Contents
Contributors xiii
1 The citrus genome
Frederick G. Gmitter, Jr., Guohong Albert Wu,
Daniel S. Rokhsar, Manuel Talon
1.1 Concept of genome 1
1.2 Citrus genomes 1
1.3 Genomes: Pure, admixed, and domesticated 2
1.3.1 Inference of pure and admixed genome regions 2
1.3.2 Identification of the ancient progenitor citrus species 4
1.3.3 A whole-genome perspective of citrus hybrids and admixtures 5
1.3.4 Comparative analyses of citrus genomes: The example of evolution and domestication of mandarins 5
References 8
Further reading 8
2 The origin of citrus
Manuel Talon, Guohong Albert Wu,
Frederick G. Gmitter, Jr., Daniel S. Rokhsar
2.1 The mythological origin of citrus 9
2.2 The origin of citrus 9
2.2.1 The concept of citrus 9
2.2.2 Phylogeny of citrus pure species 10
2.2.3 Genealogy of cultivated citrus 11
2.2.4 Paleontology of citrus 13
2.2.5 Chronology of citrus speciation 15
2.2.6 Biogeography of citrus 16
2.2.7 The center of origin of citrus 18
2.3 Citrus radiation and evolution 21
2.3.1 Citrus radiation 21
2.3.2 Late Miocene: Global cooling and the Southeast Asian radiation 22
2.3.3 Dispersal routes of ancestral citrus 24
2.3.4 Early Pliocene: Wallacea orogeny and the dispersal of Australian limes 25
2.3.5 Early Pleistocene: Glacial maxima and the diversification of mandarins 27
2.4 A new evolutionary framework for the genus Citrus 27
Acknowledgments 28
References 28
3 Domestication and history
Xiuxin Deng, Xiaoming Yang, Masashi
Yamamoto, Manosh Kumar Biswas
3.1 The taxonomy, cultivars, and genetic
origin of citrus 33
3.1.1 The taxonomy and the true citrus
group 33
3.1.2 The genetic origin of some
hybrid citrus 36
3.2 The cultivation history and distribution
of citrus 38
3.2.1 Ancient Chinese citrus 38
3.2.2 Ancient citrus in Japan 41
3.2.3 Ancient citrus in India 44
3.2.4 The origin, spread, and
introduction of citrus 46
3.2.5 The genetic diversity of Citrus 49
References 51
4 Citrus taxonomy
Patrick Ollitrault, Franck Curk, Robert Krueger
4.1 The genus Citrus definition 57
4.1.1 The botanical treatment of the
genus Citrus 57
4.1.2 Phenotypical traits of the true Citrus 57
4.1.3 Reproductive biology,
cytogenetics and molecular data,
and the definition of the
genus Citrus 60
4.2 The genus Citrus classifications; an
historical, biological, genetic, and
phylogenomic perspective 62
4.2.1 The history of citrus botanical
classifications 62
4.2.2 1967–2017, from traditional
taxonomy to phylogenomy:
50 years to clarify the genetic
organization of the genus Citrus
and the origin of modern citrus
varieties 64
4.2.3 The ancestral and admixture
taxa 65
4.3 Phenotypic diversity structure strongly
reflects evolutionary history 73
4.3.1 Reticulate evolution, apomixis,
and the correlation between
the structures of genetic and
phenotypic diversities in the
Asian edible Citrus species 74
4.3.2 Traits of the four Asian ancestral
taxa of the edible Citrus 74
4.3.3 Traits of some modern citrus taxa
resulting from admixture 76
4.4 Conclusion 77
References 77
5 Commercial scion varieties
Graham H. Barry, Marco Caruso,
Frederick G. Gmitter, Jr.
5.1 Pummelos/shaddocks
(Citrus maxima) 83
5.1.1 Principal commercial pummelo
varieties 83
5.1.2 Pigmented pummelo
varieties 84
5.1.3 Pummelo hybrids 85
5.2 Grapefruit (Citrus paradisi) 86
5.2.1 Principal commercial varieties 87
5.3 Lemons (Citrus limon) 89
5.3.1 Principal commercial varieties 89
5.4 Limes (Citrus aurantiifolia and
Citrus latifolia) 92
5.5 Oranges (Citrus sinensis) 93
5.5.1 Sugar or acidless orange varieties 94
5.5.2 Blood or pigmented orange
varieties 95
5.5.3 Navel oranges 96
5.5.4 Common orange varieties 96
5.6 Mandarins (Citrus reticulata) 97
5.6.1 Principal commercial mandarin
varieties 98
5.6.2 Other mandarin hybrids of
current or potential commercial
importance 102
References 103
Further reading 104
6 Citrus rootstocks
Kim D. Bowman, Johan Joubert
6.1 Introduction 105
6.2 Reasons for a rootstock 105
6.3 Important rootstock attributes 106
6.4 Rootstock use by region 113
6.5 The major rootstocks 113
6.6 Rootstock trends and future prospects 120
Acknowledgments 122
References 122
Further reading 127
7 Traditional breeding
Marco Caruso, Malcolm W. Smith, Yann Froelicher,
Giuseppe Russo, Frederick G. Gmitter, Jr.
7.1 Introduction 129
7.2 Scion breeding 130
7.2.1 Somatic mutations and chimeras 130
7.2.2 Nucellar selections 132
7.2.3 Hybridization 134
7.2.4 Mutation breeding 138
7.3 Rootstock breeding 141
7.3.1 Objectives 141
7.3.2 Conventional methods to
generate new rootstocks 141
7.3.3 Propagation 141
7.3.4 Phenotyping methods for
diseases and abiotic stress
resistance before field trials 142
7.3.5 Rootstock trials 143
7.4 Perspectives 143
References 144
8 Genomic breeding
Tokurou Shimizu
8.1 Introduction 149
8.2 DNA markers 153
8.2.1 Types of DNA markers 153
8.2.2 SSR and indel markers 153
8.2.3 SNP markers 154
8.2.4 RFLP and CAPS markers 154
8.2.5 NGS-based high-throughput
genotyping 154
8.3 Linkage mapping analysis toward MAS 155
8.3.1 Linkage-map construction using
transferrable DNA markers 155
8.3.2 DNA-marker development for
monogenic traits 156
8.3.3 Polyembryony 156
8.3.4 Fruit traits 156
8.3.5 Aroma 159
8.3.6 Disease, stress resistance, and
other traits 159
8.4 MAS for complex traits 160
8.4.1 QTL analysis of complex traits 160
8.4.2 Linkage disequilibrium (LD)
analysis 160
8.4.3 Association mapping (AM) analysis 161
8.4.4 Genomic selection (GS) 161
8.5 Future trends 163
References 163
9 Citrus biotechnology
Maria Antonietta Germanà, Pablo Aleza,
Jude W. Grosser, Manjul Dutt, Nian Wang,
Jose Cuenca, Prabhjot Kaur
9.1 Introduction 171
9.2 Micropropagation 171
9.3 Organogenesis and rooting 172
9.4 Gametic embryogenesis 174
9.5 Somaclonal variation 176
9.6 Allotetraploids via somatic hybridization 176
9.7 Somatic cybridization 178
9.8 Molecular marker development for
Alternaria brown spot disease 178
9.9 Reducing juvenility via viral vectors 180
9.10 Genetic transformation of citrus 181
9.11 Direct DNA incorporation into
citrus 181
9.11.1 Protoplast transformation 181
9.11.2 Particle bombardment/biolistics 182
9.11.3 Agrobacterium-mediated
transformation of citrus 182
9.12 CRISPR gene editing 183
9.13 Concluding remarks 184
References 184
10 Vegetative growth
Eduardo Primo-Millo, Manuel Agustí
10.1 Seed germination 193
10.1.1 Imbibition of water 193
10.1.2 Breathing 194
10.1.3 Protein synthesis 195
10.1.4 Mobilization of the reserves
contained in cotyledons 195
10.1.5 Seedling development 199
10.1.6 Polyembryony 201
10.1.7 Juvenile characters 201
10.2 Dormancy and vegetative activity 201
10.3 Development of the canopy 202
10.3.1 Stem growth 202
10.3.2 Secondary stem growth 204
10.3.3 Sprouting development 206
10.3.4 Factors affecting vegetative
development 207
10.4 Leaf development 207
10.4.1 Leaf abscission 209
10.5 Formation of the root system 211
10.5.1 Development of the primary root 211
10.5.2 Lateral root development 213
10.5.3 Secondary root growth 213
10.5.4 Root distribution 214
10.5.5 Factors affecting root
development 214
10.6 Trees of reduced size 215
10.7 Control of vegetative development
through the use of growth retardants 216
References 216
11 Flowering and fruit set
Manuel Agustí, Eduardo Primo-Millo
11.1 The process of flowering 219
11.2 Type of inflorescences 220
11.3 Control of flowering 220
11.3.1 Environmental control 220
11.3.2 Other factors affecting
flowering 221
11.3.3 Control of flowering 224
11.4 Pollination and fertilization 224
11.5 Fruit set 225
11.6 Parthenocarpy 226
11.7 Endogenous regulation of fruit set 226
11.7.1 Influence of hormone levels 227
11.7.2 Competition for
photoassimilates 229
11.7.3 Interactions between
hormones and photoassimilates 230
11.8 Factors affecting fruit set 231
11.8.1 Temperature 231
11.8.2 Irrigation 231
11.8.3 Nitrogen fertilization 231
11.8.4 Mineral deficiencies 232
11.8.5 Flowering intensity 232
11.8.6 Position of the flower in
the tree 232
11.9 Improvement of fruit set: Cultural
practices 233
11.9.1 The application of GA3 233
11.9.2 Girdling or ringing 233
11.9.3 Treatment with GA3
combined with girdling 234
11.9.4 Other practices that favor
fruit set 234
11.10 Fruit development 235
11.11 Factors affecting fruit development 236
11.11.1 Endogenous factors 236
11.11.2 Tree age 236
11.11.3 Fruit position on the tree 236
11.11.4 Foliar area 236
11.11.5 Seed number 236
11.11.6 Flowering intensity 236
11.11.7 Competition among
developing fruits 236
11.11.8 Environmental factors 237
11.11.9 Cultural practices 237
11.12 Techniques to improve fruit size 238
11.12.1 Pruning 238
11.12.2 Manual thinning 238
11.12.3 Chemical thinning 239
11.12.4 Girdling or ringing 240
11.13 Seed development 240
References 241
Further reading 244
12 Fruit growth and development
Francisco R. Tadeo, Javier Terol, María J. Rodrigo,
Concetta Licciardello, Avi Sadka
12.1 The long, complex, and intriguing
journey from set fruitlets to ripe fruit 245
12.2 The fruit of citrus is a modified berry
called hesperidium 246
12.2.1 The fruit rind or peel provides
an interface of the fruit with
the external environment 246
12.2.2 The fleshy pulp is composed of
segments, which contain the
juice vesicles 248
12.2.3 Vascular system of the citrus fruit 249
12.3 Citrus fruit dimensions are genetically
determined but are influenced by
environmental and cultural practices 249
12.4 Metabolism and accumulation of
carbohydrate and organic acids,
determinants of fruit flavor quality 252
12.4.1 The physiology and practical
aspects of carbohydrate and
organic acid accumulation 252
12.4.2 The genetic basis of BRIX
and TA 252
12.4.3 The biochemistry of
carbohydrate and organic acid
accumulation 252
12.4.4 Contribution of Omics
techniques to the
understanding of sugar
and acid metabolism and
accumulation 254
12.5 Color change during fruit
development and ripening 255
12.5.1 Biochemical, molecular, and
structural changes related to
chlorophylls and carotenoids 255
12.5.2 Environmental, nutritional,
and hormonal cues affecting
chlorophylls and carotenoids 258
12.5.3 General aspects of blood
oranges during fruit
development and ripening 260
12.6 Preharvest drop impacts on and
determines, respectively, citrus
fruit production and harvesting
time 262
12.7 Transcriptome evolution during
ripening: A next-generation view 263
12.8 Future perspective: Basic knowledge
and advanced techniques should
result in improved products 264
Author contribution 264
References 264
13 Citrus in changing environments
Christopher Vincent, Raphaël Morillon,
Vicent Arbona, Aurelio Gómez-Cadenas
13.1 Limitations to geographical expansion
of citrus 271
13.2 Predicted climate in citrus growing
regions 271
13.2.1 Mediterranean climates 272
13.2.2 Humid subtropics 272
13.2.3 Semiarid regions 272
13.2.4 Overall climate trends in
citrus-producing regions 272
13.3 Citrus responses to climateinfluenced
environmental factors 273
13.4 Soil moisture 273
13.4.1 Optimal water requirements in
citrus 273
13.4.2 Flooding 275
13.4.3 Management of soil flooding
in citrus orchards 275
13.4.4 Water deficit—Effects on crop
productivity 275
13.4.5 Irrigation to mitigate water deficit 276
13.5 Soil salinity 276
13.5.1 Salinity effect on vegetative
and reproductive growth 277
13.5.2 Salinity effects on mineral
nutrition 277
13.5.3 Salinity effects on citrus
physiology 277
13.5.4 Mitigation of salinity effects 278
13.6 Air moisture 279
13.7 Temperature 280
13.7.1 Heat 280
13.7.2 Mechanisms involved in heat
tolerance 280
13.7.3 Management of high
temperature and breeding
heat-tolerant varieties 280
13.7.4 Chilling and freezing 281
13.7.5 Management of freezing
temperature in citrus orchards 281
13.7.6 Mechanisms involved in
chilling and freezing tolerance 281
13.7.7 Breeding cold-tolerant varieties 282
13.8 Increased carbon dioxide 282
13.8.1 Effects of CO2 on overall
growth and photosynthesis 282
13.8.2 Effects on partitioning and
growth habit 282
13.8.3 Interactions with other abiotic
stresses 283
13.8.4 Maximizing benefits of
increased [CO2] 283
13.9 Conclusions 283
Acknowledgments 284
References 284
Further reading 289
14 Salinity and water deficit
José M. Colmenero-Flores, Vicent Arbona,
Raphaël Morillon, Aurelio Gómez-Cadenas
14.1 Introduction 291
14.2 Salinity 292
14.2.1 Salinity components 292
14.2.2 Salinity avoidance mechanisms 293
14.2.3 Citrus responses to salinity 297
14.3 Water deficit 298
14.3.1 Resistance mechanisms and
differences among genotypes 298
14.3.2 Citrus responses to water
deficit 299
14.4 Resistance and tolerance mechanisms
common to water deficit and salinity 301
14.4.1 Osmotic adjustment and
synthesis of compatible
osmolytes 301
14.4.2 Antioxidant defense 302
14.4.3 Synthesis of protective proteins 302
14.5 Agronomic and biotechnological
approaches to improve crop stress
resistance 302
14.5.1 Agronomic and palliative
practices 302
14.5.2 Molecular approaches 303
14.6 Concluding remarks 303
References 304
15 Soil and nutrition interactions
Dirceu Mattos, Jr., Davie M. Kadyampakeni,
Ana Quiñones Oliver, Rodrigo Marcelli Boaretto,
Kelly T. Morgan, Jose Antonio Quaggio
15.1 Introduction 311
15.2 Soils of major citrus-producing
regions in the world 311
15.2.1 Soils of tropical and
subtropical regions 312
15.2.2 Soils of the Mediterranean and
similar regions 313
15.3 The role of mineral nutrients in citrus
production 314
15.3.1 Nitrogen 314
15.3.2 Phosphorus 315
15.3.3 Potassium 316
15.3.4 Calcium, magnesium, and sulfur 316
15.3.5 Micronutrients 317
15.4 Monitoring soil fertility and plant
nutritional status 318
15.4.1 Soil analysis 318
15.4.2 Plant analysis 320
15.5 Nutrient management strategies 322
15.5.1 Acidity and alkalinity 322
15.5.2 Fertilization with solubles and
solids 322
15.5.3 Fertigation 323
15.5.4 Foliar fertilization 324
15.5.5 Organic fertilization 325
15.5.6 Fertilization and stress
alleviation 325
15.6 Concluding remarks 326
References 326
Further reading 331
16 Citrus pests in a global world
Alberto Urbaneja, Tim G. Grout, Santin Gravena,
Fengnian Wu, Yijing Cen, Philip A. Stansly
16.1 Introduction 333
16.2 Citrus pest management in Asia 334
16.3 Citrus pest management in the
Mediterranean basin 336
16.4 Citrus pest management in
North America 340
16.4.1 Florida 340
16.4.2 California and Texas 341
16.5 Citrus pest management in
South America 342
16.6 Citrus pest management in Africa 344
16.6.1 Production pests 344
16.6.2 Cosmetic pests 345
16.6.3 Phytosanitary pests 345
16.7 Epilogue 346
References 346
17 Diseases caused by fungi and
oomycetes
Ozgur Batuman, Mark Ritenour, Antonio Vicent,
Hongye Li, Jae-Wook Hyun, Vittoria Catara,
Haijie Ma, Liliana M. Cano
17.1 Greasy spot disease of citrus caused
by Zasmidium citri-griseum 349
17.1.1 Introduction 349
17.1.2 Disease symptoms 349
17.1.3 Infection process 349
17.1.4 Pathogenicity and virulence 350
17.1.5 Disease management 350
17.2 Root rot, foot rot, brown rot of fruits,
canopy blight, and damping-off
diseases of citrus caused by
Phytophthora 350
17.2.1 Introduction 350
17.2.2 Disease symptoms 350
17.2.3 Infection process 351
17.2.4 Pathogenicity and virulence 351
17.2.5 Disease management 351
17.3 Melanose disease of citrus caused by
Diaporthe citri 352
17.3.1 Introduction 352
17.3.2 Disease symptoms 352
17.3.3 Infection process 353
17.3.4 Pathogenicity and virulence 353
17.3.5 Disease management 353
17.4 Citrus black spot disease caused by
Phyllosticta citricarpa 353
17.4.1 Introduction 353
17.4.2 Disease symptoms 354
17.4.3 Infection process 355
17.4.4 Pathogenicity and virulence 355
17.4.5 Disease management 355
17.5 Brown spot, leaf spot and black
rot diseases of citrus caused by
Alternaria 356
17.5.1 Introduction 356
17.5.2 Disease symptoms 356
17.5.3 Infection process 357
17.5.4 Pathogenicity and
virulence 358
17.5.5 Disease management 358
17.6 Postbloom fruit drop disease caused
by Colletotrichum 358
17.6.1 Introduction 358
17.6.2 Disease symptoms 359
17.6.3 Infection process 359
17.6.4 Pathogenicity and virulence 360
17.6.5 Disease management 360
17.7 Citrus scab diseases caused
by Elsinoë 361
17.7.1 Introduction 361
17.7.2 Disease symptoms 361
17.7.3 Infection process 362
17.7.4 Pathogenicity and virulence 362
17.7.5 Disease management 363
17.8 Mal secco disease caused by
Plenodomus tracheiphilus 363
17.8.1 Introduction 363
17.8.2 Disease symptoms 363
17.8.3 Infection process 363
17.8.4 Pathogenicity and virulence 364
17.8.5 Disease management 365
References 365
18 Bacterial pathogens of citrus: Citrus
canker, citrus variegated chlorosis
and Huanglongbing
Dean Gabriel, Timothy R. Gottwald,
Silvio A. Lopes, Nelson A. Wulff
18.1 Introduction 371
18.2 Citrus canker 372
18.2.1 History and background 372
18.2.2 Symptoms and epidemiology
of ACC 373
18.2.3 ACC control through
eradication 374
18.2.4 Endemic control/mitigation
of ACC 375
18.2.5 Implications of citrus canker
quarantines and trade 375
18.3 Citrus variegated chlorosis 375
18.3.1 History and background 375
18.3.2 Disease management, control,
and mitigation 376
18.3.3 Recent discoveries and
advances 377
18.4 Huanglongbing 377
18.4.1 History and background 377
18.4.2 Symptoms 379
18.4.3 Etiology and diagnosis 380
18.4.4 Pathogen biology: Phloem
restriction in citrus, systemic
infection in psyllid, and lack of
axenic culture 382
18.4.5 Genomics and taxonomy 383
18.4.6 Epidemiology: Latency and
incubation 384
18.4.7 Control/management 384
References 384
Further reading 389
19 Citrus viruses and viroids
Changyong Zhou, John V. da Graça, Juliana Freitas-
Astúa, Georgios Vidalakis, Nuria Duran-Vila,
Irene Lavagi
19.1 Introduction 391
19.2 Citrus tristeza virus (Closterovirus,
Closteroviridae) 391
19.3 Satsuma dwarf virus (Sadwavirus,
Secoviridae) 392
19.4 Citrus leprosis viruses 392
19.5 Citrus psorosis virus (Ophiovirus,
Aspiviridae) 394
19.6 Citrus tatter leaf virus (Apple
stem grooving virus) (Capillovirus,
Betaflexiviridae) 394
19.7 Citrus variegation virus/Citrus leaf
rugose virus (Ilarvirus, Bromoviridae) 395
19.8 Citrus leaf blotch virus (Citrivirus,
Betaflexiviridae) 395
19.9 Citrus vein enation virus (Enamovirus,
Luteoviridae) 395
19.10 Citrus yellow mosaic virus
(Badnavirus, Caulimoviridae) 396
19.11 Indian citrus ringspot virus
(Mandarivirus, Alphaflexivirdae) 396
19.12 Citrus yellow vein clearing virus
(Mandarivirus, Alphaflexivirdae) 396
19.13 Citrus chlorotic dwarf-associated
virus (Geminiviridae) 396
19.14 Citrus concave gum-associated
virus and Citrus virus A (tentative
Coguvirus, Bunyavirales) 397
19.15 Diseases of unknown etiology 397
19.16 Citrus sudden death-associated virus
(Marafivirus, Tymoviridae) 397
19.17 Miscellaneous viruses 398
19.18 Citrus exocortis viroid (Pospiviroid,
Pospiviroidae) 398
19.19 Hop stunt viroid (Hostuviroid,
Pospiviroidae) 398
19.20 Citrus bent leaf viroid (Apscaviroid,
Pospiviroidae) 399
19.21 Citrus dwarfing viroid (Apscaviroid,
Pospiviroidae) 400
19.22 Citrus viroid V (Apscaviroid,
Pospiviroidae) 401
19.23 Citrus viroid VI (Apscaviroid,
Pospiviroidae) 401
19.24 Citrus viroid VII (tentative
Apscaviroid, Pospiviroidae) 401
19.25 Citrus bark cracking viroid
(Cocadviroid, Pospiviroidae) 401
19.26 Diagnosis 402
19.27 Control 402
19.28 Conclusion 402
Acknowledgment 403
References 403
20 Horticultural practices
Fernando Alferez
20.1 Grove planning and tree spacing 411
20.1.1 Site selection 411
20.1.2 Variety and rootstock selection 411
20.1.3 Tree spacing 412
20.2 Irrigation and water management
planning 412
20.2.1 Water management 413
20.3 Canopy management and tree size
control 413
20.3.1 Mechanical pruning cuts 413
20.3.2 Manual pruning 415
20.3.3 Effects of pruning on tree
physiology 416
20.3.4 Other considerations 416
20.4 Crop load management 416
References 417
21 Postharvest technology of citrus fruits
Lorenzo Zacarias, Paul J.R. Cronje, Lluís Palou
21.1 Introduction 421
21.2 Postharvest Physiology 421
21.2.1 Responses of citrus fruits to
postharvest stress conditions 421
21.2.2 Postharvest physiological
disorders 424
21.3 Postharvest pathology 427
21.3.1 Main postharvest diseases 427
21.3.2 Preharvest and postharvest
factors affecting disease incidence 429
21.3.3 Disease management strategies 431
21.4 Postharvest handling and storage 434
21.4.1 Harvesting and orchard practices 434
21.4.2 Packinghouse practices 435
21.4.3 Transport and international
shipment procedures 440
21.4.4 Postharvest quarantine
treatments for citrus exports 442
References 442
22 Chemistry of citrus flavor
Yu Wang, Siyu Wang, Simona Fabroni, Shi Feng, Paolo Rapisarda, Russell Rouseff
22.1 Introduction 447
22.2 Lemon 447
22.2.1 Seasonal changes 450
22.2.2 Lemon oil extraction 451
22.2.3 Aroma volatiles 451
22.2.4 Aldehydes 453
22.2.5 Esters 456
22.2.6 Terpenoid hydrocarbon 456
22.2.7 Alcohols, ketones, and oxygen heterocycles 457
22.2.8 Lemon oil sulfur compounds 458
22.3 Orange and mandarin 458
22.3.1 Aldehydes 459
22.3.2 Esters 460
22.3.3 Terpenoid hydrocarbons 461
22.3.4 Alcohols, ketones, acids, and oxygen heterocycles 461
22.3.5 Sulfur- and nitrogencontaining compounds 463
22.3.6 Differences between orange and mandarin 463
22.4 Grapefruit 464
22.5 Conclusion 466
References 466
Further reading 470
23 Global economics and marketing of citrus products
Thomas H. Spreen, Zhifeng Gao,
Waldir Fernandes, Jr., Marisa L. Zansler
23.1 Introduction 471
23.2 Sweet oranges 471
23.2.1 Sweet orange industry organization in Brazil 474
23.2.2 Sweet orange industry organization in Florida 475
23.2.3 Trade of fresh sweet oranges 475
23.3 Grapefruit and pummelos 478
23.4 Mandarins/tangerines 479
23.4.1 Production and consumption by country 479
23.4.2 Exports and imports by country 479
23.4.3 Mandarins/tangerines used for processing by country 483
23.5 Lemons and limes 484
23.6 Price Determination for citrus 485
23.7 Trade agreements and citrus 490
23.8 Marketing and promotion of citrus 491
23.9 By-products from citrus processing 493
References 493
Further reading 493
24 Citrus and health
Gang Ma, Lancui Zhang, Minoru Sugiura, Masaya Kato
24.1 Introduction 495
24.2 Carotenoid in citrus fruits 495
24.2.1 Carotenoid accumulation in citrus fruits 495
24.2.2 The metabolism of β- cryptoxanthin in citrus fruits 497
24.2.3 The role of β-cryptoxanthin in human health 498
24.3 Flavonoid in citrus fruits 500
24.3.1 Flavonoid composition in citrus fruits 500
24.3.2 Heath benefits of citrus flavonoids 501
24.3.3 The biosynthesis of flavonoids in citrus fruits 503
24.4 Ascorbic acid in citrus fruits 504
24.4.1 The roles of ascorbic acid in human health 504
24.4.2 The accumulation of AsA in citrus fruits 505
24.4.3 The metabolism of AsA in citrus fruits 506
24.4.4 The regulation of AsA in citrus fruits 507
24.5 Conclusion 508
References 508
Index 513