Plant Biotechnology and Agriculture

Prospects for the 21st Century

Arie Altman, Paul Michael Hasegawa, Arie Altman, Paul Michael Hasegawa

• Publisher: Academic Press
• Year: 2011
• ISBN:
  9780123814678
• Topic: Biological Sciences
• Subtopic: Genetics & Genomics
• Index: Biological Sciences

As the oldest and largest human intervention in nature, the science of agriculture is one of the most intensely studied practices. From manipulation of plant gene structure to the use of plants for bioenergy, biotechnology interventions in plant and agricultural science have been rapidly developing over the past ten years with immense forward leaps on an annual basis.

This book begins by laying the foundations for plant biotechnology by outlining the biological aspects including gene structure and expression, and the basic procedures in plant biotechnology of genomics, metabolomics, transcriptomics and proteomics. It then focuses on a discussion of the impacts of biotechnology on plant breeding technologies and germplasm sustainability. The role of biotechnology in the improvement of agricultural traits, production of industrial products and pharmaceuticals as well as biomaterials and biomass provide a historical perspective and a look to the future. Sections addressing intellectual property rights and sociological and food safety issues round out the holistic discussion of this important topic.

• Includes specific emphasis on the inter-relationships between basic plant biotechnologies and applied agricultural applications, and the way they contribute to each other

• Provides an updated review of the major plant biotechnology procedures and techniques, their impact on novel agricultural development and crop plant improvement

• Takes a broad view of the topic with discussions of practices in many countries

1. Genetics and genomics of crop domestication

J.S. (Pat) Heslop-Harrison and Trude Schwarzacher

University of Leicester, Leicester, UK

Table of Contents

Plants and Domestication3

Scope3

Domesticated crops3

Weeds4

Invasive species4

Model species and crop sciences5

Understanding Domestication Processes5

Evidence of relatives and processes of early domestication5

Genes of domestication6

Genetic variation and domestication6

Genetic control related to diversity and speciation6

Domestication of maize7

Domestication of legumes7

Yield traits8

Hybrid Species and New Polyploids in Domestication8

Post-Domestication Selection8

Modifications in crop characteristics8

New Domestication9

Domesticated species9

Lost crops9

Trees and biofuels9

Genetics and breeding for new uses: Ecosystem services10

Features of Domesticated Genomes11

Superdomestication14

Acknowledgments16

Domesticated species or crop plants typically include only a fraction of the genetic diversity in their wild relatives and have a range of genetically controlled features that were selected at the time of domestication, such as lack of seed dispersal gigantism in the harvested parts, determinate and synchronized growth, increased harvest index, and change in sweetness or bitterness. They were also adapted to agricultural practices and technology, lacking dormancy, easy to propagate and grow, and carrying resistances to diseases and pests. Most of today’s major crops were cultivated at the start of agriculture and genetic improvements have continued, although a number of species have been lost over subsequent millennia. Weeds species (and invasive plants) have been co-selected with crops. The genetic bases of the changes from wild ancestors are now well understood, and this research provides the basis for future improvements in crops for uses including food, feed, fuel, and pharmaceuticals. The introduction of new crops, and the selection of crops for new uses such as ecosystem services, is possible with better direction of the breeding. Superdomestication, involving the definition of crop requirements and use of appropriate germplasm and technology to give crops the required characters, has the potential to provide solutions to the challenges now facing agriculture and the environment.

Keywords

biodiversity, chromosomes, crops, domestication, genomics, molecular markers

Plants and Domestication

Scope

In this review of genetics and genomics related to plant biotechnology and agriculture, we consider the nature of species that are grown as crops and used by mankind, or otherwise associated with people. We will then review aspects of the genetics and genome changes that have been associated with crop plants and their domestication from their wild relatives before speculating about some of the new opportunities for plant biotechnology to meet the challenges faced in the twenty-first century.

Domesticated crops

Domesticated crops are a subset of all plants. Domesticated species, whether plants or animals, are considered as those grown by people for economic or other reasons, and that differ from their closest wild relatives. Domesticated species are reliant on human intervention for their reproduction, nutrition, health, planting, and dispersal. They are harvested with the possibility that a different species will be planted in their place. Additional characteristics selected for domestication include size of harvested parts, yield or yield stability, and quality for the use of the product. There are extensive genetic differences in all of these characteristics between individuals within a species, as well as between species, and multiple characteristics are selected at the time of domestication that make the crop worth growing by farmers for millennia and now by today’s plant breeders.

Genomic techniques ...