Robin D. Graham
Bio: Robin D. Graham is an academic researcher from University of Adelaide. The author has contributed to research in topics: Hordeum vulgare & Shoot. The author has an hindex of 55, co-authored 157 publications receiving 12027 citations.
Papers published on a yearly basis
TL;DR: The world's agricultural community should adopt plant breeding and other genetic technologies to improve human health, and the world's nutrition and health communities should support these efforts.
Abstract: Over three billion people are currently micronutrient (i.e. micronutrient elements and vitamins) malnourished, resulting in egregious societal costs including learning disabilities among children, increased morbidity and mortality rates, lower worker productivity, and high healthcare costs, all factors diminishing human potential, felicity, and national economic development. Nutritional deficiencies (e.g. iron, zinc, vitamin A) account for almost two-thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Importantly, these crops can be enriched (i.e. ‘biofortified’) with micronutrients using plant breeding and/ or transgenic strategies, because micronutrient enrichment traits exist within their genomes that can to used for substantially increasing micronutrient levels in these foods without negatively impacting crop productivity. Furthermore, ‘proof of concept’ studies have been published using transgenic approaches to biofortify staple crops (e.g. high b-carotene ‘golden rice’ grain, high ferritin-Fe rice grain, etc). In addition, micronutrient element enrichment of seeds can increase crop yields when sowed to micronutrient-poor soils, assuring their adoption by farmers. Bioavailability issues must be addressed when employing plant breeding and/or transgenic approaches to reduce micronutrient malnutrition. Enhancing substances (e.g. ascorbic acid, S-containing amino acids, etc) that promote micronutrient bioavailability or decreasing antinutrient substances (e.g. phytate, polyphenolics, etc) that inhibit micronutrient bioavailability, are both options that could be pursued, but the latter approach should be used with caution. The world’s agricultural community should adopt plant breeding and other genetic technologies to improve human health, and the world’s nutrition and health communities should support these efforts. Sustainable solutions to this enormous global problem of ‘hidden hunger’ will not come without employing agricultural approaches.
TL;DR: The case for and the rationale behind the project that is underway to improve the micronutrient quality of some staple food crops is reviewed, an overview of the results to date is given, and the critical issues that still remain to be confronted are looked at.
Abstract: Five years ago, with international funding, several international agricultural research centers set out to explore the potential to improve the micronutrient quality of some staple food crops Five objectives were identified, and all needed a favorable result if breeding for higher micronutrient density in the staples were to be deemed feasible Useful genetic variation to exploit was needed The traits needed to be manageable in a breeding program (simple screening and high heritability), and stable across a wide range of environments if impact was to be large Above all, the traits needed to be combinable with traits for high yield to ensure that farmers chose the improved lines Finally, it was necessary to show that the new types actually improved the health of humans of low nutrient status representing the target populations The extra nutrients needed to be bioavailable to the gut Today, only this last essential criterion remains to be fully satisfied All other criteria are met to levels that lead us to claim that breeding for nutritional quality is a viable, practicable, and cost-effective strategy to complement existing interventionist strategies Subject to satisfying the last criterion, and results are encouraging, we call for a major funding initiative, and the installation of a new paradigm for 21st century agriculture: one espousing food systems that are highly productive, sustainable, and nutritious This paper reviews the case for and the rationale behind the project that is underway, gives an overview of the results to date and looks at the critical issues that still remain to be confronted
TL;DR: It is suggested that ways in which agriculture can contribute to finding sustainable solutions to food system failures through holistic food-based system approaches, thereby closely linking agricultural production to improving human health, livelihood and well being are considered.
Abstract: Micronutrient malnutrition (‘Hidden Hunger’) now afflicts over two billion people worldwide, resulting in poor health, low worker productivity, high rates of mortality and morbidity, increased rates of chronic diseases (coronary heart disease, cancer, stroke, and diabetes), and permanent impairment of cognitive abilities of infants born to micronutrient-deficient mothers. The consequences of food system failures include lethargic national development efforts, continued high population growth rates, and a vicious cycle of poverty for massive numbers of underprivileged people in all nations. Our food systems are failing us globally by not providing enough balanced nutrient output to meet all the nutritional needs of every person, especially resource-poor women, infants and children in developing countries. Agriculture is partly responsible because it has never held nutrient output as an explicit goal of its production systems. Indeed, many agricultural policies have fostered a decline in nutrition and diet diversity for the poor in many countries. Nutrition and health communities are also partly responsible because they have never considered using agriculture as a primary tool in their programs directed at alleviating poor nutrition and ill health globally. Now is the time for a new paradigm for agriculture and nutrition. We must consider ways in which agriculture can contribute to finding sustainable solutions to food system failures through holistic food-based system approaches, thereby closely linking agricultural production to improving human health, livelihood and well being. Such action will stimulate support for agricultural research in many developed countries because it addresses consumer issues as well as agricultural production issues and is, therefore, politically supportable. # 1999 Elsevier Science B.V. All rights reserved.
TL;DR: This article reviewed current and past efforts in breeding for industrial quality (processing, malting, baking, extruding, etc.) as a prelude to discussion of the criteria that need to be met in breeding programs to improve the nutritional quality of crops for human consumption.
Abstract: Current and past efforts in breeding for industrial quality (processing, malting, baking, extruding, etc.), as opposed to yield, are reviewed as a prelude to discussion of the criteria that need to be met in breeding programs to improve the nutritional quality of crops for human consumption. In field crops, almost no attempts to improve nutritional value have been made. Recent studies in fact indicate that most criteria can be easily satisfied: existence of sufficient genetic variation, suitable selection methods and markers, workable heritabilities, and compelling reasons for doing so. However, establishing the efficacy in deficient human populations of elite material chosen by simple selection criteria is a major challenge that requires collaboration with human nutritionists. In some cases, developing marketing strategies for nutritionally superior types that may not – by color or other characteristics – appeal to target communities is also an issue breeders must bear in mind. Nevertheless, the fact recently established that desirable traits can be combined with high yield overcomes many obstacles. The widely demonstrated acceptance of new cultivars by farmers, in developing as well as industrialized countries, will ensure high impact of worthwhile improvements in nutritional value. To combine these new traits with high yield will increase the cost of breeding programs considerably, but the benefit–cost ratio is likely to be larger also.
University of Adelaide1, Agricultural Research Service2, International Maize and Wheat Improvement Center3, International Food Policy Research Institute4, International Potato Center5, International Fertilizer Development Center6, International Center for Tropical Agriculture7, Cornell University8, International Crops Research Institute for the Semi-Arid Tropics9
TL;DR: In this article, a conceptual framework is proposed to widen the range of tools and strategies that could be adopted in the HarvestPlus Challenge Program to achieve its goals of eliminating micronutrient deficiencies in the food systems of resource-poor countries.
Abstract: The major subsistence food systems of the world that feed resource‐poor populations are identified and their capacity to supply essential nutrients in reasonable balance to the people dependent on them has been considered for some of these with a view to overcoming their nutrient limitations in sound agronomic and sustainable ways. The approach discusses possible cropping system improvements and alternatives in terms of crop combinations, external mineral supply, additional crops, and the potential for breeding staples in order to enhance their nutritional balance while maintaining or improving the sustainability and dietary, agronomic, and societal acceptability of the system. The conceptual framework calls for attention first to balancing crop nutrition that in nearly every case will also increase crop productivity, allowing sufficient staple to be produced on less land so that the remaining land can be devoted to more nutrient‐dense and nutrient‐balancing crops. Once this is achieved, the additional requirements of humans and animals (vitamins, selenium, and iodine) can be addressed. Case studies illustrate principles and strategies. This chapter is a proposal to widen the range of tools and strategies that could be adopted in the HarvestPlus Challenge Program to achieve its goals of eliminating micronutrient deficiencies in the food systems of resource‐poor countries.
TL;DR: In this article, the range of heavy metals, their occurrence and toxicity for plants, and their effects on the ecosystem is discussed, where the authors focus mainly on zinc, cadmium, copper, mercury, chromium, lead, arsenic, cobalt, nickel, manganese and iron.
Abstract: Metal contamination issues are becoming increasingly common in India and elsewhere, with many documented cases of metal toxicity in mining industries, foundries, smelters, coal-burning power plants and agriculture. Heavy metals, such as cadmium, copper, lead, chromium and mercury are major environmental pollutants, particularly in areas with high anthropogenic pressure. Heavy metal accumulation in soils is of concern in agricultural production due to the adverse effects on food safety and marketability, crop growth due to phytotoxicity, and environmental health of soil organisms. The influence of plants and their metabolic activities affects the geological and biological redistribution of heavy metals through pollution of the air, water and soil. This article details the range of heavy metals, their occurrence and toxicity for plants. Metal toxicity has high impact and relevance to plants and consequently it affects the ecosystem, where the plants form an integral component. Plants growing in metal-polluted sites exhibit altered metabolism, growth reduction, lower biomass production and metal accumulation. Various physiological and biochemical processes in plants are affected by metals. The contemporary investigations into toxicity and tolerance in metal-stressed plants are prompted by the growing metal pollution in the environment. A few metals, including copper, manganese, cobalt, zinc and chromium are, however, essential to plant metabolism in trace amounts. It is only when metals are present in bioavailable forms and at excessive levels, they have the potential to become toxic to plants. This review focuses mainly on zinc, cadmium, copper, mercury, chromium, lead, arsenic, cobalt, nickel, manganese and iron.
TL;DR: The principles, advantages and disadvantages of immobilization, soil washing and phytoremediation techniques which are frequently listed among the best demonstrated available technologies for cleaning up heavy metal contaminated sites are presented.
Abstract: Scattered literature is harnessed to critically review the possible sources, chemistry, potential biohazards and best available remedial strategies for a number of heavy metals (lead, chromium, arsenic, zinc, cadmium, copper, mercury and nickel) commonly found in contaminated soils. The principles, advantages and disadvantages of immobilization, soil washing and phytoremediation techniques which are frequently listed among the best demonstrated available technologies for cleaning up heavy metal contaminated sites are presented. Remediation of heavy metal contaminated soils is necessary to reduce the associated risks, make the land resource available for agricultural production, enhance food security and scale down land tenure problems arising from changes in the land use pattern.
TL;DR: In this paper, the authors give an overview of those chemical processes that are directly induced by plant roots and which can affect the concentration of P in the soil solution and, ultimately, the bioavailability of soil inorganic P to plants.
Abstract: In most soils, inorganic phosphorus occurs at fairly low concentrations in the soil solution whilst a large proportion of it is more or less strongly held by diverse soil minerals. Phosphate ions can indeed be adsorbed onto positively charged minerals such as Fe and Al oxides. Phosphate (P) ions can also form a range of minerals in combination with metals such as Ca, Fe and Al. These adsorption/desorption and precipitation/dissolution equilibria control the concentration of P in the soil solution and, thereby, both its chemical mobility and bioavailability. Apart from the concentration of P ions, the major factors that determine those equilibria as well as the speciation of soil P are (i) the pH, (ii) the concentrations of anions that compete with P ions for ligand exchange reactions and (iii) the concentrations of metals (Ca, Fe and Al) that can coprecipitate with P ions. The chemical conditions of the rhizosphere are known to considerably differ from those of the bulk soil, as a consequence of a range of processes that are induced either directly by the activity of plant roots or by the activity of rhizosphere microflora. The aim of this paper is to give an overview of those chemical processes that are directly induced by plant roots and which can affect the concentration of P in the soil solution and, ultimately, the bioavailability of soil inorganic P to plants. Amongst these, the uptake activity of plant roots should be taken into account in the first place. A second group of activities which is of major concern with respect to P bioavailability are those processes that can affect soil pH, such as proton/bicarbonate release (anion/cation balance) and gaseous (O2/CO2) exchanges. Thirdly, the release of root exudates such as organic ligands is another activity of the root that can alter the concentration of P in the soil solution. These various processes and their relative contributions to the changes in the bioavailability of soil inorganic P that can occur in the rhizosphere can considerably vary with (i) plant species, (ii) plant nutritional status and (iii) ambient soil conditions, as will be stressed in this paper. Their possible implications for the understanding and management of P nutrition of plants will be briefly addressed and discussed.
TL;DR: An overview of the nutritional requirements of different plants for Ca is provided, and how this impacts on natural flora and the Ca content of crops is reviewed.
Abstract: Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter-cation for inorganic and organic anions in the vacuole, and the cytosolic Ca2+ concentration ([Ca2+]cyt) is an obligate intracellular messenger coordinating responses to numerous developmental cues and environmental challenges. This article provides an overview of the nutritional requirements of different plants for Ca, and how this impacts on natural flora and the Ca content of crops. It also reviews recent work on (a) the mechanisms of Ca2+ transport across cellular membranes, (b) understanding the origins and specificity of [Ca2+]cyt signals and (c) characterizing the cellular [Ca2+]cyt-sensors (such as calmodulin, calcineurin B-like proteins and calcium-dependent protein kinases) that allow plant cells to respond appropriately to [Ca2+]cyt signals.
TL;DR: Plant breeding strategy (e.g., genetic biofortification) appears to be a most sustainable and cost-effective approach useful in improving Zn concentrations in grain, and application of Zn fertilizers or Zn-enriched NPK fertilizers offers a rapid solution to the problem.
Abstract: Zinc deficiency is a well-documented problem in food crops, causing decreased crop yields and nutritional quality. Generally, the regions in the world with Zn-deficient soils are also characterized by widespread Zn deficiency in humans. Recent estimates indicate that nearly half of world population suffers from Zn deficiency. Cereal crops play an important role in satisfying daily calorie intake in developing world, but they are inherently very low in Zn concentrations in grain, particularly when grown on Zn-deficient soils. The reliance on cereal-based diets may induce Zn deficiency-related health problems in humans, such as impairments in physical development, immune system and brain function. Among the strategies being discussed as major solution to Zn deficiency, plant breeding strategy (e.g., genetic biofortification) appears to be a most sustainable and cost-effective approach useful in improving Zn concentrations in grain. The breeding approach is, however, a long-term process requiring a substantial effort and resources. A successful breeding program for biofortifying food crops with Zn is very much dependent on the size of plant-available Zn pools in soil. In most parts of the cereal-growing areas, soils have, however, a variety of chemical and physical problems that significantly reduce availability of Zn to plant roots. Hence, the genetic capacity of the newly developed (biofortified) cultivars to absorb sufficient amount of Zn from soil and accumulate it in the grain may not be expressed to the full extent. It is, therefore, essential to have a short-term approach to improve Zn concentration in cereal grains. Application of Zn fertilizers or Zn-enriched NPK fertilizers (e.g., agronomic biofortification) offers a rapid solution to the problem, and represents useful complementary approach to on-going breeding programs. There is increasing evidence showing that foliar or combined soil+foliar application of Zn fertilizers under field conditions are highly effective and very practical way to maximize uptake and accumulation of Zn in whole wheat grain, raising concentration up to 60 mg Zn kg−1. Zinc-enriched grains are also of great importance for crop productivity resulting in better seedling vigor, denser stands and higher stress tolerance on potentially Zn-deficient soils. Agronomic biofortification strategy appears to be essential in keeping sufficient amount of available Zn in soil solution and maintaining adequate Zn transport to the seeds during reproductive growth stage. Finally, agronomic biofortification is required for optimizing and ensuring the success of genetic biofortification of cereal grains with Zn. In case of greater bioavailability of the grain Zn derived from foliar applications than from soil, agronomic biofortification would be a very attractive and useful strategy in solving Zn deficiency-related health problems globally and effectively.