# Molecular Genetic Research and Genetic Engineering of _Taraxaxacum kok-saghyz_ [PERSON]
## 2 Molecular Genetic and Genome-Wide Studies  
The simplest and cheapest methods for assessing the genetic diversity of plants include the methods of RAPD and ISSR analysis. For example, we used these methods to analyze the polymorphism of three TKS lines, two forms of _T. hybernum_, and some other dandelion species [18]. The RAPD primers OPD-07 and FS-10 are best suited for the detection of interspecific polymorphism, while the RAPD primers FS-10, OPC-05, and OPC-08 can be used for the detection of intraspecific dandelion polymorphism. The ISSR primers HB10, ISSR17, and ISSR36 were most effective for detecting interspecific polymorphism. For identification of the brown-achened and pinkish-achened forms of _T. hybernum_, primers HB10 and ISSR38 can be used. Primers HB10 and ISSR14 are best suited for identifying the three studied TKS lines. More accurate data on plant genotypes can be obtained by analyzing microsatellite DNA polymorphisms. [PERSON] et al. [24] were the first to develop a large number of highly effective primers for the detection of SSR markers. In total, the authors were able to select primers for 767 loci, of which 192 pairs were tested in laboratory experiments. As a result, 48 primer pairs were effective for identifying single-locus polymorphisms. The best and most reliable 17 of these primer pairs were used to genotype 176 individuals from 17 natural TKS populations. The primers selected by these authors can also be successfully used for genotyping _T. officinal_ (L.) Weber ex F.H.Wigg. [24] and _T. hybernum_[41]. In our further studies, it was shown that SSR primers TKS0091, TKS0097, TKS0107, and TKS0110 are suitable for identification of pinkish-achened and brown-achened forms of _T. hybernum_. Locus TKS0111 is suitable for unambiguous SSR identification of all three studied TKS lines [18]. Subsequently, studies were also carried out to search for new more universal SSR markers; for this, de novo sequencing was used [5]. The authors were able to select the 25 most convenient genomic SSRs (gSSR) and additionally, using previously known EST-SSR (eSSR) [24], the genotyping of TKS DNA samples from the germplasm bank and herbarium was carried out. It was shown that the TKS samples available in the collection were characterized by a rather low level of genetic diversity. It should be noted that 14 gSSRs in this study were also effective in the analysis of the genetic diversity of _T. officinal_ samples and, according to the analysis of nucleotide sequences, they can also be used in the study of other Asteraceae species. In the early days, genetic studies of TKS were complicated by the lack of information on the complete genome. The first draft TKS genome was sequenced and assembled by [PERSON] et al. [34], using the PacBio SMRT sequencing method. The genome size was 1.29 Gb and 46,731 protein-coding genes were predicted. The large size of the genome was determined to a greater extent by repetitive DNA, for example, LTR-RT elements. Since then, research on dandelion genomics has continued to a new level. For example, sequencing of 58 TKS samples was carried out, which, according to the results of the analysis, were divided into three large groups: Zhaosu County in Xinjiang (populations A and B); Tkes county in Xinjiang (population C); Lake Tuzkol in Kazakhstan (population D). The D population showed a closer genetic relationship with the C population, compared with the AB populations. A comparative analysis of the genomes of different populations showed differences in the genes involved in their adaptation to different environmental conditions [42]. In another study, high-quality genomes of the rubber-bearing TKS and the medicinal plant _T. mongolicum_ Hand.-Mazz. were sequenced and assembled. For this, PacBio SMRT sequencing technologies, BioNano optical-mapping, and Hi-C technologies, supplemented with the Illumina whole-genome shotgun data, were used [43]. The genome of TKS was expected to be larger and to contain more genes associated with rubber biosynthesis.