ISTA Purity Seminar 15. June 2009 Zürich TlTools for seed identifi cati on species classification and nomenclature by Norbert Leist and Andrea Jonitz Prof. Dr. Norbert Leist Dr. Andrea Jonitz Brahmsstr.25 LTZ Augustenberg 76669 Bad Schönborn Neßlerstr.23 Germany 76227 Karlsruhe [email protected] Germany [email protected] Aquilegia vulgaris, Variation Variation • Variation is everywhere in biological systems. Natural variation at the population level is usualy not continuous, but occurs in discrete units or taxa. Easily the most important taxonomic level is the species because it is often the smallest clearly recognizable and discrete set of populations. • Understanding how species form and how to recognize them have been major challenges to systematists. The variation in one population becomes interrupted, the way to a split into two species strong hairy nearly glabrous Variation on species • Sources of variation: MttiMutation Recombination Independent assortment of the chromosomes Random genetic drift Selection Conservation of species characteristics avoiding gene flow Isolating barriers: temporal (seasonal, diurnal) habitat (wet, dry; calceous, silicious) floral (structural, behavioral eg. adaptations for pollinators) reproductive mode (self fertilisation, agamospery) incompatibility (pollen, seeds) hybrid inviability hybrid floral isolation hybrid sterility hybrid break down Iris germanica Iris sibirica Isolation by habitat Definition of „species“ is not easy A species is the smallest aggregation of populations (sexual) or lineages (asexual) diagnostible by a unique combination of character states in comparable individuals (Nixon and Wheeler 1990) Phy logeny Systematics Taxonomy Classification Nomenclature What does this mean? Systematic, Taxonomy Two concepts: • Systematic is the science of the diversity of organism • Taxonomy is the science of the clifiilassification of the organism Nowadays many biologists do not make a differentiation between systematics and taxonomy and use the terms equally How to define species • Heritable characters are needed. A heritable character is any aspect of the pl`lant`s morphlhology that can be passed down genetically through evolutionary time and still be recognizable. Eg: Petal color, inflorescence structure and general growth pattern are all known to be under genetic control and therefore stably inherited from one generation to the next. Basis for systematics • Systematics need the precise observation of organism. The assessment of similarity is the basis of comparative biology, and of systematics in particular. Two structures may be considered to be similar if – they are found in a similar position in both organism – they are similar in their cellular and histological structure – they are linked by intermediate forms of the structure (Remane`s criteria of similarity) Such structures may be – morphological: flowers, fruits, seeds, pollen, stem woodyness, root habit, annual – perennial lifespan – anatomical features: eg. Trachees – physiological features: chemical components eg. Alkaloids, protiteins – DNA sequences Tools for systematists work • Morphology Anatomy Physiology • Biochmistry Orgggpyanography Phyygpytography • Phytochoreology Phylogenetics Paleontology • Karyology Histology Cytology • Genetics • Only all the tools together lead to reliable results for a natural system Lunaria rediviva Thalictrum aquilegifolium Papaver paucifoliatum Anemone sylvestris One of the „natural systems“ of plants Aquilegia vulgaris, Variation Classification • Order Ranunculales • Family Ranunculaceae • Genus Aquilegia • Species vulgaris • Population • Individual plants Variability Classification of the plant kingdom • Kingdom • Division, Phylum ‐ phyta Spermatophyta • Subdivision ‐ phytina Magnoliophytina • Class ‐ opsida Liliopsida • Subclass ‐ idae Liliidae • Order ‐ ales Asparagales • Suborder ‐ ineae • Family ‐ aceae Amaryllidaceae • Subfamily ‐ oideae • Tribe ‐ eae • Subtribe ‐ inae • Genus Narcissus • Species blbbulbocodium • Suspecies subsp. bulbocodium • Variety var. citrinum • Cultivar `Kenellis` Phylogeny • The knowledge about many characteristics of plants is rapidly increasing. Therefore also the understanding of the natural system, based on the relationships of the taxa is increasing. • That leads in some cases to new arrangements in the phylogenetic tree of species, genera or even families. A consequence is that nomenclature has to follow this knowledge. Further readings Poales Poaceae, Andropogon glomeratus Juncaceae, Juncus dichotomus Poaceae, Oryza sativa Typhaceae, Typha domingensis Cyperaceae, Rhynchospora colorata Poaceae, Uniola paniculata Restionaceae, Elegia capensis Cyperaceae, Carex verrucosa Bromeliaceae, Tillandsia hotteana Ex: Plant Systematics, Judd et al. 2008 Carl von Linnaeus 1753 • introduced the binear nomenclature and based his artificial system on the floral characteristics • the principle of his concept is still today valid and was a great bkbreak throug h • before that time the species were named descripitivly: • Fumaria bulbosa radice non cava major or • Trifoliastrum pratense corymbiferum majus repens, corymbis forum magis sparsis, pediculis longissimis insidentibus, siliquis tetraspermis Rules to check and to set up correct plant names Started 1753 New findings Need for a new scientific name • A new species has been discovered • The check of the herbarium in a museum showed under the description of one species more than one species • By comparing the specimens of a species it becomes eviden t, that the same species has been described two times (eg. Cactus specimen collected by a botanist from Argentine and from Canada) • New studies on a genus elucidated, that one of their species belongs to another genus Nomenclature Taxonomic groups require names to ensure efficient communication regarding their identity, phylogenetic relationships and other aspects of their biology. The naming of plants is called botanical nomenclature. The principles and rules of botanical nomenclature have been developed and adapted by a series of international botanical congresses and are lis te d in the In terna tiona l CdCode of BtBotan ica l Nomenclature, ICBN (2006). The major goal of the ICBN is to provide one correct name for each taxonomic group or taxon wiihithin a stable system of names (classification) ICBN Requirements for naming new species • The species must be named. The name must be in LiLatin or latinized, in a binomial format and it must not ducplicate any name already in existence • The rank of the name must be clearly indicated • A type specimen must be designated • The specices must be described in Latin, or described in another language and accompanied by a Latin diagnosis (a brief statement of the character of the species or a comparison with a similar species) or linked to a reference with a Latin description. • All of this information must be effectively published; that means it must be presented in a publication that is availale to other botanists, such as a botanical journal or book. Publishing in a seed catalogue, newspaper, e‐mail message or other ephemeral sources do not qualify as effective publication. Nomenclature, Scientific Names • Nomenclatural Principles Botanical nomenclature is independent of zoological nomenclature • The application of names to taxonomic groups is determined by means of nomenclatural types, documented as holotype in a hbiherbarium (= type specimen or name‐bibearing speci)imen). Duplicates of holotypes are isotypes • The nomenclature of taxonomic groups is based on priority of publication. Later published names of the same taxon are called syyy,nonyms, that are not the correct names. • Each taxon can bear only one correct name • Scientific names are in Latin or Greek regardless their derivation. The use of latinised names facilitates communication among systematists from diverse cultural and language groups • The rules of nomenclature are retroactive . The ICBN system of rules has to be followed, even if there is no biological basis Examples for Synonyms • The name behind the species is the describer, very often L. for ClCarl von Linnaeus • Chenopo dium vulilvaria L. • If the name is changed, the first describer is in brackets • Cerastium cerastioides (L.)Britt. (= C. trigynum Vill.) • Chenopodium strictum Roth (Ch. strictum (Kras.) Murr; = Ch. album L. ssp. strictum (Kras)J .M urr) • Silene latifolia Poir. (= Melandrium album (Mill.) Garcke, = S. alba (Mill. )E. H. L. Krause) Nomenclature, examples Amaryllidaceae: • Descriptor Traub: Rauhia peruviana Traub 1957 • Ravenna recognized it conspecific with Phaedranassa multiflora Kunth 1850 • New name: Rauhia multiflora (Kunth) Ravenna Cactaceae: • Opuntia caespitosa found 1828, described by Poeppig 1835 • This name is preoccupied by the north american OiOpuntia cespitosa Rafinesque 1830 • Therefore Pfeiffer named Poeppigs discovery Opuntia poeppigii Otto • The same species described as Opuntia maihuenia Gay 1847 • Systematic research lead to Peireskia poeppigii • Maihuenia poeppigii Philippi ex K. Schum. 1898 …………. B.E. Leuenberger, 2008, Pereskia, Maihuenia, and Blossfeldia – Taxonomic history, updates, and notes. Haseltonia No.14,54‐93 Subspecies • In the case of subspecies, sensu strictu, the subspecies with holotype gets the name without author and the second one the name of the author responsible for the new description: • Carex atrata L. Hoppe found that there were different subspecies they were named: • Carex atrata L. ssp. atrata • Carex atrata