**5. Application of doubled haploid technology**

Visual selection based on classic pedigree breeding methods within segregating populations for numerous generations is the most common strategy for inbred development in maize [25]. Recurrent selection is another method for improving the breeding population mean by recombining superior progeny after selection [26]. However, using these approaches takes longer to obtain the appropriate amount of homozygosity. In comparison to other approaches, the DH method may achieve homozygosity in a single generation (**Figure 5**). As a result, DH production would be a feasible alternative to conventional methods for rapidly generating homozygous lines [3]. Because they are 100 percent homozygous, DH lines meet all of the DUS (Distinctness, Uniformity, and Stability) requirements for varietal development [1]. The DH population may also be used to gain knowledge on the genetic architecture of complex characteristics through breeding. Because the DH population is made up entirely of additive genetic variation due to homozygosity at all loci, the selection response is substantially higher than in other segregating populations [27, 28]. Additionally, DH breeding can be used with a marker-assisted backcrossing program to transfer the favorable allele of the concerned trait through either phenotypic or marker-assisted procedures, or a mix of both, by omitting the self-pollination stages at the end of the program [29]. Many commercial breeding programs have recently combined DH technology with genomic selection to improve genetic gain, especially for characteristics governed by a large number of QTL with low heritability [30]. Individual haploid plants are genotyped to find superior haploids, followed by selfpollination to establish homozygous lines using genomic selection [1]. Recently, after genetic alterations of three essential genes involved in meiotic recombination (*REC8*, *PAIR1*, and *OSD1* genes) and a single gene involved in haploid induction (*MTL*),

**Figure 5.**

*Chromosome constitution of various stages during homozygous lines development in a single generation.*

*Accelerated Generation of Elite Inbreds in Maize Using Doubled Haploid Technology DOI: http://dx.doi.org/10.5772/intechopen.105824*

parthenogenesis was designed to fix heterosis [31–34]. Therefore, there are plenty of opportunities to combine these strategies in order to boost breeding yield.
