DOCSLIB.ORG

Kinetics of Spore Germination NEIL G

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Kinetics of Spore Germination NEIL G JOURNAL OF BACTERIOLOGY, May, 1965 Vol. 89, No. 5 Copyright @ 1965 American Society for Microbiology Printed in U.S.A. Kinetics of Spore Germination NEIL G. McCORMICK Department of Microbiology, School of Medicine, University of Virginia, Charlottesville, Virginia Received for publication 23 November 1964 ABSTRACT MCCORMICK, NEIL G. (University of Virginia, Charlottesville). Kinetics of spore germination. J. Bacteriol. 89:1180-1185. 1965.-An empirically derived equation was developed which accurately describes the time-course of the decrease in optical density during spore germination. A method is described for calculating the final value, the inflection point, and the maximal velocity from knowledge of three experimental values and the initial value at time-zero. A number of germination curves were ana- lyzed by application of the equation, and the effects of various environmental condi- tions on the parameters of the equation (k, c, and a) are noted. The constant c was found to be dependent upon the temperature and perhaps upon the degree of heat activation and the L-alanine concentration. The constants k and a appear to be more basic functions of the initial state of the spore suspension. Variation of the concentra- tion of spores changes only the initial optical density, but does not change any of the three constants. The conversion of a spore to an actively me- decrease in OD during a constant time interval tabolizing vegetative cell occurs in three separate (Rode and Foster, 1962) or as the slope of the stages: (i) activation, (ii) initiation, and (iii) straight line portion of a semilogarithmic plot of outgrowth (Murrell, 1961). Activation is de- the percentage of ungerminated spores versus fined as a treatment which conditions the dor- time (Hachisuka et al., 1955; Woese and mant state to allow rapid germination. Activa- Morowitz, 1958; O'Connor and Halvorson, 1961). tion by treatment with heat or reducing agents Woese, Morowitz, and Hutchinson (1958) pro- is a reversible process (Keynan et al., 1964). posed that, after an initial lag, the fraction of Initiation involves the irreversible degradation of ungerminated spores decreased according to the the rigid spore wall, and outgrowth describes the first-order kinetic equation stages from initiation to subsequent vegetative growth. Since activation and initiation may be ODt- ODf = -kt studied separately from outgrowth, an accurate ODi- ODf (1) kinetic analysis should provide clues as to the mechanism involved in the breaking of dormancy. where ODt is the optical density at time t, ODi is Throughout this paper, the term germination the initial optical density, and ODf is the final will refer to the initiation stage only. limiting value of optical density at the comple- The kinetics of germination were measured by tion of germination. following the loss in heat resistance, the increase Analysis of a large number of germination in stainability, or the decrease in optical density curves obtained by continuously recording the (OD; Powell, 1950, 1951); by observing phase- decrease in OD during germination demonstrated contrast darkening (Pulvertaft and Haynes, that the straight-line portion of the semilog- 1951); and by the release of dipicolinic acid arithmic a (Woese and Morowitz, 1958). Good agreement plot spans relatively short period of exists among thes various methods (Campbell, time, and that, as germination proceeds, each 1957; Woese and Morowitz, 1958). OD measure- curve deviates from linearity. ments provide the most convenient method for It is the purpose of this communication to studying the process of spore germination. The derive an empirical expression describing the inability to fit the time-course curve of the de- entire time-course of events during spore ger- crease in OD to any classically employed kinetic mination and to analyze the effects of various equation has made it difficult to obtain a kinetic experimental conditions on the parameters of the description of the germination process. Germina- equation. Preliminary reports of this work have tion rates have been expressed as the percentage appeared (McCormick, 1964a, b). 1180 VOL. 89, 1965 KINETICS OF SPORE GERMINATION 1181 MATERIALS AND METHODS OD at time t, equation 4 becomes Clean spore suspensions of Bacillus cereus strain T were prepared as described by Church, lnln F Yi-Yf 1- lnln rYi Yf Halvorson, and Halvorson (1954). The germina- LYi-Yt2J LYi-Yt j tion reaction mixture consisted of 100 ,moles of -C = -iln t2/tl tris(hydroxymethyl)aminomethane (Tris) buffer (6) (pH 8.5); sufficient spores to insure an initial OD of 0.800 (approximately 1.5 X 109 spores per milli- lnln Yi Yf -lnlnm rYi Yf liter); and distilled water to a total of 0.9 ml. At = vi - Yt3iiyt2/- zero-time, 0.10 ml of L-alanine solution (concen- ln t3/t2 tration as described in text) was added, and the decrease in OD was measured at 625 m,u in a Gil- Equation 6 may be simplified by selecting yt ford recording spectrophotometer. Spores were values such that t2/t1 = t3/t2. This procedure activated by heating concentrated spore suspen- eliminates the denominators and permits the sions (OD = 1.5) in a water bath (65 C) for varying solution for the final limiting OD, yf. lengths of time as described in the text. [ln(yi- yt1)][ln(yi -Yt3)] RESULTS - [ln(yi - yt2)I[ln(yi -Yt2)] An ln(yi- yf) = (7) Mathematical development of the equation. (yi- - Yt3) empirically derived equation was reported which n Yt)(Yi accurately describes the time-course of spore (yi - Yt2)(Yi - Yt2) germination (McCormick, 1964a). As the OD of Thus, it is possible to predict the limiting (equilib- a germinating spore suspension decreases, it rium) value, Yf, of the reaction (as well as all asymptotically approaches a limiting value as other values) from knowledge of a minimum of germination approaches completion. This limit- three experimental values at selected times if the ing value has usually been determined by allow- initial value at exactly t = 0 is known. ing the reaction to proceed until no further change From equation 3, the basic expression used in OD is detected. Normalization of the data to throughout this is represent the total decrease in OD as unity allows study obtained any part of the reaction to be expressed as a Y = e-kt-c (8) fraction of the total reaction completed. If this fraction is designated as Y, then where k = In 1 /Yo. This equation generates a sigmoid curve from zero to unity as the variable Y = f(t) (2) (t) goes from zero to infinity. Since the function exists only for positive values of time between A plot of lnln 1/Y versus ln t results in a linear zero and infinity, the value of the function and relationship with a negative slope. This linear all of its derivatives can be shown to vanish function takes the form identically at zero by application of the Theorem of Mean Values. This is of some interest, because lnln I/Y = -c In t + lnln l/Yo (3) it implies that a reaction described by the equa- tion does not start at its maximal velocity, but where Yo is the value of Y at t = 1, and -c is the accelerates from an initial velocity of zero to its slope. To calculate Y, it is necessary that the maximal velocity in a finite interval of time. The final limiting value be known precisely. If the importance of this is more apparent when reaction proceeds in accordance with equation 3, considering reactions which conform to the equa- then the following relationship holds: tion but which do not appear to possess any lnln 1/Y2 - nln induction period. 1/Y, The velocity or rate expression given by the In t2/tl first derivative of equation 8 is lnln 1/Y3-lnln 1/Y2 (4) kcY In t3/t2 dY/dt = (9)+(9) Since which generates a skewed distribution function. y Yt-Yi Yi Y(5 Equation 9, when equated to zero, yields two Yf-Yi Yi-Yf solutions for t (t = 0, t = oo), which represent, respectively, the limits of the times at which the where yf is the limiting OD as t approaches xc, reaction approaches zero from the right and y i is the initial OD at t = 0, and Yt is the observed completion (equilibrium) from the left. These 1182 McCORMICK J. BACTERIOL. z w -j (-) 0. 20 TIME (min.) 2.0[- a.o- 1.0 1.0 ,m .1 .5 0 0.10 I .06 .1 .01 .0o d f I I,,,11 i lll 1 2 6 7 10 I25 67 10 20 . 25ta a5 7 20 TIME (min.) TIME (min.) TIME (min.) FIG. 1. Effect of temperature, heat activation, and L-alanine concentration on L-alanine-induced germi- nation of spores of Bacillus cereus T. (a) Germination was conducted at the temperatures indicated, with the use of spores heat-shocked 4 hr, and at a final L-alanine concentration of 0.10 1t; (b) loglog 1IY versus log t plot of the data in (a). (c) Germination was conducted at 30 C and 0.01 M final L-alanine concentra- tion with the use of spores heat-shocked for the number of hours noted; (d) loglog 11Y versus log t plot of the data in (c). (e) Germination was carried out at 30 C with 4-hr heat-shocked spores at the L-alanine concentrations depicted; (f) loglog 11Y versus log t plot of the data in (e). limiting values for an existing process can, at best, at by application of equation lOb. It thus becomes only be approached but never achieved, for in possible to determine the inflection point, even achieving them the process itself ceases to exist.
Load more

Recommended publications
  • 1 5 Chapter 1 Introduction I. LIFE CYCLES and DIVERSITY of VASCULAR PLANTS the Subjects of This Thesis Are the Pteri
    Chapter 1-15 Chapter 1 Introduction I. LIFE CYCLES AND DIVERSITY OF VASCULAR PLANTS The subjects of this thesis are the pteridophytes and seed plants that are conventionally classified as the vascular plants or tracheophytes. Vascular plants were traditionally defined by the possession of specialized conducting tissues, called phloem and xylem. Mosses are now believed to have inherited their conducting tissues from a common ancestor with the tracheophytes (Mishler & Churchill 1984) but are not considered in this thesis. Vascular plants can be divided into four groups with respect to life cycle. These groups are homosporous pteridophytes, heterosporous pteridophytes, gymnosperms and angiosperms. This is not intended to be a phylogenetic classification. There are about a quarter of a million species of vascular plant alive today. The vast majority are angiosperms and most of the remainder are homosporous pteridophytes. Heterosporous pteridophytes and gymnosperms contribute only a small number of species (Table 1.1). TABLE 1.1 Estimated number of extant species in each of the major groups of vascular plants (data from Parker 1982). Homosporous pteridophytes 12,000 species Heterosporous pteridophytes <1,000 species Gymnosperms <1,000 species Angiosperms >200,000 species A. Homosporous pteridophytes Homosporous pteridophytes produce a single type of spore. Spores are dispersed and develop into photosynthetic or mycoparasitic gametophytes. A gametophyte's gender is indeterminate at the time of spore dispersal, and a single gametophyte may produce eggs and/or sperm. Sperm are motile, and require free water to fertilize eggs. The young sporophyte is nourished by the maternal gametophyte during early development but later becomes Chapter 1-16 nutritionally independent.
    [Show full text]
  • Reproduction in Plants Which But, She Has Never Seen the Seeds We Shall Learn in This Chapter
    Reproduction in 12 Plants o produce its kind is a reproduction, new plants are obtained characteristic of all living from seeds. Torganisms. You have already learnt this in Class VI. The production of new individuals from their parents is known as reproduction. But, how do Paheli thought that new plants reproduce? There are different plants always grow from seeds. modes of reproduction in plants which But, she has never seen the seeds we shall learn in this chapter. of sugarcane, potato and rose. She wants to know how these plants 12.1 MODES OF REPRODUCTION reproduce. In Class VI you learnt about different parts of a flowering plant. Try to list the various parts of a plant and write the Asexual reproduction functions of each. Most plants have In asexual reproduction new plants are roots, stems and leaves. These are called obtained without production of seeds. the vegetative parts of a plant. After a certain period of growth, most plants Vegetative propagation bear flowers. You may have seen the It is a type of asexual reproduction in mango trees flowering in spring. It is which new plants are produced from these flowers that give rise to juicy roots, stems, leaves and buds. Since mango fruit we enjoy in summer. We eat reproduction is through the vegetative the fruits and usually discard the seeds. parts of the plant, it is known as Seeds germinate and form new plants. vegetative propagation. So, what is the function of flowers in plants? Flowers perform the function of Activity 12.1 reproduction in plants. Flowers are the Cut a branch of rose or champa with a reproductive parts.
    [Show full text]
  • Heterospory: the Most Iterative Key Innovation in the Evolutionary History of the Plant Kingdom
    Biol. Rej\ (1994). 69, l>p. 345-417 345 Printeii in GrenI Britain HETEROSPORY: THE MOST ITERATIVE KEY INNOVATION IN THE EVOLUTIONARY HISTORY OF THE PLANT KINGDOM BY RICHARD M. BATEMAN' AND WILLIAM A. DiMlCHELE' ' Departments of Earth and Plant Sciences, Oxford University, Parks Road, Oxford OXi 3P/?, U.K. {Present addresses: Royal Botanic Garden Edinburiih, Inverleith Rojv, Edinburgh, EIIT, SLR ; Department of Geology, Royal Museum of Scotland, Chambers Street, Edinburgh EHi ijfF) '" Department of Paleohiology, National Museum of Natural History, Smithsonian Institution, Washington, DC^zo^bo, U.S.A. CONTENTS I. Introduction: the nature of hf^terospon' ......... 345 U. Generalized life history of a homosporous polysporangiophyle: the basis for evolutionary excursions into hetcrospory ............ 348 III, Detection of hcterospory in fossils. .......... 352 (1) The need to extrapolate from sporophyte to gametophyte ..... 352 (2) Spatial criteria and the physiological control of heterospory ..... 351; IV. Iterative evolution of heterospory ........... ^dj V. Inter-cladc comparison of levels of heterospory 374 (1) Zosterophyllopsida 374 (2) Lycopsida 374 (3) Sphenopsida . 377 (4) PtiTopsida 378 (5) f^rogymnospermopsida ............ 380 (6) Gymnospermopsida (including Angiospermales) . 384 (7) Summary: patterns of character acquisition ....... 386 VI. Physiological control of hetcrosporic phenomena ........ 390 VII. How the sporophyte progressively gained control over the gametophyte: a 'just-so' story 391 (1) Introduction: evolutionary antagonism between sporophyte and gametophyte 391 (2) Homosporous systems ............ 394 (3) Heterosporous systems ............ 39(1 (4) Total sporophytic control: seed habit 401 VIII. Summary .... ... 404 IX. .•Acknowledgements 407 X. References 407 I. I.NIRODUCTION: THE NATURE OF HETEROSPORY 'Heterospory' sensu lato has long been one of the most popular re\ie\v topics in organismal botany.
    [Show full text]
  • Spore Reproduction of Japanese Climbing Fern in Florida As a Function of Management Timing
    Spore Reproduction of Japanese Climbing Fern in Florida as a Function of Management Timing Candice M. Prince1, Dr. Gregory E. MacDonald1, Dr. Kimberly Bohn2, Ashlynn Smith1, and Dr. Mack Thetford1 1University of Florida, 2Pennsylvania State University Photo Credit: Chris Evans, University of Illinois, Bugwood.org Exotic climbing ferns in Florida Old world climbing fern Japanese climbing fern (Lygodium microphyllum) (Lygodium japonicum) Keith Bradley, Atlas of Florida Vascular Plants Chris Evans, University of Illinois, Bugwood.org Japanese climbing fern (Lygodium japonicum) • Native to temperate and tropical Asia • Climbing habit • Early 1900s: introduced as an ornamental1 • Long-distance dispersal via wind, pine straw bales2,3 Chris Evans, University of Illinois, Bugwood.org Dennis Teague, U.S. Air Force, Bugwood.org Distribution • Established in 9 southeastern states • In FL: present throughout the state, USDA NRCS National Plant Data Team, 2016 but most invasive in northern areas • Winter dieback, re-sprouts from rhizomes1 • Occurs in mesic and temporally hydric areas1 Atlas of Florida Vascular Plants, Institute of Systemic Botany, 2016 Impacts Chris Evans, University of Illinois, Bugwood.org • Smothers and displaces vegetation, fire ladders • Florida Exotic Pest Plant Council: Category I species Chuck Bargeron, University of Georgia, Bugwood.org • Florida Noxious Weed List • Alabama Noxious Weed List (Class B) Japanese climbing fern: life cycle John Tiftickjian, Sigel Lab, University of Delta State University Louisiana at Lafayette
    [Show full text]
  • Educator Guide
    Educator Guide Presented by The Field Museum Education Department INSIDE: s )NTRODUCTION TO "OTANY s 0LANT $IVISIONS AND 2ELATED 2ESEARCH s #URRICULUM #ONNECTIONS s &OCUSED &IELD 4RIP !CTIVITIES s +EY 4ERMS Introduction to Botany Botany is the scientific study of plants and fungi. Botanists (plant scientists) in The Field Museum’s Science and Education Department are interested in learning why there are so many different plants and fungi in the world, how this diversity is distributed across the globe, how best to classify it, and what important roles these organisms play in the environment and in human cultures. The Field Museum acquired its first botanical collections from the World’s Columbian Exposition of 1893 when Charles F. Millspaugh, a physician and avid botanist, began soliciting donations of exhibited collections for the Museum. In 1894, the Museum’s herbarium was established with Millspaugh as the Museum’s first Curator of Botany. He helped to expand the herbarium to 50,000 specimens by 1898, and his early work set the stage for the Museum’s long history of botanical exploration. Today, over 70 major botanical expeditions have established The Field’s herbarium as one of the world’s preeminent repositories of plants and fungi with more than 2.7 million specimens. These collections are used to study biodiversity, evolution, conservation, and ecology, and also serves as a depository for important specimens and material used for drug screening. While flowering plants have been a major focus during much of the department’s history, more recently several staff have distinguished themselves in the areas of economic botany, evolutionary biology and mycology.
    [Show full text]
  • Plant Propagation Lab Exercise Module 2
    Plant Propagation Lab Exercise Module 2 PROPAGATION OF SPORE BEARING PLANTS FERNS An introduction to plant propagation laboratory exercises by: Gabriel Campbell-Martinez and Dr. Mack Thetford Plant Propagation Lab Exercise Module 2 PROPAGATION OF SPORE BEARING PLANTS FERNS An introduction to plant propagation laboratory exercises by: Gabriel Campbell-Martinez and Dr. Mack Thetford LAB OBJECTIVES • Introduce students to the life cycle of ferns. • Demonstrate the appropriate use of terms to describe the morphological characteristics for describing the stages of fern development. • Demonstrate techniques for collection, cleaning, and sowing of fern spores. • Provide alternative systems for fern spore germination in home or commercial settings. Fern spore germination Fern relationship to other vascular plants Ferns • Many are rhizomatous and have circinate vernation • Reproduce sexually by spores • Eusporangiate ferns • ~250 species of horsetails, whisk ferns moonworts • Leptosporangiate • ~10,250 species Sporophyte Generation Spores are produced on the mature leaves (fronds) of the sporophyte generation of ferns. The spores are arranged in sporangia which are often inside a structure called a sorus. The sori often have a protective covering of living leaf tissue over them that is called an indusium. As the spores begin to mature the indusium may also go through physical changes such as a change in color or desiccating and becoming smaller as it dries to allow an opening for dispersal. The spores (1n) may be wind dispersed or they may require rain (water) to aid in dispersal. Gametophyte Generation The gametophyte generation is initiated with the germination of the spore (1n). The germinated spore begins to grow and form a heart-shaped structure called a prothallus.
    [Show full text]
  • Histochemistry of Spore Mucilage and Inhibition of Spore Adhesion in Champia Parvula, a Marine Alga
    University of Rhode Island DigitalCommons@URI Open Access Dissertations 1994 Histochemistry of Spore Mucilage and Inhibition of Spore Adhesion in Champia parvula, A Marine Alga Martha E. Apple University of Rhode Island Follow this and additional works at: https://digitalcommons.uri.edu/oa_diss Recommended Citation Apple, Martha E., "Histochemistry of Spore Mucilage and Inhibition of Spore Adhesion in Champia parvula, A Marine Alga" (1994). Open Access Dissertations. Paper 783. https://digitalcommons.uri.edu/oa_diss/783 This Dissertation is brought to you for free and open access by DigitalCommons@URI. It has been accepted for inclusion in Open Access Dissertations by an authorized administrator of DigitalCommons@URI. For more information, please contact [email protected]. HISTOCHEMISTRY OF SPORE MUCILAGE AND INHIBITION OF SPORE ADHESION IN CHAMPIA PARVULA, A MARINE RED ALGA. BY MARTHA E. APPLE A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN BIOLOGICAL SCIENCES UNIVERSITY OF RHODE ISLAND 1994 DOCTOR OF PHILOSOPHY DISSERTATION OF MARTHA E. APPLE APPROVED: Dissertation Committee Major Professor DEAN OF THE GRADUATE SCHOOL UNIVERSITY OF RHODE ISLAND 1994 Abstract Spores of the marine red alga, Champja parvu!a, attached initially to plastic or glass cover slips by extracellular mucilage. Adhesive rhizoids emerged from germinating spores, provided a further basis of attachment and rhizoidal division formed the holdfast. Mucilage of holdfasts and attached spores stained for sulfated and carboxylated polysaccharides. Rhizoids and holdfast cells but not mucilage stained for protein. Removal of holdfasts with HCI revealed protein anchors in holdfast cell remnants. Spores detached when incubated in the following enzymes: 13-galactosidase, protease, ce!!u!ase, a-amylase, hya!uronidase, sulfatase, and mannosidase.
    [Show full text]
  • Structure and Function of Spores in the Aquatic Heterosporous Fern Family Marsileaceae
    Int. J. Plant Sci. 163(4):485–505. 2002. ᭧ 2002 by The University of Chicago. All rights reserved. 1058-5893/2002/16304-0001$15.00 STRUCTURE AND FUNCTION OF SPORES IN THE AQUATIC HETEROSPOROUS FERN FAMILY MARSILEACEAE Harald Schneider1 and Kathleen M. Pryer2 Department of Botany, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, Illinois 60605-2496, U.S.A. Spores of the aquatic heterosporous fern family Marsileaceae differ markedly from spores of Salviniaceae, the only other family of heterosporous ferns and sister group to Marsileaceae, and from spores of all ho- mosporous ferns. The marsileaceous outer spore wall (perine) is modified above the aperture into a structure, the acrolamella, and the perine and acrolamella are further modified into a remarkable gelatinous layer that envelops the spore. Observations with light and scanning electron microscopy indicate that the three living marsileaceous fern genera (Marsilea, Pilularia, and Regnellidium) each have distinctive spores, particularly with regard to the perine and acrolamella. Several spore characters support a division of Marsilea into two groups. Spore character evolution is discussed in the context of developmental and possible functional aspects. The gelatinous perine layer acts as a flexible, floating organ that envelops the spores only for a short time and appears to be an adaptation of marsileaceous ferns to amphibious habitats. The gelatinous nature of the perine layer is likely the result of acidic polysaccharide components in the spore wall that have hydrogel (swelling and shrinking) properties. Megaspores floating at the water/air interface form a concave meniscus, at the center of which is the gelatinous acrolamella that encloses a “sperm lake.” This meniscus creates a vortex-like effect that serves as a trap for free-swimming sperm cells, propelling them into the sperm lake.
    [Show full text]
  • 81 Vascular Plant Diversity
    f 80 CHAPTER 4 EVOLUTION AND DIVERSITY OF VASCULAR PLANTS UNIT II EVOLUTION AND DIVERSITY OF PLANTS 81 LYCOPODIOPHYTA Gleicheniales Polypodiales LYCOPODIOPSIDA Dipteridaceae (2/Il) Aspleniaceae (1—10/700+) Lycopodiaceae (5/300) Gleicheniaceae (6/125) Blechnaceae (9/200) ISOETOPSIDA Matoniaceae (2/4) Davalliaceae (4—5/65) Isoetaceae (1/200) Schizaeales Dennstaedtiaceae (11/170) Selaginellaceae (1/700) Anemiaceae (1/100+) Dryopteridaceae (40—45/1700) EUPHYLLOPHYTA Lygodiaceae (1/25) Lindsaeaceae (8/200) MONILOPHYTA Schizaeaceae (2/30) Lomariopsidaceae (4/70) EQifiSETOPSIDA Salviniales Oleandraceae (1/40) Equisetaceae (1/15) Marsileaceae (3/75) Onocleaceae (4/5) PSILOTOPSIDA Salviniaceae (2/16) Polypodiaceae (56/1200) Ophioglossaceae (4/55—80) Cyatheales Pteridaceae (50/950) Psilotaceae (2/17) Cibotiaceae (1/11) Saccolomataceae (1/12) MARATTIOPSIDA Culcitaceae (1/2) Tectariaceae (3—15/230) Marattiaceae (6/80) Cyatheaceae (4/600+) Thelypteridaceae (5—30/950) POLYPODIOPSIDA Dicksoniaceae (3/30) Woodsiaceae (15/700) Osmundales Loxomataceae (2/2) central vascular cylinder Osmundaceae (3/20) Metaxyaceae (1/2) SPERMATOPHYTA (See Chapter 5) Hymenophyllales Plagiogyriaceae (1/15) FIGURE 4.9 Anatomy of the root, an apomorphy of the vascular plants. A. Root whole mount. B. Root longitudinal-section. C. Whole Hymenophyllaceae (9/600) Thyrsopteridaceae (1/1) root cross-section. D. Close-up of central vascular cylinder, showing tissues. TABLE 4.1 Taxonomic groups of Tracheophyta, vascular plants (minus those of Spermatophyta, seed plants). Classes, orders, and family names after Smith et al. (2006). Higher groups (traditionally treated as phyla) after Cantino et al. (2007). Families in bold are described in found today in the Selaginellaceae of the lycophytes and all the pericycle or endodermis. Lateral roots penetrate the tis detail.
    [Show full text]
  • Reproductive Morphology
    Week 3; Wednesday Announcements: 1st lab quiz TODAY Reproductive Morphology Reproductive morphology - any portion of a plant that is involved with or a direct product of sexual reproduction Example: cones, flowers, fruits, seeds, etc. Basic Plant Life cycle Our view of the importance of gametes in the life cycle is shaped by the animal life cycle in which meiosis (the cell division creating haploid daughter cells with only one set of chromosomes) gives rise directly to sperm and eggs which are one celled and do not live independently. Fertilization (or the fusion of gametes – sperm and egg) occurs inside the animal to recreate the diploid organism (2 sets of chromosomes). Therefore, this life cycle is dominated by the diploid generation. This is NOT necessarily the case among plants! Generalized life cycle -overhead- - alternation of generations – In plants, spores are the result of meiosis. These may grow into a multicellular, independent organism (gametophyte – “gamete-bearer”), which eventually produces sperm and eggs (gametes). These fuse (fertilization) and a zygote is formed which grows into what is known as a sporophyte - “spore-bearer”. (In seed plants, pollination must occur before fertilization! ) This sporophyte produces structures called sporangia in which meiosis occurs and the spores are released. Spores (the product of meiosis) are the first cell of the gametophyte generation. Distinguish Pollination from Fertilization and Spore from Gamete Pollination – the act of transferring pollen from anther or male cone to stigma or female cone; restricted to seed plants. Fertilization – the act of fusion between sperm and egg – must follow pollination in seed plants; fertilization occurs in all sexually reproducing organisms.
    [Show full text]
  • How to Collect Fern Spores!
    HOW TO COLLECT FERN SPORES! by Barbara Joe ! Hoshizaki Layout and Design by ! Karen ‘Kiwi’ Burch ©2006 Presented by The American Fern Society The American Fern Society Outreach Program sponsors this presentation to provide information on how to collect fern spores. It is hoped that this tutorial will encourage viewers to collect quality spores for themselves and others as a source to grow new ferns. 3 CONTENTS • About fern spores - 6 • A pictorial: young, ripe and old sporangia - 52 • Spore seasons - 17 • Unusual problems - 78 • Sterile ferns - 19 • Collecting spores - 86 • Finding fertile leaves - 21 • Cleaning spores - 102 • Finding sporangia - 27 • Storing spores - 106 • Finding ripe sporangia - 37 • Review - 110 4 ABOUT FERN SPORES Spores, like seeds, are used to grow new plants. Even if you do not grow ferns from spores, collecting them will give you the pleasure of knowing you are helping other gardeners or botanists. You may also be safeguarding the survival of rare or endangered species, or adding brand new species to cultivation. 5 Spores are abundant About spores but very inconspicuous. • On the back of this tree fern leaf are clusters of spore cases containing spores. • Below, a closer view shows the clusters of spore cases as brown round dots. • The individual spores and spore cases are too small to be seen in this view. Sphaeropteris cooperi 6 Spores versus Seeds About spores Aboutspores Both are reproductive bodies • These sketches of fern spores are greatly magnified, by about 1000x. • Spores vary in size, shape, color, and surface patterns, and have only one set of chromosomes.
    [Show full text]
  • Club Mosses, Ferns & Horsetails: the Seed-Free Vascular Plants
    Club Mosses, Ferns & Horsetails: the Seed-free Vascular Plants Vascular Plants - a quick review Two unrelated groups within “cryptogams” – seed free vascular plants – are recognized as phyla: 1. Lycopodiophyta : lycopods 2. Polypodiophyta: ferns, horsetails, and whisk ferns Vascular Plants - a quick review Why were the seed-free plants “grouped” together? They produce free spores, the principal dispersal units, via meiosis. Spore: a reproductive cell, capable of developing into an adult without fusion with another cell. spores Vascular Plants - a quick review Why were the seed-free plants “grouped” together? Spores develop within a sporangium (pl. sporangia) sporangium spores Vascular Plants - a quick review Why were the seed-free plants “grouped” together? Spores germinate and develop into gametophytes that exist independently of the spore-producing plants. The gametophytes (haploid, n) tend to be inconspicuous and short-lived. sporangium gametophyte spores Vascular Plants - a quick review Why were the seed-free plants “grouped” together? Like all plants, seed-free plants produce two kinds of gametes in their gametophytes: sperm and egg that unite to form a zygote (2n or diploid) via fertilization! sporangium zygote gametophyte spores Vascular Plants - a quick review Why were the seed-free plants “grouped” together? The sporophyte (2n) develops from the zygote and is more conspicuous, usually perennial and lives for an indefinite period! sporangium sporophyte zygote gametophyte spores Wisconsin Seed-free Plants The best website to identify
    [Show full text]