Practical Plant Physiology

M. C. Rayner, Frederick Keeble

Description

First published in 1910, “Practical Plant Physiology” is an accessible guide to elementary botany. Originally designed for students and teachers, it offers an introductory outline of the experiments and experimental methods used in botany and plant investigation, as well as other useful information related to the subject. This volume will be of considerable utility to those with an interest in plants and botany, and it would make for a fantastic addition to collections of allied literature. Contents include: “The Problem of Plant-Physiology and the Method by which They are to be Solved”, “Germination”, “The Mode of Germination of Seeds”, “The Parts of the Seed and Seedling”, “The Resting and Active States of Seeds”, “The Food-Materials of Seeds”, “Changes During Germination”, etc. Many vintage books such as this are increasingly scarce and expensive. It is with this in mind that we are republishing this volume now complete with a specially-commissioned new introduction on botany.

Sujets

• Osmotic pressure

Informations

• Publié par: Read Books Ltd.
• Date de parution: 22 mars 2021
• Nombre de lectures: 0
• EAN13: 9781528767323
• Langue: English

Extrait

PRACTICAL
PLANT PHYSIOLOGY
BY
FREDERICK KEEBLE, Sc.D.
PROFESSOR OF BOTANY AND DEAN OF THE FACULTY OF SCIENCE UNIVERSITY COLLEGE, READING AUTHOR OF PLANT-ANIMALS
ASSISTED BY
M. C. RAYNER, B.Sc.
LECTURER IN BOTANY IN UNIVERSITY COLLEGE, READING
Copyright 2018 Read Books Ltd. This book is copyright and may not be reproduced or copied in any way without the express permission of the publisher in writing
British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library
Botany
The term botany comes from the Ancient Greek word botan , meaning pasture , grass , or fodder , in turn derived from boskein , meaning to feed or graze . It chiefly involves the study of plant life, as a branch of biology.
Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists study approximately 400,000 species of living organisms of which some 260,000 species are vascular plants and about 248,000 are flowering plants.
Botany originated in prehistory as herbalism with the efforts of early humans to identify - and later cultivate - edible, medicinal and poisonous plants, making it one of the oldest branches of science. Examples of early botanical works have been found in ancient texts from India dating back to before 1100 BCE, in archaic Avestan writings (an Iranian language known only from its use in Zoroastrian scriptures), and in works from China before it was unified in 221 BCE.
Modern botany traces its roots back to Ancient Greece, specifically to Theophrastus (c. 371-287 BCE), a student of Aristotle who invented and described many of its principles. Today, he is widely regarded in the scientific community as the Father of Botany . Theophrastus s major works, Enquiry into Plants and On the Causes of Plants (both looking at plant structure, variety, reproduction and growth), constitute the most important contributions to botanical science until the Middle Ages, almost seventeen centuries later. Another work from Ancient Greece that made an early impact on botany is De Materia Medica ; a five-volume encyclopaedia about herbal medicine written in the middle of the first century by Greek physician and pharmacologist Pedanius Dioscorides. De Materia Medica was widely read for more than 1,500 years subsequently.
Medieval physic gardens, often attached to monasteries, contained plants of great medicinal importance. They were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards. In the mid-sixteenth century, botanical gardens were founded in a number of Italian universities - and the Padua botanical garden in 1545 is the first of such, still in its original location. These gardens continued the practical value of earlier physic gardens of the monasteries, and further supported the growth of botany as an academic subject.
Botanic gardens encouraged the work of academics such as the German physician Leonhart Fuchs (1501-1566). Fuchs was one of the three German fathers of botany , along with theologian Otto Brunfels (1489-1534) and physician Hieronymous Bock (1498-1554). Fuchs and Brunfels broke away from the tradition of copying earlier works to make original observations of their own, whilst Bock created his own system of plant classification. In 1665, using an early microscope, another famed botanist, the Polymath Robert Hooke (1635 - 1703) discovered cells in plant tissue, a term he coined. During this early period, lectures were also given about the plants grown in the specially constructed botanic gardens, and their medical uses demonstrated. Botanical gardens came much later to northern Europe - largely due to the obvious differences in temperature. The first in England was the University of Oxford Botanic Garden, constructed in 1621.
Efforts to catalogue and describe the collections of these gardens were the beginnings of plant taxonomy, and led in 1753 to the binomial system of Carl Linnaeus that remains in use to this day. Linnaeus s system was a hierarchical classification of plant species providing a solid reference point for modern botanical nomenclature. This established a standardised binomial or two-part naming scheme where the first name represented the genus and the second identified the species within the genus. For the purposes of identification, Linnaeus s Systema Sexuale classified plants into twenty-four groups according to the number of their male sexual organs. The twenty-fourth group, Cryptogamia , included all plants with concealed reproductive parts, mosses, liverworts, ferns, algae and fungi.
Increasing knowledge of plant anatomy, morphology and life cycles led to the realisation that there were more natural affinities between plants than Linnaeus had indicated however. Scholars such as Adanson (1763), De Jussieu (1789), and Candolle (1819), all proposed various alternative natural systems of classification that grouped plants using a wider range of shared characters and were extensively followed. The Candollean system reflected his ideas of the progression of morphological complexity and were developed the classifications by Bentham and Hooker, influential until the mid-nineteenth century. Darwin s publication of the Origin of Species in 1859 and his concept of common descent, further required modifications to the Candollean system to reflect evolutionary relationships as distinct from mere morphological similarity.
In the nineteenth and twentieth centuries, new techniques were developed for the study of plants, including methods of optical microscopy and live cell imaging, electron microscopy, analysis of chromosome number, plant chemistry and the structure and function of enzymes and other proteins. In the last two decades of the twentieth century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Particularly since the mid-1960s there have been advances in understanding of the physics of plant physiological processes such as transpiration (the transport of water within plant tissues), the temperature dependence of rates of water evaporation from the leaf surface and the molecular diffusion of water vapour and carbon dioxide through stomatal apertures.
Twentieth century developments in plant biochemistry have been driven by modern techniques of organic chemical analysis, such as spectroscopy, chromatopgraphy and electrophoresis. With the rise of the related molecular-scale biological approaches, the relationship between the plant genome and most aspects of the biochemistry, physiology, morphology and behaviour of plants can be subjected to detailed experimental analysis. Such developments have enabled advances in areas as diverse as pesticides, antibiotics and pharmaceuticals, as well as the practical application of genetically modified crops designed for traits such as improved yield.
The study of botany is an incredibly important science, as plants underpin almost all life on earth. They generate a large proportion of the oxygen and food that provide humans and other organisms with aerobic respiration with the chemical energy they need to exist. In addition, they are influential in the global carbon and water cycles and plant roots bind and stabilise soils, preventing soil erosion. Plants and the science of botany are crucial to the future of human society - allowing insight into our food, natural environment, medicine and products. It is a branch of human endeavour with an incredibly long and varied history, and it is hoped the current reader enjoys this book on the subject.
S AND C ULTURES .-P OPPIES GROWING IN S TERILE S AND .
A. Watered with normal culture solution. B. Watered with a solution lacking nitrates. (See Chapter VIII .) (From a photograph.)
PREFACE
T HE purpose of this book is to provide students and teachers with an outline of the experimental investigations on which our knowledge of the physiology of plants is based.
It would have been easier to present the most attractive of the facts and theories of this branch of science than to make the attempt, of which this book is the outcome, to provide a practical text-book which should serve as an educational instrument and as a stimulus to independent observations.
The student, however, cannot grasp the facts of Natural Science by reading books on the subject. Though the man of mature mind, trained in the art of sifting and grouping facts, and in the habit of seizing essential truths, may gain a useful acquaintance with Natural Science by the perusal of text-books, the student cannot. He needs a method of education which serves, not only to furnish, but also to train the mind. In other words, the student requires both information and discipline. He should be told less, and find out more. It cannot be disputed that the element of intellectual discipline is ignored too much by modern educational methods, nor that, as a result, students suffer from lack of training.
In science, in particular, the teacher is too much concerned with rendering the subject attractive and too little with making it to serve the end of developing the reasoning and imaginative faculties of his pupils.
The method of teaching Natural Science by means of lectures and a ritual of practical work associated therewith is fundamentally wrong. It appeals to the memory but sterilizes the imagination. It preaches comfortable things to the student, who ought, instead of being submitted to scientific sermons, to be experiencing the process, at once pleasurable and painful, of teaching himself.
In the course o