| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Cotton Enhancement Program, USDA-ARS, WICS, Res. Unit, Shafter, CA 93263
(mulloa{at}pw.ars.usda.gov)
International Plant Genetic Resources Institute (IPGRI), Via dei Tre Denari, 472/a, 00057 Maccarese, Rome. 2004. CD, $40.00. ISBN 92-9043-627-1.
Volume 1. Using Molecular Marker Technology in Studies on Plant Genetic Diversity. M. CARMEN de VICENTE and THERESA FULTON.
In this day and age when most food crops are known to have narrow genetic variability and breeders continue to face tremendous pressure to use wild germplasm in their breeding programs, there is limited useful genetic information available from germplasm collections. Thus disseminating information on plant genetic diversity is a useful activity that will help characterize and understand genetic resources, providing important information for future crop improvement. Knowledge of variation in wild germplasm may enable collection and conservation of genetic diversity before the inevitable demise of wild germplasm because of loss of habitats. It is difficult to determine how much genetic diversity has been lost without knowing the status of this resource 50 or 100 years ago. As wild germplasm disappears, the accessions that are preserved ex situ will be the surviving source of genetic diversity that once resided in situ in centers of diversity around the world. The future improvement of crops relies on introgression of genetic variability from wild germplasm and/or landraces. Commonly, phenotypic characters have been used to characterize accessions. However, DNA marker technology is becoming more and more feasible and useful for a range of basic and applied scientific objectives in plant improvement.
The authors, M. Carmen de Vicente and Theresa Fulton, present in Using Molecular Markers Technology in Studies on Plant Genetic Diversity an introduction and general overview of the fundamental principles of genetic diversity and the most widely used marker technologies, including those based on protein, DNA, and the polymerase chain reaction (PCR). This volume consists of 350 slides, each containing brief, precise information that helps the user navigate easily through specific topics, capturing the main concepts of each subject. This volume is divided into six modules: I. Introduction, II. Protein-based technologies, III. DNA-based technologies, IV. PCR-based technologies, V. Complementary technologies, and VI. Final considerations. In addition, it contains a glossary (module VII) which is definitely a valuable resource for the reader, and a feedback form (module VIII) which the editors, recognizing the importance of keeping abreast of changes in this very fast evolving field of molecular genetics, recommend to readers to provide information for future updates. Each module (I–VI) is organized into complementary submodules that users can select separately depending on relevance or interest with the exception of the introduction which is relevant to all modules. These modules present graphics and photographs that illustrate key experimental procedures and simple diversity experiments, making it a wonderful educational resource for teaching or for use as a self-tutorial. The general content of this volume is suitable for undergraduates or scientists with a minimal background in genetics and plant molecular biology and will be particularly useful to scientists in developing countries.
After working in the area of plant genetic diversity, including exploration trips and morphological and molecular evaluations of collections, I find these modules refreshing and simple to understand. However, there are certain submodules that contain too much superficial information and/or terms that are difficult to understand. These submodules could mislead users, especially those in developing countries, about the feasibility and skills needed to use a particular marker system, and it does not mention the dangers of the chemical waste produced by these procedures. A good example of this problem can be found in the module III DNA-based technology submodule on restriction fragment length polymorphisms (RFLP), the most important marker technology in the 1990s. I feel that more emphasis on polymerase chain reaction (PCR) and other emerging technologies and inclusion of deeper intensive study examples will be more interesting to possible users. The consumables used in PCR technology today are cheaper than when this module was completed, making PCR even more available.
These modules of Volume 1 are companions of a more advanced volume, Volume 2, Genetic Diversity Analysis with Molecular Marker Data, which covers the analysis of marker data from genetic diversity studies, and they can be used in many ways. It is always helpful to have a reference that contains all the information on marker technology in one place. This volume helps readers understand the abbreviations, acronyms, and jargon that often confuse and intimidate nonexperienced scientists in this field, and will help disseminate information and draw attention to the importance of the study of plant genetic diversity.
Volume 2. Genetic Diversity Analysis with Molecular Marker Data: Learning Module. M. CARMEN de VICENTE, CESAR LOPEZ, and THERESA FULTON.
Morphological characters have commonly been used to measure genetic diversity. Molecular methods provide an additional tool to measure genetic relatedness and evolution. Marker technology is useful for a range of basic and applied scientific investigations in plant improvement. The combination of morphological and molecular approaches will eventually produce a better description of the variation in germplasm collections, provide a framework for future data collection and description of germplasm, and may reveal relationships between the markers and morphological traits (i.e., linkage to genes). However, as we all know, it is important to have a clear idea about how to apply the scientific method when planning genetic diversity research. The authors, M. Carmen de Vicente, Cesar Lopez, and Theresa Fulton, present in this volume, sampling strategies for diversity studies, basic concepts of population genetics, mathematical and statistical measures used to describe genetic diversity (genetic distance indices and methods used to express relatedness among samples), and software and available internet resources. These modules were designed to help those who want to analyze genetic diversity by molecular data.
The volume consists of a total of 171 slides, each containing brief, precise information that helps one navigate easily through specific topics, capturing the main concepts. Volume 2 is divided into four modules: I. Introduction, II. Basic concepts of population genetics, III. Measures of genetic diversity, and IV. Software programs for analyzing genetic diversity. In addition, this volume contains a glossary (Module V) and a feedback form (Module VI) which the editors recommend to readers to provide information for future updates, recognizing the importance of updates in this rapidly evolving field of molecular data gathering. Each module (I–IV) is organized into complementary submodules that users can select separately, depending on relevance or interest, with the exception of the introduction which is relevant to all modules. Each module presents graphics, figures, and tables containing useful information. The user can see how mathematical expressions are applied in simple examples, even though the calculations are often performed by a computer program. These modules are a wonderful educational resource that will facilitate the learning of students and serve as support material for classroom lectures about applying molecular techniques to genetic diversity studies. A basic knowledge of genetics, algebra, and statistics is necessary to follow the content of these modules and, if the user is not familiar with molecular marker technology, Volume 1, Using Molecular Marker Technology in Studies on Plant Genetic Diversity is recommended.
When planning research on genetic diversity, it is always important to be familiar with the causes of genetic diversity and the tools and resources available for examining the data to provide accurate interpretations. These learning modules are an excellent resource for these activities. However, because the modules present examples of gene frequency and the results from formulas are not fully explained, a user unfamiliar with population genetics and statistics may have difficulty understanding this material. The failure to derive statistical formulas contributes to this problem. After reading Volumes 1 and 2 (Using molecular marker technology in studies on plant genetic diversity and Genetic diversity analysis with molecular marker data), I feel that there is a gap between them. If the authors intend Volume II to be a stand-alone tool for students and other users to choose and apply molecular techniques in studies of genetic diversity, additional information focusing on mathematical and statistical calculations is necessary with the incorporation of examples of real data to facilitate a better understanding of the various methods. The glossary needs to be expanded to incorporate some of the words used in the submodules. In addition, in my personal experience, one of the most difficult aspects of studying genetic diversity is the interpretation of results. These modules could be improved by expanding this topic. Methods such as bootstrapping, which is the method-of-choice for checking phenetic trees, could be discussed in more detail. These modules can be used by beginners with basic knowledge of genetics, algebra, and statistics, and they provide a great deal of information for those interested in genetic diversity. It is wonderful to have so much information in one place as a reference for teaching, preparation of classroom lectures, and as a guide for researchers.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
