Adaptation In Plant Breeding

Plant adaptation is a fundamental process in plant breeding. It was the first criterion in the initial domestication of plants thousands of years ago. Adaptedness is generally a quantitative complex feature of the plant, involving many traits, many of which are quantitative. Adaptation to stresses like cold, drought or diseases are among the most central problems in a world grappling with global food security. Modern plant breeding, based on mendelian genetics, has made plant improvement more effective and more precise and selective. Molecular genetics and genetic engineering has considerably increased this selectivity down to single genes affecting single traits. The time has come when plant breeding efficiency may cause loss of genetic resources and adaptation. In these proceedings an effort is made to merge modern plant breeding efficiency with ecological aspects of plant breeding, reflected in adaptation. It is hoped that this merger results in more sustainable use of genetic resources and physical environments. The book is based on 10 keynotes addressing a wide spectrum of themes related to adaptation. In addition each subject is further elaborated in up to three case studies on particular plant species or groups of plants. The keynotes do in fact overlap to some degree and there are articles in this volume that seemingly contradict each other, a common aspect in advanced fields of research. The keen reader may conclude that, in a world where climates and environments are under continuous change and where human society is more and more polarized into a developed and a developing part, adaptation of our cultivated plants has different constraints on yields depending on ecology, and indeed economy.

An overview of crop improvement; Analysis of genotype by environment interactions; Interpretation of genotype by environment interactions; Integrated approaches to plant improvement; Synthesis of strategies for crop improvement.

In this major 1993 work, Lloyd Evans provides an integrated view of the domestication, adaptation and improvement of crop plants, bringing together genetic diversity, plant breeding, physiology and aspects of agronomy. Considerations of yield and maximum yield provide continuity throughout the book. Food, feed, fibre, fuel and pharmaceutical crops are all discussed. Cereals, grain legumes and root crops, both temperate and tropical, provide many of the examples, but pasture plants, oilseeds, leafy crops, fruit trees and others are also considered. After the introductory chapter, the increasing significance of crop yields to the world's food supply is highlighted. The next three chapters consider changes to crop plants over the last ten thousand years, including domestication, adaptation and improvement. Aimed at research workers and advanced students in crop physiology and ecology, agronomy and plant breeding, this book also reaches conclusions of relevance to those concerned with developmental policy, agricultural research and management, environmental quality, resource depletion and human history.

The Indian Society of Genetics and Plant Breeding was established in 1941 in recognition of the growing contribution of improved crop varieties to the country's agriculture. Scientific plant breeding had started inIndia soon after the rediscovery of Mendel's laws of heredity. The Indian Agricultural Research Institute set up in 1905 and a number of Agricultural Colleges in different parts of the country carried out some of the earliest work mostly inthe form of pure-line selections. In subsequent years, hybridization programmes in crops like wheat, rice, oilseeds, grain legumes, sugarcane and cotton yielded a large number of improved cultivars with significantly higher yields. A turning point came in the 1960s with the development of hybrids in several crops including inter-specific hybrids in cotton. And when new germplasm with dwarfing genes became available in wheat and rice from CIMMYT and IRRI, respectively,Indian plant breeders quickly incorporated these genes into the genetic background of the country's widely grown varieties with excellent grain quality and other desirable traits. This was to mark the beginning of modem agriculture in India as more and more varieties were developed, characterized by a high harvest index and response to modem farm inputs like the inorganic fertilizers . India's green revolution which has led to major surpluses offood grains and othercommodities like sugar and cotton has been made possible by the work of one of the largest groups of plant breeders working in a coordinated network.

This publication opens with the inevitable introduction, moves on to the present traditional approach to breeding for yield stability, and then enumerates a detailed discussion of the physiological approach to breeding for resistance to specific stresses. Not all environmental stresses are covered, omitting those for which little can be said today on practical breeding solutions.

Our requirement for plant breeders to be successful has never been greater. However one views the forecasted numbers for future population growth we will need, in the immediate future, to be feeding, clothing and housing many more people than we do, inadequately, at present. Plant breeding represents the most valuable strategy in increasing our productivity in a way that is sustainable and environmentally sensitive. Plant breeding can rightly be considered as one of the oldest multidisciplinary subjects that is known to humans. It was practised by people who first started to carry out a settled form of agriculture. The art, as it must have been at that stage, was applied without any formal underlying framework, but achieved dramatic results, as witnessed by the forms of cultivated plants we have today. We are now learning how to apply successfully the results of yet imperfect scientific knowledge. This knowledge is, however, rapidly developing, particularly in areas of tissue culture, biotechnology and molecular biology. Plant breeding's inherent multifaceted nature means that alongside obvious subject areas like genetics we also need to consider areas such as: statistics, physiology, plant pathology, entomology, biochemistry, weed science, quality, seed characteristics, repro ductive biology, trial design, selection and computing. It therefore seems apparent that modern plant breeders need to have a grasp of wide range of scientific knowledge and expertise if they are successfully to a exploit the techniques, protocols and strategies which are open to them.

Latest figures suggest that approximately 20% of the world's population of six billion is malnourished because of food shortages and inadequate distrib ution systems. To make matters worse, it is estimated that some 75 billion metric tons of soil are removed annually from the land by wind and soil ero sion, much of it from agricultural land, which is thereby rendered unsuitable for agricultural purposes. Moreover, out of a total land area under cultivation 9 6 of approximately 1. 5 x 10 ha, some 12 x 10 ha of arable land are destroyed and abandoned worldwide each year because of unsustainable agricultural practices. Add to this the fact that the world population is increasing at the rate of a quarter of a million per day, and the enormity of the task ahead becomes apparent. To quote the eminent wheat breeder E. R. Sears, It seems clear that plant geneticists can look forward to an expanded role in the 21st century, particularly in relation to plant improvement. The suc cess of these efforts may go a long way towards determining whether the world's increasing billions of humans will be adequately fed. Food for an ever-increasing population will have to be produced not only from an ever-diminishing, but from what will become an ever-deteriorating land resource unless justifiable environmental concerns are taken into account.