Studies on heterosis and combining ability in bittergourd. After maize hybrid was first utilized in field on a large scale in usa in 1930s, heterosis of other crops such as rice, sorghum, rape, and vegetable etc began to be widely used in production, and had made great achievements in crop breeding by the end of last century, mainly contributed to notable increasing of crop yield. The bonus from heterosis should be approximately 5% for production and 10% for mortality, fertility, health and survival. Quantitative genetics and selection in plant breeding.
Recent research on the mechanism of heterosis is important for crop. Heterosis breeding and inbreeding depression authorstream. Khalil5 a study on heterosis and inbreeding depression in sunflower. Heterosis, also called hybrid vigour, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. A similar level of heterosis in all f 1 individuals is expected as they are genetically identical. Heterosis and combining ability for yield and yield components were determined in a population derived from half diallel crossing of six cotton genotypes. The fixation of heterosis by apomixis is common in citrus fruits, black berries, roses, blue grasses and many other flowering plants. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudooverdominance.
Breeding crops with a high yield and superior adaptability is vital to maintaining global food security. In this perspective, we consider that it might be useful to the field to abandon these. Heterosis plays a decisive role in maize production worldwide, but its genetic basis remains unclear. Heterosis is prevalent for multiple traits in diverse maize. However, leng reports that row number is affected in widely different degrees by heterosis, and that number of kernels per row ear length is the only primary yield component in which large positive effects of heterosis.
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. It relies on variation in dna sequences but also on variability in the presence and absence of genes and regulatory elements, or structural polymorphisms sp. Natural genetic diversity within and among species is the basis of most plant breeding programs. Despite its importance in maize production, we know surprisingly little about the genetic basis of heterosis. Plant breeding is the art and science of changing the traits of plants in order to produce desired characteristics. Perhaps improved or new disease resistance is required, or increased seed size, or simply increased yield to make the crop profitable. In addition to conventional plant breeding, anther culture, shoot tip culture, mutation breeding and marker assisted selection have been increasingly applied to breed the varieties. This method can be used for conserving heterosis in vegetatively propagated crops such as sugarcane, potato, sweet potato, banana etc. This explanation of heterosis has been an undercurrent in ongoing discussions from 1936 east, 1936 to the present time e. In breeding depression has been recognised by man for a long time. Heterosis and combining ability for yield and yield. Standard heterosis when heterosis is estimated over standard commercial hybrid it is called as standard heterosis. Average heterosis it is the heterosis where f 1 is superior to mid parent value. Assessment of heterosis in two arabidopsis thaliana common.
Breeding vegetable crops download ebook pdf, epub, tuebl. These observations provide strong support for the model that trueoverdominant genes exist and can drive yield heterosis. Shull 1952 coined the term heterosis and defined it as. 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.
Click download or read online button to get quantitative genetics and breeding methods book now. Hand pollination of tomato for breeding and seed production. Predicting arabidopsis freezing tolerance and heterosis in. Transcriptomic and proteomic analysis of heterosis various transcriptomic es have been carried out to explore the gene expression changes between hybrid analys and its parents to correlate the changes to heterosis. Edwards heterosis is the foundation of modern maize breeding programs. In 1909, shull found increased grain yields in hybrid. More branches per panicle and more grains per branch. Heterobeltiosis when heterosis is estimated over better parent it is called as heterobeltiosis. Pdf heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of. Heterosis, inbreeding depression, various theories of heterosis. This site is like a library, use search box in the widget to get ebook that you want. Mechanisms of inbreeding depression and heterosis for profitable dairying bennet cassell extension dairy scientist, genetics and management virginia polytechnic institute and state university, blacksburg genes in diploid organisms operate singly, in pairs, and in conjunction with genes at other locations throughout the nuclear dna. Department of agriculture, agricultural research service, department of genetics, north carolina state university, raleigh, north. Heterotic groups are created by plant breeders to classify inbred lines, and can be progressively improved by reciprocal recurrent selection.
Pearl millet, fertility restoration, gca, sca, heterosis, correlation coefficient, path coefficient abstract. Among those who would benefit from taking this session are. The latter was estimated in comparison to commercial varieties. In this study, we explored heterosis for earweight ewrelated traits using a north carolina experiment iii design design iii population derived from the elite maize hybrid zhengdan 958. Impacts of crossbreeding on profitability in vertically coordinated beef industry marketing systems final report david a. Here, we conducted a systematic survey of the degree of heterosis in arabidopsis thaliana. Three classical models have served as the foundation for dissecting heterosis into genetic and molecular components1,3,12. After 2010, plant breeding is more science based, business oriented and less art. Frontiers identification of heterosisassociated stable. Combining ability heterosis maize plant breeding introduction types of hybrids, which exhibit high heterosis when the maize is the worlds most widely grown cereal and is uniformity. A study was conducted to assess the combining ability and heterosis of 14 parental lines by developing 91 single cross hybrids following half diallel mating design in maize at the department of genetics and plant breeding, uas, bengaluru. Exploring the molecular basis of heterosis for plant breeding liu. Heterosis or hybrid vigour is a phenomenon in which hybrid progeny exhibit superior yield and biomass to parental lines and has been used to breed f 1 hybrid cultivars in many crops.
Click download or read online button to get breeding vegetable crops book now. Breeding of f1 hybrid cultivars based on heterosis is used in many crops and vegetables. Heterosis is a term used in genetics and breeding and is also known as hybrid vigor. Pearsons correlation coefficients among yieldrelated traits in the rils a across four environments, the if 2 c populations across three environments, and the midparent heterosis mph dataset.
Structural polymorphisms as causes of heterosis in populus. Heterosis is an additional gain above the average genetic level of the two parent breeds. Hybrid breeding methods are used in maize, sorghum, rice, sugar beet, onion, spinach, sunflowers, broccoli and to create a more psychoactive. Jul 30, 2017 heterosis is a term used in genetics and breeding and is also known as hybrid vigor. Since then, heterosis has been widely utilized in crop breeding, ly in mespeciala ize. Mechanisms of inbreeding depression and heterosis for. Heterosis is commercially exploited in rapeseed brassica napus l. Contemporary plant breeding is under pressure to improve crop. Phase 1 the breeder identifies the needs of the farmers and the deficiencies in the current varieties. Pdf hybrid wheat offers promises to break the yield stagnation in global wheat productivity due to heterosis. One of the reasons for using such wide crosses is to obtain heterosis. A free powerpoint ppt presentation displayed as a flash slide show on id. Heterosis most of the maize varieties grown in the u. Moench the results revealed that the standard heterosis for fruit yield per plant was maximum in.
Climate change plants use energy from the sun to convert water from the soil and co 2 from the air into sugars and oxygen. Formation of heterotic pools and understanding relationship. Submitted to submitted by derpartment of genetics and plant breeding, college of agriculture, jau, junagadh. Pdf estimation of heterosis and combining abilities of us. Based on degree of depression, the plant species can be grouped into 4 broad categories. American hereford association craig huffhines kansas city, mo. Ir36 and ir42 yield 45 tha in wet season trials and 78 tha in dry season trials.
Opinion paper heterosis, stress, and the environment. 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. Amaryl lids to download pdf you need some things, like my website and the name of the file. One of the fascinating techniques of plant breeding the heterosis, know about the hypothesis and application in plant breeding.
New technologies on multiple scales are reengineering traditional plant breeding to meet. Twenty five germplasm lines were crossed with three cytoplasmic male sterile lines of a1 cytoplasm, namely, hms 41a, hms 42a and icma 97444 in line x tester fashion to produce 75 hybrids. Jbar diallel analysis heterosis single cross maize hybrids. Heterosis and combining ability in a diallel cross of. Innovative male sterility system and exploitation of hybrid vigour in crop plants i. Objectives communicate and discuss the discipline of practical plant breeding and its importance to us agriculture and food systems. High heterosis values can be obtained using hybrid okra seeds.
The converse or complement to inbreeding depression in which the value d a inbreeding can result in loss of vigor, size, etc. The study was undertaken with an objective of testing seven inbred lines of maize for their combining ability and to know the gene action involved in inheritance of different traits in maize viz. Department of plant breeding and genetics, ghazi university, d. Studies on heterosis in okra abelmoschus esculentus l. The sym posia is held every other year and alternately hosted by the two societies. 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. Patel assistant professor department of genetics and plant breeding junagadh agricultural university junagadh 362 001 gujarat speaker kamlesh kumar chandel m. Heterosis is a phenomenon in which hybrids exhibit superior performance relative to parental phenotypes. When two homozygous inbreeds a true breeding line obtained by continuous inbreeding of 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. Genetic dissection of yieldrelated traits and midparent.
In selfpollinated crops, utilization of hybrid vigour is dependent upon a system for economically producing f 1 seeds. Heterosis, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. Heterosis and inbreeding depression are complementary phenomena, both important to the establishment of breeding strategies, such as conventional hybrids and population breeding. Importance of plant breeding, cytological principles of plant breeding, heterosis, inbreeding and its consequences or applications, selfincompatibility in plants, cytoplasmic male sterility, breeding. Sandeep kumar bangarwa the term heterosis was first used by shull in 1914. Hand pollination is a technique that is used for breeding new tomato varieties with desirable characteristics such as plant vigor, disease resistance, and uniform fruit quality and plant growth. Hybrid vigour, or heterosis, has been of tremendous importance in agriculture for the improvement of both crops and livestock. Heterosis for biomassrelated traits in arabidopsis investigated by.
Heterosis breeding heterosis breeding is here to stay as a potent genetic tool for exploiting the predominantly nonadditive gene action. The flowering gene single flower truss drives heterosis for. However, leng reports that row number is affected in widely different degrees by heterosis, and that number of kernels per row ear length is the only primary yield component in which large positive effects of heterosis are manifested consistently 20. Plant breeding consists of four main phases all of which run concurrently in an established program.
It is also referred as useful or economic heterosis. This was interpreted as heterosis in cell number due to an enhancement of the rate of cell division. P7 f1 crosses significantly surpassed the highest parental genotype for number of branches per plant, flower set, pod set, number of pods per plant, maturity time, 100seed weight and seed yield per plant. 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. Heterosis definition types of heterosis heterosis in. When two homozygous inbreeds a true breeding line obtained by continuous inbreeding of genetically unlike constituents are crossed together, the resulting hybrids obtained from.
However, despite high heterotic values, it is very difficult to produce hybrid okra. Heterosis in plant breeding request pdf researchgate. Quantitative genetics and breeding methods download. Completion of selfpollinated plant breeding for professionals, genetic resources for plant breeding, and outcrossing in plant breeding is recommended. Heterosis it is defined as the superiority of f 1 hybrid over both the parents in terms of yield or some other characters. Springer3 1usdaars, plant genetics research unit, and division of plant sciences, university of missouri, columbia, missouri, united states of america, 2usdaars, u. 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. A study on heterosis and inbreeding depression in sunflower helianthus annuus l. Exploring the molecular basis of heterosis for plant breeding. Genomic architecture of heterosis for yield traits in rice. Ppt heterosis powerpoint presentation free to view id.
Science is the knowledge gathered through scientific method. Sajjad ahmad1, muhammad sayyar khan2, muhammad siraj swati3, gul sanat shah4 and iftikhar hussain khalil5 abstract ahmad, s. Earley california state university, chico college of agriculture cooperators. Impacts of crossbreeding american hereford association. Despite such an extensive use in agriculture, the underlying mechanisms of heterosis are still poorly understood. The flowering gene single flower truss drives heterosis. Heterosis is prevalent for multiple traits in diverse maize germplasm sherry a. Heterosis, or hybrid vigor, is one of the most important tools in plant breeding and has previously been demonstrated for plant freezing tolerance. Department of agriculture, agricultural research service, department of genetics, north carolina state university, raleigh, north carolina 27695.
The scientific method consists of observation, formulation of hypothesis, experimentation and conclusion either to accept or reject the hypothesis. Heterosis, inbreeding depression, various theories of. Improving plants using hybrid vigor module agronomy and. Lacey livestock john and mark lacey paso robles and independence. In this article we will discuss about heterosis or hybrid vigour. Heterosis refers to the phenomenon that progeny of diverse varieties of a.
Heterosis and heterobeltiosis occurred in varying degrees. Plant breeding and genetics all semester notes pdf, principles of genetics pdf, introductory genetics see pdf, principles of plant breeding pdf, introductory plant breeding, principle of genetics and cytogenetics, principles of plant biotechnology pdf, fundamentals of food technology pdf, breeding of crops pdf, principles of genetics, history, mendels laws and exceptions, types of gene. Heterosis is used to increase yields, uniformity, and vigor. Heterosis is prevalent for multiple traits in diverse maize germplasm. Heterosis for some physiomorphological plant traits in. Plant breeding is not so advanced in nepal and need to develop many competitive plant. Plant breeding is considered as the current phase of crop evolution. An effort has been made in the present paper to critically assess the level of success and future strategies in the development and adoption of hybrid technology in selected field crops under three categories. Quantitative trait loci qtl analysis was conducted based on phenotypic data collected from five.
Genotypebyenvironment interactions affecting heterosis in. Freezing tolerance is an important trait because it can limit the geographical distribution of plants and their agricultural yield. Heterosis breeding in eggplant solanum melongena l. Owing to heterosis hybrid vigor in plants, these hybrids often have superior agricultural performances in yield or disease resistance. Arabidopsis thaliana has emerged as a leading model species in plant genetics and functional genomics including research on the genetic causes of heterosis. Plant breeding and genetics all semester notes pdf file. Heterosis, combining ability and components of genetic.
In the late 1990s, it was estimated that 65% of the worldwide maize zea mays area was planted as hybrids. Plant breeding will be important in developing these significant new characteristics in crops. Plant and animal breeders exploit heterosis by mating two different purebred lines that have certain desirable traits. The results indicated that in general heterosis and heterobeltiosis occurred on plant height, date of flowering, date of fruit set, fruit length, and number of fruits per plant on 4 population of f1 resulted from crossing of 2 x 14, 14 x 30, 17 x 14, and 30 x journal of agricultural science, 4 11 teknik pemuliaan tanaman plant breeding techniques. Heterosis for some physiomorphological plant traits in spring wheat crosses shahzadi mahpara1, muhammad ishaq asif rehmani2, safdar hussain2, javaid iqbal2, muhammad kamran qureshi3, muhammad ahmed shehzad4 and javed shabbir dar5 1. Combining ability and heterosis for yield and component. Notwithstanding large efforts to study the phenomenon of heterosis in the last decades, the identification of common molecular mechanisms underlying hybrid vigour remain rare. Mar 28, 2014 thus, plant breeding is purely science with very little art involved. The objectives of this project are to characterize the extent of sp between and. Therefore, in a search for the basis of heterosis in yield and.
In addition to the heterosis of aboveground agronomic traits on which most existing studies have focused, root heterosis is also an indispensable component of heterosis in the entire plant and of major importance to plant breeding. Heterotic plants will probably have slightly different distributions of cell types. Transcriptome analysis of rice root heterosis by rnaseq. 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. 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. Plant breeding david luckett and gerald halloran what is. Insights into the genomic architecture of heterosis for grain yield in rice are presented, and further mapping of grain yield loci resolves candidate genes that could be useful for breeding. View enhanced pdf access article on wiley online library html view download pdf for offline viewing.
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