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. Doubled haploid production in crop plants a manual. 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. 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. This includes countries in north and south america, africa, asia, and europe. The stateoftheart maize doubled dh facility for africa has been established by the international maize and wheat improvement. Improved efficiency of doubled haploid generation in. Tissue culture has been exploited to create genetic variability from which. 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. Development of a haploidinducer mediated genome editing. Genetics and plant breeding course structure at a glance.
Development of a sorghum doubled haploid breeding system. Doubled haploid production is a key technology in triticale research and breeding. A sorghum doubled haploid breeding system will revolutionize sorghum crop improvement worldwide. 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. Review on concept and impact of double haploid techniques. Doubled haploid production for thousands of years, farmers have worked to improve their crop varieties, slowly breeding new traits over many generations. In this study we investigated the applicability of an in vitro approach for chromosome doubling based on microspore culture. 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. A critical component of this method depends on chromosome doubling, which is traditionally achieved by in vivo treatment of seedlings with colchicine. Homozygosity at a particular locus is always desirable feature for crop improvement programs. Production and identification of doubled haploids in tropical maize g. Doubled haploid dh technology has a significant and valuable advantage over traditional approaches in crop breeding. Doubled haploids versus conventional breeding in cimmyt wheat breeding programs huihui li, ravi p.
Doubled haploid production in crop plants a manual, plant. A scientific explanation of the doubled haploid dh technique, including a step by step guide for the creation of a dh line. Doubled haploid production heartland plant innovations. This volume provides an excellent overview of haploid induction and the application of doubled haploids. Everything you need to know about doubled haploids in crop improvement. Growing interest in doubled haploidy for improvement of. 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. Production and identification of doubled haploids in. Haploids provide a relatively easier system for the induction of mutations. Crop improvement through tissue culture aggie horticulture.
Pdf development of haploid and double haploid in fruit. A milestone in the doubled haploid pathway of cassava. Genome mapping, a recent development in molecular biology, can be more conveniently achieved by using doubled haploid plant species. Using double haploid technique new varieties have been developed in barley, brassica, rice, maize, rye, potato, pepper and asparagus. Generation of maize zea mays doubled haploids via traditional methods. The scottish crop research institute receives grant. However, the development of new, more efficient and cheaper large scale production protocols has meant that doubled haploids are also. Genome editing technologies have paved the way for exciting and novel applications in plant biotechnology. In addition, haploids and doubled haploids can accelerate the generation of homozygous lines and pure cultivars. Before sharing your knowledge on this site, please read the following pages. Doubled haploids dhs are plants derived from a single pollen grain and doubled artificially to form homozygous diploids. It takes between 8 to 10 years from the time the cross is made until phenotypically advanced uniform lines are produced.
Pdf recent advances and application of doubled haploids. It contains various protocols and approaches of dh production proven for different germplasm of the same species. An individual with the doubled chromosome number of the haploid gupta. Pdf haploids and doubled haploids in plant breeding. Microspore reprogramming was induced in cassava by cold or heat stress of anthers. Nowadays, maternal haploids are routinely created by pollinating with a haploid inducer hi line such as. A dh individual has two identical homologs, so that the amount of recombination information is equivalent to a backcross. 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. Mutants with resistance to disease is of prime importance in crop improvement. Doubled haploid technology is an important tool for plant breeding. The important use of haploids is based on the fact that marked improvements in the economics of plant breeding can. For companies like corteva, dh techniques help improve plant breeding efficiency and.
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. Doubled haploids in crop improvement crops plant breeding. Unlike traditional breeding processes, which may take over eight generations to stabilize the genetic background of interest, dh allows homozygous. Agronomy free fulltext haploid and doubled haploid. Accelerating crop breeding using doubled haploids, dna markers, and data management.
Faster breeding of vegetable crops through doubledhaploid. Haploids and doubled haploids in plant breeding intechopen. Role of double haploids in crop improvement authorstream. It allows for significant time reduction in the achievement of homozygous breeding lines of value in crop improvement. Practical learning the cytogenetics laboratory, various chemicals to be used for fixation, dehydration. The incorporation of haploids in breeding programs is one of the latest techniques used for crop improvement. The production of doubled haploids has become a necessary tool in advanced plant breeding institutes and commercial companies for breeding many crop species. For each site, the inducers were sown in twenty 5m rows to. Haploids in crop improvement i from fundamentals to. Breeding is one of the approaches to attain this but it requires minimum 67 cropping years.
Doublehaploid induction speeds up plantbreeding process. The line that professor coe found, the haploid inducer, has really underpinned the success of corn as a crop in the marketplace, kelliher says. 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. 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. Sorghum is known for its drought and heat tolerance and is grown in many arid and semiarid regions of the world. The presence of xwmc221 marker 200bp was observed in 29 haploid plants and in 24 spontaneously doubled haploids. Doubled haploids versus conventional breeding in cimmyt. 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. 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. Haploids in crop improvement ii biotechnology in agriculture and forestry pt. 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. Doubled haploid production in crop plants a manual m. The doubled haploid technology is already being used in other crops like corn and canola.
Optimization of doubled haploid production in maize zea. Haploids provide an effi cient research tool for studies on induced mutagenesis castillo et al. Utilization of haploids and doubled haploids can simplify the identification of genotypes that can provide a significant improvement in a variety of agronomic traits. 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. The use of doubled haploids in recurrent selection and hybrid development in maize gallais 2007 crop science wiley online library. The doubled haploid technology is one of themost important modern ways of accelerating the development of improved maize varieties. Genome editing and doublefluorescence proteins enable. Doubled haploid production in crop plants springerlink. While considered as a poor mans crop because it is mainly consumed by people. Haploid and doubled haploid techniques in perennial. The most efficient way to produce doubled haploids in corn is through haploid induction, he adds. 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. The use of doubled haploids in recurrent selection and. The production of doubled haploids, through tissue culture techniques.
The development of crop cultivars by crossbreeding is both time and resource consuming. Doubled haploids in genetics and plant breeding plant. Haploids and doubled haploids in plant breeding, plant breeding, ibrokhim y. They have become routine tools in several major crop species, such as maize zea mays l. The authors are also grateful to members of the eu cost action 851 gametic cells and molecular breeding for crop improvement for valuable comment. Role of double haploids in crop improvement authorstream presentation. In research, doubled haploid lines have been used for structural and functional genomics, markertrait association studies, and molecular cytogenetics chang and coe, 2009. Besides these, focus articles on the production of haploids in brassicas, solanaceous vegetables, melons, gourds, cucumbers and legumes are also covered. Doubled haploids refer to the diploid lines which are obtained by doubling the chromosome number of a haploid line by colchicine treatment. The protocols describe in detail all steps of dh production from donor plants growth conditions, through in. The release of the wheat varieties jinghua 1 and florin is a typical example of what can be achieved with other crops. A comparison of di haploids doubled haploids with diploid wild plant species will be useful to trace the evolutionary origin of various plants. Among the most promising emerging technologies is the production of doubled haploids genetically pure. 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.
Double haploids are plants those carry two sets of chromosomes that are created from the haploid plants. Today, advanced plant breeding technologies enable far more significant improvements in far less time. 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. 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. Overall, there is a growing interest in haploidy for horticultural crop improve ment in india and the prospects for utili. A doubled haploid dh is a genotype formed when haploid cells undergo chromosome doubling. 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. 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.