Advances in Agronomy

1. Auflage 2015
ISBN: 978-0-12-802347-1
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, Band Volume 129, 348 Seiten

Reihe: Advances in Agronomy

Advances in Agronomy continues to be recognized as a leading reference and a first-rate source for the latest research in agronomy. As always, the subjects covered are varied and exemplary of the myriad of subject matter dealt with by this long-running serial. Six volumes are published yearly which ensures that authors' contributions are disseminated to the readership in a timely manner. - Timely and state-of-the-art reviews - Distinguished, well recognized authors - A venerable and iconic review series - Timely publication of submitted reviews

Autoren/Hrsg.

Inhaltsverzeichnis

1;Front Cover;1
2;Advances in AGRONOMY;2
3;Advances in Agronomy;3
4;Advances in AGRONOMY
;4
5;Copyrights
;5
6;Contents;6
7;Contributors;10
8;Preface;14
9;Advances in Host Plant and Rhizobium Genomics to Enhance Symbiotic Nitrogen Fixation in Grain Legumes;16
9.1;1. Introduction;18
9.2;2. Host Plant and Environmental Stress Factors Impacting SNF;24
9.2.1;2.1 Host–Rhizobium Physiological and Biochemical Factors;24
9.2.2;2.2 Mineral Nutrition of the Host Plant, High Nitrates in Soils, and Starter Nitrogen;25
9.2.3;2.3 Drought, Salinity, and Heat Stress;27
9.3;3. Genomics-led Intervention to Select for Promiscuous Germplasm;29
9.3.1;3.1 Selection Environment for Evaluating Germplasm and Breeding Populations for SNF;29
9.3.2;3.2 From Conventional to High-Throughput Assays to Phenotype N2-Fixing Traits;30
9.3.3;3.3 Genetic Variation and Traits Associated with SNF;32
9.3.3.1;3.3.1 Variability for SNF in Germplasm;32
9.3.3.2;3.3.2 Genotype, Environment, and Strain Interactions;40
9.3.3.3;3.3.3 Relationships of SNF with Agronomic Traits;41
9.3.4;3.4 Abiotic Stress and N2 Fixation;45
9.3.5;3.5 Identifying Promiscuous Germplasm for Use in Breeding;47
9.3.6;3.6 QTL Associated with SNF Traits;49
9.3.7;3.7 Cloning and Gene Expression Associated with SNF;58
9.3.7.1;3.7.1 Plant Genes and SNF;58
9.3.7.1.1;3.7.1.1 Model Legumes;58
9.3.7.1.2;3.7.1.2 Grain Legumes;62
9.3.7.2;3.7.2 Plant Genes Expression and SNF;63
9.3.7.2.1;3.7.2.1 Model Legumes;63
9.3.7.2.2;3.7.2.2 Grain Legumes;64
9.4;4. Genomics-led Intervention to Select for Effective Rhizobium Strains;67
9.4.1;4.1 Rhizobium Genetic Resources, Host Specificity, and Diversity;67
9.4.2;4.2 Host–Rhizobium Interaction and Competition with Indigenous Rhizobium Strains;69
9.4.3;4.3 Host (Wild Relatives)–Rhizobium Symbiosis to Identifying Stress Tolerant Rhizobium Strains;75
9.4.4;4.4 Harnessing Sequence Diversity among the Rhizobium Genomes to Enhance Host–Rhizobium Symbiosis;78
9.4.5;4.5 Rhizobial Endophytes in Host and Nonhost on Plant Growth and Development;85
9.5;5. Challenges and Opportunities to Combining High SNF Traits Into Improved Genetic Background;88
9.5.1;5.1 Abiotic Stress Tolerance and Host–Rhizobium Symbiosis: a Breeding Challenge;88
9.5.1.1;5.1.1 Plant–Rhizobium Interactions for Alleviating Abiotic stress(es);89
9.5.1.2;5.1.2 Mycorrhizal Fungi Alleviate Abiotic Stress in Plants;89
9.5.1.3;5.1.3 Selecting for Nitrogen Fixation Drought Tolerance in Breeding Programs;90
9.5.1.4;5.1.4 Overexpressing Trehalose-6-Phosphate Synthase Gene Improves Drought Tolerance and SNF;90
9.5.2;5.2 Delayed Leaf Senescence in Relation to Photosynthesis, Symbiosis, and Productivity;91
9.5.3;5.3 Selecting for High Nitrogen Fixation Ability into Improved Genetic Background;94
9.5.4;5.4 SNF Projects to Harness Host–Rhizobium Symbiosis;96
9.6;6. Metabolic Reconstruction and Modeling to Predicting SNF;98
9.6.1;6.1 Reconstructing Metabolic Network to SNF;98
9.6.2;6.2 Modeling to Predict Nitrogen Fixation;100
9.7;7. Perspectives;101
9.8;Acknowledgments;103
9.9;References;104
10;Climate Change: Implications for Stakeholders in Genetic Resources and Seed Sector;132
10.1;1. Introduction;134
10.1.1;1.1 Improved Seed: Major Contributor to Crop Yield Gains;136
10.2;2. Plant Genetic Resources;137
10.2.1;2.1 Conserving Crop Wild Relatives and Landraces;138
10.2.2;2.2 Gene Banks;139
10.2.3;2.3 Global Plan of Action;140
10.2.4;2.4 International Treaties/Conventions/Networks;142
10.2.5;2.5 International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA);142
10.2.6;2.6 Convention on Biological Diversity;143
10.2.7;2.7 Genetic Diversity Usage;144
10.2.8;2.8 Managing Pollination;145
10.2.9;2.9 Seed Systems;148
10.3;3. Breeding Strategies;149
10.3.1;3.1 Screening for Traits of Interest;149
10.3.2;3.2 Pre-Breeding Using Wide Crosses;152
10.3.3;3.3 Breeding Varieties for Adaptation in New Areas;153
10.3.4;3.4 Marker-Assisted Selection (MAS)—Breeding;154
10.3.5;3.5 Genomics/Proteomics/Metabolomics;155
10.3.6;3.6 Genetic Engineering;156
10.3.7;3.7 Participatory Plant Breeding;157
10.3.8;3.8 Resilient Crops and Systems;157
10.3.9;3.9 New Approaches;158
10.3.10;3.10 Public/Private Partnership;159
10.4;4. Environment for Quality Seed Production;161
10.4.1;4.1 Adjusting the Crop Calendar for Quality Seed Production;162
10.4.2;4.2 Strengthening Hybrid Seed Production;162
10.5;5. Strengthening Seed Supply Systems;163
10.5.1;5.1 Postharvest Management of Seed;164
10.5.2;5.2 Seed Enhancement Technologies in Formal Seed System;165
10.5.3;5.3 Seed Treatment Technologies;166
10.5.4;5.4 On-Farm Seed Priming;167
10.5.5;5.5 Integrating Informal and Formal Seed Supply Systems;168
10.6;6. Adaptation and Adoption;169
10.6.1;6.1 Adaptation;170
10.6.2;6.2 Adoption;171
10.7;7. Harmonizing Seed Testing and Certification;173
10.8;8. IPR Management;174
10.8.1;8.1 Harmony among Various IPRs and/or Organizations;175
10.8.2;8.2 Phytosanitary Measures and International Seed Health Initiatives;176
10.8.3;8.3 Facilitating Seed Trade, Managing Barriers, and Market Development;178
10.9;9. Role of Public and Private Seed Sectors and Investment;180
10.10;10. Conclusions;182
10.11;Acknowledgments;184
10.12;References;184
11;Weedy (Red) Rice: An Emerging Constraint to Global Rice Production;196
11.1;1. Introduction;197
11.2;2. Background;198
11.3;3. Biology of Weedy Rice;201
11.4;4. The Origin, Evolution and Seed Dormancy of Weedy Rice;204
11.5;5. Past, Present, and Future Distribution;210
11.5.1;5.1 Current Distribution;211
11.6;6. Management of Weedy Rice in DSR;214
11.7;7. Emerging Management Strategies;222
11.8;8. Future Research Needs;229
11.9;9. Conclusions;232
11.10;Acknowledgments;233
11.11;References;233
12;The Challenge of the Urine Patch for Managing Nitrogen in Grazed Pasture Systems;244
12.1;1. Introduction;245
12.2;2. The Urine Patch in Grazed Pasture Systems;247
12.2.1;2.1 Urine Composition;247
12.2.2;2.2 Urination Volume and Frequency;252
12.2.3;2.3 Urine Patch Area;252
12.2.4;2.4 Urine Patch N Loading Rate;253
12.2.5;2.5 Conditions in the Urine Patch;254
12.3;3. Nitrogen-Removal Processes in the Urine Patch;255
12.3.1;3.1 Ammonia Volatilization;255
12.3.1.1;3.1.1 The Process and Factors Affecting NH3 Volatilization;255
12.3.1.2;3.1.2 Typical N Losses and Management of NH3 Volatilization;256
12.3.2;3.2 Denitrification and Associated Processes;260
12.3.2.1;3.2.1 The Processes and Factors Affecting Denitrification;260
12.3.2.1.1;3.2.1.1 N and C Availability;261
12.3.2.1.2;3.2.1.2 pH, O2 Availability, and Moisture;261
12.3.2.1.3;3.2.1.3 Urine Composition;262
12.3.2.2;3.2.2 Typical N Losses and Management of Denitrification;262
12.3.2.2.1;3.2.2.1 Nitrification Inhibitors;267
12.3.2.2.2;3.2.2.2 Soil Additives;267
12.3.3;3.3 Nitrogen Leaching;268
12.3.3.1;3.3.1 The Process and Factors Affecting Leaching;268
12.3.3.1.1;3.3.1.1 Rate of Urine N Application;268
12.3.3.1.2;3.3.1.2 Deposition Time;270
12.3.3.1.3;3.3.1.3 Irrigation;270
12.3.3.2;3.3.2 Typical N Losses;271
12.3.3.2.1;3.3.2.1 Nitrate–N;271
12.3.3.2.2;3.3.2.2 Ammonium–N, Urea–N;271
12.3.3.2.3;3.3.2.3 Dissolved Organic N;274
12.3.3.3;3.3.3 Management of Leaching;274
12.3.4;3.4 Nitrogen Immobilization;275
12.3.4.1;3.4.1 The Process and Factors Affecting Immobilization;275
12.3.4.2;3.4.2 Typical N Removal and Management of Immobilization;276
12.3.5;3.5 Pasture Nitrogen Uptake;279
12.3.5.1;3.5.1 The Process and Factors Affecting N Uptake;279
12.3.5.1.1;3.5.1.1 Edge Effects;280
12.3.5.1.2;3.5.1.2 Urine Scorch;281
12.3.5.2;3.5.2 Typical Pasture N Uptake and Opportunities to Improve Uptake;281
12.3.5.2.1;3.5.2.1 Pasture Species;282
12.3.5.2.2;3.5.2.2 Process Inhibitors;282
12.3.5.2.3;3.5.2.3 Urine Spread;282
12.4;4. Scale Issues in Understanding the Effects of Urine Patches;283
12.4.1;4.1 Spatial Distribution of Urine Patches;283
12.4.1.1;4.1.1 Scaling to the Paddock Level;283
12.4.1.1.1;4.1.1.1 Estimating Paddock-Scale Urinary N Deposition;284
12.4.1.2;4.1.2 Scaling to the Farm Level;285
12.4.2;4.2 Modeling at the Paddock and Farm Scale;285
12.4.2.1;4.2.1 Paddock Scale;286
12.4.2.2;4.2.2 Farm Scale;286
12.5;5. Managing Urine Patch Nitrogen in the Farm System;287
12.5.1;5.1 Target: Soil;287
12.5.2;5.2 Target: Plant;287
12.5.3;5.3 Target: Animal;290
12.5.4;5.4 Target: Farm Management;291
12.6;6. Conclusions;291
12.7;Acknowledgments;295
12.8;References;295
13;Biologically Regulated Nutrient Supply Systems: Compost and Arbuscular Mycorrhizas—A Review;308
13.1;1. Introduction and Scope of Review;309
13.2;2. AMs: A Brief Overview;311
13.3;3. Review—Methods;313
13.4;4. Compost Effects on the Formation of AM;314
13.4.1;4.1 AM Colonization and Compost—Conclusions;318
13.5;5. Compost Effects on Propagules and Extraradical Growth of AMF;319
13.5.1;5.1 Compost Effects on Propagules and Extraradical Growth of AMF—Conclusions;321
13.6;6. Interactive Effects of Compost and AMF on Plant Growth and Nutrition;322
13.6.1;6.1 Plant Growth and Nutrition, AMF, and Compost—Conclusions;326
13.7;7. Interactive Effects of Compost and AMF on Soil Properties;326
13.7.1;7.1 Soil Structure, AMF, and Compost—Conclusions;329
13.8;8. Conclusions and Future Directions;329
13.9;Acknowledgments;330
13.10;References;331
14;INDEX;338

Leseproben

2. Host Plant and Environmental Stress Factors Impacting SNF

2.1. Host–Rhizobium Physiological and Biochemical Factors

Ontogenetic interactions between photosynthesis and SNF in legumes are of critical importance. This importance of photosynthesis for SNF in legumes has been inferred from various physiological studies that altered the availability of photosynthetic products and resulted in corresponding change in SNF (Wilson et al., 1933; Hardy and Havelka, 1975). For example, it has been shown that the photosynthesis rates at different stages of development in bean and pea are related to SNF in the root nodules, while the net carbon exchange rate of each leaf in these two pulses varied directly with carboxylation efficiency and inversely with the CO2 compensation point. The net carbon exchange of the lowest leaves, which supplies fixed carbon to root nodules decreased in parallel with H2 evolution from root nodules (Bethlenfalvay and Phillips, 1977). Furthermore, it is known that the photosynthates are imported into nodules, and are used as carbon skeletons in ammonia assimilation (Larrainzar et al., 2009). When photosynthates are not metabolized due to partial or complete blockage of SNF, the accumulation of starch likely occurs (Ben Salah et al., 2009). An appropriate amount of SNF in bacteroids, however, can be achieved by maintaining the levels of photoassimilates, which are mainly sucrose at threshold levels (Ben Salah et al., 2009, 2011).

In a recent study on the role of nitrogen and carbon metabolism on SNF in cowpea, Rodrigues et al. (2013) reported that plants co-inoculated with Bradyrhizobium species and/or two plant growth-promoting bacteria (PGPB: Paenibacillus durus and Paenibacillus graminis) induced higher nitrogen content in nodules, total nitrogen accumulation, and shoot dry weight compared in the triple inoculation with other combinations when evaluated at the beginning of senescence. This increased nitrogen performance was positively correlated with the nodule sucrose content, but not with the content of total soluble carbohydrates, reduced sugars, and starch. Furthermore, their research showed that higher SNF under triple inoculation treatment was not significantly associated with sucrose synthase activity, but was weakly associated with soluble acid invertase activity in nodules at the beginning of senescence. Glutamate synthase, glutamine synthetase, and glutamate dehydrogenase were stimulated by double (Bradyrhizobium species plus P. durus or Bradyrhizobium plus P. graminis) and triple inoculation compared with only Rhizobium inoculation. These authors concluded that the inoculation with Bradyrhizobium species and PGPB is favorable for stimulating SNF activity in cowpea. However, legumes are not C-limited under symbiotic conditions (Neves and Hungria, 1987; Kaschuk et al., 2009), and indeed, that SNF can stimulate photosynthesis and vice versa (Kaschuk et al., 2012).

2.2. Mineral Nutrition of the Host Plant, High Nitrates in Soils, and Starter Nitrogen

Mineral nutrition of the host plant can affect SNF via host plant growth and development as well as through the process of nodule development and function as this process rests on the symbiosis between the rhizobium and the legume. The essential mineral nutrients required for legume SNF are those required for a normal establishment and functioning of the symbiosis. They are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), boron (B), molybdenum (Mo), chlorine (Cl), nickel (Ni), and cobalt (Co). Each essential nutrient performs specific physiological and biochemical roles, and is required in optimum concentrations in the medium for the establishment and function of symbiosis between the legume host and the rhizobium. The role of mineral nutrients on SNF has been reviewed elsewhere (O'Hara et al., 1988; Zahran, 1999; O'Hara, 2001; Weisany et al., 2013), and we provide a synthesis below.

Among the major nutrients, phosphorus is essential for both nodulation and N2 fixation. Indeed, nodules are strong sinks for phosphorus; as a consequence, symbiotic nitrogen-fixing plants require more phosphorus than those supplied with mineral fertilizers. The mode of nitrogen nutrition of legumes affects their phosphorus requirement (Cassman et al., 1981a,b). For achieving the potential of SNF by legumes, an adequate supply of phosphorus is a prerequisite because some legumes do not get established in conditions of insufficient soil P (Sahrawat et al., 2001). Mycorrhizal infection of roots of legumes stimulates both nodulation and nitrogen fixation under low phosphorus soil conditions (Redecker et al., 1997).

A relationship between SNF, P concentration, and soil pH exists that is important to researchers and agronomists alike. Soil pH in the neutral range optimizes the availability of all nutrients. In acidic pH soils, the availability of nutrients such as Ca, Mg, and P becomes limiting; on the other hand in soils with pH in the alkaline range the toxicity of sodium is the likely stressful that affects nodulation and nitrogen fixation. Thus soil pH is an important soil characteristic that indicates the availability of plant nutrients. Moreover, soil pH also directly influences nodulation and SNF through its effect on the numbers of naturally occurring rhizobium in noncultivated soils (Brockwell et al., 1991).

A review of the published literature on the effects of starter N application on SNF by legumes indicates mixed results relative to the basal application of small amount of mineral N. However, it is widely accepted that in high fertility soils, especially those rich in organic matter, the application of starter N is not necessary; and at times can reduce nodulation and SNF in crops such as soybean (Mendes et al., 2003; Hungria et al., 2006b) and bean (Vargas et al., 2000). In soybean, the application of N at later stages of plant growth also do not promote yield (Hungria et al., 2006b). On the other hand, in soils of low to very low in fertility and organic matter, the application of starter N at rate of 20–30 kg ha-1 has generally been reported to be beneficial to the growth and yield of several legumes (Erman et al., 2009; Sulfab et al., 2011; Sogut et al., 2013). Clearly, there is no single recommendation on starter N application because the beneficial effect of the basal N to legumes depends on the fertility status of the soil relative to N concentration in the soil and the N needs of the plant.

It has long been established that nitrates in the soil inhibit root infection, nodule development, and nitrogenase activity. Likewise, adequate nodulation is necessary for maximizing SNF by a legume (Atkins et al., 1984; Imsande, 1986; Sanginga et al., 1996). Moreover, poor and scanty nodulation is generally not able to satisfy the N needs of the plants, and therefore they rely on soil N to grow and produce (Zahran, 1999).

2.3. Drought, Salinity, and Heat Stress

Agricultural operations during crop production especially tillage, soil, nutrient and water management practices, and the use of crop protection practices greatly influence the population and efficacy of rhizobia in diverse production systems (Zahran, 1999; Hungria and Vargas, 2000; Giller, 2001). However, it has been observed that rhizobia can survive and exist in drier areas, but their population densities are at their lowest ebb under dry soil conditions. Therefore, drought seriously affects SNF, in addition to of course the effect of drought on the growth and development of the host legume. At times, it is hard to separate the effect of drought from that of heat stress as these two generally occur simultaneously especially in semiarid and arid tropical regions (Wery et al., 1994; Sinclair and Serraj, 1995; Zahran, 1999; Giller, 2001; Serraj and Adu-Gyamfi, 2004). Suitable strains of rhizobia that can survive and perform under moisture shortage and heat stress conditions in symbiosis with legumes are of critical importance, and research attention have been devoted to this aspect with some success (Busse and Bottomley, 1989; Hunt et al., 1981; Osa-Afina and Alexander, 1982; Rai and Prasad, 1983; Hungria et al., 1993; Giller, 2001).

To make the symbiosis effective under water and heat stresses, legumes tolerant to these stresses need to be combined with effective Rhizobium strains appropriate for each legume species and each type of growing environment. There are legume landraces and cultivars tolerant of high N2 fixation under drought or high temperature (Keck et al., 1984; Rai and Prasad, 1983; Venkateswarlu et al., 1983, 1989; Devi et al., 2010).

Apart from high-alkaline low P soils with drought and heat stresses, salinity is one of the major constraints to growing of legumes in the semiarid and arid regions of the world. Salts have direct detrimental effects on the crop and have deleterious effect on the microbial populations including rhizobium (Tate, 1995; Serraj and Adu-Gyamfi, 2004). For salt-affected environments, salinity tolerance of both the host legume and the rhizobium are a...