The N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) is developing new approaches to documentation of national cultivars, taking into account recommendations of the International Code of Nomenclature for Cultivated Plants in parallel with methods of genetic certification. The nomenclatural standard of a particular cultivar represented by a herbarium specimen can be used as a reference for verifying authenticity and uniformity of cultivar specimens obtained from various sources. The verification requires fast and reliable methods for cultivar genotyping. This paper presents protocols for modified methods of DNA extraction, PCR-analysis and SSR-genotyping, which allow potato cultivars identification without the use of expensive reagent kits. A set of ten chromosome-specific microsatellite markers was used to study polymorphisms in 66 modern Russian potato cultivars, as well as in 11 pre-cultivars and breeding clones, represented by nomenclatural standards and voucher specimens, respectively. This subset of 77 specimens has demonstrated a high level of polymorphism in ten studied microsatellite loci. The SSR analysis identified 73 alleles; 7.3 alleles per locus were observed on average, the number of which varied from 3 (STG0025 locus) to 11 (locus StI046). The PIC values varied from 0.544 (STG0025 locus) to 0.836 (StI046 locus). The alleles, unique for this subset, were found at six studied loci. The high level of polymorphism at the SSR loci made it possible to unambiguously identify almost every cultivar, with the exception of the expected coincidence of microsatellite profiles of two cultivars, which are somaclonal variants. Using an optimized set of eight microsatellite markers, the genetic relationships of modern Russian potato cultivars were studied.

In order to preserve the genetic diversity of cultivars, it is recommended to develop documentation approaches through the registration of cultivar nomenclatural standards in accordance with the International Code of Nomenclature for Cultivated Plants. The N.I Vavilov Institute of Plant Genetic Resources keeps developing this approach along with the DNA marker technologies: SSR genotyping and molecular screening with DNA markers of genes controlling valuable traits. In 2018, VIR, together with the leading national centre for potato breeding – the A.G. Lorkh All-Russian Scientific-Research Institute of Potato Farming (now the A.G. Lorkh Russian Potato Research Center), initiated the preparation of nomenclatural standards for potato cultivars bred both at the A.G. Lorkh institute and in co-authorship with other breeding institutions. This paper presents 30 nomenclatural standards which are maintained in the Nomenclature standard fund of the Herbarium of cultivated plants and their wild relatives and weeds (VIR Herbarium, WIR). Also, the paper presents genetic passports of the mentioned 30 cultivars, developed using DNA samples extracted from the plant material of nomenclatural standards. Genetic passports include information about the polymorphism of the 8 chromosome-specific microsatellites and data on the results of molecular screening with 15 markers of 11 genes conferring resistance to the most dangerous pathogens and pests: potato viruses Y and X, late blight and potato cyst nematodes. A comparison of SSR-profiles of nomenclatural standards with those of 66 cultivar samples obtained from various sources made it possible to verify authenticity and homogeneity of the latter.

Breeding of potato cultivars adapted to the climatic conditions of the Middle Volga region and resistant to various harmful organisms has always been an urgent task for breeders of the Tatarstan Republic. In the present paper, the potato cultivars bred at the Tatar Research Institute of Agriculture – Kazan Scientific Center of the Russian Academy of Sciences, were taken as an example for demonstrating the results of application and elaboration of methodological approaches that are currently developed at the N.I. Vavilov Institute of Plant Genetic Resources (VIR) for the preparing of nomenclatural standards and their genotyping. At the initiative of the VIR researchers in collaboration with the authors of potato cultivars E.A. Gimaeva and Z. Stashevski plant material was collected and nomenclatural standards for potato cultivars bred at the Kazan Scientific Center of the Russian Academy of Sciences were prepared. Four nomenclatural standards for Tatarstan potato cultivars (‘Zumba’, ‘Kortni’, ‘Reggi’, ‘Samba’) were prepared in accordance with the provisions of the International Code of Nomenclature For Cultivated Plants, registered in the VIR Herbarium Database, and transferred to the VIR herbarium type collection. Besides, voucher specimens of cv. ‘Tango’ and breeding clone ‘Sal’sa’, which is undergoing the State Variety Test at present, were produced. Genetic passports of Tatarstan varieties (‘Zumba’, ‘Kortni’, ‘Reggi’, ‘Samba’) and one breeding clone (‘Sal’sa’)* were developed using DNA samples from plant material transferred by the authors of the cultivars to the VIR herbarium. The genetic passports include information of the polymorphism of eight chromosome-specific microsatellites, data on the presence/ absence of the diagnostic fragments of 15 markers of the 11 R-genes conferring resistance to various harmful organisms and the information about cytoplasm types. A comparison of the data from genetic passports developed using DNA samples from nomenclatural standard specimens with the results of genotyping of 22 samples of Tatarstan cultivars obtained from different sources (e.g., samples undergoing ecogeographic tests within the framework of the Comprehensive Research Plan of the subprogram “Development of potato breeding and seed production in the Russian Federation”; as well as accessions from the VIR in vitro collection) made it possible to assess the authenticity and uniformity of the studied plant material.

At the end of the 1920s, Vavilov organized several potato-collecting missions in South and Central America. Vavilov and his colleagues, Juzepczuk and Bukasov, participated in these expeditions and worked on gathered material, designated two centers of potato varietal riches and diversity—the Peru–Bolivia high-mountain center and the southern coast of Chile. The WIR Herbarium holds authentic specimens of many taxa described by Russian taxonomists. Here, a set of 20 plastid DNA-specific markers was applied for 49 authentic herbarium specimens of Solanum tuberosum L. from the WIR Herbarium to analyze the genetic diversity of the landrace population collected by Juzepczuk in 1928 in southern–central Chile. Two plastid DNA types, T and A, and two chlorotypes were identified in herbarium specimens, with a clear predominance (96%) of chlorotype cpT_III. In addition, we analyzed 46 living Chilean accessions from the VIR field potato gene bank that were collected after the appearance of Phytophthora infestans in Chile. These living accessions were differentiated into four chlorotypes. Finding a D-type cytoplasm in living Chilean accessions that possess two new chlorotypes indicates a replacement of native cultivars and introgression from the wild Mexican species S. demissum that was actively used in breeding as a source of race-specific resistance to late blight.

The present paper discusses methodological approaches to the creation of nomenclatural standards and genetic passports for Russian cultivars, currently being developed at the N.I. Vavilov Institute of Plant Genetic Resources (VIR) in collaboration with different breeding research centers. Plant material of potato cultivars bred in the Siberian Research Institute of Plant Cultivation and Breeding was collected by the cultivar creator A.D. Safonova in the experimental field of this institute and transferred to the VIR herbarium for preparation of their nomenclatural standards. Plant shoots and tubers of potato cultivars bred in other Siberian research centers in collaboration with the A.G. Lorkh All-Russian Research Institute of Potato Farming (VNIIKH) was collected by the representative of this institute in the experimental field of VNIIKH. As a result of joint research, nomenclatural standards were accomplished for 11 cultivars, namely ‘Аntonina’, ‘Zlatka’, ‘Lina’, ‘Lûbava’, ‘Nakra’, ‘Pamâti Rogačeva’, ‘Sarovskij’, ‘Safo’, ‘Solnečnyj’, ‘Tuleevskij’, ‘Ûna’** bred in five different Siberian breeding institutes including cultivars developed in collaboration with VNIIKH. Nomenclatural standards were prepared according to the ‘International Code of Nomenclature for Cultivated Plants’. DNA samples isolated from nomenclatural standards were used for preparation of genetic passports of these 11 cultivars. These genetic passports include information of the polymorphism of eight chromosome-specific microsatellites, data on the markers of 11 R-genes conferring resistance to various harmful organisms, as well as the information about cytoplasm types. Voucher specimens of additional three Siberian cultivars ‘Kemerovčanin’, ‘Kuznečanka’, ‘Tanaj’ and five Ural cultivars ‘Аlâska’, ‘Bravo’, ‘Irbitskij’, ‘Lûks’, ‘Terra’ from the Ural Research Institute for Agriculture were also registered in the VIR herbarium collection. For these eight cultivars, the genetic passports were not issued, but the results of SSR genotyping and molecular screening of voucher specimens performed with the same set of the DNA markers are presented in this report. A similar set of DNA markers was used for genotyping cultivar accessions from the in vitro and field collections of various institutes as well as cultivar specimens from eco-geographical tests performed within the framework of the Comprehensive Research Plan of the subprogram “Development of potato breeding and seed production in the Russian Federation”. The comparison of cultivar genetic passport data with genotyping results of specimens having the same name, but obtained from different sources made it possible to verify this plant material.

Potato is one of the most important food crops in the world and also in the Russian Federation. Among harmful organisms reducing potato yield potential, the potato cyst nematodes (PCN) are considered to be ones of the most damaging pests. Information on PCN resistant cultivars is important for potato breeding and production. Russian potato cultivars are characterized in the state-bio-test program for resistance to only one PCN species Globodera rostochiensis and one pathotype Ro1 which is reported to be present in the country. This study aimed to find domestic cultivars with multiple resistances to different PCN species and different pathotypes using phenotyping coupled with molecular marker analysis due to the risk of the occasional introduction of new pests. The phenotypic response was determined by the inoculation of plants with pathotypes Ro5 of G. rostochiensis and Pa3 of G. pallida. The obtained results were supplemented by the state-bio-test data on resistance to Ro1 of G. rostochiensis. Nine of 26 Russian cultivars were resistant both to Ro5 and Ro1 pathotypes and two cultivars possess multiple resistances to both PCN species. Most tested molecular markers associated with the Gpa2, GpaV_vrn, GpaV^s_spl, Grp1 loci showed discrepancies with phenotyping. However, a predictive haplotype and epistatic effect were detected.