Breeding and Productivity in Ending Hunger and Achieving Food Security and Nutrition
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Breeding is the art of altering the original traits of plants or animals to produce desired characteristics to advance the quantity and/or quality of products for humans and animals’ benefits (Fehr 1987; Sleper and Poehlman 1995; Bernardo 2010). The US national association of plant breeders () define “plant breeding” as the science driven creative process of developing new plant varieties that include cultivar development, crop improvement, and seed improvement. Kor Oldenbroek and van der Waaij (2014) and Nature () define Animal Breeding as a process involving the selective mating of domestic animals with desirable genetic traits, to maintain or enhance these traits, with the intention to improve desirable (and heritable) qualities in the next generations. In plant and animals, breeding requires biological assessment in relevant target environments and knowledge of genes and genomes. Progress is assessed based on gain under selection, which is a function of genetic variation, selection intensity, and time (Xu et al. 2017).
Introduction: Overview of Breeding and Importance for Food Production and SDG2
The challenge of global population growth, climate change, and pressure on finite natural resources requires producing more output with limited resources and balancing that productivity gain with reduced environmental impact. This approach of production defined as sustainable agricultural intensification is well captured in the 2030 Sustainable Development Agenda adopted in September 2015 (UN 2015). Five out of the 17 Sustainable Development Goals (SDG), namely, SDG1, SDG2, SDG6, SDG7, and SDG15 have been identified to be related to agricultural sectors, with eight of their indicators proposed as measurement baseline for SDGs achievements (Nhemachena et al. 2018). Moreover, FAO (2017) stressed that the full range of SDGs could not be achieved without substantial progress on SDG2 on “Ending hunger, achieving food security and improved nutrition and promoting sustainable agriculture.” Agriculture is the principal source of livelihood for the hundreds of millions of people worldwide, who manage earth’s natural resources for farming, livestock, fishing, and forestry-based production (FAO 2017).
It is recommended that more than 80% of the improvement of agricultural production needed to feed the estimated 8.3 billion people by 2030 should be based on the intensification of the current agricultural systems rather than the conversion from other land use types if fewer alteration of the agricultural environmental footprints is to be maintained (Asaduzzaman et al. 2011). Evidence from the history of agricultural improvement since the 1900s offer optimistic reasons for addressing this agricultural sustainability and intensification challenges through improved management practices and breeding (Duvick 2005). These two interacting and complementary tools were integrated parts of the Green revolution technologies package which have contributed to the dramatic yield gains for major staple and coarse cereal at the rate outpacing population growth in the global scale (Defries 2018; Ricciardi et al. 2018). The rapid growing knowledge in genetics, pathology, entomology, and molecular biology has paved the evolution of agricultural breeding from farmer-led selection for preferred varieties to molecular and genomic breeding with very huge benefits for agricultural productivity. Recent review by Xu et al. (2017) highlighted that genetic gain could be further enhanced through more integrated breeding strategy, combining conventional, marker-assisted, and genomic breeding and therefore allowing to unlock favorable genetic variations, to refine field experiments for more precise envirotyping, to heighten selection intensity and to shorten selection cycle. It is demonstrated that agricultural breeders contribute to improve sustainability in farming systems through various approaches, including increased harvestable yield and end use quality, improved pest and disease resistance, efficient land, soil, and other resources use and conservation, better nutrient and input use efficiency, and improved resilience to a changing climate (Edgerton 2009).
Therefore, it is hypothetical that the current knowledge and potential in agricultural breeding technologies could contribute to close the productivity gap and provide access to food for the estimated 800 million of chronically hungry, improve the availability of vitamins and mineral-rich food to address malnutrition-related health problems affecting more than 2 billion of the world population, and address associated need for improved agronomic management with low-inputs, energy-effective breeds, as well as more biodiverse agricultural systems. By so doing, agricultural breeding will significantly contribute to achieve the SDG2, the other four agricultural-related SDGs, and therefore, facilitate the achievement of all the range of SDGs (FAO 2017).
The aim of this article is to highlight the contribution and challenges of crop and livestock breeding in addressing the SDG2 of the agenda 2030 of the United Nations. The study approach consists in exploring the conceptual linkages between the various targets set under the SDG2 on the one hand and the objectives and outcomes of agricultural breeding on the other hand, focusing on the contribution of breeding for ending hunger and malnutrition sustainably (SDG2 targets 1 & 2), improving productivity and income of small-scale producers (SDG2 target 3), ensuring sustainable food production system and implementing resilient agricultural practices to climate change and extreme events (SDG2 Target 4), and maintaining the genetic diversity and adaptability of food systems (SDG2 target 5). This contribution is not only meant to refresh breeders on the height of their task but also to guide policy makers on the potentiality of breeding tools to contribute to improve agricultural productivity and therefore for better livelihoods of populations.
The Challenge of Food System in Achieving the SDG2 and the Need for an Improvement of Food Production to Meet the Five Targets of SDG2
Breeding is achieved through many different techniques ranging from simple selection of individuals with desirable traits for multiplication, to advanced methods that make use of knowledge in genetics and chromosomes, and more complex genomic techniques (Edgerton 2009).
Overview of few breeding methods used in agricultural improvement
In a nutshell
365体育网站Crossing and selection
365体育网站Parental individuals with the desired characteristics are cross bred with each other. The most performant individuals are used again for the next generation
365体育网站Original and fundamental type of breeding
365体育网站Requires a long time to achieve the desired results
Almost all plant and animals
365体育网站Two parent lines that complement each in desired properties as much as possible are crossbred. From the offspring, homozygotic lines are developed, which are called line-bred varieties.
365体育网站Line-bred varieties are very similar, and the offspring genetically stable.
Time-consuming: Several cycles/generations must be cross-bred and in-bred before the desired result is achieved.
365体育网站Barley and wheat breeding
365体育网站Two genetically different parent lines are crossbred
The hybrids are bigger, more fruitful and more resilient than their parental lines (hybrid vigor).
The heterosis effect is maintained for only one generation
Breeding of corn, sugar beets, rapeseed, rye, and sunflowers
Cell and tissue culture, cloning
365体育网站Using individual cells, entire individuals are regenerated in the lab.
Quickly generate many identical offspring of one parent.
365体育网站All individuals and tissue types require their own “recipe”
Cultivation of sugar beets, corn, rapeseed, wheat, barley, and rye
Marker technology and genomic selection
365体育网站With the help of molecular markers, individual’s characteristics are analyzed
Quick selection of the desired characteristics, independent of environmental influences
Molecular markers (MAS) are routinely used for all crops.
365体育网站The properties of a breeding in the farm are examined. This is done using modern technologies for automated analysis
365体育网站Noninvasive method and does not affect development. Allows, for example, to draw conclusions about infestations with parasites
365体育网站The “correct aspect” must be measured. The researcher must be able to quickly analyze large quantities of data, which requires broadband data lines to the breeding stations
365体育网站Efficient selection of genotypes in the field and in greenhouses
365体育网站Green genetic engineering is a highly targeted method to provide plants with new genetic properties. It involves transferring genes or other sections of the genetic material (DNA), for instance, from bacteria to the genetic material of plants
365体育网站Genetic engineering methods enable a very targeted approach: Only the gene for the desired new characteristic is transferred directly to the crop
365体育网站Critics view the transfer of genes from other species as a safety risk
365体育网站To create genetically modified herbicide-resistant sugar beets
The holistic structure and biological function of the genome are explored
Complex characteristics that are not based on individual genes but on networks of genes can be analyzed and accurately adapted
365体育网站To analyze the genetic material of sugar beet, corn, rapeseed, sunflowers, wheat, barley, or rye. Many research projects are carried out worldwide
The term “genome editing” includes a number of methods. They can all change individual building blocks of DNA in a precise and targeted manner
365体育网站Many examples show that this allows new varieties of plants to be bred quicker and more precisely than ever before
Social acceptance still in the balance
Potential of this innovative methods still under investigation
Nowadays, MAS has become an inseparable component in most of the breeding programs, involving almost all fields of agriculture, and depending upon classical to modern techniques. It is strongly believed that breeding is imperative for ensuring food security through development of new crops and livestock types that are higher yielding, disease resistant, drought tolerant, or regionally adapted to different environments and growing conditions, therefore improving productivity for societal benefits (Xu et al. 2017).
Agricultural Breeding, Productivity, and the Target 1 and 2 of the SDG2
The Green Revolution and major breeding break-through technologies have contributed to increase food production and alleviate chronic hunger (access to calories) since the years 1950s. These achievements have fairly reached small-scale farmers currently supplying 28–31% of the world crop production but affected by poverty and food insecurity (Ricciardi et al. 2018). Recent estimates indicated that the number of people suffering from hunger has slowly increased for several years, with more than 820 million people worldwide lacking access to calories to meet their daily needs. African subregions topping the list with 20% prevalence of undernourishment (FAO et al. 2019). Moreover, hidden hunger defined as micronutrient (minerals and vitamins) deficiencies is affecting more than 25% of the world population and emerge as one of the most challenging issue of the current food system (FAO 2017). Therefore, the first challenge of the current food system in achieving the SDG2 is to increase the production of nutrient-rich food crops, enrich the nutrient content of commonly eaten food, and improve the livelihood of the small-scale farmers. These will facilitate the shift in behavior toward healthier food and improved productivity, and therefore reduce food waste and make farming an attractive opportunity for people. Recent advances in agricultural breeding offered several opportunities in addressing these challenges (Table 1365体育网站). Maximizing performances and physical yields and the return on investment has been the main aim of many breeding programs. However, the rising of hidden hunger among world population calls for more integrative breeding objectives with increased emphasis on food quality improvement. This means that the breeding objectives should be directed at improving the traits that will positively influence access to quality and quantity food and therefore revenue from product sales.
Crop Breeding for Improved Access to Quantity Food
Example of the impact of plant breeding on specified traits of major staple crops
Crop Breeding for Quality Food: Overcoming Malnutrition, Food Stunting, and Wasting
Inadequate consumption of even one of the 49 micronutrients required to meet human metabolic needs could result in adverse physiological disturbance leading to sickness, poor health, increased morbidity and mortality rates among vulnerable populations, lower worker productivity, and therefore diminishing human potential, felicity, and national economies. Earlier breeding objectives were giving much emphasis on yield improvement (accessibility) for the global commodity market (feed, fuel, etc.) at the expense of nutrient quality, food diversity, and preference (Bradbury et al. 2005). But with emerging dietary problems and cultural preference, breeders and scientists are challenged to produce more healthier food, which in some cases could mean lowering fat and sugar content of commonly eaten food, specifically for obesity-related malnutrition in wealthier countries or increasing micronutrients, vitamin, and protein in most undeveloped and developing worlds (Welch and Graham 2004; River et al. 2015). During the last two decades, micronutrients enrichment traits, their physiological processes, and genetic potential in the genome of many staple food crops (rice, wheat, maize, cassava, and beans) have been documented mainly for iron (Fe), zinc (Zn), Selenium (Se), and Provitamin A carotenoid (Graham et al. 2001). Some evidence of biofortification of staple crops using transgenic approaches have been published among which are golden and fragrant rice grain enriched with β-carotene, high ferritin-Fe, and fragrant (Graham et al. 2000; Bradbury et al. 2005). Another notable example of food-quality improvement is the breeding for high-fiber barley (with roughly twice the fiber content of other barley varieties) with the aim to preserve and promote beneficial intestinal bacteria and associated decreased of bowel cancer as well as other health benefits (Tuohy et al. 2012). Breeding and/or transgenic strategies are being used for biofortification by increasing the level of micronutrients in the edible parts of some food crops eaten daily by most afflicted population for their sustenance. These breeding initiatives had shown that crop nutritional quality is a multigenic trait, most of which are lost during the initial phase of crop domestication.
Moreover, the high level of genetic diversity observed within the genome of some crops (Welch and Graham 2002) as well as correlation among some micronutrient’s traits paved the way to plant breeders to pursue the improvement of micronutrient density in staple food crops as one of the most important objectives of their work in many developing countries where resource-poor people are affected by hidden hunger (Welch and Graham 2004). Interestingly, it is demonstrated that breeding for micronutrient enrichment of staple food crops could positively affect crop yield, therefore contributing to address both target 1 and 2 of the SDG2 by increasing the availability of food while at the same time reducing malnutrition and associated health issues (Graham et al. 2001). In addition, genomic breeding associated with throughput metabolomics (data on gene controlling the production of specific metabolites such as essential oils) could significantly contribute to achieve the twin objective of quality and quantity crop improvement without tradeoff or sequential optimization of one of these breeding objectives (River et al. 2015). In tropical countries, such approaches are being promoted to increase access and improve the quality of some highly nutritious, culturally important, and economically valued indigenous fruits trees species that are still being gathered from the wild such as Adansonia digitata or baobab fruits, Dacryodes edulis or African plum, and Vitellaria paradoxa or shea among others (Muchugi et al. 2016).
Animal Breeding for Improved Access to Quantity Livestock Products
Livestock is central to the livelihoods of rural dwellers and is strategically important to the world’s food and nutritional security as well as global trade opportunities. Animal products form a great source of protein that are essential in a healthy and balanced diet. In an environmental point of view, livestock contribute in transforming materials such as grass, straws, agro-industrial, and household wastes into high-quality protein. It provides 14% of the total calories and 33% of the protein in people’s diets at global level (FAOSTAT 2017). Livestock likewise make a significant contribution to food security, serving to tackle micronutrients deficiency, or “hidden hunger,” by providing people with essential vitamins and minerals. Another vital role played by livestock is providing animal traction and manure for fertilization, which helps boost crop productivity while, as an economic asset and a source of income, they contribute directly to households’ purchasing power and food security.
Worldwide demand for livestock products is likely to double in the following decades due to an increasing global population and wealth. To satisfy this rising need, animal production should increase while considering issues of environmental sustainability, food safety, and animal welfare. Because of increased demand for meat and the deterioration and loss of agricultural land, there is a pressure to utilize the potential for biotechnology to improve productivity in animal agriculture. Breeding acts as technology catalyst to enhance livestock’s contribution to ending hunger as it plays an important role in increasing animal productivity, in synergy with the use of wisely formulated feeds and other production system’s parameters (Boichard et al. 2016).
Before the twentieth century, animal breeding was basically done using artificial selection based on own phenotypes of animals. New genetic development during the twentieth century had led to the successful selection of known phenotypic traits with appreciable heritability. For the last 25 years, mapping of Quantitative Trait Loci had paved the way to Marker-Assisted Selection found to be successful for traits with simple genetic determinism. In early 2000, a novel approach of breeding based on both phenotypes and markers information was proposed by Meuwissen et al. (2001). The development of large-scale and cheap genotyping methods had significantly contributed to the feasibility of this approach and therefore to the improvement of animal breeding technologies. In dairy cattle, for example, genomic selection has replaced progeny testing and revolutionized selection by simplifying the process, decreasing the cost, reducing the generation interval, and thus significantly increasing the yearly genetic trend. With these advantageous attributes, much larger numbers of bulls are being selected, leading to better management of genetic resources with limiting inbreeding trends and easy satisfaction of a diversity of needs and objectives. Therefore, genomic selection, thought already documented as successful in cattle, still offer some important, often overlooked but huge opportunities for traits not yet selected, but that could significantly contribute to sustainable production and long-term management of genetic resources (Boichard et al. 2016365体育网站). Based on this example with cattle, breeding sector can contribute to finding solutions that are cost and resource efficient, moderate or eradicate environmental burden, adaptiveness to climate variation, beneficial for animal health and welfare, improve food quality and safety, and that meet the needs of citizens of today and future generations.
Demand-Led Breeding for Quality Adapted to Market’s Needs: Target 3 of the SDG2
For industrial and high-market commodities food crops, the two main traits related to market needs are improved quantity to satisfy the actual demand, but also quality adjustment to meet requirements for industries processes and consumers preferences. Breeding objectives related to market’ needs could therefore include protecting and enhancing marketable yield, but also improving some quality traits to meet these industrial and consumers’ requirements. For example, based on requirements from Indian Barley’ industries, the minimum acceptable quality standards for grain and malt traits were set and used as guidelines in barley’ improvement projects (Verma et al. 2008).
In the same line, animal breeding must respond and adopt new techniques in response to social, economic, or competitive pressures; exploit new opportunities that offer greater productivity; and abolish procedures which become unacceptable, carry risks, or threaten costs that might outweigh short-term benefits. Simultaneously, the livestock sector is sensitive to societal concerns related to food safety, ethics, cultural values, genetic diversity, animal welfare, and “naturalness” (Fanzo 2015). To deal with all these issues, it is important for breeders to cooperate with other researchers and professionals, policymakers, and society in order to have a participatory approach in breeds’ development that meets the needs of all the stakeholders (Halewood et al. 2007).
Improvements for food quality and food safety are important aspects with growing interest over time in animal breeding. Hence, nutritional value, human health, sensory qualities, visual appeal, and processing characteristics are becoming targets traits for animal breeders. Although animal breeding has more indirect possibilities in improving food safety, by, for example, decreasing the incidence of food-borne infections, breeders are encouraged to improve the natural genetic resistance by selecting robust animals, and by so doing, they will decrease the need for medication as well as the occurrence of zoonoses, and consequently, reduce the risk of residues and improve the safety in animal-sourced food with associated benefits for human health (Verma et al. 2008).
The development of molecular markers and genetic maps had allowed the identification of markers linked to genes of economically important traits which are being exploited through marker-assisted selection for great interest in agricultural breeding. As examples, improved milling and malting quality are key selection criteria in wheat and barley breeding, with associated benefits for reduced wastage and enhanced processing efficiency (Verma et al. 2008). In addition, breeders have also improved digestibility in oats (Winfield et al. 2007), introduced healthier oil profiles, and targeted a reduction in anti-nutritional factors in oilseed rape to meet market requirements and promote use in nonruminant diets (Nega and Woldes 2018). Breeding is also playing a crucial role in forage and fodder science and production by improving dry matter and energy content as well as starch content and digestibility to maximize livestock performance (Cairns 2002). With emerging health and environmental issues, a clear shift has been observed in the market needs in crop and livestock’s production towards increased demand for low carbon footprints and nutrient-efficient commodities. Thornton (2010) proposed five possible modifiers for future food production and consumption trends among which human health and ethical concerns, sociocultural changes were found to be the most related to agricultural products demand. Therefore, the future agricultural breeding objectives will focus on other attributes in addition to production and productivity such as improving products quality in relation to health issues, sociocultural beliefs, increasing animal welfare based on ethic requirements (for livestock), disease resistance, and reducing environmental impacts. Hence, molecular genetics tools will be particularly useful for breeding of traits difficult to measure such as quality and diseases resistance, while transgenic production and genomic selection are expected to more than double the rate of genetic gain for quantitative traits (Haynes et al. 2009).
An innovative and participatory approach of consumers and markets demand-led breeding has been developed for the domestication of indigenous plants providing foods, medicine, and other nontimber forest products to low-income populations in many tropical countries in Africa, India, Asia, and southern America (Simons and Leakey 2004). This approach uses mainly ethnobotanical and horticultural sciences to assess genetic diversity and promote cultivation of scientifically overlooked, yet culturally and socioeconomically important species described by Leakey (2019) as “socially modified crops.” It has been documented as offering the opportunity to critically raising the productivity of staple food crops and to fight against food insecurity, malnutrition, and poverty among poor smallholder farmers in tropical countries through maximization of total factor productivity and minimization of environmental and social tradeoff (Leakey 2018).
Breeding for Better Standing Ability of Crops, Animal Rusticity and Welfare
Thought quality components are gaining more importance in food production systems. They were found to be affected by many biotic and abiotic variables, therefore calling for significant considerations when breeding in order to achieve quality in different environmental conditions (Knežević et al. 2004). Addressing these attributes would particularly be important if breeding objectives are to contribute in meeting not only the targets 1, 2, and 3 of the SDG2 on access to quantity, quality food, improving market value, and consumers’ preference but also the target 4 on sustainable food production systems through resilient agricultural practices in the context of global warming.
In plant breeding, resistance to lodging has been a driver of plant breeding to protect harvestable yield across most crop groups (SDG2-target 1&3). The development of varieties with better adaptation to agronomic processes and environments mainly requires traits related to standability, height, drought resistance, winter hardiness, maturation period, and steady growth. Varieties that stand better protect their yield potential, making standing ability an important breeding objective for most industrial crops such as maize, wheat, and Barley. Breeding success has come from identifying trait-related genes and developing molecular markers to improve selection for optimal height, stem strength, and rooting. In maize breeding, improvement for the ability to overcome both large and small stress bottlenecks, rather than for primary productivity, has been the primary driving force of higher yielding ability of newer hybrids during the last decades (Duvick 2005).
For wheat breeding programs, recent research in the same area has focused on identifying height-related genes which can allow high yielding varieties with the optimal height and develop molecular markers to exploit genetic variation in stem and anchorage strength between wheat cultivars (Nadolska-Orczyk et al. 2017).
Animal welfare (Vitality and Integrity) is becoming a significant priority in the livestock sector. In animal husbandry, there is a general assumption that certain breeds or genetic resources are well adapted to local production environments, though the production levels of these local breeds are usually lower, compared to the specialized more broadly used breeds. However, such animals may become more vulnerable if climate change results in more variable and extreme circumstances. Numerous studies in various farm animals including chickens, bison, and pigs have demonstrated that animals can adapt to their environments by changing their behavioral and biological characteristics including genetic sequence (Wolff 1998; Crawley et al. 2005; Cheng 2010). Hence, heritable traits that are beneficial to individuals of a population in an environment can be passed on to future generations. The enhanced knowledge on Genes controlling the behavioral, physiological, immunological, and psychological responses of animals to stressors, including environmental stimulations and the discovery of the genome sequences of many animal species, can contribute to the improvement in both speed and efficiency of many animal breeding programs. Breeding has developed over centuries locally adapted breeds, on which genetic selection could be used for improving the coping capability for a production environment and for increasing economic benefits (Laible 2009). Moreover, through crossbreeding strategies between local breeds and specialized breeds, the productivity gap between both categories of breeds can be reduced in a short period of time. Balanced crossbreeding strategies are needed because highly productive and specialized breeds often cannot keep their expected productivity in more extreme climatic or endemic disease situations. Because of heat stress, highly productive breeds often produce at the expense of health and vitality with the risk of being replaced much faster than locally adapted breeds (Cheng 2010). The development of efficient information management systems for health monitoring, health detection, etc. can accompany animal breeding in its contribution to the SDG target 2.
Breeding for Stronger and More Durable Disease/Pest Resistance, and for Adaptation to Extreme Environmental Conditions
High resistance to pests and diseases, but also an increased tolerance to changing environmental factors such as drought and cold, are becoming the key goals for agricultural breeders. Climate change, bringing unexpected drought, unpredicted heavy rains, and cold with associated crop failures, also keeps posing new challenges such as rising of harmful organisms that were previously considered ordinary. Against these stressing factors, breeders are working on new, adapted varieties, to ensure the stability of agricultural yields, hence positioning breeding at the forefront to achieve SDG 2-target 3, 4, and 5. This is being done by identifying, understanding, and introducing disease resistant genes as the first line of defense for the crops, therefore reducing harvest losses and protecting yield potential. By developing crop varieties resistant to pests, breeders have reduced harvest losses, contributing to quantity, quality, and sustainable food production and therefore addressing all the targets of SDG2. For example, breeding companies such as “The Andersons Centre” (2011) have succeeded in commercializing varieties with resistance to orange wheat blossom midge which would have affected long-term storage of wheat grains and seeds, hindering also the conservation of their genetic diversity. Same results were obtained for turnip yellows virus in oilseed rape and beet cyst nematode in sugar beet. Work is in progress to introduce aphid resistance in cereals, stem nematode resistance in field beans, and corn borer resistance in maize. Breeding may have started working to prevent and control the devastating effects of the fall army worms.
In the livestock sectors, breeding for disease resistance offers improved animal welfare and increased returns for breeders. It is now practiced in cattle, sheep, pig, chicken, and fish farming. For example, tick resistance is an integral part of cattle breeding programs in subtropical Australia; mastitis resistance, either in terms of clinical cases of mastitis or reduced somatic counts, is incorporated into many dairy cow and sheep breeding programs; and Marek’s disease resistance is a feature of modern chicken breeding. Breeding for resistance to post-weaning E. coli diarrhea in pigs is also in undergoing as well as scrapie resistance selection. Moreover, the evidence from Henryon et al. (2001) demonstrated that within the context of well-designed breeding programs, there is ample opportunity to select for decreased disease incidence. In addition to those mentioned above, specific temperate climate diseases that could conceivably and easily be selected against include PRRS in pigs, paratuberculosis and nematodiasis in cattle and footrot, paratuberculosis, and fly stroke in sheep and goats (Kim et al. 2008; Ewald et al. 2011; Tohidi et al. 2011). Nowadays, in poultry breeding, direct selection show that it is possible to breed for colibacillosis resistance without penalizing the improvement in the key traits. Similar work was executed by Pavlidis et al. (2007) who selected the ascites incidence divergently in chickens. Wise et al. (2008) indicated that Transgenics technologies would pave the way for further research in livestock resistant breeding. Transgenic breeding for disease resistance is not yet widely applied to the livestock industry, while genomic selection is becoming the hot spot in the study of animal breeding with the advantages of time-saving and low-costing compared with the traditional methods (Boichard et al. 2016).
With the declining cost of gene chips and sequencing, more candidate genes and QTL will be revealed, and more tremendous progress on the breeding for disease resistance could be obtained to introduce greater social profits in the domain of food security and safety, income generation, etc.
Breeding for Sustainable Food Production and Climate-Resilient Agricultural Practices: Meeting the Target 3 of the SDG2
Predictions of climate change indicate high temperature, variability, and irregularity of precipitations, water and nutrient scarcity, rising of crop, and livestock pests and diseases. These predictions are known to affect the inputs availability for food production resulting in yield stagnation and stability even for high-yielding breeds in optimal agronomics conditions. As demonstrated by Fess et al. (2011), in 2030, the decline of resource availability curve will be crossing that of population growth. Situation of the so-called peak society which highlight the urgency of breeding crops and livestock for low-input systems and improved resource management, as population and food demands are expected to increase while global resources decline (Cordell et al. 2009). In order to attain SDG2 targets at global level, breeding strategies should accommodate future food demands in a world of decreasing resource availability, by using more energy-effective approaches to breed new strains, lines, and varieties of crop and livestock that could be best suited to specific agricultural and climatic conditions, allowing for maximum productivity in that setting (FAO 2017). Therefore, the focus of breeding objectives to address these shortfalls is oriented towards nutrient-use efficient varieties. Specific breeding targets to increase resource use efficiency have focused on improving plant uptake and use of resources, principally water and nutrients such as Nitrogen and Phosphorus. Resource use efficiency in plant breeding has also focused on improving the efficiency with which the plant uses water and nutrients, which is linked to improving yield, while using the same inputs and hence reduced emissions per ton of outputs. Plant varieties with good nutrient efficiency have the capacity for outstanding productivity across a wide range of nutrients, i.e., from shortage to surplus. Plants with enhanced nitrogen efficiency, for instance, are better able to absorb the nitrogen available in the soil and convert it to biomass. In this respect, plant breeding can provide a significant contribution to sustainable agriculture as nutrient-efficient varieties can help reduce the use of fertilizers and manure on fields (SDG2-target 4 on resilient agriculture practices that increase productivity and production).
One important aspect of sustainability is to increase productivity through biological processes known to have less negative impact on the environment. Breeding for plants that promote soil biology and chemistry, for example, could become easier by applying genomic plant-breeding techniques alongside high throughput microbiome sequencing (metagenomics) and noninvasive, below-ground plant analyses (Chaparro et al. 2012).
Breeding animals for sustainable food production includes elements such as the efficient use of resources, the maintenance of profitability and productivity, continued availability of high quality, diverse food products, the promotion of appropriate levels of animal welfare, and the preservation of biodiversity. Sustainable breeding means balancing, safe and healthy food, robust, adapted, healthy animals, biodiversity, social responsibility, a competitive and distinctive world. A sustainable animal agriculture can be created with the contribution of animal breeding. Improved biological efficiency and specifically reduced production of waste per unit output is an important goal for breeders and there are emerging research results providing new opportunities to breed or select for environmental efficiency of animal agriculture.
Breeding to Maintain and Improve the Genetic Diversity.
It is well acknowledged that nineteenth and twentieth centuries agricultural revolution has significantly contributed to increase overall food production. However, concerns are being raised about the world’s reliance on a smaller number of food crops that may make global food security more susceptible to local interruptions in production (Ray et al. 2013). The negative consequences offsetting the success of breeding strategies are the decreased trend of diversity across and within crop species. Genetic erosion from loss of landraces and associated local knowledge on their beneficial traits has become serious concern in many countries for cereals, vegetable, and food legumes as well as domesticated animals’ species (FAO 2010). Moreover, modern agriculture always focused on a few high-yielding species/breeds to maximize productivity and therefore contribute to less biodiverse agricultural systems. Small-scale farmers in many developing countries maintained a broad diversity of food-based species in their environment to provide more than 80% of the world food that may deliver a broader array of vital micronutrients than modern breed varieties (Dutfield 2018365体育网站). In order to achieve the target 5 of the SDG2 on preserving genetic diversity of cultivated and domesticated plants and their wild relatives, there is a need for an integrated innovation breeding approach for plants and animals used for food, recognizing not only modern and farmer’s breeds for current domesticated species but also the wide range of cultivated and wild food species in developing countries.
Plant breeders have taken steps to contribute to and maintain the genetic diversity of crop species by maintaining collections of genetic sources such as the Germplasm Resource Unit, the Watkins Landrace Wheat Collection (Wingen et al. 2014), The John Innes Pisum Collection (Ambrose and Coyne 2008), Gediflux collection (Aradottir et al. 2017365体育网站), and others. Plant breeders have also participated in research designed to maintain and improve the genetic diversity within crop species such as the Wheat Improvement Strategic Program and are also part of Defra funded initiatives to improve genetic diversity such as the Wheat Genetic Improvement Network (WGIN) and Oilseed Rape Genetic Improvement Network (OREGIN and Pulse Crop Genetic Improvement Network (PCGIN).
In the livestock sector, breeders attempt to maintain genetic diversity in their breeding stock, and to monitor and control the rate of inbreeding. Breeders contribute semen and/or embryos to gene banks for relevant breeds/lines to ensure conservation of biodiversity. Diversity of breeds and their farming systems highly contribute to food products quality and diversity. Farm animal genetic resources are opportunities to maintain a vital countryside.
Challenges and Way Forward for Ending Hunger by 2030
Challenges in Crop and Livestock Breeding
Small animal populations and populations at risk of extinction: In such populations, breeding opportunities are limited; nearly all animals have to be used as parents for the next generation (at least the females) to get enough offspring. This gives no opportunity to select for traits related to food production. The main concern is to maintain the population by conserving the genetic diversity and to manage inbreeding which causes lower fitness and increases the incidence of recessive genetic defects. Selection for breeding goal traits is hardly possible.
Maintenance of both within-breed and across-breed genetic diversity365体育网站: In conservation genetics, this is primary aim, as they play different but critical roles in sustaining animal production, hence breeding programs should cautiously monitor genetic variation. In designing selection programs for small populations, a main challenge is to maximize genetic gain at an acceptable inbreeding rate.
Genetic Variation among Breeds: Selection for increased output while ignoring traits correlated to traits of conservation interest, such as adaptation, specific genetic variants, and quality of products, can reduce breed distinctiveness and between-breed variation. Identification of selection traits in local breeds should be accurate.
Economic Sustainability: Breeding programs require significant investments. The breeding strategy and system that maximize genetic response may not be optimal from an economic standpoint. Recording of performance and pedigrees may not be economically sustainable, even if restricted to a portion of the population (e.g., the nucleus).
Lack of infrastructure:365体育网站 Lack of infrastructure in marginal areas where local breeds are often found may impair the introduction of breeding programs, and the development of the infrastructure may be costly. Additionally, organizational and infrastructural shortcomings are often associated to local breeds and varieties.
Quantitative Genetics Theory365体育网站: One of the challenges faced by breeders is that many traits, and sometime the most “important” ones, deviate from that ideal system, because of gene interactions (essentially dominance) that are often evidenced for traits related to fitness. Statistical efficiency has indeed increased considerably, owing to the possibility to analyze samples of enormous size with proper computing algorithms. This is sometimes done at the expense of a reduction of the number of parameters in the model, as can be seen with the restricted maximum likelihood-animal model estimations, which frequently lead to “under-parameterizations.” Quantitative genetics theory should otherwise be able to accommodate even more complex situations than simple dominance effects.
The CBD, Nagoya protocol, and ABS issues behind the research and business of breeding: Breeding can be sustained by business, but the associated questions are: whose business, or who is making the profits? Breeds and varieties improvement is the result of complex interactions between various economic agents, and the sharing of benefits among them has always been problematic. The ultimate objective of breeding is more efficient production and products better adapted to market conditions that maximize the profit of the producer. But efficient production has resulted in lower market prices, which implies that the benefits have essentially been for the consumers. Profit of the breeding organizations should also be taken into account.
Prioritizing the breeding programs365体育网站: Formulation and execution of breeding programmes is typically top-down. The execution of the states’ level policies in developing countries typically fails due to a lack of prioritization of the breeding program, low outreach of the schemes, along with inadequacy of funds and infrastructure.
Lack of strong performance control policy in crop and livestock: A successful breeding program requires discarding low producing breeds and varieties to restrict their gene flow to the next generation. Crop and livestock with low productivity are a great burden as they compete for nutritional resources with higher yielding ones. A rigorous selection policy is required.
Lack of livestock identification system: The absence of livestock identification system severely hampers the data recording in field, resulting in failure to execute the selection schemes and also to quantify the impact of improvement programmes.
A gap between projects’ objectives and ground reality: Most often in developing countries, the breeding programs objectives are decided at the top level of administration but the real stakeholders seldom care for that. Therefore, farmers get no incentive, as a result they do not show any interest in data recording, selection, and the use of germplasm considered superior by governmental agencies that operate breeding programmes.
Failure to identify the market priorities: This also affects the success of the breeding program.
Need of skilled manpower in livestock breeding programs: Breeding with cutting-edge technologies needs highly skilled manpower at every step of its execution. The economic challenge for the governments is hiring such staff for the execution of the breeding program. Despites the progress made in breeding sciences over the previous decades, the demand for skilled livestock and plant breeders remains very high (Alberts et al. 2014; Jones 2014) due to the stagnation in research and capacity building funding (Butler 2008).
Breeding involves a major investment in people, technology, and facilities: Research and development take place over many years, with no guarantee of success. Developing an individual breed, line, or variety could be expensive. For example, the cost of maintaining a competitive United Kingdom wheat breeding program is estimated at £1.5 to £2 million per year. The breeder’s principal return to fund for the ongoing process of agricultural improvement is a royalty on seed or breeding stock used with only breed and varieties which succeed in the marketplace being rewarded.
Lack of long-term policies: Well-considered breeding plans are needed to develop breeds that have a higher production while maintaining climate adaptive qualities. In most developed countries, lack of long-term policies is more often a handicap for the implementation of breeding programs. In practice, this seems to be hard to organize, especially when government interest and government investments are limited.
The sustainable approach is to bridge public, private, and consumers interests in breeding programs that could be built on public-private-partnerships and promotion for the investments of leading breeding companies in tropical countries or countries with extreme or variable climates. This approach has the potential to address the challenges related to lack of sustainable funding while at the same time meeting the interest of all stakeholders.
It is crucial for academic and research sectors, industry, and governments to work together to remind the public and investors that food security cannot be taken for granted, and to inspire more of our brightest young people to pursue careers in breeding sciences.
Establishment of progeny testing program for indigenous breeds: Indigenous and orphan crops and livestock with relatively low production potential have been largely neglected. Progeny testing is essentially required for accurate selection of the best germplasm. Traits of importance (milk, meat, and egg yield and quality, tick or disease resistance or resilience, heat tolerance, somatic cells score, etc.) should be included in a selection program depending on the local need and utility of the breed. However, such effective program needs extensive infrastructure for its implementation.
Development of Community-based breeding programs (CBBP): The model of CBBP has proven beneficial in developing countries context. The CBBP can help make the breeding programs a self-sustaining commercial activity in the developing world.
365体育网站Integration of information technology CBBP: Tools that can guide the farmers for choosing the best animal or crops are not so common. A mobile and web-based platform for breeds and varieties database management system for collection of data related to all aspects of production system will support selection decision. This is essential for real time evaluation of breeding programs.
365体育网站Tailored high-end reproductive technology: High-end reproductive biotechnology is required to accelerate the multiplication of the outstanding crops and livestock. This will help to tackle the problem of disposal of unwanted individuals and will increase the number of offspring per parent under progeny testing for accurate evaluation. Although the available technology is still in its infancy and also costly, the gains offered are tremendous.
Genomic selection (GS) in breeding programs for higher coverage and better accuracy: One of the major problems with the genetic evaluation program in developing countries is lack of pedigree records. This restricts the inclusion of sufficient numbers of individuals in each genetic evaluation program. With the advent of GS, many animals without pedigree can be included in the selection program for more intense selection, increasing accuracy and reducing generation interval.
The need for selection programs in small animal breeds: The inferior economic performance of a breed leads to decreased interest among farmers and its eventually extinction. Therefore, some approach to selection is needed to increase economic performance: more output, less costs. In principle, all livestock breeds should be able to benefit from the advances in animal breeding and improvement.
Strengthening of existing physical infrastructure: Across Africa, a number of breeding infrastructures exist under private government ownership. There is an urgent need to strengthen these facilities for effective utilization. The co-operatives, NGOs, farmers’ organizations, and other private organizations can be associated with this scheme. Linkages of these organizations with advanced agricultural research institutes can help for further strengthening of these structures. This will go along side with capacity development in big data management to be able to extract the best information generated by the already existing high-throughput approaches in all –omics disciplines.
365体育网站Investment must be made for more, and better, data collection, helping breeders to work more closely with farmers and other relevant science domains to increase the quality and availability of livestock and plant phenotypic data will increase the potential of genomic informed breeding and productivity improvement. These data should be made available to the broader scientific community to avoid unnecessary duplication.
Additional research on the application of genomic selection (GS) in breeding programs is extremely desirable. It is expected that this approach will advance selection routines, especially in species with long reproduction cycles, late or sex-limited or costly trait recording and for complex traits. Integrating GS into existing breeding agendas is, however, not forthright. Despite successful integration into breeding programs as exemplified in dairy cattle, it has yet to be shown how much emphasis can be given to the genomic information and how much additional phenotypic information is needed from new selection candidates to boost productivity. Genomic selection is already part of future planning in many crops and livestock breeding companies, but further research is needed to fully estimate how effective the use of genomic information will be for the prediction of the performance of future breeding stock. Genomic prediction of production in crossbreeding and across-breed schemes, costs and choice of individuals for genotyping are reasons for a reluctance to fully rely on genomic information for selection decisions. Breeding objectives remain highly dependent on the industry and the additional gain when using genomic information must be considered judiciously. Also, the public should be more educated on the possible advantages of modern breeding tools for sustainable food safety and security.
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