Nomenclatural standards and genetic passports of potato cultivars bred in the A.G. Lorkh All-Russian Research Institute of Potato Farming

Abstract

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.

Phenotypic and DNA Marker-Assisted Characterization of Russian Potato Cultivars for Resistance to Potato Cyst Nematodes

“…According to A. Barone with colleagues (1990) [84], a major dominant gene Gro1 confers resistance to all pathotypes of G. rostochiensis including Ro5. In our previous research it was shown the extremely low frequency of the Gro1-4 marker in the Russian cultivar genepool [42,[56][57][58][59]. A few Gro1-4-positive cultivars were involved in the present study, however, any association with resistance to Ro5 pathotype was not detected.…”

“…The obtained results indicated high (87%) predictive association between the presence of two markers of the H1 gene-57R and TG689-and phenotypic resistance to Ro1. The diagnostic value of these markers can be increased up to 90% in the case of counting moderately resistant cultivars as resistant genotypes [42,[56][57][58][59]. This study also demonstrated the extremely low frequency of Gro1-4 resistance-predictive allele within the subset of Russian potato cultivars.…”

“…Vavilov All-Russian Institute of Plant Genetic Resources (VIR). In our previous research, all these cultivars were genotyped in SSR analysis and tested using molecular markers of the H1 and Gro1-4 genes conferring resistance to pathotype Ro1 of G. rostochiensis as well as with DNA markers associated with R-genes of extreme resistance to PVY, PVX and resistance to late blight [57][58][59]. Data about their resistance to Ro1 of golden nematode were obtained from the results of bioassays recorded in the State Register of Breeding Achievements [22].…”

“…In the case of Russian cultivars, molecular screening for H1 resistance was first applied by V. Birukova and colleagues [55] who screened with marker TG689 a set of 109 cultivars of different origin (Western European, Ukrainian, Belarusian) including 36 cultivars bred in Russia. Later in a series of our research, a bigger subset of 211 cultivars bred in the Russian Federation were screened with several markers of the H1 and Gro1-4 genes [42,[56][57][58][59]. These subsets included cultivars with declared resistance/susceptibility to Ro1 of golden nematode [22].…”

“…Bio-testing of Russian cultivars for resistance to pathotypes other than Ro1 pathotype of G. rostochiensis and to G. pallida has never been performed. Information about the presence of cultivars potentially resistant to the pale nematode pathotypes was obtained in molecular screening with the intragenic marker Gpa2-2 of the Gpa2 gene which is involved in control of resistance to the pathotypes Pa2/3 of G. pallida [57][58][59]61]. However, for cultivars which were selected in molecular screening and had marker Gpa2-2, resistance was not validated in bio-testing.…”