Physiological and molecular wheat breeding
Encyclopedia
Plant breeding
is the process of improving the heredity
of plants for benefit of humankind. In evolutionary concept, plant breeding is merely a continuation of the natural evolution of the crop species, changing its course of direction in the benefit of greater use to humanity.
This also be defined as science of selection – plant breeding is essentially an election made by man of the best plants within a variable population as a potential cultivar. In other words plant breeding is a "selection
" made possible by the existence of variability. Selections become the earliest form of plant breeding.
, and incorporation of genes
via plant transformation. Molecular markers have enabled the identification of genes or genomic regions associated with the expression of qualitative and quantitative traits and made manipulating genomic regions feasible through marker assisted selection
. Molecular marker applications have also helped us understand the physiological parameters controlling
plant responses to biotic and abiotic stress or, more generally, those involved in plant development.
) and marker assisted selection
. Such changes aim to alter the physiological pathways through change in genetic structures. There are many successful examples of such kind.
Plant breeding
Plant breeding is the art and science of changing the genetics of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular...
is the process of improving the heredity
Heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...
of plants for benefit of humankind. In evolutionary concept, plant breeding is merely a continuation of the natural evolution of the crop species, changing its course of direction in the benefit of greater use to humanity.
This also be defined as science of selection – plant breeding is essentially an election made by man of the best plants within a variable population as a potential cultivar. In other words plant breeding is a "selection
Selection
In the context of evolution, certain traits or alleles of genes segregating within a population may be subject to selection. Under selection, individuals with advantageous or "adaptive" traits tend to be more successful than their peers reproductively—meaning they contribute more offspring to the...
" made possible by the existence of variability. Selections become the earliest form of plant breeding.
Physiological and molecular wheat breeding
Plant breeding has traditionally applied a trial-and-error approach in which large numbers of crosses are made from many sources of parental germplasm. Progenies are evaluated for characters of direct economic interest (e.g., grain yield and grain quality) in target environments. Good performing parental germplasm, crosses, and progenies are selected for further use or testing. In many programs “breakthroughs” in improvement are made simply by finding superior sources of parental germplasm among the numerous sources tested. This conceptually simple approach has been highly successful in many crop species and numerous breeding programs. The approach has often succeeded in the absence of in-depth knowledge about the physiological basis for superior performance. In some crops such knowledge has been obtained by doing retrospective analyses of prior genetic gains. Breeders have not applied this knowledge to a significant extent as a guide to further improvements, but instead have taken any avenue of improvement that happens to arise from direct selection for yield and economic performance. However with increased population, there is need to increase yield further and breeding require more scientific approaches to handle the problem.Genetic basis of physiological traits
During the past two decades, molecular tools have aided tremendously in the identification, mapping, and isolation of genes in a wide range of crop species. The vast knowledge generated through the application of molecular markers has enabled scientists to analyze the plant genome and have better insight as to how genes and pathways controlling important biochemical and physiological parameters are regulated. Three areas of biotechnology have had significant impact: the application of molecular markers, tissue cultureTissue culture
Tissue culture is the growth of tissues or cells separate from the organism. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, such as broth or agar...
, and incorporation of genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
via plant transformation. Molecular markers have enabled the identification of genes or genomic regions associated with the expression of qualitative and quantitative traits and made manipulating genomic regions feasible through marker assisted selection
Marker assisted selection
Marker assisted selection or marker aided selection ' is a process whereby a marker is used for indirect selection of a genetic determinant or determinants of a trait of interest...
. Molecular marker applications have also helped us understand the physiological parameters controlling
plant responses to biotic and abiotic stress or, more generally, those involved in plant development.
Molecular wheat breeding
Molecular wheat breeding is application of biotechnological tools in wheat improvement such as gene transfor (genetic engineeringGenetic engineering
Genetic engineering, also called genetic modification, is the direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest...
) and marker assisted selection
Marker assisted selection
Marker assisted selection or marker aided selection ' is a process whereby a marker is used for indirect selection of a genetic determinant or determinants of a trait of interest...
. Such changes aim to alter the physiological pathways through change in genetic structures. There are many successful examples of such kind.
Physiological traits for abiotic stress tolerance breeding
- Physiological Traits to Improve the Yield of Rainfed Wheat: Can Molecular Genetics Help CIMMYT site link
- Evaluating Potential Genetic Gains in Wheat Associated with Stress-Adaptive Trait Expression in Elite Genetic Resources under Drought and Heat Stress Crop science
- Setter, T. L., Waters, I., Sharma, S. K., Singh, K. N., Kulshreshtha, N., Yaduvanshi, N. P. S., Ram, P. C., Singh, B. N., Rane, J., McDonald, G., Khabaz-Saberi, H., Biddulph, T. B., Wilson, R., Barclay, I., McLean, R., Cakir, M. Review of wheat improvement for waterlogging tolerance in Australia and India: the importance of anaerobiosis and element toxicities associated with different soils. Annals of Botany, Volume 103(2): 221-235.
Physiological traits for biotic stress tolerance breeding
- M. J. Foulkes, N. D. Paveley, A. Worland, S. J. Welham, J. Thomas, J. W. Snape. Major Genetic Changes in Wheat with Potential to Affect Disease Tolerance. Phytopathology, July, Volume 96, Number 7, Pages 680-688 (doi: 10.1094/PHYTO-96-0680)click link
- Rosyara, U.R., K. Pant, E. Duveiller and R.C. Sharma. 2007. Variation in chlorophyll content, anatomical traits and agronomic performance of wheat genotypes differing in spot blotch resistance under natural epiphytotic conditions. Australasian Plant Pathology 36 : 245–251.
- Rosyara, U.R., R.C. Sharma, and E. Duveiller. 2006. Variation of canopy temperature depression and chlorophyll content in spring wheat genotypes and association with foliar blight resistance. J. Plant Breed. Gr. 1 : 45-52.
- Rosyara, U.R., R.C. Sharma, S.M. Shrestha, and E. Duveiller. 2005. Canopy temperature depression and its association with helminthosporium leaf blight resistance in spring wheat. Journal of Institute of Agriculture and Animal Science 26: 25-28.
- Rosyara, U.R., R.C. Sharma, S.M. Shrestha, and E. Duveiller. 2006. Yield and yield components response to defoliation of spring wheat genotypes with different level of resistance to Helminthosporium leaf blight. Journal of Institute of Agriculture and Animal Science 27. 42-48.
- Rosyara, U. R. 2002. Physio-morphological traits associated with Helminthosporium leaf blight resistance in spring wheat. Masters’ Thesis. Tribhuvan University, Institute of Agriculture and Animal Science, Rampur, Chitwan, Nepal. supported by CIMMYT International. Available at CIMMYT library
Further reading
- Hayward, M. D., N. O. Bosemark, and I. Romangosa. 1993. Plant Breeding: Principle and Prospects. Chapman and Hall, London.
- Wood, D. R., K. M. Rawal, and M. N. Wood (eds). 1983. Crop Breeding. American Society of Agronomy, Crop Science Society of America, Madison, Wisconsin.
- Allard, R. W. 1960. Principles of Plant Breeding. John Wily and Sons Inc. New York.
- Simmonds, N. W. 1979. Principles of Crop Improvement. Longman Group Limited, London.
- Singh, B. D. 2000. Plant Breeding. Sixth ED. Kalyani Publishers, New Delhi.