 102, Department of Infectious Diseases, Kansas Agricultural Experiment Station, Manhattan, Kansas.  相似文献   

16.
Intraspecific variation in sociosexual behavior has typically been investigated in the context of its relationship with environmental factors, but neurogenetic factors can also influence sociosexual behavior. In laboratory studies of prairie voles (Microtus ochrogaster), length polymorphism of microsatellite DNA within the gene (avpr1a) encoding the vasopressin 1a receptor is correlated with variation in male sociosexual behavior. However, field studies of prairie voles have found the relationship between male avpr1a microsatellite allele length and sociosexual behavior to be more ambiguous, possibly because most males had alleles of intermediate length. We tested the hypothesis that avpr1a microsatellite allele length mediates male sociosexual behavior in field settings by releasing voles into field enclosures where every male possessed two avpr1a microsatellite alleles at least one standard error longer or shorter than the mean length in their population of origin. Voles from an Illinois and Kansas population were examined separately as social monogamy appears more prevalent in the Illinois population. Illinois males with long avpr1a microsatellite alleles had smaller home ranges and overlapped a greater proportion of the home range of the female that they overlapped the most. Kansas males showed the opposite pattern. Illinois, but not Kansas, males with long avpr1a microsatellite alleles sired offspring with more females and sired more litters. Our results support the hypothesis that genetic variation associated with the avpr1a gene plays a role in mediating male prairie vole sociosexual behavior in nature. However, the relationship between specific male behaviors and male avpr1a microsatellite allele length sometimes differed significantly between Kansas and Illinois voles, suggesting relationships between specific male sociosexual behaviors and polymorphism associated with the avpr1a locus are complex, possibly involving specific nucleotide sequences or other population‐specific genetic differences.  相似文献   

17.
A polymorphism of purine nucleoside phosphorylase is described in sheep erythrocytes. Two isozymes were distinguished electrophoretically, one with high activity (NP-1) and one with low activity (NP-2). Breeding data suggest that the two isozymes are the product of two codominant alleles, NP 1and NP 2. The K m 's for inosine did not differ between NP-1 and NP-2; however, NP-2 had a lower pH optimum and was relatively unstable when incubated at 48 C.Contribution No. 421-J, from the Department of Pathology, Kansas Agricultural Experiment Station, Manhattan, Kansas. Supported in part by USPHS Grants HL-70119 and HL 12072.  相似文献   

18.
The Fusarium isolates molecularly grouped in this experiment were isolated from the roots of three cassava genotypes (TMS 30572, TMS 4(2)1425 and TME-1) harvested in Ibadan derived savanna, Sabongidda-Ora humid forest and the Onne humid forest regions of Nigeria in 2004 and 2005. Isolates were previously identified using conventional morphological characters at the Plant Pathology Laboratory of the International Institute of Tropical Agriculture, Ibadan. Molecular grouping was done using amplified fragment length polymorphism at the Fusarium Laboratory of the Kansas State University, Kansas, USA. The molecular groupings agreed with the conventional morphological identification. Ten distinct amplified fragment length polymorphism (AFLP) groups of Fusarium were distinguishable, each group probably a distinct species, and many of them might represent previously undescribed Fusarium species. The two largest of the AFLP groups correspond to F. oxysporum and F. solani species complex. F. solani is an important root rot pathogen of cassava Nigeria.  相似文献   

19.
Leisman , Gilbert A. (Kansas State Teachers Coll., Emporia.) The morphology and anatomy of Callipteridium Sullivanti. Amer. Jour. Bot. 47(4) : 281—287. Illus. 1960.–Previously undescribed pinnules of Callipteridium Sullivanti (Lesq.) Weiss have been studied in Iowa and Kansas coal balls. Conventional peel techniques revealed the anatomy while deliberately fracturing the coal ball revealed morphological features. Epidermal studies were also conducted after macerating small portions of the coal ball. Evidence indicates that these pinnules were borne on Myeloxylon petioles. Arguments are advanced for removing this species from the genus Alethopteris and returning it to Callipteridium.  相似文献   

20.
Summary Restriction endonuclease patterns of chloroplast DNA (cpDNA) were consistently distinguishable between fertile and male-sterile cytoplasms of sorghum [Sorghum bicolor (L.) Moench], whereas no differences in restriction patterns of cpDNA among male-sterile (A1) lines, including six isocytoplasmic strains, were revealed in this study. It is suggested that chloroplast DNA may contribute to the male sterility of A1 lines used currently in hybrid sorghum production.This research was supported by a research grant from Kansas Grain Sorghum Commission, Kansas Board of Agriculture. Contribution 90-293-J from the Kansas Agricultural Experiment Station  相似文献   

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