The doubled haploid technology is one of themost important modern ways of accelerating the development of improved maize varieties. A critical component of this method depends on chromosome doubling, which is traditionally achieved by in vivo treatment of seedlings with colchicine. Requests from researchers and trainees for systematised protocols dealing with the production of doubled haploids in various species were instrumental in initiating work on this manual, and the idea to prepare it was strongly supported by european scientists working under the eu large scale. The protocols describe in detail all steps of dh production from donor plants growth conditions, through in. Review on concept and impact of double haploid techniques. The development of crop cultivars by crossbreeding is both time and resource consuming. The scottish crop research institute receives grant. Double haploid a plant or line obtained by doubling the chromosome number of a haploid plant or individual the genetic upgradation of crops through conventional breeding approaches require longer time so there is a need to assist these methods following certain biotechnological tools to shorten. The stateoftheart maize doubled dh facility for africa has been established by the international maize and wheat improvement. A doubled haploid dh is a genotype formed when haploid cells undergo chromosome doubling.
The production of doubled haploids, through tissue culture techniques. In this study we investigated the applicability of an in vitro approach for chromosome doubling based on microspore culture. 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. The chromosome number of haploid could be doubled spontaneously or artificially to obtain doubled haploids carrying two sets of chromosomes from a single parent homozygous. Goals objectives the overall objective is to recover homozygous doubled haploid dhplants from several vegetable crops in order to speed the breeding of lines with improved resistance to diseases or other stresses or with other desirable traits. Doubled haploid technology is an important tool for plant breeding. This volume provides an excellent overview of haploid induction and the application of doubled haploids. Microspore reprogramming was induced in cassava by cold or heat stress of anthers. Doubled haploid production for thousands of years, farmers have worked to improve their crop varieties, slowly breeding new traits over many generations. While considered as a poor mans crop because it is mainly consumed by people.
The importance of haploid and doubled haploid dh techniques for basic and applied research, as well as to improve the speed of genetic gain when applied in breeding programs, cannot be overstated. Haploids provide a relatively easier system for the induction of mutations. Using double haploid technique new varieties have been developed in barley, brassica, rice, maize, rye, potato, pepper and asparagus. Sorghum is known for its drought and heat tolerance and is grown in many arid and semiarid regions of the world. Breeding is one of the approaches to attain this but it requires minimum 67 cropping years. Doubled haploids dhs are plants derived from a single pollen grain and doubled artificially to form homozygous diploids. Pdf haploids and doubled haploids in plant breeding. Haploid and doubled haploid techniques in perennial. Growing interest in doubled haploidy for improvement of. Genome editing and doublefluorescence proteins enable. An individual with the doubled chromosome number of the haploid gupta. Generation of maize zea mays doubled haploids via traditional methods. Nowadays, maternal haploids are routinely created by pollinating with a haploid inducer hi line such as. Role of double haploids in crop improvement authorstream presentation.
Doubled haploids in crop improvement crops plant breeding. In addition, haploids and doubled haploids can accelerate the generation of homozygous lines and pure cultivars. It allows for significant time reduction in the achievement of homozygous breeding lines of value in crop improvement. 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. Everything you need to know about doubled haploids in crop improvement. Optimization of doubled haploid production in maize zea. Agronomy free fulltext haploid and doubled haploid. Accelerating crop breeding using doubled haploids, dna markers, and data management. The incorporation of haploids in breeding programs is one of the latest techniques used for crop improvement. Doubled haploid production in crop plants springerlink.
Doubled haploid production heartland plant innovations. However, the development of new, more efficient and cheaper large scale production protocols has meant that doubled haploids are also. The presence of gb marker bp was observed in 27 geno types with the haploid number of chromosomes and in 27 spontaneously doubled haploid plants. Genome editing technologies have paved the way for exciting and novel applications in plant biotechnology. This includes countries in north and south america, africa, asia, and europe. Before sharing your knowledge on this site, please read the following pages. They have become routine tools in several major crop species, such as maize zea mays l.
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. Mutants with resistance to disease is of prime importance in crop improvement. Introduction plant breeding improving is traditionally a slow process, with the release of new cereal varieties taking up to 12 years as process include developing lines, evaluating and identification, crossing and obtaining true breeding by selfing for longer period broughton,1999. The release of the wheat varieties jinghua 1 and florin is a typical example of what can be achieved with other crops. Haploids in crop improvement ii biotechnology in agriculture and forestry pt. The important use of haploids is based on the fact that marked improvements in the economics of plant breeding can. Today, advanced plant breeding technologies enable far more significant improvements in far less time. Practical learning the cytogenetics laboratory, various chemicals to be used for fixation, dehydration. The presence of xwmc221 marker 200bp was observed in 29 haploid plants and in 24 spontaneously doubled haploids.
A scientific explanation of the doubled haploid dh technique, including a step by step guide for the creation of a dh line. The doubled haploid technology is already being used in other crops like corn and canola. Role of double haploids in crop improvement authorstream. A dh individual has two identical homologs, so that the amount of recombination information is equivalent to a backcross. Doubled haploids versus conventional breeding in cimmyt wheat breeding programs huihui li, ravi p. For companies like corteva, dh techniques help improve plant breeding efficiency and. Haploids provide an effi cient research tool for studies on induced mutagenesis castillo et al. Tissue culture has been exploited to create genetic variability from which. Thorpe plant tissue culture comprises a set of in vitro techniques, methods and strategies that are part of the group of technologies called plant biotechnology. Besides these, focus articles on the production of haploids in brassicas, solanaceous vegetables, melons, gourds, cucumbers and legumes are also covered.
Unlike traditional breeding processes, which may take over eight generations to stabilize the genetic background of interest, dh allows homozygous. 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. A sorghum doubled haploid breeding system will revolutionize sorghum crop improvement worldwide. The use of doubled haploids in recurrent selection and hybrid development in maize gallais 2007 crop science wiley online library. Doubled haploid production in crop plants a manual m. Production and identification of doubled haploids in tropical maize g.
Haploids and doubled haploids in plant breeding intechopen. For each site, the inducers were sown in twenty 5m rows to. Doubled haploid production in crop plants a manual. Haploids in crop improvement i from fundamentals to. The most efficient way to produce doubled haploids in corn is through haploid induction, he adds. Genetics and plant breeding course structure at a glance. Doubled haploid production is a key technology in triticale research and breeding. Improved efficiency of doubled haploid generation in.
The line that professor coe found, the haploid inducer, has really underpinned the success of corn as a crop in the marketplace, kelliher says. Production of haploids and doubled haploids haploids produced from diploid species 2n 2x, known as monoploids, contain only one set of chromosomes in the sporophytic phase 2nx. A milestone in the doubled haploid pathway of cassava. The production of doubled haploids has become a necessary tool in advanced plant breeding institutes and commercial companies for breeding many crop species. Double haploids are plants those carry two sets of chromosomes that are created from the haploid plants. Homozygosity at a particular locus is always desirable feature for crop improvement programs. It contains various protocols and approaches of dh production proven for different germplasm of the same species. Production and identification of doubled haploids in. Genome mapping, a recent development in molecular biology, can be more conveniently achieved by using doubled haploid plant species. Doubled haploid techniques help improve sorghum breeding.
Doubled haploid production in crop plants a manual, plant. Doubled haploids versus conventional breeding in cimmyt. 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 programmes. The present volume comprises 30 chapters by international experts and informs on the methods involved, such as in vitro production of haploids by culture of anthers, studies of pollen embryogenesis, genetic analysis of haploids. A comparison of di haploids doubled haploids with diploid wild plant species will be useful to trace the evolutionary origin of various plants.
Development of a haploidinducer mediated genome editing. Doublehaploid induction speeds up plantbreeding process. Pdf recent advances and application of doubled haploids. Utilization of haploids and doubled haploids can simplify the identification of genotypes that can provide a significant improvement in a variety of agronomic traits. In research, doubled haploid lines have been used for structural and functional genomics, markertrait association studies, and molecular cytogenetics chang and coe, 2009. Crop improvement through tissue culture aggie horticulture. Different methods such as androgenesis microspore or anther, gynogenesis ovule or ovary haploid inducer lines and wide crosses are used for developing haploid thereby double. The use of doubled haploids in recurrent selection and. Double haploid a plant or line obtained by doubling the chromosome number of a haploid plant or individual the genetic upgradation of crops through conventional breeding approaches require longer time so there is a need to assist these methods following certain. Doubled haploids refer to the diploid lines which are obtained by doubling the chromosome number of a haploid line by colchicine treatment.
Doubled haploid dh technology has a significant and valuable advantage over traditional approaches in crop breeding. Haploids and doubled haploids in plant breeding, plant breeding, ibrokhim y. Pdf development of haploid and double haploid in fruit. Development of a sorghum doubled haploid breeding system. Among the most promising emerging technologies is the production of doubled haploids genetically pure. Rapid technique homozygous plants can be achieved in one generation inbred lines production of homozygous lines of the cross pollinating species and hybrids are highly desirable to avoid inbreeding depression the conventional method of inbreeding is impractical for self incompatible, male sterile and. Doubled haploids in genetics and plant breeding plant. The authors are also grateful to members of the eu cost action 851 gametic cells and molecular breeding for crop improvement for valuable comment. Haploids and doubled haploi ds in plant breeding 89 chromosome elimination occurs in early embryogenesis or fertilization of the egg cell does not occur, and the development of the haploid embryo is triggered by pollination of polar. During the last decade, in vitroproduced haploids have been incor porated into breeding programs of many agricultural crops, and positive results have been obtained especially with rice, wheat, potato, barley, maize, asparagus, sunflower, brassica, tobacco, etc. Doubled haploids dh technology, which is based on in vivo haploid induction, has become very popular for accelerating crop breeding, particularly in maize geiger, 2009. Faster breeding of vegetable crops through doubledhaploid.
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