MOLECULAR MARKERS EFFICIENCY FOR THE ANALYSIS OF GENETIC DIVERSITY OF TEA PLANTS (СAMELLIA SINENSIS (L.) KUNTZE)

Genomic and transcriptomic technologies allow revealing the fundamental basis of inheritance of valuable traits and increasing the efficiency of the breeding process. Currently, the solution of tea breeding problems can no longer do without the use of biotechnological and genetic tools. As a result of their integration into breeding programs, some progress has already been made in obtaining new cultivars that surpass the original ones not only in terms of productivity and quality, but also in resistance to abiotic environmental factors. In this study, sets of primers have been tested and effective molecular markers (SSR, ISSR, SCoT) have been identified for the analysis of genetic diversity and genotyping of the collection of tea germplasm in FRC SSC of RAS. From 36 SCoT primers, 25 showed poor amplification quality and weak fuzzy bands, which were subsequently excluded from the analysis. The remaining 11 SCoT primers generated reproducible results with clear polymorphism and resolution for tea genotypes. In the collection of cultivars and mutant tea forms, the average level of polymorphism was 55 %. The analysis of genetic distances by SCoT markers showed the absence of a clear clustering on the basis of the leaf blade size, which may indicate the presence of one branch of the pedigree for the genotypes of the ‘extra-large’ group with a possible admixture of the Assam tea subspecies. The results of chloroplast primers testing showed the same length of amplified fragments in Chinese and Assam tea cultivars. At the same time, four chloroplast primers (Chlo2, 5, 8, 17) revealed differences in the melting curves of amplified fragments. The presence of two haplotypes in tea collection is shown by three of these markers, whose amplicons differ in melting temperature, and heat maps reflect the presence of two different groups in the tea collection.