Practical Manual on Plant Cytogenetics

Ram J. Singh

• Publisher: CRC Press
• Year: 2017
• Print ISBN:
  9781498742979
• eBook ISBN:
  9781351230742
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Earlier books on the handling of plant chromosomes have not included many of the innovations in cytological techniques for many important crops that have become available in recent years, including information on associating genes with chromosomes. The aim of this book is to compile all the plant cytogenetic techniques, previously published in earlier books, into a laboratory manual. The first part of the book describes standard cytological techniques that are routinely used by students. The second part covers methods used for specific crops for which common cytological methods do not work satisfactorily. The third part discusses cytogenetic techniques (cytology and genetics) for physically locating genes on specific chromosomes. This novel book will be highly useful to students, teachers, and researchers as it is a convenient and comprehensive reference for all plant cytogenetic techniques and protocols.

1 Introduction

Cytology is a branch of biology that deals with the study of cells, chromosomes, and other cell organelles including their structure, function, and formation. Robert Hooke (1635–1703) coined the term cell in 1665 after observing a piece of cork under a microscope (Figure 1.1), and with keen observations, Hooke perceived the structure to be “all perforated and porous, much like a honeycomb, but pores were not regular; yet it was not unlike a honey-comb in these particulars (Figure 1.2).” He published his findings in his book Micrographia in 1665 (http://www.gutenberg.org/files/15491/15491-h/15491-h.htm#obsXVIII).

FIGURE 1.1 Hooke’s microscope. (Available at http://www.gutenberg.org/files/15491/​15491-h/images/scheme-01.png.)

FIGURE 1.2 Hooke’s observation on thin film of cork showing microscopical pores or cells (like wax in a honeycomb). (Available at http://www.gutenberg.org/files/15491/15491-h/images/scheme-11.png.)

Antoni van Leeuwenhoek wrote a letter on June 12, 1716, in which he described his discoveries such as bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, and microscopic nematodes and rotifers (http://www.ucmp.berkeley.edu/history/leeuwenhoek.html). Robert Brown (December 21, 1773–June 10, 1858), a botanist and paleo botanist, described a cell nucleus and cytoplasmic streaming. He examined pollens from Clarkia pulchella suspended in water under a microscope and observed minute particles, now known as amyloplasts (starch organelles) and spherosomes (lipid organelles), ejected randomly from the pollen grains—known as Brownian motion (https://en.wikipedia.org/wiki/Robert_Brown_%28Scottish_botanist_from_Montrose%29).

Matthias Jakob Schleiden (April 5, 1804–June 23, 1881) examined plant structure and Theodor Schwann (December 7, 1810–January 11, 1882) inspected animal tissues under the microscope, and from their observation, they recognized the importance of cell nucleus and developed the cell theory. Theodor Schwann isolated an enzyme pepsin (https://en.wikipedia.org/wiki/Theodor_Schwann). Rudolf Ludwig Carl Virchow (October 13, 1821–September 5, 1902) was known as “the father of modern pathology” because his work discredited humourism, bringing more science to medicine. He linked the origin of cancer cells from normal cells. Robert Remak (July 26, 1815–August 29, 1865) showed the origins of cells from the division of preexisting cells.

Eduard Adolf Strasburger (February 1, 1844–18 May 18, 1912) was the first to describe accurately the embryo sac in gymnosperms (conifers) and angiosperms (flowering plants), and double fertilization in angiosperms. He conceived the modern law of plant cytology: “New cell nuclei can arise from the division from other nuclei” and coined the terms cytoplasm and nucleoplasm. Walther Flemming (April 21, 1843–August 4, 1905) and Édouard Joseph Louis Marie Van Beneden (March 5, 1846–April 28, 1910) independently investigated the process of cell division and the distribution of chromosomes to daughter nuclei, a process he called mitosis (from the Greek word for “thread”) (https://archive.org/details/zellsubstanzker02flemgoog).

August Friedrich Leopold Weismann (January 17, 1834–November 5, 1914) developed germ plasm theory (i.e., that inheritance only takes place by means of the germ cells or the gametes [egg cells and sperm cells]). Based on this theory, he concluded that two kinds of single reproductive cells are mutually attracted to one another, and then unite in the process of amphimixis, to constitute what we are accustomed to call the fertilized egg cell, which contains the combined hereditary substances of two individuals. He used the term nuclear rod or idants (chromosomes) as in “half the idants of two individuals become united in the process of amphimixis (sexual reproduction), and thus a fresh intermixture of individual characters results” (Weismann 1893). Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836–23 January 1921), a German anatomist, invented and coined the term chromosome (meaning colored bodies) in 1888 (https://en.wikipedia.org/wiki/Heinrich_Wilhelm_Gottfried_von_Waldeyer-Hartz).

Walther Flemming (April 21, 1843–August 4, 1905) used aniline stain to observe a structure which strongly absorbed basophilic dyes. In naming this, he coined the term chromatin and was the first to conduct a systematic study of chromosomes during division. He called this process mitosis (Figure 1.3) and explained that the nucleus of reproductive cells divides twice, producing four genetically different daughter cells, each containing one set of chromosomes. However, he did not use the term meiosis (http://www.uni-kiel.de/grosse-forscher/index.php?nid=flemming&lang=e). Farmer and Moore (1905) described the terms maiosis or maiotic phase (reduction division) changed to meiosis.

FIGURE 1.3 Diagrammatic sketch of mitosis by Walther Flemming. (From Flemming, W., Zellsubstanz, Kern, und Zelltheilung, 1882, F.C.W. Vogel, Leipzig.)

Monumental progress in cytology was initiated shortly after the rediscovery of Mendel’s laws of inheritance in 1900. Sutton (1903) reported the chromosomal basis of heredity (Sutton 1903). Boveri (1902) also published a paper. Edmund Beecher Wilson (1925) wrote a book entitled The Cell in Development and Heredity. On page 923, he wrote “Cytological Basis of the Mendelian Phenomena; The Sutton–Boveri Theory” and gave credit to Sutton and Boveri for the Sutton–Boveri hypothesis. Since then, it has been known as the Sutton–Boveri hypothesis (also known as the chromosomal theory of inheritance or Sutton–Boveri theory). For some time, it was thought that Sutton and Boveri discovered the chromosomal theory of inheritance independently. Peters (1959) gave equal credit to Sutton and Boveri in his summary, with the statement that Sutton and Boveri published their findings “in the same year” but Lilian and Martins (1999) examined the facts of papers published between 1902 and 1903 and concluded that credit should be given only to Sutton, and not to Boveri, because Boveri did not publish any hypothesis of that kind during the relevant period.

Prior to development of the squash technique for studying chromosomes, published by Belling (1921), chromosome counts were conducted through staining of microtome sections, and sketches of cells and chromosomes were performed by Camera Lucida, known as Camera Lucida drawings, a technique which was patented in 1807 by William Hyde Wollaston (https://en.wikipedia.org/wiki/William_Hyde_Wollaston).

Numerous chemicals were tested for pretreatment and staining of the cells and chromosomes of plants, animals, and humans. Tjio and Levan (1956) determined the correct chromosome number (2 n = 56) (Figure 1.4) of humans. Since then, human cytology has progressed at a much faster pace than plant cytology...

Table of contents

• Cover
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Foreword
• Preface
• Acknowledgments
• Author
• Chapter 1 Introduction
• Chapter 2 Conventional Methods for Handling Plant Chromosomes
• Chapter 3 Smear Technique for Plant Chromosomes
• Chapter 4 Fluorescence In Situ Hybridization
• Chapter 5 Flow Analysis and Sorting of Plant Chromosomes
• Chapter 6 Pollen Staining
• Chapter 7 Cell Division
• Chapter 8 Mode of Reproduction in Plants
• Chapter 9 Karyotype Analysis
• Chapter 10 Classical Methods for Associating Genes with the Chromosomes
• Chapter 11 Structural Chromosome Changes for Locating the Genes
• Chapter 12 Wide Hybridization
• Glossary
• Index