The study of the sorghum genetic diversity using the mul¬tiplex microsatellite analysis

This study is focused on evaluation of the genetic structure and diversity of the national sorghum collection. Analyzing the genetic diversity of crop species is of great importance for genetic resources management and food security of any country. Huge genetic diversity of sorghum provides a great opportunity to improve the agronomic characteristics of this crop. The efficiency of microsatellite  analysis has been demonstrated in many studies on the genetic diversity of different races and geographical groups of sorghum plants. Development of multiplex PCR analysis systems based on a set of polymorphic microsatellite loci will facilitate genetic tests on a large number of plant samples, thus making the research on sorghum diversity more efficient and comprehensive. A system of multiplex PCR analysis based on 12 polymorphic microsatellite loci was developed to perform single-stage high-throughput screening of cultivated and wild forms preserved in the sorghum germplasm collection. As a result of the microsatellite analysis of 200 sorghum plants, 229 alleles were detected. The studied loci showed high polymorphism. More than 17 alleles were identified in most loci, their polymorphic index content (PIC) ranging from 0.694 to 0.954. The value of the effective multiplex ratio (EMR) in the developed system was estimated at 0.833. The microsatellite analysis of sorghum accessions resulted in obtaining quantized gene expressions profiles, with a DNA profile for each accession, and revealed significant polymorphism among the plants of different sorghum varieties (races). The developed multiplex PCR system was shown to be efficient for evaluation of the genetic diversity and genetic relationships of sorghum plants from different races. The analysis of the obtained data using three bioinformatic techniques, NJ cluster analysis, PCoA, and the Bayesian model-based clustering, helped to classify the analyzed sorghum accessions into cluster groups according to their morphological and agronomic traits

Multiplexed set of 10 microsatellite markers for identification of potato varieties

Genetic identification of potato varieties is a demanded instrument for development of new cultivars registration system, protection of plant breeders’ rights, and variety homogeneity control. The most perspective approach for distinction and identification of varieties continues to remain the use of short tandem repeats. STR amplification with the subsequent high resolution electrophoresis allows such a unique characteristic of a variety to be obtained as the DNA profile. A large scale of samples requires the creation of a robust and time-saving technique based on fragment sizing. We selected 10 polymorphic STR loci of potato: STI0032, STG0016, STI0001, STI0004, STM1104, STM5127, STI0030, STI0033, STI0014, STM5114 and designed a multiplex panel for potato DNA profiling. Fluorescent labelling of primers and size distinction of amplicones allowed us to use one tube for PCR and capillary electrophoresis. We also modified the CTAB-protocol for DNA extraction from tubers and other parts of potato plants, the PCR mix recipe and the amplification protocol for good results. Using Genetic Analyzer allows the length of alleles to be defined with an accuracy of one nucleotide and digitized genetic profiles to be developed. We created a unique DNA profile for each of 40 varieties and 23 breeding lines from Russia and other countries and evaluated the homogeneity of 8 varieties. The proposed technique оf potato DNA profiling allows a large number of samples to be rapidly analyzed in the 96-well plate format