Contents

Preface

Acknowledgments

PART I: EVOLUTIONARY PROCESSES

1 Chromosome Structure and Genetic Variability

Introduction

Gene and Chromosome Structure

Types of Mutation

Measurement of Variability

Variation in Gene Expression Patterns

Tracing the Evolutionary and Geographical Origins of Crops

Construction of Genetic Maps and Genome Evolution

Summary

2 Assortment of Genetic Variability

Introduction

Random Mating and Hardy–Weinberg Equilibrium

Migration

Selection

Types of Selection

Factors Limiting the Effect of Selection

Finding Loci Subject to Strong Selection

Coevolution

Genetic Drift

Evolution in Organelles

Interaction Between Forces

Summary

3 The Multifactorial Genome

Introduction

Intra-genomic Interactions

Coadaptation

Canalization

Paradox of Coadaptation

Summary

4 Polyploidy and Gene Duplication

Introduction

Factors Enhancing the Establishment of Polyploids

Evolutionary Advantages of Polyploids

Genetic Differentiation in Polyploids

Chromosomal Repatterning

Genome Amplification and Chance

Summary

5 Speciation

Introduction

What is a Species?

Reproductive Isolating Barriers

Nature of Isolating Genes

Modes of Speciation

Genetic Differentiation During Speciation

Hybridization and Introgression

Hybridization and Extinction

Crop–Weed Hybridizations

Risk of Transgene Escape into the Environment

Summary

PART II: AGRICULTURAL ORIGINS AND CROP EVOLUTION

6 Origins of Agriculture

Introduction

Rise of Our Food Crops

Evolution of Our Genus Homo

Spread of Homo sapiens

Agricultural Origins

Early Crop Dispersals

Transcontinental Crop Distributions

Summary

7 The Dynamics of Plant Domestication

Introduction

Evolution of Farming

Early Stages of Plant Domestication

Origins of Crops

Characteristics of Early Domesticants

Changes During the Domestication Process

Genetic Regulation of Domestication Syndromes

The Causative Changes in Domestication Genes

Rate of Domestication

Evolution of Weeds

Genetic Diversity and Domestication

Domestication and Native Diversity Patterns

Summary

8 Cereal Grains

Introduction

Barley

Maize

Millets

Oat

Rice

Rye

Sorghum

Wheat

9 Protein Plants

Introduction

Chickpea

Cowpea

Pea

Lentil

Phaseolus Beans

Faba Beans

Soybean

10 Starchy Staples and Sugar

Introduction

Banana

Cassava

Potato

Sugarbeet

Sugarcane

Sweet Potato

Taro

Yam

11 Fruits, Vegetables, Fibers and Oils

Introduction

Fruits

Vegetables

Fibers and Oils

12 Postscript: Germplasm Resources

Introduction

Ex Situ Conservation

In Situ Conservation

References

Index

A

B

C

D

E

F

G

H

I

K

L

M

N

O

P

Q

R

S

T

V

W

X

Y

Z