Equally, the other emerging biotechnologies such as ZFN, ODM, transgenesis and cisgenesis, RdDM, grafting on GM stock, reverse breeding, agro-infiltration, and synthetic genomics, though requiring further refinements to varying degrees, will also become quite important in the very near future. Countries will increasingly require support in navigating the IPR regimes that govern access to these technologies and the regulatory issues pertaining to their adoptions.
As massive numbers of new breeding materials are generated through pre-breeding, MAS must be complemented by phenomics in order that reliable predictions of the breeding values can be made. Private sector plant breeding and seed companies have taken the lead in leveraging these innovations in producing highly successful crop varieties and provide models for re-tooling the public sector crop improvement programs. Certainly, an enabling environment is required for breeding to be relevant and, hence, thrive.
The erstwhile piecemeal interventions at the three components of the PGRFA value chain, namely, conservation, breeding, and dissemination of seeds and planting materials is, simply, inadequate. A result-oriented plant breeding must have access to the widest possible source of heritable variations just as it needs an effective mechanism to deliver high quality seeds and planting materials to the growers. This is the PGRFA continuum that significantly enhances the ability of plant breeding to deliver need-based outputs.
We posit that not only all three individual components but their intervening linkages must be strengthened in tandem. A National PGRFA Strategy helps to institutionalize this paradigm that demonstrably mirrors the operations of the highly successful private sector crop improvement multinationals. The increasingly pivotal roles of the private sector must be factored into policy-making and in the development of strategies. The private sector is not only marketing seeds and planting materials but also breeding the new varieties; its continued participation in these activities must be encouraged especially where comparative advantages are demonstrated.
Enabling policy, legal, and market environments that spur innovation and investments of capital are key to fostering the much needed public-private partnerships required for operating at scale. A healthy balance must be struck between IPR and the innovations and investments that they encourage and the imperative of contributing to public good.
The roles of the International Convention for the Protection of New Varieties of Plants, that is UPOV, and various national, regional, and global industry interest groups will be critically important in this regard. What is the profile of the 21st century plant breeder? Technically, the multidisciplinary team driving a breeding program will include persons skilled in the traditional disciplines of plant breeding as well as those with in-depth knowledge of various ancillary biotechnological techniques.
Skills in information technology, business management, law, and so on will also be required in such teams. Aside from private sector plant breeding and seed companies, such a suite of expertise does not exist in most public sector breeding concerns. The training of the future plant breeder, though mentioned often now, is still not receiving as much attention, in terms of funding, facilities, skilled trainers, and the number of available opportunities, which it deserves.
Capacity building will require wide-ranging public-private partnerships in order that the curriculum being developed can be effective. The highly successful land grant universities scheme of the United States demonstrates the lasting impacts that concerted investment of resources in training can have. Finally, the re-oriented crop improvement programs require a sustaining platform, in this case, the NARES. Equally disturbing is the dearth of reliable mechanisms for the dissemination of high quality seeds and planting materials of improved varieties. Indeed, while the work of the CGIAR centers in filling this gap cannot but be commended, the manifest over dependence of many NARES on these centers can only be injurious in the long run.
For one thing, the mandates of these centers preclude work on many important food security crops. The strengthening of the NARES, the ultimate bulwark between hunger and the populace in many developing countries, must be at the top of the agenda. Bold initiatives underpinned by political will have strengthened and re-oriented agriculture in the past. For instance, the contributions of the land grant universities, including the extension services, to the food security of the US are legendary.
Many national governments sadly lack the political will to strengthen their NARES as means for ending hunger. Support to national governments must therefore include mechanisms that contribute to fostering the nurturing policy environments for investments to bear fruit. In the final analysis, the ultimate responsibilities for crop improvement, just as in safeguarding food security in general, lies with national governments and by extension, their NARES.
These responsibilities may be abdicated only at the peril of food security and at the certain risk of consequent instability and retarded development. Multilateral organizations, civil society, and national governments must ride the momentum of the current reinvigorated attention to food security and strengthen capacities for crop improvement in innovative manners. Countries need assistance with suites of actionable policy interventions that leverage validated technologies and strategies in aid of result-oriented crop improvement. Such policy items or measures that countries can adopt in strengthening the three components of, and the linkages between, the PGRFA continuum in tandem are not readily available in forms amenable to ease of dissemination.
The work of the GIPB and similar multi-stakeholder platforms in articulating and assembling such tools serve as examples of multi-stakeholder efforts that deserve continued support especially in order to operate successfully at scale. African Agricultural Technology Foundation.
African Centre for Crop Improvement. Bacillus thuringiensis. Convention on Biological Diversity.
About FACTS Reports
Consultative Group on International Agricultural Research. Food and Agriculture Organization of the United Nations. International Fund for Agricultural Development. International Food Policy Research Institute. Marker-Assisted or, Aided Selection. National Agricultural Research and Extension Systems. New Rice for Africa. Oligonucleotide directed mutagenesis. Plant Genetic Resources for Food and Agriculture. Participatory Plant Breeding. Participatory Varietal Selection. West Africa Centre for Crop Improvement.
World Information and Early Warning System.
- Naruto, Vol. 45: Battlefied, Konoha (Naruto Graphic Novel).
- Climate change and agriculture.
- Edgar Allan Poe und seine Abhängigkeit von Frauen (German Edition).
- Blue Mesa.
Zinc finger nuclease. This article is published under license to BioMed Central Ltd.
The views expressed in this article are those of the author s and do not necessarily reflect the views of the Food and Agriculture Organization of the United Nations. Review Open Access. Re-orienting crop improvement for the changing climatic conditions of the 21st century.
The frequent occurrences of drought and floods, that invariably result in acute food shortages such as the very recent ones in the Horn of Africa [ 5 ], are symptomatic of the grave implications of extreme weather conditions for crop production and, hence, food security. Indeed, the overwhelming prognosis is that extreme weather events such as heavy precipitation, heat waves, and rising sea levels will occur in many parts of the world during the 21st century [ 7 ] with resulting floods, drought, and salinity as the most critical consequences.
The strategies for devising solutions to these constraints will vary across geographical regions as the types and magnitudes of the problems will vary. For instance, though there is the consensus that rainfall is expected to increase globally overall, some places will actually be receiving less annual rainfalls while the seasonality of rains and hence the timing of the cultivation of crops will also change. More worrisome yet, the frequencies of occurrence and durations of the extreme weather events are also expected to increase.
Table 1 Some expected negative impacts of climate change on crop production by regions a. Widening the sources of heritable variations Scientists are mindful of the shortcomings in the genetic diversity - and hence, increased vulnerabilities - of crops. Theme Priority activity In situ conservation and management 1. Promoting in situ conservation and management of crop wild relatives and wild food plants Ex situ conservation 5. Regenerating and multiplying ex situ accessions Sustainable use 8. Supporting seed production and distribution Building sustainable institutional and human capacities Participatory plant breeding Factoring in the perspectives of the growers and other stakeholders such as consumers, extensionists, vendors, industry, and rural cooperatives in the crop improvement endeavor of developing new varieties is known as Participatory Plant Breeding PPB; [ 68 ].
Novel plant-breeding techniques The incredible advances in biotechnology demonstrably hold great promise for crop improvement [ 73 ]. Marker-assisted selection The increasingly available rapid, efficient, high throughput, and cost-effective molecular biology tools for identifying the sources, and tracing the inheritance, of desired traits are revolutionizing the management of PGRFA in general and plant breeding in particular.
Genetic transformation Recombinant DNA technology, involving the use of molecules containing DNA sequences derived from more than one source to create novel genetic variation, has become an important crop improvement option. Emerging biotechnology techniques of relevance to plant breeding The integration of biotechnologies into crop improvement is a very dynamic field of endeavor that is changing continually.
Broadened genetic diversity of crops Firstly, the extremely narrow genetic base of crops, which puts food security at risk, must be broadened at both the intra- and inter-specific levels. Global Environmental Change. Food security and climate change in dry areas: proceedings of an International Conference, February , Amman, Jordan. Food Sec. The Genetics and Exploitation of Heterosis in Crops. World Development. The Developing Economies. Agron J. Outlook on Agriculture.
PLoS Biol. Annals of Botany. Genetic Resources and Crop Evolution. Theor Appl Genet.
Plant Molecular Biology. Marker-assisted selection: Current status and future perspectives in crops, livestock, forestry and fish. Plant Physiol. Plant J. BMC Plant Biol.
Improvement of Crops in the Era of Climatic Changes - Volume 1 | Parvaiz Ahmad | Springer
Nat Biotechnol. Breeding Science. BMC Plant Biology. Mol Genet Genomics. Molecular Techniques in Crop Improvement. Edited by: Shu QY. Trends Plant Sci. Plant Breeding and Farmer Participation.
Varietal selection and breeding methods and their impact on biodiversity. Experimental Agriculture. Plant Physiology. Animal Genetics. Evaluation of near-isogenic lines carrying single-donor introgressions for desireable wild QTL alleles derived from Lycopersicon hirsutum and L. Identification of QTLs for traits of agronomic importance from Lycopersicon hirsutum. Crop Sci. J Sci Food Agric. Google Scholar Ribaut J-M, Ragot M: Marker-assisted selection to improve drought adaptation in maize: the backcross approach, perspectives, limitations, and alternatives. Warming will be unevenly distributed, being greater in summer in lower and middle latitudes but greater in winter at higher latitudes, and this differential will increase.
The increase in winter precipitation is due to the increased water carrying capacity of the atmosphere resulting from the higher temperature. Global warming will increase the frequency of soil freeze-thaw cycles FTCs in cool-temperate and high-latitude regions previously subject to prolonged winter soil frost Kreyling et al.
Warmer winters will result in fewer soil freezing days and in boreal Europe, lowland permafrost is expected to eventually disappear Harris et al. The length of the frost-free season has already increased in most mid- and high-latitude regions of both hemispheres over the values established in the middle of the 20th century.
In the Northern Hemisphere, this is mostly manifested as an earlier start to spring, which will arrive progressively earlier in Europe by 2. Increased precipitation in winter, when there is little plant growth, increases the probability of leaching, runoff and erosion from unprotected boreal soils.
Climatic warming can paradoxically lead to colder soil temperatures in winter when it reduces the thickness of the insulating snow cover Henry, and references therein leading to root injury Kreyling, Increased soil freezing when snow was removedledto root injury, increased leaching of C, N and P, and decreased soil microarthropod abundance Groffman et al.
The intensity and frequency of summer heat waves is likely to increase IPCC, Between and , these trends were more extreme in central and north-eastern Europe and in mountainous regions than in the Mediterranean region. Temperatures are increasing more in winter than summer. Furthermore, an increase in variability of daily temperatures was established during — due to an increase in warm extremes, rather than a decrease of cold extremes. Thus Nordic summers are predicted to show more frequent heat waves, while the summer rainfall comes in less frequent, heavier intervals, and the net effect for crops will be more frequent heat and drought stress.
Climate change alters the inputs of photosynthetically active radiation while CO2 and temperature both rise and boreal daylength is long. These factors affect leaf anatomy, branching and flower development. Indeterminate crops need to stop flowering in order to ripen in time. Autumn-sown crops are subject to several winter-related stresses. Rooting depth is important to withstand drought, and broadleaf crops usually have a strong taproot.
Key aspects of the N cycle include nitrate leaching when snow melts, release of N2O from soil after summer rains, the use of N-fixing legumes in the rotation, and the potential to improve N uptake efficiency in cereals and oilseeds to counter the increased C:N ratio that results from the higher availability of CO2. These cycles of wet and dry could also lead to increased releases of N 2 O from the soil, as the intervals of anaerobiosis following the heavy rains, combined with the warmth of the soil, increase the activity of denitrifying prokaryotes Philippot et al.
In an in situ ecosystem manipulation experiment, short-term N 2 O-N losses slightly increased when elevated CO 2 was combined with warming and drought Cantarel et al. Potential management strategies include slowly released N sources, such as plant residues, along with rapid N uptake, promoted by cover crops in autumn and well managed crop stands in summer Figure 1. Crop physiological responses to temperature largely determine plant adaptation to different climatic zones and seasons; the level of photosynthetically active radiation and the length of the growing season determine the upper limit of productivity, and the phenological development of crops is influenced by temperature and light quality.
Plant responses to temperature and their sensitivity to temperature changes differ during ontogeny. Growth and development are accelerated by an increase in ambient temperature up to some optimum or maximum, whereafter rates decrease again. Generally crops are more sensitive to temperature changes at generative than at vegetative stages. In oilseed rape Brassica napus L. These morphological and anatomical changes could explain the decrease in plant biomass. High temperature during seed filling resulted in reductions in seed yield and oil content in this species, with strong differences among cultivars in the ability to adapt to a gradual increase in temperature Aksouh et al.
The sowing temperature has a marked role especially in crops that require vernalization before flowering. Heide, Base temperatures for vernalization range from The occurrence of high temperature during grain filling and drought during stem elongation has decreased wheat yields in France Brisson et al. An increase in night temperature has been found especially detrimental for grain filling processes Prasad et al. Root growth is even more sensitive to temperature changes than shoot growth. Root growth responds to diurnal temperature changes in the upper soil layers.
However, when Patil et al. Since the developmental stage in cereals is determined by the apex, soil warming might affect the developmental rate only when the apex is close to the soil surface Patil et al. Flowering needs to occur in the window between risk of late spring frosts and risk of summer heat, both of which affect ovule and pollen viability and embryo growth. An adjustment to flowering date needs to be compensated by a corresponding adjustment to the grain-filling period, in order to allow timely harvest while maintaining the duration of light interception.
If earlier-flowering cultivars are selected, the risk of low temperatures during spring can cause yield reductions by slowing growth Figure 2A , affecting fertility, or killing the young plants Figure 2B. When frost occurs during the flowering time of winter rye or another cereal with a determinate growth habit, the harvest fails. Pests and pathogens decrease yield either by depressing the formation of reproductive branches and hence reducing both photosynthetic green area and grain number, or by destroying the photosynthetic green area and thus decreasing energy capture Duveiller et al.
In rainfed systems, such as Nordic areas, where short periods of drought are common, soil-borne pathogens are frequent. Increasing temperatures, irregular precipitation together with longer growing season will add to the risks of severe infestations of pathogens in boreal agriculture Luck et al. Drought, a temporary inadequacy of water supply to a plant, is widely considered the main limitation to crop yields Boyer, Spring drought is already a part of the cropping season in many Nordic regions, restricting imbibition and establishment of spring-sown crops, and affecting the formation of generative organsof cereals, since the change from vegetative to generative stage occurs early, close to the two-leaf stage.
Thus, the number of sterile florets and abortion increases in cereals. These changes are irreversible and decrease the final yield. Transient summer drought is predicted to increase and drought resistance of the cool-temperate crops suitable to the boreal region is important. The effects of drought are mainly due to limitation of gas exchange until relative water content is reduced to a certain point, after which biochemical changes become more important.
Net photosynthesis of turnip rape Brassica rapa L. Oilseed rape adjusts readily to prevailing growing conditions through morphological and anatomical changes. Water deficit causes reductions in its stem height and diameter as well as in leaf number and area and thus, in total dry matter Qaderi et al. Drought-stressed oilseed brassicas form short, thick roots that, after rewatering, rapidly elongate, exploring large soil volumes Deleens et al.
Water deficit also increases the amount of epicuticular wax in oilseed rape Qaderi et al. Sugar beet Beta vulgaris var. Elevated CO 2 can override some of the yield decreasing effects of drought. The water status of barley Hordeum vulgare L. In elevated CO 2 , photosynthesis was, surprisingly, also stimulated more under drought than under well watered conditions, and photorespiration decreased.
Spring frosts damage crops at early growth stages. A, spring barley leaves are damaged by spring frost, decreasing the photosynthetic leaf area and slowing biomass accumulation. The apical meristem is at this stage below soil surface and does not get damaged. B, the apical meristem of sugar beet is sensitive to frost and sometimes the seedlings die, as shown around the surviving seedling in the picture. Oxygen deficiency is typical for both ice encasement and waterlogging, since the plants consume O 2 while entry of O 2 is prevented.
Thus, metabolic anoxia tolerance plays a major role in short-term anoxia, whereas in long-term anoxia, aerenchyma formation is important. In overwintering plants, often the problem is starvation during winter when the C reserves are utilized. Timothy Phleum pratense L. Winter waterlogging also decreased the supply of nitrogen to the shoot in the early spring. The reduced size of the root system and leaf area limits the ability of the crop to take up nutrients and intercept radiation, and later, make it more vulnerable to drought.
The root system is restricted since the nodal roots located in the top 20 cm of soil are predominant, whereas the seminal roots located at deeper soil layers are killed due to waterlogging Dickin et al. Sairam et al. Formation of NO could be related to maintenance of ATP levels and energy charge, providing time for development of adventitious roots Sairam et al.
Crop production and climate change
Moreover, NO could be involved in aerenchyma formation in waterlogged roots by means of apoptosis Sairam et al. While CO 2 is considered as a greenhouse gas that contributes to climate change, it is also essential for photosynthesis and hence plant growth. High CO 2 down-regulates Rubisco activity in C3 plants including wheat, oilseed brassicas, and legumes that are the main crops in the boreal region, stimulates dark respiration via transcriptional reprogramming of metabolism, and decreases photorespiration reviewed in Leakey et al.
The photosynthesis of C3 plants, such as potato Solanum tuberosum L. Even though assimilation is stimulated, partitioning is not, and yield increases are sink-limited unless additional N is supplied Leakey et al. Elevated CO 2 concentration has also been shown to attenuate the effects of water deficit and to improve the efficiency of water use at both the leaf and canopy scale by maintaining the stomatal conductance, carboxylation rate and RuBP Ribulose-1,5-bisphosphate regeneration Robredo et al.
When the photosynthesis is limited by RuBP regeneration capacity, the increase in photosynthesis results mostly from decrease in photorespiration Leakey et al. Elevated CO 2 increased the leaf thickness, leaf area, stomatal density and photosynthesis in potato, but decreased the stomatal conductance by reducing stomatal aperture Lawson et al. Photosynthesis was increased and respiration decreased in potato in the same conditions and the decrease in respiration was attributable to the lowered protein content of the plant tissues Fleisher et al.
Moreover, the majority of additional photosynthate was partitioned to tubers and roots instead of above-ground biomass, and no marked differences were observed in the area, appearance rate, expansion rate, and senescence rate of leaves Fleisher et al. When the irrigation rate under elevated CO 2 was increased, photosynthate was partitioned more to leaves and stems, decreasing the harvest index, and this was attributable to the increased respiratory costs of increased biomass. Under elevated CO 2 , theincreased tuber sink may play an important role in reducing the drought-induced feedback inhibition of photosynthesis.
Low glycoalkaloid and nitrate content represents better product quality, but lowered citric acid content allows greater discolouration after cooking. At the same time, the higher temperature that is part of global change causes a contrasting decrease in dry matter content, and irregular precipitation can cause secondary growth of tubers. Similarly, in oilseed rape, elevated CO 2 resulted in taller plants with thicker stems and larger and thicker leaves Qaderi et al. Photosynthesis increased, as did chlorophyll fluorescence and content, contributing to the higher biomass production of plants grown under elevated CO 2 Qaderi et al.
In the vegetative stage, biomass was higher in elevated CO 2 , particularly in old cultivars, but the difference between growing conditions disappeared at later stages, which was attributed to the lack of carbon storage Franzaring et al. When wheat was grown under high CO 2 , its photosynthetic capacity was decreased, probably due to down-regulation of Rubisco activity Alonso et al. Elevated CO 2 also increased the temperature optimum of the crop. Alonso et al. Hybrid cultivars have generally responded more positively than inbred lines to elevated CO 2 , probably due to their larger sinks, in which carbon assimilation is less restricted by feedback inhibition Sun et al.
When sink capacity is insufficient, CO 2 elevation results in increased leaf carbohydrate concentration and down-regulation of photosynthesis Leakey et al. In contrast, the effects of elevated CO 2 on C4 photosynthesis are small, and generally significant only in drought conditions Leakey et al. Crops under elevated CO 2 required more N than those under current ambient levels in order to produce optimum yield Sun et al. In light of population growth and climate changes, investment in agriculture is the only way to avert wide scale food shortages.
Re-orienting crop improvement for the changing climatic conditions of the 21st century
Life Sciences Plant Sciences. Free Preview. Written by a diverse group of internationally known scholars Presents strategies for translating current research into applied solutions Illuminates various aspects of plant responses in molecular and biochemical ways to create strong yields and overall crop improvement see more benefits.