1 5 Chapter 1 Introduction I. LIFE CYCLES and DIVERSITY of VASCULAR PLANTS the Subjects of This Thesis Are the Pteri

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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.
Auxin Regulation Involved in Gynoecium Morphogenesis of Papaya Flowers

Zhou et al. Horticulture Research (2019) 6:119 Horticulture Research https://doi.org/10.1038/s41438-019-0205-8 www.nature.com/hortres ARTICLE Open Access Auxin regulation involved in gynoecium morphogenesis of papaya flowers Ping Zhou 1,2,MahparaFatima3,XinyiMa1,JuanLiu1 and Ray Ming 1,4 Abstract The morphogenesis of gynoecium is crucial for propagation and productivity of fruit crops. For trioecious papaya (Carica papaya), highly differentiated morphology of gynoecium in flowers of different sex types is controlled by gene networks and influenced by environmental factors, but the regulatory mechanism in gynoecium morphogenesis is unclear. Gynodioecious and dioecious papaya varieties were used for analysis of differentially expressed genes followed by experiments using auxin and an auxin transporter inhibitor. We first compared differential gene expression in functional and rudimentary gynoecium at early stage of their development and detected significant difference in phytohormone modulating and transduction processes, particularly auxin. Enhanced auxin signal transduction in rudimentary gynoecium was observed. To determine the role auxin plays in the papaya gynoecium, auxin transport inhibitor (N-1-Naphthylphthalamic acid, NPA) and synthetic auxin analogs with different concentrations gradient were sprayed to the trunk apex of male and female plants of dioecious papaya. Weakening of auxin transport by 10 mg/L NPA treatment resulted in female fertility restoration in male flowers, while female flowers did not show changes. NPA treatment with higher concentration (30 and 50 mg/L) caused deformed flowers in both male and female plants. We hypothesize that the occurrence of rudimentary gynoecium patterning might associate with auxin homeostasis alteration. Proper auxin concentration and auxin homeostasis might be crucial for functional gynoecium morphogenesis in papaya flowers.
Genetics of Dioecy and Causal Sex Chromosomes in Plants

c Indian Academy of Sciences REVIEW ARTICLE Genetics of dioecy and causal sex chromosomes in plants SUSHIL KUMAR1,2∗, RENU KUMARI1,2 and VISHAKHA SHARMA1 1SKA Institution of Research, Education and Development (SKAIRED), 4/11 SarvPriya Vihar, New Delhi 110 016, India 2National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110 067, India Abstract Dioecy (separate male and female individuals) ensures outcrossing and is more prevalent in animals than in plants. Although it is common in bryophytes and gymnosperms, only 5% of angiosperms are dioecious. In dioecious higher plants, ﬂowers borne on male and female individuals are, respectively deﬁcient in functional gynoecium and androecium. Dioecy is inherited via three sex chromosome systems: XX/XY, XX/X0 and WZ/ZZ, such that XX or WZ is female and XY, X0 or ZZ are males. The XX/XY system generates the rarer XX/X0 and WZ/ZZ systems. An autosome pair begets XY chromosomes. A recessive loss-of-androecium mutation (ana) creates X chromosome and a dominant gynoecium-suppressing (GYS) mutation creates Y chromosome. The ana/ANA and gys/GYS loci are in the sex-determining region (SDR) of the XY pair. Accumulation of inversions, deleterious mutations and repeat elements, especially transposons, in the SDR of Y suppresses recombination between X and Y in SDR, making Y labile and increasingly degenerate and heteromorphic from X. Continued recombination between X and Y in their pseudoautosomal region located at the ends of chromosomal arms allows survival of the degenerated Y and of the species. Dioecy is presumably a component of the evolutionary cycle for the origin of new species.
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.
The Diversity of Plant Sex Chromosomes Highlighted Through Advances in Genome Sequencing

G C A T T A C G G C A T genes Review The Diversity of Plant Sex Chromosomes Highlighted through Advances in Genome Sequencing Sarah Carey 1,2 , Qingyi Yu 3,* and Alex Harkess 1,2,* 1 Department of Crop, Soil, and Environmental Sciences, Auburn University, Auburn, AL 36849, USA; [email protected] 2 HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA 3 Texas A&M AgriLife Research, Texas A&M University System, Dallas, TX 75252, USA * Correspondence: [email protected] (Q.Y.); [email protected] (A.H.) Abstract: For centuries, scientists have been intrigued by the origin of dioecy in plants, characterizing sex-specific development, uncovering cytological differences between the sexes, and developing theoretical models. Through the invention and continued improvements in genomic technologies, we have truly begun to unlock the genetic basis of dioecy in many species. Here we broadly review the advances in research on dioecy and sex chromosomes. We start by first discussing the early works that built the foundation for current studies and the advances in genome sequencing that have facilitated more-recent findings. We next discuss the analyses of sex chromosomes and sex-determination genes uncovered by genome sequencing. We synthesize these results to find some patterns are emerging, such as the role of duplications, the involvement of hormones in sex-determination, and support for the two-locus model for the origin of dioecy. Though across systems, there are also many novel insights into how sex chromosomes evolve, including different sex-determining genes and routes to suppressed recombination. We propose the future of research in plant sex chromosomes should involve interdisciplinary approaches, combining cutting-edge technologies with the classics Citation: Carey, S.; Yu, Q.; to unravel the patterns that can be found across the hundreds of independent origins.
Cryptic Dioecy of Symplocos Wikstroemiifolia Hayata (Symplocaceae) in Taiwan

Botanical Studies (2011) 52: 479-491. REPRODUCTIVE BIOLOGY Cryptic dioecy of Symplocos wikstroemiifolia Hayata (Symplocaceae) in Taiwan Yu-Chen WANG and Jer-Ming HU* Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei 10617, Taiwan (Received November 25, 2010; Accepted March 24, 2011) ABSTRACT. Symplocos wikstroemiifolia Hayata is one of the few morphologically androdioecious spe- cies in Symplocaceae. Although this species has been proposed as cryptically dioecious, little is known about its patterns of sexual expression in the field. We studied the breeding system and reproductive biology of S. wikstroemiifolia in Taiwan. Field investigations showed that anthers of most morphologically hermaphroditic flowers did not produce pollen grains; thus, this flower type should be considered female. Nearly all flowering individuals produced only male or female flowers. The sex ratios were slightly male-biased, but did not sig- nificantly deviate from 1:1, congruent with the proposed cryptic dioecy status. However, two individuals pro- duced flowers that may have been functionally hermaphroditic, suggesting a variation of sexual expression in S. wikstroemiifolia. There were about 12 stamens per male flower but only five staminodes per female flower. No locules and ovules existed in the male flowers, while two locules within the ovary of the female flowers con- tained four ovules each (two large, two small). Male individuals produced cymes and thyrses, whereas female individuals only produced cymes. Some of these morphological characteristics differed from those previously described. Anthesis of most male and female flowers began before dawn and lasted for one to two days. Nev- ertheless, anther dehiscence, which only occurred under dry conditions, was not restricted to a specific time period during the day.
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
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.
Evolutionary Consequences of Dioecy in Angiosperms: the Effects of Breeding System on Speciation and Extinction Rates

EVOLUTIONARY CONSEQUENCES OF DIOECY IN ANGIOSPERMS: THE EFFECTS OF BREEDING SYSTEM ON SPECIATION AND EXTINCTION RATES by JANA C. HEILBUTH B.Sc, Simon Fraser University, 1996 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (Department of Zoology) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA July 2001 © Jana Heilbuth, 2001 Wednesday, April 25, 2001 UBC Special Collections - Thesis Authorisation Form Page: 1 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. The University of British Columbia Vancouver, Canada http://www.library.ubc.ca/spcoll/thesauth.html ABSTRACT Dioecy, the breeding system with male and female function on separate individuals, may affect the ability of a lineage to avoid extinction or speciate. Dioecy is a rare breeding system among the angiosperms (approximately 6% of all flowering plants) while hermaphroditism (having male and female function present within each flower) is predominant. Dioecious angiosperms may be rare because the transitions to dioecy have been recent or because dioecious angiosperms experience decreased diversification rates (speciation minus extinction) compared to plants with other breeding systems.
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.
Marsileaceae (Pteridophyta)

FLORA DE GUERRERO No. 66 Isoëtaceae (Pteridophyta) Marsileaceae (Pteridophyta) ERNESTO VELÁZQUEZ MONTES 2015 UNIVERSIDAD NACIONAL AU TÓNOMA DE MÉXICO FAC U LTAD DE CIENCIAS COMITÉ EDITORIAL Alan R. Smith Francisco Lorea Hernández University of California, Berkeley Instituto de Ecología A. C. Blanca Pérez García Leticia Pacheco Universidad Autónoma Metropolitana, Iztapalapa Universidad Autónoma Metropolitana, Iztapalapa Velázquez Montes, Ernesto, autor. Flora de Guerrero no. 66 : Isoëtaceae (pteridophyta). Marsileaceae REVISOR ESPECIAL DE LA EDICIÓN (pteridophyta) / Ernesto Velázquez Montes. –- 1ª edición. –- México, D.F. : Universidad Nacional Autónoma de México, Facultad de Ciencias, 2015. Robin C. Moran 24 páginas : ilustraciones ; 28 cm. New York Botanical Garden ISBN 978-968-36-0765-2 (Obra completa) EDITORES ISBN 978-607-02-6862-5 (Fascículo) Jaime Jiménez, Rosa María Fonseca, Martha Martínez 1. Isoetaceae – Guerrero. 2. Isoetales – Guerrero. 3. Marsileaceae Facultad de Ciencias, UNAM – Guerrero. 4. Flores – Guerrero. I. Universidad Nacional Autónoma de México. Facultad de Ciencias. II. Título. III. Título: Isoetaceae IV. Título: Marsileaceae. 580.97271-scdd21 Biblioteca Nacional de México La Flora de Guerrero es un proyecto del Laboratorio de Plantas Vasculares de la Facultad de Ciencias de la U NAM . Tiene como objetivo inventariar las especies de plantas vasculares silvestres presentes en Gue- rrero, México. El proyecto consta de dos series. La primera comprende las revisiones taxonómicas de las familias presentes en el estado y será publicada con el nombre de Flora de Guerrero. La segunda es la serie Estudios Florísticos que comprende las investigaciones florísticas realizadas en zonas particulares Flora de Guerrero de la entidad. No. 66. Isoëtaceae (Pteridophyta) - Marsileaceae (Pteridophyta) 1ª edición, 9 de junio de 2015.
Salviniales 1 Polypodiidae, Polypodiopsida

Salviniales 1 Polypodiidae, Polypodiopsida Salviniales – Wasserfarne (Polypodiidae, Polypodiopsida) 1 Systematik und Verbreitung Die Ordnung Salviniales ist recht klein und umfasst ca. 100 Arten aus drei Familien (Azollaceae, Marsileaceae und Salviniaceae) mit 5 Gattungen: 1. Azolla, ca. 6 Arten (Azollaceae); 2. Marsilea, ca. 50-70 Arten (Marsileaceae); 3. Pilularia, 3-6 Arten (Marsileaceae); 4. Regnellidium, 1 Art (Marsileaceae); 5. Salvinia, 10-12 Arten (Salviniaceae). Die Salviniales sind kosmopolitisch verbreitete Wasser- oder Sumpfpflanzen mit einem tropischen Verbreitungsschwerpunkt. In Mitteleuropa kommen Marsilea quadrifolia (Kleefarn, Marsileaceae), Pilularia globulifera (Pillenfarn, Marsileaceae), Azolla filiculoides (Algenfarn, Azollaceae) sowie Salvinia natans (Schwimmfarn, Salviniaceae) vor. Die Gattung Azolla ist bei uns ein aus Nordamerika stammender Neophyt, der wahrscheinlich durch Aquarianer eingeschleppt wurde. 2 Morphologie 2.1 Habitus Die Arten der Gattungen Azolla und Salvinia sind überwiegend auf der Wasseroberfläche treibende Pflanzen, die gelegentlich terrestrisch auf Sumpfstandorten wachsen. Abb. 1: Salvinia molesta, Habitus; 3 Blätter je Nodus; Abb. 2: Azolla filiculoides, Habitus; die Sprossachsen jeweils 2 laubartige Schwimmblätter und 1 stark tragen auf der Unterseite zahlreiche echte Wurzeln; zerschlitztes Unterwasserblatt mit Wurzelfunktion; © PD DR. VEIT M. DÖRKEN, Universität Konstanz, FB Biologie Salviniales 2 Polypodiidae, Polypodiopsida Pilularia lebt temporär sogar submers. Die Sprossachsen sind in