John E. Bradshaw – författare

The potato (Solanum tuberosum) is the world’s fourth most important food crop after maize, rice and wheat with 377 million tonnes fresh-weight of tubers produced in 2016 from 19.2 million hectares of land, in 163 countries, giving a global average yield of 19.6 t ha-1 (http://faostat.fao.org). About 62% of production (234 million tonnes) was in Asia (191), Africa (25) and Latin America (18) as a result of steady increases in recent years, particularly in China and India. As a major food crop, the potato has an important role to play in the United Nations “2030 Agenda for Sustainable Development” which started on 1 January 2016 (http://faostat.fao.org). By 2030 the aim is to “ensure access by all people, in particular the poor and people in vulnerable situations, including infants, to safe, nutritious and sufficient food all year round”. By then, the world population is expected to reach 8.5 billion and continue to increase to 9.7 billion in 2050. For potatoes, theneed is to increase production and improve nutritional value during a period of climate change, a key aspect of which will be the breeding of new cultivars for a wide range of target environments and consumers.

The aim of the book is to help this endeavour by providing detailed information in three parts on both the theory and practice of potato breeding. Part I deals with the history of potato improvement and with potato genetics. Part II deals with breeding objectives, divided into improving yield, quality traits and resistance to the most important diseases and pests of potatoes. Part III  deals with breeding methods: first, the use of landraces and wild relatives of potato in introgression breeding, base broadening and population improvement; second, breeding clonally propagated cultivars as a way to deliver potato improvement to farmers’ fields; third, as an alternative, breeding potato cultivars for propagation through true potato seed; and fourth, gene editing and genetic transformation as ways of making further improvements to already successful and widely grown cultivars. Included are marker-assisted introgression and selection of specific alleles, genomic selection of many unspecified alleles and diploid F1 hybrid breeding.

By 2050 the United Nations (UN) predicts a world population of 9.7 billion compared with 8 billion in 2022. Increases in food and energy production and the supply of fresh water will be needed to sustain this population, whilst reducing greenhouse gas emissions to limit global warming. The average global temperature is likely to be 2 to 3 degrees Celsius above that in pre-industrial times, unless there is a greater sense of urgency following the UN Climate Change Conference (COP26) in Glasgow in 2021, which still wanted to limit the rise to 1.5 degrees. There is also increasing concern about the loss of biodiversity on Earth from human activity, including farming, as seen in the outcomes of the UN Biodiversity Conference (COP15) in Montreal in 2022. More encouragingly, on 1 December 2023, 134 countries at COP28 in Dubai endorsed the landmark sustainable agriculture, resilient food systems and climate action declaration which put food systems transformation on the global climate agenda. “While food systems are vital for meeting societal needs and enabling adaptation to climate impacts, they are also responsible for as much as a third of global greenhouse gas emissions.” A warmer climate and loss of biodiversity will make life more difficult for humankind; but can potatoes at least help with food security? It is a scientific and technological question set in a political, economic and societal context. It has arisen because potatoes have made the journey from wild species to global food crop. The contribution of the potato to the United Nations Millennium Development Goals of providing food security and eradicating poverty was recognized when an International Year of the Potato 2008 (IYP 2008) was officially launched at the United Nations (UN) headquarters in New York on 18 October 2007 by the Director-General of FAO (Food and Agriculture Organization of the United Nations).

Today the importance of potatoes can be seen in the context of the United Nations “2030 Agenda for Sustainable Development” which was adopted in 2015 and started on 1 January 2016. The agenda has 17 goals, the second of which (SDG2) is to end hunger, achieve food security and improved nutrition, and promote sustainable agriculture. By 2030, the aim of the agenda is to ‘ensure access by all people, in particular the poor and people in vulnerable situations, including infants, to safe, nutritious and sufficient food all year round’. However, the projection in the 2023 Sustainable Development Goals Report was not zero-hunger but 600 million people still facing hunger. Hence a greater sense of urgency is required and also a need to look beyond 2030 to 2050. This book explores how potatoes can contribute to SDG2 by increasing potato production and improving the nutritional value of potatoes, in particular to alleviate micronutrient deficiencies (‘hidden hunger’), having first explained how potatoes became a major food crop and the lessons to be learnt from a major crop failure and resulting famine.

This book aims to help plant breeders by reviewing past achievements, currently successful practices, and emerging methods and techniques. Theoretical considerations are also presented to strike the right balance between being as simple as possible but as complex as necessary.

The United Nations predicts that the global human population will continue rising to 9.0 billion by 2050. World food production will need to increase between 70-100 per cent in just 40 years. First generation bio-fuels are also using crops and cropland to produce energy rather than food. In addition, land area used for agriculture may remain static or even decrease as a result of degradation and climate change, despite more land being theoretically available, unless crops can be bred which tolerate associated abiotic stresses. Lastly, it is unlikely that steps can be taken to mitigate all of the climate change predicted to occur by 2050, and beyond, and hence adaptation of farming systems and crop production will be required to reduce predicted negative effects on yields that will occur without crop adaptation. Substantial progress will therefore be required in bridging the yield gap between what is currently achieved per unit of land and what should be possible in future, with the best farming methods and best storage and transportation of food, given the availability of suitably adapted cultivars, including adaptation to climate change. My book is divided into four parts: Part I is an historical introduction; Part II deals with the origin of genetic variation by mutation and recombination of DNA; Part III explains how the mating system of a crop species determines the genetic structure of its landraces; Part IV considers the three complementary options for future progress: use of sexual reproduction in further conventional breeding, base broadening and introgression; mutation breeding; and genetically modified crops.