The Teaching Manual on Plant Taxonomy Anjula Pandey Kuldeep Tripathi K Pradheep S Rajkumar Veena Gupta ICAR-National Bureau of Plant Genetic Resources Pusa Campus, New Delhi 110 012, India Pandey et al. Citation: Anjula Pandey, Kuldeep Tripathi, K Pradheep, S Rajkumar and Veena Gupta (2019) The Teaching Manual on Plant Taxonomy. ICAR-National Bureau of Plant Genetic Resources, New Delhi, India, 119p. Layout and design: Sh Shashi Kant Sharma Cover page photo identity: (top to bottom) flowers of Vigna stipulacea, Papaver rhoeos, Abelmoschus tetraphyllus; herbarium specimen of Momordica cochinchinensis Technical support: Ms Rita Gupta and Ms Urmila Singh Published by: The Director ICAR-National Bureau of Plant Genetic Resources New Delhi 110 012, India © 2019 ICAR-National Bureau of Plant Genetic Resources New Delhi 110 012, India Printed at: Yugantar Prakashan Pvt. Ltd. WH-23, Mayapuri Industrial Area Phase-I, New Delhi-64 Ph.: 011-28115949, 28116018, 9811349619, 9953134595 E-mail: [email protected], [email protected] The Teaching Manual on Plant Taxonomy About the Teaching Manual The ‘Teaching Manual on Plant Taxonomy’ has been developed for students of plant genetic resources (PGR) with an objective to provide an overview on taxonomy relevance to agriculture and PGR. The teaching course in PGR at ICAR-Indian Agricultural Research Institute, Post Graduate School was started in 1999 when taxonomy was included as a ‘core course’ in the discipline of PGR. Since then the syllabus in Plant Taxonomy for post-graduate studies was revised several times. Simplistic approach with basic understanding of various topics of taxonomy for the students coming from different backgrounds of agricultural sciences created interest towards better learning. Need to develop the “Teaching Manual on Taxonomy” was felt as there was insufficient information in various taxonomic treatises with respect to PGRs. This manual contains ten chapters, including various concepts used in understanding the basic aspects of taxonomy covering theory and practical exercises. “Learning by observing” has been emphasized while conducting of practical exercises. Study of taxonomy has been demonstrated through use of few simple equipment like measuring scale, pen and pencil, dissection needle, hand- lens and dissection microscope. In this manual, for smooth flow of the text, some topics have been divided whereas others have been merged together with the relevant topics. The practical considerations are put in chapter 10 of manual including important families (only agriculturally important ones) to ‘How to describe’ a taxon. We hope that the contents are not only useful to the students of PGR but also the agriculturists, amateur scientists, non-taxonomists, parabotanists and others working in related fields. Technical terms have been simplified and put as the understandable words; botanical terms have been included to know the traits associated with the species. The authors put on record the motivation and guidance by the Director, ICAR-NBPGR and Head, Division of Plant Exploration and Germplasm Collection, ICAR-NBPGR. While preparing this manual, contributions of our colleagues especially Dr ER Nayar the founder course leader for the Taxonomy Course in 1999 and other scientists particularly Dr KC Bhatt are greatly acknowledged. Chapter on Modern tools in Taxonomy for chemotaxonomy part was developed with the help of Dr R Bhardwaj and Ms Poonam Suneja, Division of Germplasm Evaluation, ICAR-NBPGR for which we greatly acknowledge their contributions. Our colleagues at the ICAR-NBPGR who have directly or indirectly helped in developing this manual but their names have not been reflected individually are also duly acknowledged. Authors The Teaching Manual on Plant Taxonomy Table of Contents About the Teaching Manual Introduction i Theory 1 Plant Taxonomy in Relation to Plant Genetic Resources 1 2 Terminology Used for Plant Description 7 3 The Species Concept and Variation in Species 15 4 Rules of Taxonomy, International Codes of Nomenclature (ICN) and 21 International Code of Nomenclature : Cultivated Plants (ICNCP) 5 Taxonomic System of Classification 31 6 Biosystematics Studies on Crop Taxa 37 7 Modern Tools in Plant Taxonomy 47 8 Field Studies: Collection and Identification of Plants 59 9 Field & Herbarium Methods 65 10 Taxonomic Literature: Role in Plant Systematics Study 79 Practical Exercise 11 Study of Angiosperm Families 87 a Alliaceae 98 b Asteraceae 100 c Brassicaceae 102 d Cucurbitaceae 104 e Fabaceae 106 f Malvaceae 108 g Poaceae 110 h Rosaceae 112 i Rutaceae 114 j Solanaceae 116 References / Selected Readings 118 The Teaching Manual on Plant Taxonomy Introduction Taxonomy is a basic science catering to other fields of science through its application. Majority of users working in agricultural crops are ignorant of taxonomic boundaries, intergeneric and intertribal hierarchy and hybridization potential in many crops. Traditional taxonomic methods generally use flowers, seeds and other identifiable parts to ascertain species the identity of a plant. But the Plant Genetic Resources (PGR) science deals with 'part of material' in the form of seed/or pod and vegetative propagules which are augmented while collecting and conserving the germplasm. Taxonomy of crop wild relatives and their use in crop improvement has been studied in some important taxa but there exists a gap for less-known crop/potential/underutilized crops. ‘Seed and seedling biology as aid in identification’ goes beyond the traditional methods to resolve identity issues. Taxonomic treatment of agriculturally important families will facilitate in generating interest of the users in taxonomy and will guide them to be confident while working with PGRs. Some of the important issues on plant taxonomic research in India are: z Confusion arising due to presence of large number of morphological variants leading polymorphism and identification of new species/taxa z Neglect of taxonomy of cultivated plants by the genetic resource personnel and agriculturists z Difficulty in Taxonomic validation/authentication z Meager referable material (as herbarium specimens) and information z Missing evidences on source data on gross morphology vs. phylogeny of species of PGR value Updating the knowledge on botanical nomenclature and information on economic plants is must before initiating an experimental work. There are many standard websites currently available - IPNI, Kew grasses, synonyms database, ILDIS database (for legumes), Conifer database, Checklist of selected families by Royal Botanical Gardens, Kew, Efloras, Species 2008, GRIN database, TROPICOS, etc. which can be used for validation; identification of voucher specimens of experimental material at herbarium can also serve as reference material. Training of the scientific/technical staff in field of taxonomy and phylogenetics such as cladistics, phenentics, and molecular approaches is desired for holistic understanding of various aspects in taxonomy and systematics. i The Teaching Manual on Plant Taxonomy 1 Plant Taxonomy in Relation to Plant Genetic Resources Introduction Taxonomy plays a direct or indirect role in execution of major activities of PGR management including plant exploration and germplasm collection, exchange and quarantine, characterization/ evaluation and multiplication, conservation and documentation. The knowledge on taxonomy with reference to genepools of crop taxa and crossability aspects among the related taxa are well understood and applied in PGR science in a broader way. In PGR management, correct identification of materials is the first step to enhance its utilization which can be achieved through knowledge of taxonomy. By furnishing correct information and references to a plant, an identifier helps all other fields of science. Unlike the traditional methodology used for identification of plants, identification of germplasm using material received as seed, vegetative buds, tubers, rhizomes, etc. for ex situ conservation requires good knowledge on taxonomy. Material incorporated into genebanks as unknown species or species identified only up to genus level (Triticum sp., Solanum sp., Mangifera sp.) or group level (as cucurbits, orchids, legumes) is of limited conservation and utilization value. Large germplasm holdings when processed for evaluation, seed increase or for growing out for validation have resulted into misidentification of the material. The PGR researchers should be familiar with fundamentals of plant taxonomy and identification procedures to enable them to identify the material. Indian Council of Agricultural Research-National Bureau of Plant Genetic Resources (ICAR- NBPGR) is continuously involved in capacity building in field of PGRs including plant taxonomy teaching programmes affiliated to the Post Graduate School, ICAR-IARI, New Delhi in developing taxonomic skills among the students. Awareness on value of taxonomy was imparted through conducting various trainings, workshops and brainstorming sessions at various platforms. This chapter provides information on PGR management with special reference to plant taxonomy. Plant exploration and germplasm collection Plant exploration and germplasm collection activity pertains to the collection of materials from cultivated and wild habitats. In addition to knowledge of plant morphology, the details of characters of the propagules (seed/tubers, rhizomes, etc.) (e.g. in seed-shape, size, colour, seed coat texture, etc. and in vegetatively propagated materials-bulb/ rhizome