Scope and importance of botany

Early botany

The history of botany includes many ancient writings and classifications of plants found in several early cultures. Examples of early botanical works have been found in ancient sacred texts from India, ancient Zoroastrian writings, and ancient Chinese works.

Modern botany traces its roots back more than twenty three centuries, to the Father of Botany, Theophrastus (c. 371–287 BC), a student of Aristotle. He invented and described many of the principles of modern botany.His two major works, Enquiry into Plants and On the Causes of Plants constitute the most important contribution to botanical science during antiquity and the Middle Ages, and held that position for some seventeen centuries after they were written. Also from Greece, Pedanius Dioscorides, in the middle of the first century, wrote De Materia Medica, a five-volume encyclopedia about herbal medicine that was widely read for more than 1,500 years.^[7] Works from the medieval Muslim world included Ibn Wahshiyya's Nabatean Agriculture, Abū Ḥanīfa Dīnawarī's (828–896) the Book of Plants, and Ibn Bassal's The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, and Ibn al-Baitar (d. 1248) also wrote on botany.

German physician Leonhart Fuchs (1501–1566) was one of "the three German fathers of botany", along with Otto Brunfels (1489–1534) and Hieronymus Bock (1498–1554) (also called Hieronymus Tragus).

Valerius Cordus (1515–1544) authored a pharmacopoeia of lasting importance, the Dispensatorium in 1546.Conrad von Gesner (1516–1565) and Nicholas Culpeper (1616–1654) also published herbals covering the medicinal uses of plants. Ulisse Aldrovandi (1522–1605) was considered the "father of natural history", which included the study of plants. In 1665, using an early microscope, Robert Hooke discovered cells, a term he coined, in cork, and a short time later in living plant tissue.

During the 18th century, systems of classification were developed that are comparable to diagnostic keys, where taxa are artificially grouped in pairs. The sequence of the taxa in keys is often unrelated to their natural or phyletic groupings. By the 18th century an increasing number of new plants had arrived in Europe from newly discovered countries and the European colonies worldwide and a larger number of plants became available for study. Botanical guides from this time were sparsely illustrated. In 1754 Carl von Linné (Carl Linnaeus) divided the plant Kingdom into 25 classes in a taxonomy with a standardized binomial naming system for animal and plant species. He used a two-part naming scheme where the first name represented the genus and the second the species. One of Linnaeus' classifications, the Cryptogamia, included all plants with concealed reproductive parts (mosses, liverworts and ferns), and algae and fungi. The increased knowledge of anatomy, morphology and life cycles, led to the realization that there were more natural affinities between plants than the sexual system of Linnaeus indicated. Adanson (1763), de Jussieu (1789), and Candolle (1819) all proposed various alternative natural systems that were widely followed. The ideas of natural selection as a mechanism for evolution required adaptations to the Candollean system, which started the studies on evolutionary relationships and phylogenetic classifications of plants.

Botany was greatly stimulated by the appearance of the first "modern" text book, Matthias Schleiden's Grundzuge der Wissenschaftlichen, published in English in 1849 as Principles of Scientific Botany. Carl Willdenow examined the connection between seed dispersal and distribution, the nature of plant associations, and the impact of geological history. The cell nucleus was discovered by Robert Brown in 1831

Modern botany

A considerable amount of new knowledge comes from studying model plants such as Arabidopsis thaliana. This weedy species in the mustard family (Brassicaceae) was one of the first plants to have its genome sequenced. The sequencing of the rice (Oryza sativa) genome, its relatively small genome, and a large international research community have made rice an importantcereal/grass/monocot model. Another grass species, Brachypodium distachyon is also an experimental model for understanding genetic, cellular and molecular biology. Other commercially important staple foods like wheat, maize, barley, rye, pearl millet and soybean are also having their genomes sequenced. Some of these are challenging to sequence because they have more than two haploid (n) sets of chromosomes, a condition known as polyploidy, common in the plant kingdom. A green alga, Chlamydomonas reinhardtii, is a model organism that has proven important in advancing knowledge of cell biology.

In 1998 the Angiosperm Phylogeny Group published a phylogeny of flowering plants based on an analysis of DNA sequences from most families of flowering plants. As a result of this work, many of the questions such as which families represent the earliest branches of angiosperms have now been answered. Investigating how plant species are related to each other allows botanists to better understand the process of evolution in plants. Despite the study of model plants and increasing use of DNA evidence, there is ongoing work and discussion among taxonomists about how best to classify plants into various taxa.

Scope and importance of botany

Molecular, genetic and biochemical level through organelles, cells, tissues, organs, individuals, plant populations, and communities of plants are all aspects of plant life that are studied. At each of these levels, a botanist may be concerned with the classification (taxonomy), structure (anatomy andmorphology), or function (physiology) of plant life.

Historically, all living things were grouped as either animals or plants, and botany covered the study of all organisms not considered to be animals. Now, plants are considered to be organisms that obtain their energy from sunlight through photosynthesis, and other closely related, chlorophyll-free parasitic plants. Organisms previously studied in the field of botany include bacteria (studied in bacteriology), fungi (mycology)—including lichen-forming fungi (lichenology), non-chlorophyte algae (phycology), and viruses (virology). However, attention is still given to these groups by botanists, and fungi (including lichens) and photosynthetic protists are usually covered in introductory botany courses.

The study of plants is vital because they are a fundamental part of life on Earth, and generate the oxygen and food that allow humans and other organisms to exist. Through photosynthesis, plants absorb carbon dioxide, a greenhouse gas that in large amounts can affect global climate. Just as importantly for humans, plants release oxygen into the atmosphere during photosynthesis. Additionally, they prevent soil erosion and are influential in the water cycle. Plants are crucial to the future of human society as they provide food, oxygen, medicine, and products for people; as well as creating and preserving soil. Paleobotanistsstudy ancient plants in the fossil record. The evolution of photosynthetic plants early in the Earth's history altered the atmosphere of the Earth, changing the ancient atmosphere throughoxidation.

Human nutrition

Nearly all the food we eat comes (directly and indirectly) from plants, such as this American long grain rice

Virtually all foods come either directly from plants, or indirectly from animals that eat plants. Plants are the fundamental base of nearly all food chains because they use the energy from the sun and nutrients from the soil and atmosphere, converting them into a form that can be consumed and utilized by animals; this is what ecologists call the first trophic level. Botanists also study how plants produce food we can eat and how to increase yields and therefore their work is important in mankind's ability to feed the world and provide food security for future generations, for example, throughplant breeding. Botanists also study weeds, plants which are considered to be a nuisance in a particular location. Weeds are a considerable problem in agriculture, and botany provides some of the basic science used to understand how to minimize 'weed' impact in agriculture and nativeecosystems. Ethnobotany is the study of the relationships between plants and people. When this kind of study is turned to the investigation of plant-people relationships in past times, it is referred to as archaeobotany or paleoethnobotany.

Date: 2016-01-03; view: 2456