“Applications of Doubled Haploids in Plant Breeding and Applied Research”, 2021-07-17 (; similar):
Manifold and diverse applications of doubled haploid (DH) plants have emerged in academy and in the plant breeding industry since the first discovery of a haploid mutant in the Jimson Weed (Datura stramonium), followed by the first reports about anther culture in the same species, maternal haploids by wide crosses in tobacco (Nicotiana tabacum L.) and barley (Hordeum vulgare L.), interspecific hybridization, ovary culture (gynogenesis), isolated microspore culture, and more recently the CENH3 approach in thale cress (Arabidopsis thaliana L.) and other species. Research and development efforts were and are still substantial in both user groups.
Luckily, often academic and industrial partners cooperate in challenging and sometimes voluminous projects worldwide. Not only to develop innovative DH protocols and technologies per se, but also to exploit the advantages of DH plants in a huge variety of research and development experiments. This review concentrates not on the DH technologies per se, but on the application of DHs in plant-related research and development projects.
[Keywords: DH, doubled haploids, homozygosity, molecular markers, selection, genetic variability, recombination, biostatistics, genome editing, genomic selection, breeding strategy]
…While the primary application of DHs was to fix genetic variability as fast as possible by immediately reaching full homozygosity (one “step” versus several selfing generations), this advantage of DHs was later and is still widely used in marker-assisted selection in academy. Later, with the development of cheaper and easier molecular biological and genomic tools and technologies, the link between DHs and marker applications in commercial breeding programs was accelerated as well.
Today, DHs in many plant species are routinely used, often combined with diverse tool kits from the fields of genomics, transgenics (eg. reverse breeding), bioinformatics, tissue culture, genome editing, epigenetics, but phenotyping and sophisticated field nursery technologies as well. This is often possible in species in which the efficiency of DH production was improved by optimization of several steps, being it either in vitro or in vivo. Those improvements (described in other chapters of this book) led mainly to accelerated in vitro haploid cell induction, better quality and quantity of organogenesis and regeneration, in vivo haploid induction, and genome doubling.
…This review article here starts with the use of DHs to analyze their genetics and agronomic characters and the comparison of DH populations with conventionally generated (selfed) populations under field conditions. In the following sections, the use of DHs in diverse genetic mapping studies and gene cloning approaches (and other genomic applications) is described, as well as their use in breeding and research of transgenic plants. The most recent reports from large biostatistical projects, genome editing, and phenotyping applications are mentioned too.
In particular, the following applications of DHs in plant breeding and applied research will be discussed:
Recombination and fixation of genetic variance
Use of haploid and DH technologies to develop wide crosses and use of hybridization
DHs for mapping and diverse range of MAS procedures and strategies
DHs for genomic selection and genomic prediction
Haploid tissues used for genetic transformation and development of stable transgenic lines and DHs for breeding with transgenic lines
Use of haploid cells and tissues for increasing genetic variation by mutation
Genome editing by the use of DH technologies
Epigenetics and DHs
Reverse Breeding