Mycorrhizal Symbiosis (eBook)

Front cover 1
Mycorrhizal symbiosis 4
Copyright page 5
Contents 6
Preface 8
Introduction 12
Section 1 Arbuscular mycorrhizas 22
Chapter 1 The symbionts forming arbuscular mycorrhizas 24
Introduction 24
Arbuscular mycorrhizal fungi 26
The range of plants forming arbuscular mycorrhizas 37
Non-mycorrhizal plants 41
Fossil history of arbuscular mycorrhizas 43
Fungus–plant specificity 45
Ecological considerations 49
Conclusions 51
Chapter 2 Colonization of roots and anatomy of arbuscular mycorrhizas 53
Introduction 53
Sources of inoculum–overview 53
Morphology and anatomy of arbuscular mycorrhizas 66
Conclusions 100
Chapter 3 Genetic, cellular and molecular interactions in the establishment of arbuscular mycorrhizas 102
Introduction 102
Key steps in colonization 106
Cytological changes during root colonization 107
Genetic approaches to understanding AM colonization – interactions of AM fungi with non-hosts and mutants 111
Changes in gene transcription during AM colonization 120
Effects of AM colonization on plant defence responses 123
Conclusions 126
Chapter 4 Growth and carbon economy of arbuscular mycorrhizal symbionts 128
Introduction 128
Effects of AM colonization on plant nutrition and growth – overview 129
C transfer to the fungal partner 133
Cost-benefit analysis 143
Variations in AM responsiveness of plants 145
AM mycelial links between plants: importance in carbon allocation in a plant community 152
Conclusions 154
Chapter 5 Mineral nutrition, toxic element accumulation and water relations of arbuscular mycorrhizal plants 156
Introduction 156
Phosphorus availability in soil 158
Effects of arbuscular mycorrhizal colonization on plant phosphorus nutrition 159
Nitrogen nutrition 182
Uptake of other nutrients 186
Interplant transfer of nutrients 192
Water relations 193
Conclusions 197
Section 2 Ectomycorrhizas 200
Chapter 6 Structure and development of ectomycorrhizal roots 202
Introduction 202
Taxonomic, evolutionary and geographic aspects of the ectomycorrhizal symbiosis 203
Specificity in ectomycorrhizal symbioses 220
Genetics of ectomycorrhizal fungi 222
The formation of ectomycorrhizas 227
Molecular approaches to the study of ectomycorrhizal communities 273
Succession and replacement of fungi on roots and root systems 277
Conclusions 278
Chapter 7 Ectendo- and arbutoid mycorrhizas 280
Introduction 280
Ectendomycorrhizas 281
Ectendomycorrhizal fungi 285
The occurrence, taxonomic status and function of dark septate (DS) fungi 286
Arbutoid mycorrhizas 290
Conclusions 304
Chapter 8 Growth and carbon allocation of ectomycorrhizal symbionts 306
Introduction 306
Carbon supplies for ectomycorrhizal fungi 311
Carbon distribution in intact plant–fungus systems 319
Non-nutritional effects upon carbon assimilation 324
Community level patterns of carbon allocation 327
Conclusions 330
Chapter 9 Nitrogen mobilization and nutrition in ectomycorrhizal plants 332
Introduction 332
Use of N by ectomycorrhizal fungi in pure culture 333
Use of N by mycorrhizal roots and intact plants 343
Conclusions 357
Chapter 10 Phosphorus and base cation nutrition, heavy metal accumulation and water relations of ectomycorrhizal plants 360
Introduction 360
Uptake of P by excised ECM and non-mycorrhizal roots 361
Phosphate absorption in intact plants 370
Sources and mobilization of P in soil 375
Mobilization, uptake and translocation of potassium 379
Release, uptake and transport of magnesium 382
Mobilization, uptake and transport of calcium 385
Effects of ectomycorrhizal colonization on resistance to metal ion toxicity 386
Effects of ECM colonization on plant water relations 389
Conclusions 395
Section 3 Ericoid, orchid and mycoheterotrophic mycorrhizas 398
Chapter 11 Ericoid mycorrhizas 400
Introduction 400
The colonization process 404
Penetration of the plant wall 406
Features of intracellular colonization 407
The fungi forming ericoid mycorrhizas 410
Functional aspects of ericoid mycorrhizas 416
Conclusions 428
Chapter 12 Mycorrhizas of green orchids 430
Introduction 430
The fungi forming mycorrhizas in green orchids 433
Nutritional characteristics of the fungi 444
Seed and protocorm development 446
Mycorrhizal colonization of protocorms 446
Mycorrhizas in adult orchids 454
Transfer of nutrients between symbionts 457
Mechanisms of transfer 462
Host–fungus interactions in the protocorm – mycorrhizal or not? 463
Conclusions 467
Chapter 13 Mycorrhizas in achlorophyllous plants (mycoheterotrophs) 469
Introduction 469
Fungal associations and specificity in monotropoid mycorrhizas 473
The structure of monotropoid mycorrhizas 481
Fungal associations and specificity in mycoheterotrophic orchids 488
Structural aspects of mycorrhiza in mycoheterotrophic orchids 495
Mycoheterotrophic plants with arbuscular mycorrhizas 497
Functions of mycoheterotrophic mycorrhizas 505
Conclusions 514
Chapter 14 Fungal symbioses in lower land plants 518
Introduction 518
Fungal symbioses in liverworts 519
The structures of liverwort–fungus symbioses 522
Conclusions 531
Section 4 Functioning of mycorrhizas in broader contexts 534
Chapter 15 The roles of mycorrhizas in successional processes and in selected biomes 536
Introduction 536
The roles of mycorrhizal colonization in primary succession 537
The role of mycorrhiza in secondary successions 544
Mycorrhizas in Arctic, Antarctic and alpine biomes 546
Mycorrhizas in heathland 552
Mycorrhizas in boreal and temperate forest biomes 557
Mycorrhizas in tropical and subtropical biomes 574
Conclusions 582
Chapter 16 Mycorrhizas in ecological interactions 584
Introduction 584
Roles of mycorrhizas in mediating effects at the level of single plant species 585
Multitrophic interactions 609
AM hyphae and soil structure 618
Conclusions 620
Chapter 17 Mycorrhizas in agriculture, horticulture and forestry 622
Introduction 622
Arbuscular mycorrhizas in agriculture and horticulture 622
Ectomycorrhizas and forest production 636
Edible mycorrhizal fungi 643
Conclusions 646
References 648
Index 780
A 780
B 781
C 782
D 784
E 784
F 786
G 787
H 788
I 788
K 789
L 789
M 789
N 791
O 792
P 793
Q 795
R 795
S 796
T 797
U 798
V 798
W 798
Y 798
Z 798
Colour plates 800