Golden calves or white elephants? Biotechnologies for wheat improvement

The 1990s have seen an acceleration in the development of new biotechnologies which can increase the efficiency of wheat breeding by providing new and novel sources of variation, speeding up the breeding cycle, and increasing the efficiency of selection. This paper reviews the most significant technologies and their probable impact on wheat breeding into the next millennium. Amongst techniques developed from the application of tissue culture methods, doubled haploid systems are at last making a contribution through the development of the maize pollination system. By the introduction of various improvements, this is now efficient enough to produce material from a range of adapted genotypes in large numbers, and varieties are entering national list trials from this system. Developments in tissue culture have also led to the realistic possibility of genetically engineering wheat, based on biolistic methods of gene delivery into immature embryos. Some problems relating to gene stability and expression remain to be resolved, but targets, particularly with respect to disease and pest resistance and end-use quality, are now being actively pursued. The development of the genetic wheat map using molecular marker systems has revolutionalised the power of genetical analysis in wheat, enabling agronomic trait loci, whether major genes or QTL, to be identified, located and 'tagged'. Additionally, strategies for the molecular cloning of loci are being developed, particularly by exploiting a comparative mapping approach which combines the genetical information from all cereals in a common framework. This will lead to tools for modifying crop phenotype in a directed fashion to produce improved and novel phenotypes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mapping QTLs for pre-harvest sprouting traits in the spring wheat cross ‘RL4452/AC Domain’

Pre-harvest sprouting (PHS) in spring wheat (Triticum aestivum L.) is a major downgrading factors for grain producers and can significantly reduce end-use quality. PHS resistance is a complex trait influenced by genotype, environment and plant morphological factors. A population of 185 doubled haploid (DH) lines from the spring wheat cross ‘RL4452/AC Domain’ were used as the mapping population to detect quantitative trait loci (QTLs) associated with three PHS traits, germination index (GI), sprouting index (SI) and falling number (FN). Six major QTLs linked with PHS traits were mapped on bread wheat chromosomes 3A, 3D, 4A (2 loci), 4B and 7D. ‘AC Domain’ alleles contributed to PHS resistance on 3A, 4A (locus-2) and 4B, and ‘RL4452’ alleles contributed resistance on 3D, 4A (locus-1) and 7D. QTLs detected on chromosome 4B controlling FN (QFN.crc-4B), GI (QGI.crc-4B) and SI (QSI.crc-4B) were coincident, and explained the largest amount of phenotypic variation in FN (22%), GI (67%) and SI (26%), respectively.     

Will breeding for nitrogen use efficient crops lead to nitrogen use efficient cropping systems?: a simulation study of G×E×M interactions

The benefits of improving nitrogen use efficiency (NUE) in crops are typically studied through the performance of the individual crop. However, in order to increase yields in a sustainable way, improving NUE of the cropping systems must be the aim. We did a model simulation study to investigate how improvement of NUE traits of individual crops affects the succeeding crops and the NUE of the crop rotation. Based on experimental results parameterization was altered for different types of improved NUE in the EU-Rotate_N model, e.g. through higher N harvest index, reduced litter loss or improved root depth penetration rate. The different ways of improving NUE have different effects on the cropping system, affecting either N uptake, the ability of the crop to hold on to N already taken up, or the fraction of crop N being harvested. Due to the different modes of action, the model simulations show that these changes in NUE traits will also have different effects on N leaching loss and on N availability and N loss in the following years. Simulations also show that the effect of genotypes with improved NUE depend on environment and crop management. This is true for the improved crop itself and when its effect is analyzed for the whole cropping system. The environmental conditions, crop choices and management will all affect the fate of the N left in the soil, and whether this will contribute mainly to leaching loss or be used for production in later crops. As an example, increasing pre-crop fertilization was shown to affect the leaching after the following oilseed rape crop with up to 50 kg N ha^?1 taken up before it was lost to the environment when pre-crop fertilization as well as root depth penetration rate was high. All in all, the simulations illustrate the concept of NUE as the result of interactions between genotype, environment and crop management (G×E×M).     

Hybrid necrosis in wheat: evolutionary significance or potential barrier for gene flow?

One hundred and four released varieties of bread wheat (Triticum aestivum L ssp. aestivum) in India were crossed to two T. aestivum L ssp. aestivum testers, namely, C306 (Ne ₁ Ne ₁ ne ₂ ne ₂ ) and HD2329 (ne ₁ ne ₁ Ne ₂ Ne ₂ ) to determine the frequency and distribution of genes for hybrid necrosis present in them. Sixty-seven varieties (65.4 %) showed the presence of Ne ₂ gene and only eight varieties (7.7 %) had Ne ₁ gene in their background. Twenty-nine varieties (27.9 %) were non carrier (ne ₁ ne ₁ ne ₂ ne ₂ ) for both the genes. Most of the Ne ₁-carriers are of Indian origin and their pedigree revealed the involvement of landraces and old varieties as parents. Predominance of Ne ₂ gene in Indian varieties happened after the introduction of semi-dwarf Mexican wheat varieties, which are mostly Ne ₂ carriers and also due to the extensive and continuous use of germplasm from Mexican and European origin in the hybridization programme. Moreover varieties with Ne ₂ gene is selected for their linked beneficial traits mainly rust resistance genes. The phenomenon of hybrid necrosis is one among the post zygotic barrier speciation process which acts as a barrier for either intra or inter specific gene flow. The genetic architecture of hybrid necrosis in wheat is simple following the minimal predictions of the Bateson–Dobzhansky–Muller model. Widespread occurrence of dominant genes for hybrid necrosis in Indian varieties is of great concern to wheat breeders as it often interferes in the choice of elite parents and imposes restrictions on the productivity of crosses.     

Can conventional breeding programmes provide onion varieties that are suitable for organic farming in the Netherlands?

Main stream commercial onion breeders do not select varieties for organic farming, but solely for conventional farming. Seed companies consider the organic market too small to justify investments in breeding for this sector. In order to study if their varieties also suit organic farmers’ needs we interviewed four Dutch commercial onion breeders on their breeding programme and selection criteria and compared the outcome with a variety profile composed of the priority traits of Dutch organic farmers. Breeders gave priority to the same storage and bulb quality traits that are demanded by organic farmers, because organic onions are exported to conventional supermarkets that apply the same quality standards to organic and conventional onions. However, organic farmers also need varieties that perform well in the field. Breeders give low priority to field selection. Furthermore, three of the four seed companies only breed hybrids. The cytoplasmic male sterility system used to produce these hybrids does not comply with organic principles. We conclude that at present breeders can provide varieties that meet organic farmers’ demands for storability and quality traits, but they should give higher priority to field selection to also improve required field traits. The latter will only occur, if in future the organic seed market will grow. If the organic sector wants varieties developed according to its own principles, it should either set up its own onion breeding programme or seek alliances with breeding companies that are prepared to harmonize their breeding methodology with the organic principles.     

Is there a need for a radical reorganization of publishing the results of plant breeding research?

In this article a survey is given of motives for publishing on plant breeding research. The spate of publications should be welcomed.There is no need for a radical reorganization of publishing the results. It is a utopia to include all publications in one international journal. However, as concerns documentation in the field of plant breeding, it is advisable to adhere to one international journal (Plant Breeding Abstracts).     

Should State and Local Government Bidding for Big Businesses Be More Like eBay?

During recent decades, and especially after the economic downturn that began in the late 2000s, many U.S. state and local governments have intensified their pro‐growth efforts to promote corporate investment and jobs, including ever higher incentives (such as tax breaks and grants) in their bidding wars for big businesses. This paper draws an analogy—between bidding for big businesses and bidding on eBay—to highlight the drawbacks of high‐profile bidding wars among governments given that the large corporations establish the bidding rules in their favor. The main consideration raised is whether state and local government bidding for big businesses, which operates analogously to an auction, should be more like eBay, whose rules are fair not only for sellers but also for bidders.     

Identifying the impact of multi-hazards on crop yield—A case for heat stress and dry stress on winter wheat yield in northern China

Winter wheat production in northern China severely suffered from high temperatures and low relative humidity. However, the spatio-temporal pattern of heat stress and dry stress and the impacts of these multi-hazards on winter wheat yield have rarely been investigated. Using historical climate data, phenology data and yield records from 1980 to 2008, an analysis was performed to characterize the spatio-temporal variability of heat stress and dry stress in the post-heading stages of wheat growth in northern China. Additionally, these stresses’ impacts on winter wheat yield fluctuations were evaluated. Spatially, the central and northern parts of northern China have seen more serious heat stress, while greater dry stress has been observed in the northwest and north of the research area. Temporally, the heat stress has increased in the western part but decreased in the central and eastern parts of research area. Dry stress has aggravated in the entire northern China during the past decades, indicating the complexity of the exposure to adverse climate conditions. These two hazards (heat stress and dry stress) have contributed significant yield loss (up to 1.28% yield yr⁻¹) in most parts of the research region. The yield in the west was more sensitive to heat stress, and dry stress was the main hazard in the south. Additionally, the opposite spatial pattern between the sensitivity and exposure revealed that the climate is not the only factor controlling the yield fluctuation, the local adaptation measures used to mitigate negative influences of extreme events should not be ignored. In general, this study highlighted a focus on the impacts of multi-hazards on agricultural production, and an equal importance of considering local adaptation ability during the evaluation of agricultural risk in the future. Additionally, paying more attention to higher sensitive areas and to more reasonable and practical adaptive strategies is critical and significant for food supply security.     

Importance of growth characteristics for yield of barley in different growing systems: will growth characteristics describe yield differently in different growing systems?

The interest in organic grown cereals has increased the need for variety tests under organic growing systems and/or the knowledge on whether growth characteristics describe yield differently under conventional and organic conditions. This paper is a contribution to that question by examining the relationships between some important growth characteristics in barley trials in both systems in Northern Sweden and in Denmark. Mixed model analyses were used for regressions of growth characteristics (or transformations of those) on yield (and log-transformed yield), allowing the slope to depend on the growing system. The analyses showed that diseases seemed to have a less negative effect on yield in the organic growing system than in the conventional growing system if pesticides were not applied. For other characteristics the effect depended on the country. This was the case for grain characteristics where the effect of volume weight in the Swedish trials was much larger in the conventional growing system than in the organic growing system, while a non-significant difference in the opposite direction was found for the trails from Denmark. For the trials from Denmark the effect of grain weight was much larger in the organic growing system than in the conventional growing system, but there was only a small and non-significant difference in the Swedish trials. In both countries there was a significant interaction between the two grain characteristics.     

Reconciliation or exclusion? Integrating indigenous and non-indigenous land management concepts for Australia’s Native Title era

Indigenous and non-indigenous concepts of land ownership and use are fundamental elements in Australian debate on the implications of Native Title for development. However these approaches are not necessarily incompatible but can be reconciled. Drawing on evidence from the central Australian rangelands, this paper argues that the adaptations of land use practised by indigenous people, who have converted their land tenure from pastoral leasehold to Aboriginal freehold land, suggest that such reconciliation is possible and practical. Provision of appropriate support tools, such as participatory extension for improved land management, or community land management planning, strengthen the integration of indigenous and non-indigenous land management approaches. Successful integration will be essential for the management of Australia’s rangelands under Native Title.     

Is environmental regulation a blessing or a curse for China's urban land use efficiency? Evidence from a threshold effect model

Severe land shortage causes a higher demand for domestic and foreign land‐intensive products. As a result, resource utilization, and related environmental issues, will increase in urban areas. To this respect, the analysis of the impact of environmental regulation on urban land use efficiency helps to identify potential points for interventions designed to ensure sustainable land use. This study first introduces a theoretical framework to investigate the micro‐transmission mechanism of environmental regulation on urban land use efficiency. Our profit decision‐making model concludes that the impact of environmental regulation on urban land use efficiency is influenced by changes in the industrial structure. Empirically, our preliminary analysis suggests that in addition to population density, both formal and informal environmental regulation can promote urban land use efficiency, with a significant spatial heterogeneity across the sample regions. Further, this study shows a remarkable double‐threshold relationship between formal environmental regulation and urban land use efficiency in China. We clarify and confirm that environmental regulation promoted urban land use efficiency only when regulation intensity was higher than 0.8612. Environmental regulation increased urban land use efficiency in high‐level industrial rationalization areas, whereas it had the opposite effect in low‐level ones. Furthermore, there was a clear marginal diminishing effect of the impact of environmental regulation on urban land use efficiency when the optimization of the industrial structure was set as a threshold variable.     

Are vegetation indices derived from consumer-grade cameras mounted on UAVs sufficiently reliable for assessing experimental plots?

Recent technological advances in UAV (unmanned aerial vehicle) technology offer new opportunities for assessing agricultural plot experiments using UAV imagery. Vegetation indices (VIs) based on aerial images derived from consumer-grade cameras are a simple and cheap alternative compared to VIs derived from proximal (on-ground) sensors. The objective of this study was to assess whether VIs derived from consumer-grade cameras mounted on UAVs are reliable and whether there are any shortcomings in image acquisition and analysis that need to be addressed before their general application. This objective was investigated using a rotary-wing and a fixed-wing UAV, true colour (RGB) and colour-infrared (CIR) cameras, four different VIs (ExG, NGRDI, NDVI and ENDVI), altitudes in the range of 30–100 m, different ambient lighting conditions and two different software packages for stitching images together. Results were compared with ground-based recordings by consumer-grade cameras and multispectral sensors. Field experiments in cereals were used to evaluate the assessments. The study showed that VIs based on UAV imagery have the same ability to quantify crop responses to experimental treatments as ground-based recordings with cameras and advanced sensors. However, there are shortcomings that need to be taken into consideration: (1) angular variation in reflectance (bidirectional reflectance), (2) stitching and (3) ambient light fluctuations. Bidirectional reflectance was so extensive that it could lead to misleading conclusions in sunny conditions and this effect could be amplified further by stitching. A procedure for avoiding impacts from bidirectional reflectance is demonstrated when plots were cropped from individual images and a procedure is suggested for stitching images. Camera, VIs and image acquisition altitude were of minor importance, but fluctuating ambient lighting conditions is an issue that should be addressed in future studies.     

Can additional N fertiliser ameliorate the elevated CO2‐induced depression in grain and tissue N concentrations of wheat on a high soil N background?

Elevated CO₂ stimulates crop yields but leads to lower tissue and grain nitrogen concentrations [N], raising concerns about grain quality in cereals. To test whether N fertiliser application above optimum growth requirements can alleviate the decline in tissue [N], wheat was grown in a Free Air CO₂ Enrichment facility in a low‐rainfall cropping system on high soil N. Crops were grown with and without addition of 50–60 kg N/ha in 12 growing environments created by supplemental irrigation and two sowing dates over 3 years. Elevated CO₂ increased yield and biomass (on average by 25%) and decreased biomass [N] (3%–9%) and grain [N] (5%). Nitrogen uptake was greater (20%) in crops grown under elevated CO₂. Additional N supply had no effect on yield and biomass, confirming high soil N. Small increases in [N] with N addition were insufficient to offset declines in grain [N] under elevated CO₂. Instead, N application increased the [N] in straw and decreased N harvest index. The results suggest that conventional addition of N does not mitigate grain [N] depression under elevated CO₂, and lend support to hypotheses that link decreases in crop [N] with biochemical limitations rather than N supply.     

ASEAN Forum on Migrant Labour: A space for civil society in migration governance at the regional level?

The aim of this article is to discuss and substantiate new spaces for the political participation of migrant civil society at the regional level in Southeast Asia through the lens of the Association of Southeast Asian Nations (ASEAN) Forum on Migrant Labour (AFML). The AFML process is shaped by the International Labour Organisation and mirrors its tripartite format, essentially bringing together governments, employers’ and workers’ organisations. Crucially, migrant support and self‐organisations also have access, even if somewhat restricted, to regularly held deliberations. In light of the ASEAN consensus on migration that was agreed upon at the end of 2017, the article situates the AFML within the ongoing process of migration governance in the region and focusses especially on the role of migrant civil society as an important stakeholder. Based on the specific experience of civil society organisations (CSOs) from Malaysia, the article discusses which spaces the forum provides for civil society actors and how the latter use them for their advocacy. The major argument of the article is that the development of migration policies at the regional level can benefit from the inclusion of migrant civil society in the process. The governance of migrants could thus be complemented by governance for and by migrants.     

Year-to-year variability in the biomass of macrobenthic animals on tidal flats of the Wadden Sea: How predictable is this food source for birds?

The Wadden Sea is important as a stop-over and wintering area for several species of waders, foraging for shorter or longer times on its tidal flats. The size of the food stocks these birds encounter varies from place to place and from year to year. We studied characteristics of the variability in time of such prey stocks, using long-term data series of annual estimates of biomass of macrobenthic animals collected on tidal flats in various parts of the Dutch and German Wadden Sea. Year-to-year fluctuations were stronger in nearly all individual benhos species than in total macrozoobenthic biomass. The various species differed significantly in their year-to-year variability. Everywhere the tellinid bivalve Macoma balthica was relatively stable, whereas species such as the cockle Cerastoderma edule and the polychaetes Lanice conchilega, Nephtys hombergii and Anaitides mucosa fluctuated heavily and rapidly in all parts of the Wadden Sea where they were found. Within species, fluctuations in biomass of individual age or size classes were stronger than those in total biomass of the species.Several species showed minimal biomass values in the same years over vast areas. This synchronization of scarcity was caused particularly by similar responses to winter character, which was each year similar over the entire Wadden Sea. Such similar responses included low over-winter survival during severe winters and recruitment failure after exceptionally mild winters. Immediately after severe winters, such cold-sensitivee species as C. edule, L. conchilega and N. hombegii were scarce all over the Waden Sea, thus liimiting the possibilities for birds to switch to other parts of the Wadden Sea to find their preferred prey in sufficient quantitu. Simultaneous recruitment failure in several important bivalve species (C. edule, Mytilus edulis, and Mya arenaria limited the possibility for specialized bivalve consumers to switch to alternative prey types in certain years.     

Could EST-based markers be used for the marker-assisted selection of drought tolerant barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis>) lines?

To improve our knowledge on the genetic control of drought tolerance, the Oregon Wolfe Barleys (OWB), considered as a reference population in genetic mapping, were subjected to various types of water deficit. Overall, when investigating numerous environments and replications, 40 QTLs were identified in three developmental stages. Based on these loci five QTL clusters were separated, which affect various drought-related traits in at least two developmental stages. Several candidate genes were identified for each QTL cluster using an expressed sequence tag (EST)-based map with high marker density. The putative role of the candidates in drought tolerance is discussed. The phenotypic effect of three of the five candidate genes was also tested on 39 barley landraces and cultivars and a significant relationship was found between the allelic composition of these genes and yield production under stress conditions. This study presents a relevant example of the use of reliable QTL data in the candidate gene approach, while also demonstrating how the results could be practically utilized in marker-assisted selection (MAS).