These homozygous lines are 100percent inbred lines, which otherwise would have to be produced by repeated forced selfpollinations. This article provides the state of the art on dh technology including the induction and identification of haploids, what factors influence haploid induction, molecular basis of microspore embryogenesis, the genetics underpinnings of haploid induction and its use in plant breeding. Kidwell encyclopedia of life support systems eolss despite advances in technologies, plant breeding is still based on mendels original concept of inheritance which is extended to encompass the inheritance of quantitative. Following baenziger and depauw 2009, this overview will discuss five methods of wheat breeding. Optimum hybrid maize breeding strategies using doubled. Haploids in plant breeding advances in plant breeding series. The average value of a family of dhs, in terms of combining ability, did. Production and subsequent conversion of haploids into doubled haploids has many applications in genetics and plant breeding dunwell 2010. Optimization of doubled haploid production in maize zea mays l.
Among the most promising emerging technologies is the production of doubled haploids genetically pure plant lines that offer a quick. Haploids provide an effective research tool for studies on. Novel approaches combining dhs and molecular genetics. Since the cellular origin of the plants produced is not. We 1 determined the optimum allocation of the number of s1 families, dh lines, and test. Validation of doubled haploid plants by enzymatic mismatch. A wide range of methods has been developed to produce doubled haploid dh plants and recent advances promise efficient dh production in otherwise recalcitrant species. A doubled haploid dh is a genotype formed when haploid cells undergo chromosome doubling. Recombination and genetic variance among maize doubled haploids induced from f 1 and f 2 plants. Szarejko i eds doubled haploid production in crop plants, a manual. Doubled haploidy is a fundamental tool in plant breeding as it provides the fastest way to generate populations of meiotic recombinants in a genetically fixed state. In addition, many genomic approaches such as association or qtl mapping benefit greatly from the use of dh populations 24. Optimization of doubled haploid production in maize zea.
Haploids are autonomous, sporophytic plants that have gametophytic chromosome number because they originate from a gametic cell in the embryo sac or in the pollen grain. First, obtain a genotype carrying all favorable alleles in coupling namely, h 1, n b by crossing the root genotype with a blank parent denoted h bb containing none. Theoretical benefits and working protocols are not however sufficient to justify dh deployment in breeding. Todays use of haploids in corn plant breeding sciencedirect. Doubled haploid production for thousands of years, farmers have worked to improve their crop varieties, slowly breeding new traits over many generations. The haploid embryo can arise from an egg cell gynogenesis or from a gametophytic cell other than the egg cell apogamy or a male gamete androgenesis. The protocols describe in detail all steps of dh production from donor plants growth conditions, through in vitro procedures. The production of doubled haploids dh has become a necessary tool in advanced plant breeding institutes and commercial companies for breeding many crop species. Traditionally, the maize plants crossbreeding nature required. Doubled haploid production in crop plants a manual, plant. Improved efficiency of doubled haploid generation in. Doubled haploid production in crop plants springerlink. Their generation and application in plant breeding authors.
The studies proposed will provide a test of the role doubled haploids can play in speeding. The homozygous lines are employed at least any phase of plant breeding programme. Pdf haploids and doubled haploids in plant breeding. Production and identification of doubled haploids in tropical.
Molecular plant breeding, institute of agricultural sciences, eth zurich, 8092. Doubled haploids in crop improvement crops plant breeding. Haploid plants have many uses in basic plant research disciplines such as cytogenetics, molecular genetics, crop evolution, plant biotechnology and traditional plant breeding chawla, 2002. However, producing large populations of doubled haploids is possible in only a few plant species. Haploids are plants sporophytes that contain a gametic chromosome number n. Doubled haploid technology for quickly developing inbred. Doubled haploids versus conventional breeding in cimmyt wheat breeding programs huihui li, ravi p. Haploids and doubled haploids in plant breeding 89. Doubled haploids dhs are plants derived from a single pollen grain and doubled artificially to form homozygous diploids. They can originate spontaneously in nature or as a result of various induction techniques. This is the first manual presenting a set of protocols for production of doubled haploids dh in 22 major crop plant species including 4 tree species. Haploids become valuable when scientists double them and use them to produce homozygous breeding lines. These methods are described in greater scientific detail in baenziger et al.
Doubled haploids dhs are also considered as an attractive alternative in. Doubled haploid offers a great perspective in plants having the effective role in plant selection and other breeding programs. On the use of doubled haploids in genetics and breeding of coffea. Combining ability of callus induction and plant regeneration in canola. Anther culture is a useful tool for the rapid generation of haploid plants for use in plant breeding programmes and genetic studies and also offers a means for functional genomics analysis when coupled with transgenic technology. Technique of doubling haploids was discovered in 1964 by guha and maheshwari. Thus the fixation steps we implement for our study are as follows.
Provide greater efficiency of selection in plant breeding improve the precision of genetic and mapping studies. For example, one gene set may carry a gene for disease resistance when the other set does not. Doubled haploids refer to the diploid lines which are obtained by doubling the chromosome number of a haploid line by colchicine treatment. Covariances between arbitrary relatives with linkage and epistasis in the case of linkage disequilibrium. Production and identification of doubled haploids in.
Pfeiffer, and jiankang wang abstract doubled haploid dh technology has been used in breeding programs for several decades and is currently the method of choice in a number. Chase 1951 demonstrated the practical application of doubled haploids in maize breeding, and he developed several lines from doubled haploids, some of which were used for the production of commercial maize hybrids. History of plant breeding the most rudimentary forms of plant breeding likely originated during the transition of. Artificial production of doubled haploids is important in plant breeding haploid cells are produced from pollen or egg cells or from other cells of the gametophyte, then by induced or spontaneous chromosome doubling, a doubled haploid cell is produced, which can be grown into a doubled haploid plant. The most advanced tropical inducer candidates tic combine hir of up to. Novel technologies in doubled haploid line development.
There are many factors influencing the deployment of doubled haploidy in breeding. Nov, 20 doubled haploidy is a fundamental tool in plant breeding as it provides the fastest way to generate populations of meiotic recombinants in a genetically fixed state. Geiger1 1university of hohenheim institute of plant breeding, seed science, and population genetics 70593 stuttgart, germany 2agreliant genetics llc, lebanon, in optimum hybrid maize breeding strategies using doubled haploids. Haploids and doubled haploi ds in plant breeding 91 numbers of haploids from any genotype. Doubled haploids versus conventional breeding in cimmyt. Strategies for exploiting doubled haploids dhs vary within and among species and are dependent upon available technologies. Maize breeding lines developed using doubled haploids produced through in vivo induction of maternal haploids are completely homozygous and homogeneous. Successhi applications of doubled haploids in genetic and breeding.
The production of microsporederived doubled haploid dh plants is an especially. Genome mapping, a recent development in molecular biology, can be more conveniently achieved by using doubled haploid plant species. Today, advanced plant breeding technologies enable far more significant improvements in far less time. The detection of novel induced mutations has long been a bottleneck in plant mutation breeding. Application of dh in plant breeding, genetic and molecular. Mutation techniques combine well with dh technology, because, as with. However, the development of new, more efficient and cheaper large scale production protocols has meant that doubled haploids are also recently being applied in less advanced breeding. The production of doubled haploids has become a necessary tool in advanced plant breeding institutes and commercial companies for breeding many crop species. Doublehaploid induction speeds up plantbreeding process. Doubled haploids dh are presently being used in breeding of a number of crop species. Isozyme analysis will distinguish homozygous doubled haploids from somatic diploids. However, with recent breakthroughs in highthroughput mutation detection technologies the pbg subprogram is assisting member states in acquiring and establishing appropriate capacities to increase the efficiency of screening for desired traits and to accelerate the development.
A comparison of dihaploids doubled haploids with diploid wild plant species will be useful to trace the evolutionary origin of various plants. Haploids in plant breeding advances in plant breeding. The discovery of haploids in higher plants led to the use of doubled haploid dh technology in plant breeding. Spontaneous development of haploid plants has been known since 1922, when blakeslee first described this phenomenon in datura stramonium blakeslee et al. Doubled haploid cultivars have been developed in different countries such as canada, usa, uk, spain, china, hungry, and italy etc. The authors are also grateful to members of the eu cost action 851 gametic cells and molecular breeding for crop improvement for valuable comment. Doubled haploid dh technology is a valuable tool in modern breeding programs since it allows for the production of completely homozygous lines within a few months and dramatically reduces the time required to establish new cultivars. Maes plant geneticists and microbiologists also are creating new tools that plant breeders can use when developing these plants. Use of doubled haploid technology for development of stable drought tolerant bread wheat. Maize doubled haploid dh technology provides fixed, pure lines from a donor parent. Optimum hybrid maize breeding strategies using doubled haploids.
In homozygous lines, all genes on each pair of chromosomes in every cell of the plant are identical. First, common markers between the owb and each of the other two maps were identi. Haploids and doubled haploids in plant breeding, plant breeding, ibrokhim y. Quantitative genetics of doubled haploid populations and. In typical plantbreeding practice, enough lines from a germplasm pool. Haploids not used in plant breeding until the 1950s. Stages in plant life cycle where haploid can occur or be induced. Baum cultivation of donor plants spike collection and pretreatment anther culture colchicine treatment and doubled haploid plant production stability and agronomic performance of doubled haploids. Utilization of microspore derived homozygous lines has resulted in the development of new cultivars in both rice and tobacco. Haploids and doubled haploids in plant breeding intechopen. Haploid and doubled haploid techniques in perennial ryegrass. Forster bp, thomas wtb 2005 doubled haploids in genetics and plant breeding. A comparison of di haploids doubled haploids with diploid wild plant species will be useful to trace the evolutionary origin of various plants. Doubled haploid technology for quickly developing inbred corn.
Mutation detection, plant breeding and genetics, pbg. Forster and others published doubled haploids in genetics and plant breeding find, read and cite all the research you need on researchgate. Hemizygous 1n one dose of an allele homozygous two doses of same allele. Doubled haploid technology for line development in maize. Use of doubled haploid technology for development of. Each cell contains 2 sets of genetic information which are but not exactly identical most. Inducing maize doubled haploids from f 2 plants dhf2 instead of f 1 plants dhf1 led to more recombination events.
Haploids in plant breeding advances in plant breeding series werner nitzsche, gerhard wenzel on. Kidwell encyclopedia of life support systems eolss 2. Toward a theory of markerassisted gene pyramiding genetics. Pollination with maize is also effective for inducing haploid embryos in several other cereals, such as barley, triticale x triticosecale, rye secale cereale and oats avena sativa w dzony, 2009. Cab direct platform is the most thorough and extensive source of reference in the applied life sciences, incorporating the leading bibliographic databases cab abstracts and global health. In fact, under optimal conditions, doubled haploids dh have been routinely used in. In the past decade, this type of breeding has become more increasingly used due to progress in the logistics behind doubled haploid line production. Baker center for plant breeding, has launched a doubled haploid facility at isu that can develop pure, inbred. Doubled haploids for estimating mean and variance of recombination values. Haploid plant production followed by chromosome doubling offers the possibility of developing. Everything you need to know about doubled haploids in crop improvement.
With a focus on haploid and double haploid systems in higher plants, the module will focus on variations in chromosome number, microspore embryogenesis, wide hybridization, in vivo maize parthenogenesistype, and radiation systems. Doubled haploids in breeding, in doubled haploid production in crop plants eds m. Haploids and doubled haplo ids n plant bree d ng, plant bree, dr. Doubled haploids in genetics and plant breeding plant. Doubled haploids in genetics and plant breeding request pdf. Apr 12, 2010 doubled haploid technology for quickly developing inbred corn lines. Increased efficiencies achieved in different steps of dh line production offer greater benefits to maize breeding programs. Dh lines display the complete genetic variance at the beginning of.
Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present the ploidy level. It contains various protocols and approaches of dh production proven for different germplasm of the same species. Early testing prior to doubled haploid dh production is a promising approach in hybrid maize breeding. Application in plant breeding doubled haploids are competent and valuable research tool for acquiring fast homozygosity in a heterozygous offspring in a single step. In this issue of futures, we feature just a small portion of. Although cimmyt has a few backcross populations that combine the root. The scottish crop research institute receives grant.
Implementation and optimization of the doubled haploid. However, the best dhf2 lines did not outperform the best dhf1 lines. Doubled haploid production heartland plant innovations. Use of haploids in genetics research, dh systems in selfpollinated, crosspollinated and hybrid crop breeding. It is well established for plant breeding, genetic studies andor induced.
Doubled haploids versus conventional breeding in cimmyt wheat. A dh individual has two identical homologs, so that the amount of recombination information is equivalent to a backcross. Doubled haploids created from haploid wheat plants developed by anther culture or fertilization with maize pollen are useful for genetic research and breeding. Recombination and genetic variance among maize doubled. Doubled haploid plant has cells containing 2 gene sets which are exactly identical.
The importance of haploid and doubled haploid dh techniques for basic and. The doubled haploid materials obtained will be evaluated for plant phenotype, vigor, fertility, disease resistance, and performance in hybrid combinations, in conjunction with evaluation of traditionally bred inbreds in the cornell onion breeding program. Unesco eolss sample chapters soils, plant growth and crop production vol. Introduction the use of haploid plants in the breeding was possible after detection of the line stock 6 coe, 1959, which has the ability to induce maternal haploids with a frequency of 2%.