Improving plants using hybrid vigor module agronomy and. Heterotic groups are created by plant breeders to classify inbred lines, and can be progressively improved by reciprocal recurrent selection. Vigor can be determined by measurement of a number of traits from seed yield and plant. Heterosis performance in industrial and yield components. If true, it should not be possible to obtain an inbred that performs equally as well as the best hybrid bernardo 2002 breeding for quantitative traits in plants pp 243246. Oct 23, 2017 key difference heterosis vs hybrid vigour. Key difference heterosis vs inbreeding depression breeding is a process which is used to create or produce offspring with desired phenotypes. Hybridization is one such technique used to breed crops as well as organisms. In maize hybrid breeding programs, plant breeders usually focus on the utilization of heterosis for grain yield and its related phenotypes 22. Since then, heterosis for yield, its components and quality traits were extensively studied. Department of agriculture, agricultural research service, department of genetics, north carolina state university, raleigh, north carolina 27695.
Plant breeding, application of genetic principles to produce plants that are more useful to humans. Combining ability and heterosis for yield and component characters in maize m. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudooverdominance. The bonus from heterosis should be approximately 5% for production and 10% for mortality, fertility, health and survival. Heterosis or hybrid vigour is the superiority of a hybrid offspring over the average of both its genetically distinct parents. In the late 1990s, it was estimated that 65% of the worldwide maize zea mays area was planted as hybrids. Heterosis definition types of heterosis heterosis in. New technologies on multiple scales are reengineering traditional plant breeding to meet. Janossy a, lupton fgh eds heterosis in plant breeding. The utilization potential of heterosis for maize nue. The converse or complement to inbreeding depression in which the value d a inbreeding can result in loss of vigor, size, etc.
Heterosis and hybrid rice breeding sant singh virmani. Plant and animal breeders exploit heterosis by mating two different purebred lines that have certain desirable traits. The latter was estimated in comparison to commercial varieties. For the evaluation of combining ability and heterosis in the sesame line x tester design was used. Heterosis in tomato was first observed by hedrick and booth 1907 for higher yield and more number of fruits. Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. Heterosis in plant breeding request pdf researchgate. Please view the pdf by using the full text pdf link under view to the left. Salicylic acid, senescence, and heterosis plant physiology. This hybrid vigour, or heterosis, can be manifested in many ways, including.
Plant breeding dates to the very beginnings of agriculture, though scientific plant breeding began only in the early 20th century. Heterosis may be defined as the superiority of an f 1, hybrid over both its parents in terms of yield or some other character heterosis, or hybrid vigour, describes the superior performance of heterozygous hybrid individuals compared with their homozygous parental inbred lines. Learn more about the uses and methods of plant breeding. Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. Reverse breeding rb is a novel plant breeding technique designed to directly produce parental lines for any heterozygous plant, one of the most sought after goals in plant breeding. The f1 hybrid of crosses between different genotypes is often much more vigorous than its parents. Finally, we highlight problems involved in heterosis research and crop. Rb generates perfectly complementing homozygous parental lines through engineered meiosis. Completion of selfpollinated plant breeding for professionals, genetic resources for plant breeding, and outcrossing in plant breeding is recommended.
View enhanced pdf access article on wiley online library html view download pdf for offline viewing. Studies conducted at the international rice research institute irri during 1980 and 1981 have shown up to 73% heterosis, 59% heterobeltiosis and 34% standard heterosis for yield in rice. Quantitative genetics and selection in plant breeding. Difference between heterosis and inbreeding depression. Full text of plant breeding principles and methods see other formats. Institute of plant breeding, seed science and population genetics, university of hohenheim stuttgart, germany. Introduces learners to concepts such as genetic hypotheses for hybrid vigor, quantitative genetics of heterosis, and new tools to study hybrid vigor.
These observations provide strong support for the model that trueoverdominant genes exist and can drive yield heterosis. Concepts and breeding of heterosis in crop plants, the third joint plant breeding symposia, was held on sunday, 3 november 1996 in indianapolis at the. Ppt heterosis powerpoint presentation free to view id. Concepts and breeding of heterosis in crop plants kendall r. The sym posia is held every other year and alternately hosted by the two societies. Despite its importance in maize production, we know surprisingly little about the genetic basis of heterosis. Submitted to submitted by derpartment of genetics and plant breeding, college of agriculture, jau, junagadh. Since genomic selection gs was introduced in plant breeding, its ability to predict the genetic merit of an individual has been evaluated in several crops for. Combining ability and heterosis for yield and component.
One of the fascinating techniques of plant breeding the heterosis, know about the hypothesis and application in plant breeding. Ir36 and ir42 yield 45 tha in wet season trials and 78 tha in dry season trials. Plant breeding is considered as the current phase of crop evolution. As biotechnology developed rapidly, modern techniques of breeding with the modern terminology related to them were introduced to identify these breeding methods. Another aspect in which model systems will remain invaluable is to understand genetic phenomena that are relevant for plant breeding. When two homozygous inbreeds a true breeding line obtained by continuous inbreeding of genetically unlike constituents are crossed together, the resulting hybrids obtained from. Science is the knowledge gathered through scientific method. Hybrid breeding methods are used in maize, sorghum, rice, sugar beet, onion, spinach, sunflowers, broccoli and to create a more psychoactive. Among those who would benefit from taking this session are. To discuss the utilisation of heterosis in plant breeding it is necessary to consider its genetic basis. Heterosis is prevalent for multiple traits in diverse. Sandeep kumar bangarwa the term heterosis was first used by shull in 1914.
Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to methods that make use of knowledge of. Experimental research station of plant breeding, university of hohenheim, maize and sunflower 5. Owing to heterosis hybrid vigor in plants, these hybrids often have superior agricultural performances in yield or disease resistance. Difference between heterosis and hybrid vigour compare the. More generally, heterosis is estimated over the superior parent such heterosis is referred as heterosis. The experiment was conducted during 2018 and 2019 at university of agriculture faisalabad uaf. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Exploring the molecular basis of heterosis for plant breeding liu. Breeding crops with a high yield and superior adaptability is vital to maintaining global food security.
Plant heterosis shouqian feng, xiaoliu chen, shujing wu. Physiological basis of heterosis for nitrogen use efficiency. Dec 10, 2019 in maize hybrid breeding programs, plant breeders usually focus on the utilization of heterosis for grain yield and its related phenotypes 22. Dear colleagues, the phenomenon of heterosis was first described by darwin as having a positive effect on plant traits, as displayed by crossfertilized over selffertilized progenies in the vegetable kingdom. Heterosis breeding and inbreeding depression authorstream. This chapter in concepts and breeding of heterosis in crop plants. Difference between heterosis and hybrid vigour compare.
Breeding techniques of crops and organisms have evolved over the past centuries. Therefore, average heterosis is of little or no use to the plant breeder. Heterosis is used to increase yields, uniformity, and vigor. Heterosis is a term used in genetics and breeding and is also known as hybrid vigor. When two homozygous individuals inbreeds a true breeding line obtained by continuous inbreeding genetically unlike constituents are crossed together, the resulting hybrids obtained from the crossed seeds are usually robust, vigorous, productive and taller than the either parents. In this perspective, we consider that it might be useful to the field to abandon these.
Today, heterosis is extensively exploited without detailed knowledge of the underlying molecular principles. Understanding the various mechanisms by which heterosis arises may facilitate the breeding of hybrids with increased vigor for further crop varieties or species. In this article we will discuss about heterosis or hybrid vigour. The term heterosis was first used by shull in 1914. The book contains a wealth of useful information for practicing hybrid rice breeders, seed producers, researchers, and students of plant breeding. Heterosis, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. Heterosis breeding in eggplant solanum melongena l.
Heterosis and hybrid cultivars in onions springerlink. Oct 04, 2018 introduction to heterosis basic definitions types of heterosis steps for hybrid development calculations for heterosis. Heterosis performance in industrial and yield components of sweet corn. Rohman plant breeding division, bangladesh agricultural research institute joydebpur, gazipur, bangladesh abstract. Springer3 1usdaars, plant genetics research unit, and division of plant sciences, university of missouri, columbia, missouri, united states of america, 2usdaars, u. The development of hybrid varieties differs from hybridization in that no attempt is made to produce a pure breeding population. The scientific method consists of observation, formulation of hypothesis, experimentation and conclusion either to accept or reject the hypothesis. Principles of plant breeding icar ecourse pdf book agrimoon.
Thus, plant breeding is purely science with very little art involved. Vigor can be determined by measurement of a number of traits from seed yield and plant biomass through to biotic and abiotic stress resistance. Ppt heterosis powerpoint presentation free to view. Sep 07, 2014 ii seminar on molecular basis of heterosis in crop plants manjappa ii ph. Shull 1952 coined the term heterosis and defined it as. In cross fertilized plants in which the phenomenon of heterosis is very important, such as maize, it appears that a great part can be explained by the mutation load. In modifying amd developing postgraduate course in genetics and plant breeding, emphasis has been given to keep a balance among major components like basic genetics, cytogenetics, plant breeding, quantitative genetics, molecular biology and biotechnology. However in both autogamous or allogamous plants it is difficult to exclude a role of marginal overdominance which could. During 2018 a total of 21 crosses were developed by using seven lines and 3 testers and during 2019. It has been used to improve the quality of nutrition in products for humans and animals.
Plant breeding is a common practice to develop new varieties and cultivar with beneficial characteristics. Heterosis and inbreeding depression are complementary phenomena, both important to the establishment of breeding strategies, such as conventional hybrids and population breeding. Feb 28, 2017 one of the fascinating techniques of plant breeding the heterosis, know about the hypothesis and application in plant breeding. Heterosis and the nature and combining ability was studied in 7. More branches per panicle and more grains per branch. Heterosis is observed in almost every crop species studied, the application of this phenomenon for its commercial exploitation depends on the expression of the degree of heterosis. Edwards heterosis is the foundation of modern maize breeding programs. A free powerpoint ppt presentation displayed as a flash slide show on id. However, in practical plant breeding the superiority of f1 over mid parent is of no use since it does not offer the hybrid any advantage over the better parent. Heterosis is prevalent for multiple traits in diverse maize germplasm sherry a. Despite such an extensive use in agriculture, the underlying mechanisms of heterosis are still poorly understood. We feel that the quantitative genetics of heterosis must be tied to plant improvement and that any theory of heterosis must explain and be consistent with the increase in yield of.
Agriculture university jobner303329, jaipur, rajasthan, india email. Heterosis is a common phenomenon in maize, rice and. The identification of the genetic and epigenetic framework underlying heterosis would be a landmark discovery revolutionizing modern plant breeding by allowing the optimal exploitation of crop productivity and stability. Plant breeding download book pdf plant breeding pp 451472 cite as. Since then, heterosis has been widely utilized in crop breeding, ly in mespecialaize.
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