Breeding Clones Research Articles

Adaptability, stability, and productivity of potato breeding clones and cultivars at high latitudes in Europe

The aim of potato breeding is to release cultivars that exhibit high and stable performance across the target population of environments. The objective of this research was therefore to investigate the use of various methods (site regression [SREG], coefficient of variation and regression deviation [σ2δ]) for determining the adaptability and stability of productive and quality traits in the Nordic region of Europe. The multi-environment trials included 256 breeding clones and released cultivars grown by EU farmers at three distinct testing sites over two years in Sweden. There was significant (P < 0.001) variation in tuber yield, starch percentage and reducing sugars in the tuber flesh among the breeding clones and cultivars, testing environments and the genotype by environment interaction (GEI). The environments were very diverse, as revealed by the SREG biplots and particularly for the GEI patterns noted in terms of their productive and quality characteristics. The percentage of stable high-tuber yielding germplasm was greater for breeding clones (23%) than for released European cultivars (2%), thus revealing the advantage of potato breeding in the target population of environments. SLU 1415001 and SLU 1314015 were the most promising breeding clones due to their stable high tuber yield. This characteristic was best for the starch potato cultivars, although none of them exhibited a significant different σ2δ. ‘Talent’ shows an almost stable good performance among low reducing sugar cultivars and breeding clones, which are often unstable in terms of their scoring across environments. Neither a breeding clone nor a cultivar was at the top for stable tuber yield, tuber flesh starch or reducing sugars in the tuber flesh, which shows the challenge faced by potato breeding while addressing the needs of different markets.

Mapping of a novel locus Ra conferring extreme resistance against potato virus A in cultivated potato (Solanum tuberosum L.).

The Ra extreme resistance against potato virus A was mapped to the upper of chromosome 4 in tetraploid potato. Potato virus A (PVA) is one of the major viruses affecting potato worldwide and can cause serious disease symptoms and yield losses. Previously, we determined that potato cultivar Barbara harbors Rysto (genotype: Ryryryry) and Ra (genotype: Rararara) that each independently confer extreme resistance to PVA. In this study, employing a combination of next-generation sequencing and bulked-segregant analysis, we further located this novel Ra on chromosome 4 using a tetraploid BC1 potato population derived from a Ry-free progeny (Rararararyryryry) of Barbara (RarararaRyryryry) × F58050 (rararararyryryry). Using 29 insertion-deletion (InDel) markers spanning chromosome 4, Ra was delimited by the InDel markers M8-83 and M10-8 within a genetic interval of 1.46cM, corresponding to a 1.86-Mb genomic region in the potato DM reference genome. The InDel marker M10-8, which is closely linked with the resistance against PVA in the Ry-free segregating populations, was then used to screen 43 selected Rysto-free tetraploid potato breeding clones. The phenotype to PVA was significantly correlated with the present/absent of the marker, albeit with a 9.3% false positive rate and a 14.0% false negative rate. These findings are of importance in furthering the cloning of Ra and employing the marker-assisted selection for PVA resistance.

QTL identified that influence tuber length-width ratio, degree of flatness, tuber size, and specific gravity in a russet-skinned, tetraploid mapping population.

Potato tuber shape, size, and specific gravity are important agronomic traits in the russet market class of potatoes with an impact on quality, consistency, and product recovery of processed foods such as French fries. Therefore, identifying genetic regions associated with the three traits through quantitative trait locus/loci (QTL) analysis is a crucial process in the subsequent development of marker-assisted selection for use in potato breeding programs. QTL analysis was conducted on a tetraploid mapping population consisting of 190 individuals derived from the cross between two russet-skinned parents, Palisade Russet and the breeding clone ND028673B-2Russ. Field data collected over a 2-year period and used in the QTL analyses included tuber length-width and width-depth ratios that were obtained using a digital caliper. The width-depth ratio provided an assessment of the "flatness" of a tuber, which is of importance in potato processing. To cross-validate the accuracy and differences among tuber shape measurement methods, a trained evaluator also assessed the identical tubers based on 1-5 scale (compressed to long) visual assessment method. Furthermore, the weights of analyzed tubers and specific gravities were also collected during the phenotyping process for each mapping clone. A major tuber shape QTL was consistently observed on chromosome 10 with both the length-width ratio and visual assessments. On chromosome 4, a significant QTL for tuber shape from the visual assessment phenotypic data was also detected. Additionally, a tuber shape-related QTL on chromosome 6 was also detected from the length-width ratio data from 2020. Chromosome 2 was also identified as having a significant QTL for the width-depth ratio, which is of importance in influencing the flatness of a tuber. One significant QTL for tuber weight (i.e., tuber size) was observed on chromosome 5, and a significant QTL for specific gravity was found on chromosome 3. These significant and major QTL should be useful for developing marker-assisted selection for more efficient potato breeding.

Genomic Prediction for Inbred and Hybrid Polysomic Tetraploid Potato Offspring

Potato genetic improvement begins with crossing cultivars or breeding clones which often have complementary characteristics for producing heritable variation in segregating offspring, in which phenotypic selection is used thereafter across various vegetative generations (Ti). The aim of this research was to determine whether tetrasomic genomic best linear unbiased predictors (GBLUPs) may facilitate selecting for tuber yield across early Ti within and across breeding sites in inbred (S1) and hybrid (F1) tetraploid potato offspring. This research used 858 breeding clones for a T1 trial at Umeå (Norrland, 63°49′30″ N 20°15′50″ E) in 2021, as well as 829 and 671 clones from the breeding population for T2 trials during 2022 at Umeå and Helgegården (Skåne, 56°01′46″ N 14°09′24″ E), respectively, along with their parents (S0) and check cultivars. The S1 and F1 were derived from selfing and crossing four S0. The experimental layout was an augmented design of four-plant plots across testing sites, where breeding clones were non-replicated, and the parents and cultivars were placed in all blocks between the former. The genomic prediction abilities (r) for tuber weight per plant were 0.5944 and 0.6776 in T2 at Helgegården and Umeå, respectively, when T1 at Umeå was used as the training population. On average, r was larger in inbred than in hybrid offspring at both breeding sites. The r was also estimated using multi-environment data (involving at least one S1 and one F1) for T2 performance at both breeding sites. The r was strongly influenced by the genotype in both S1 and F1 offspring irrespective of the breeding site.

Identification of QTL associated with plant vine characteristics and infection response to late blight, early blight, and Verticillium wilt in a tetraploid potato population derived from late blight-resistant Palisade Russet.

Potato late blight (causal agent Phytophthora infestans) is a disease of potatoes with economic importance worldwide. Control is primarily through field monitoring and the application of fungicides. Control of late blight with fungicides and host plant resistance is difficult, with documented cases of such control measures failing with the advent of new pathotypes of P. infestans. To better understand host plant resistance and to develop more durable late blight resistance, Quantitative Trait Locus/Loci (QTL) analysis was conducted on a tetraploid mapping population derived from late blight-resistant potato cultivar Palisade Russet. Additionally, QTL analyses for other traits such as Verticillium wilt and early blight resistance, vine size and maturity were performed to identify a potential relationship between multiple traits and prepare genetic resources for molecular markers useful in breeding programs. For this, one hundred ninety progenies from intercrossing Palisade Russet with a late blight susceptible breeding clone (ND028673B-2Russ) were assessed. Two parents and progenies were evaluated over a two-year period for response to infection by the US-8 genotype of P. infestans in inoculated field screenings in Corvallis, Oregon. In Aberdeen, Idaho, the same mapping population was also evaluated for phenotypic response to early blight and Verticillium wilt, and vine size and maturity in a field over a two-year period. After conducting QTL analyses with those collected phenotype data, it was observed that chromosome 5 has a significant QTL for all five traits. Verticillium wilt and vine maturity QTL were also observed on chromosome 1, and vine size QTL was also found on chromosomes 3 and 10. An early blight QTL was also detected on chromosome 2. The QTL identified in this study have the potential for converting into breeder-friendly molecular markers for marker-assisted selection.

Optimizing multi-environment testing in potato breeding: using heritability estimates to determine number of replications, sites, and years for field trials

Multi-environment trials (METs) of potato breeding clones and cultivars allow to precisely determine their performance across testing sites over years. However, these METs may be affected by the genotype × environment interaction (GEI) as noted in tuber yield. Furthermore, trials are replicated several times to optimize the predictive value of the data collected because knowledge on spatial and temporal variability of testing environments is often lacking. Hence, the objectives of this research were to use components of variance from METs to estimate broad sense heritability (H2) based on best linear unbiased predictors and use these estimates to determine the optimum number of sites, years, and replications for testing potato breeding clones along with cultivars. The data were taken from METs in southern and northern Sweden comprising up to 256 breeding clones and cultivars that underwent testing using a simple lattice design of 10-plant plots across three sites over 2 years. Percentage starch in the tuber flesh had the largest H2 in each testing environment (0.850–0.976) or across testing environments (0.905–0.921). Total tuber weight per plot also exhibited high H2 (0.720–0.919) in each testing environment or across them (0.726–0.852), despite a significant GEI. Reducing sugar content in the tuber flesh had the lowest, but still medium H2 (0.426–0.883 in each testing environment; 0.718–0.818 across testing environments). The H2 estimates were smaller when their variance components were disaggregated by year and site, instead of lumping them as environments. Simulating H2 with genetic, site, year, site × year, genetic × site, genetic × year, genetic × site × year, and residual variance components led to establish that two replicates at each of two sites in 2-year trials will suffice for testing tuber yield, starch and reducing sugars. This article provides a methodology to optimize the number of testing size and years for METs of potato breeding materials, as well as tabulated information for choosing the appropriate number of trials in same target population of environments.

Studies of potato resistance to Globodera rostochiensis revealed novel alleles for 57R marker.

Globodera rostochiensis resistance has been an important trait in potato (Solanum tuberosum) breeding for decades. Our aim was to complement phenotypic testing with genetic marker analysis. We analysed the results of G. rostochiensis resistance greenhouse testing in 4601 tubers of 2918 breeding clones from 11 years. Applicability of H1 gene markers TG689 and 57R was compared. We implemented the latter with the positive predictive value of 99.1% and negative predictive value of 60.0% into the breeding scheme. The 57R marker alleles of 22 Estonian cultivars and 470 breeding clones were determined. Two unique 57R alleles, 57R-887 and 57R-1155, were found in Estonian cultivar 'Anti'. The 887 bp allele has two deletions (14 bp and 490 bp) accompanied by several other indels and SNPs within the 57R marker region. The 1155 bp allele has three deletions (7 bp, 20 bp and 210 bp) accompanied by several other indels and SNPs within the same region. Partial resistance to G. rostochiensis in 'Anti' suggests that the newly described alleles could affect the H1-mediated resistance directly or indirectly.

Yield Stability of East African Highland Cooking Banana ‘Matooke’ Hybrids

East African banana (Musa sp.) breeding efforts have focused mainly on enhancing ‘Matooke’ productivity through the development of high-yielding, pathogen-resistant cultivars with adequate stability to contribute to regional food security. Before a breeding program can recommend promising cultivars for release, they must pass the sensory screens; be evaluated in the target population environments; and the data analyzed for yield, adaptability, and stability. Twenty-four primary and secondary triploid hybrids [NARITA (N)] derived from ‘Matooke’ bananas, six triploid local ‘Matooke’ cultivars, and one exotic cultivar were evaluated for their yield, adaptability, and stability across the East African region at three highland sites in Uganda’s western and central regions, as well as at three sites in Tanzania’s northeastern and southern highlands regions, from 2016–19. A randomized complete block design with four replicates was used for multisite trials. The mixed-model restricted maximum likelihood/best linear unbiased prediction approach, along with additive main effect multiplicative interaction model biplots, were used to dissect and visualize genotype-by-environment patterns. Following the likelihood ratio test, both genotype and interaction effects were highly significant, confirming the influence of genotype and site heterogeneity for selecting specific and broadly adapted cultivars. N23 had the greatest yield across all sites associated with adaptability and stability, outperforming the overall mean yield of all genotypes by 34.2%. In Tanzania, N27 (second), N7 (third), N18 (fourth), N4 (fifth), N12 (sixth), and N13 (seventh); and in Uganda, N17 (second), N18 (third), N2 (fourth), N8 (fifth), N13 (sixth), N12 (seventh), N4 (eighth), and N24 (ninth) demonstrated good adaptability and stability, as well as high yield. Furthermore, the fungal pathogen Pseudocercospora fijiensis had no significant effect (P &gt; 0.05) on yield, stability, and adaptability of the hybrids. As a result, they can be introduced into areas where black leaf streak constrains banana production significantly and threatens farmers’ livelihoods. The average site yield potential ranged from 9.7 to 24.3 t⋅ha–1 per year. The best discriminating sites for testing breeding clones were Lyamungo in Tanzania and Sendusu in Uganda. Hence, these testing sites are recommended as ideal examples of locations for selecting superior genotypes.

Selection of Sweetpotato Parental Genotypes Using Simple Sequence Repeat Markers.

Knowledge of the genetic diversity and genetic relationship is important in crop improvement. The objective of this study was to determine the genetic diversity of 31 sweetpotato genotypes and furthermore to select distantly related individuals for breeding of superior parental clones. The genotypes (sourced from the Agricultural Research Council, South Africa) originating from Africa and American continent were genotyped using eight highly polymorphic SSR markers. The SSR markers generated a total of 83 putative alleles. The polymorphic information content (PIC) of the tested simple sequence markers varied from 0.73 to 0.91, with a mean of 0.85. At least 11 different alleles were found in 8 loci within the population, with 7 effective alleles per locus. Although high diversity was found among the genotypes, genetic distances among the genotypes were relatively low. Cluster analysis revealed the existence of three distinct genetic groups, and the clustering patterns follow to some extent the geographic origin and pedigree of the genotypes. High gene flow was observed among different sweetpotato accessions. The selected SSR markers were found to be highly polymorphic with high discriminatory power for genetic characterization studies and are useful genomic tool to complement phenotyping of sweetpotato genotypes. Two heterotic groups were found in the study. The heterotic group A was composed of 14 genotypes mainly of South African origin, while the heterotic group B consisted of 17 genotypes of American origin. The two distinct groups were important for the selection of breeding clones that were distantly related to be used as parental clones in the advancement of traits of interest.

Evaluation of Genetic Resources in a Potato Breeding Program for Chip Quality

The objective of this study was to assess the ability of experimental advanced breeding clones as parental genotypes to transmit agronomic and quality traits to their progenies in breeding programs. A half diallel set of crosses (excluding reciprocals) with six parents was assayed in field trials for three years; four of the parents were Solanumtuberosum subsp. tuberosum cultivars, and two of them were advanced breeding clones that included genes from S. tuberosum subsp. andigenum with immunity to PVY virus and good agronomic performance. However, no information was available about the behavior of these clones as parental materials for quality traits, such as potato chip quality. The diallel mating design allowed us to discover their ability to transmit agronomic and quality traits to their offspring. Significant effects on general combining ability and specific combining ability were found for plant maturity, only general combining ability effects for specific gravity were found, and interactions of both general combining ability and specific combining ability with the environment for the chip color trait were found. However, no genetic effects were detected for yield. Where general combining ability significant effects were found, additive genetic effects are predominant; thus, so for those traits, it would be possible to use these genotypes as parents to obtain improved progenies. Such abilities were not found in the advanced breeding clones.

Identification of superior parental lines based on BLUP breeding values in potato (Solanum tuberosum L.)

Identification of superior parental lines require phenotypic or genotypic characterization of the germplasm, which is time consuming and laborious. The advanced potato breeding clones including control varieties were evaluated under field conditions to identify the suitable parental lines for tuber yield, late blight and specific gravity based on estimated breeding values using historical data as training population during 2008-09 to 2019-20. Pedigree of all the clones was searched to a depth of 5-6 generations. The mixed model fitting using REML was true. The minimum and maximum values for total tuber yield, late blight area under disease progress curve (AUDPC) and specific gravity were 28.33-732.2, 0-1846.25, 1.043-1.087, respectively. Pedigree had 161 founders out of total 759 individuals and the pedigree matrix showed relationship in 1,09,057 pairs. Heritability estimate was highest for specific gravity (0.77) followed by late blight AUDPC (0.49) and total tuber yield (0.24). The estimate of the BLUP breeding values (EBVs) for total tuber yield were highest for Kufri Mohan, Kufri Pukhraj, Kufri Khyati, SM/14-342 and Kufri Pushkar while SM/10-05, SM/09-99, Kufri Girdhari, SM/11-120 and Kufri Karan for late blight resistance, and Kufri Chipsona-1, SM/14-225, SM/14-229, SM/10-220 and SM/09-153 for specific gravity were the best genotypes. The prediction accuracy measured as correlation between EBV and observed phenotype score for specific gravity (0.97) was near perfect, very high for late blight AUDPC (0.75), and high for total tuber yield (0.55). The prediction bias measured as regression coefficient and scatter plots of observed phenotype values on EBVs was nil to low for specific gravity andlate blight AUDPC, while underestimation was observed for total tuber yield. Overall, the prediction accuracies for all the three traits were very good and selection of parental lines using Best Linear Unbiased Prediction breeding values could result in enhanced genetic gain in potato breeding

The CROP QUALITY ASPECTS OF POTATO VARIETIES AND BREEDING CLONES IN ORGANIC FARMING SYSTEMS

One of the indicators of quality is the starch content of the tubers. In order to evaluate the starch content for each genotype, the Institute of Agricultural Resources and Economics had set up a field trial in organic crop production system with 10 potato varieties and 10 breeding clones. A field trial was carried out in 2018-2020. The aim of the study was to evaluate and select potato varieties and clones with high starch content in the organic farming system. The results proved impact of meteorological conditions on the starch content in the potato tubers. Starch content of varieties and clones varied from 12.68% to 20.63% on average in 3 years, significant impact of genotypes and years were observed (p&lt;0.05). The highest starch content was found in 2019 for the variety ‘Kuras’ (21.32%) and for clones 19922.29 (21.0%) and 2008-6.5 (21.11%), also the following year these clones had a high starch content of (20.9%) and (21.17%), respectively. The high starch content in 2020 was also for the early varieties ‘Monta’ and ‘Rigonda’, ‘Prelma’ (21.17%). In 2018, many varieties and clones had a significantly lower starch content compared to 2019 and 2020 (p&lt;0.05).

Public potato breeding progress for the Nordic Region of Europe: evidence from multisite testing of selected breeding clones and available released cultivars

ABSTRACT The breeding of new cultivars is a powerful approach to increase both the quantity and quality of potato harvest per land unit. The aim of this research was to determine using multi-site testing the progress made by the genetic enhancement of potato in Sweden in the last 1.5 decades by comparing advanced breeding clones (T4 upwards) bred in Sweden (Svensk potatisförädling hereafter) versus available released cultivars in Europe and grown in its Nordic Region. The multi-site testing results show that potato breeding based in Scandinavia offers to the growers of the Nordic Region of Europe cultivars for prevailing farming environments and end-user needs rather than relying, as happens today in the market, on foreign cultivars. These cultivars bred elsewhere are not always very suitable for the challenging Nordic agroecosystems, as shown by the results of the multi-site testing herein. Such an approach on relying on foreign cultivars may be advocated for not funding potato breeding in, and for Fennoscandia by those ignoring the results shown by this research.

KASP markers validation for late blight, PCN and PVY resistance in a large germplasm collection of tetraploid potato (Solanum tuberosum L.)

Molecular markers are important and valuable tools in crop breeding programmes to help in the discovery and manipulation of important genes governing resistance reaction. In potato, several biotic stresses hamper quantity and quality of tuber production. Availability of molecular markers and high throughput screening method provide an excellent opportunity to practice marker assisted selection for potato improvement without waiting for phenotypic screening. In this study, we developed 20 KASP markers related to late blight, PVY and PCN resistance traits to facilitate the screening at earlier stages of potato breeding programmes. Out of these 20 markers, nine KASP assays were validated and associated with the phenotype data on respective traits for reliability in their wider application. The validation was done in a panel of 1447 potato germplasm accessions including varieties from diverse provenience and advanced breeding clones. Among traits, the best association found related to KASP markers for late blight, namely markers snp ST00106, snp ST00020 and snp ST00023. Overall, the allele calls were conclusive for all the nine markers, and the results demonstrate the usefulness of SNP KASP markers in high throughput cost effective marker assisted selection (MAS) for important biotic stress traits in potatoes.

Heritable Variation, Genetic and Phenotypic Correlations for Tuber Traits and Host Plant Resistance to Late Blight for Potato Breeding in Scandinavian Testing Sites

Potato breeding aims to improve crop productivity, quality and resilience based on heritable characteristics. Estimating the trait heritability and correlations—both genetic and phenotypic—among characteristics in a target population of environments allows us to define the best breeding method that leads to selection gains. Breeding clones (47) and released cultivars (209) were grown using simple lattice designs at three testing sites in northern and southern Sweden to estimate the best linear unbiased predictors (BLUPs) derived from mixed linear models for characteristics such as tuber weight (total and according to sizes), host plant resistance to late blight (caused by the oomycete Phytophthora infestans) and tuber quality (starch percentage based on specific gravity measurements and reducing sugars). There was significant heritable variation for all the characteristics investigated. Tuber starch percentage and total tuber weight were the traits with the highest broad-sense heritability (H2), while the weight for the smallest size (&lt;40 mm) had the highest H2 among the different tuber categories. These results show the potential for further improving these traits for Scandinavia through recombination and selection in segregating offspring. The genetic and phenotypic correlations among the tuber weight characteristics were significant (p ≤ 0.05) irrespective of their sizes, but none were significant (p &gt; 0.05) with tuber starch percentage. Host plant resistance to late blight was negatively and significantly associated with tuber weight and starch percentage, thereby showing the strong effects of this disease on the productivity and quality of the potatoes.

Correction to: Russet Potato Breeding Clones with Extreme Resistance to Potato Virus Y Conferred by Rychc as well as Resistance to Late Blight and Cold‑Induced Sweetening

Potato virus Y (PVY) impacts potato production worldwide by reducing potato yield, tuber quality, and successful certification of seed. Extreme resistance to PVY is conferred by three genes (Ryadg, Rysto, and Rychc) which have been introgressed from wild species into cultivated varieties. Both Rysto and Ryadg are used in many breeding programs worldwide, but Rychc is found in only a limited number of varieties and previously had been absent in varieties and germplasm representative of the russet market class that is widely grown in North America. Five russet breeding clones were identified as having the molecular marker associated with Rychc. Confirmation of the presence of Rychc was established following field and greenhouse screening of the clones for resistance to PVY with no infection by the virus being observed. These clones also have been characterized as having resistance to late blight and cold-induced sweetening of tubers and all are male-fertile as well. The unique assemblage of resistances in this russet germplasm will be of value to the potato breeding community in the development of russet potato varieties, especially with respect to Rychc which previously has not been reported as being present in this potato market class.

Russet Potato Breeding Clones with Extreme Resistance to Potato Virus Y Conferred by Rychc as well as Resistance to Late Blight and Cold-Induced Sweetening

Russet Potato Breeding Clones with Extreme Resistance to Potato Virus Y Conferred by Rychc as well as Resistance to Late Blight and Cold-Induced Sweetening

Breeding Late Blight Resistant Potatoes for Organic Farming—a Collaborative Model of Participatory Plant Breeding: the Bioimpuls Project

AbstractIn organic potato production, the need for varieties with durable late blight resistance developed through classical breeding programmes is urgent. Besides late blight resistance, other variety characteristics needed in organic potato production are early canopy closure for weed suppression and good tuber dormancy to eliminate the need for (chemical) sprouting inhibition during storage, amongst others. This paper is a unique example of collaboration between researchers, farmers and professional breeders of both large, medium and small breeding companies. The aim of the resulting breeding project, Bioimpuls, was to provide a substantial impulse to both the organic and conventional potato breeding sector by enlarging the access to various sources of late blight resistance. The Bioimpuls activities include providing true seed populations for variety selection with five available sources ofR-genes againstPhytophthora infestans, early and advanced introgression breeding with six newR-genes, and education and communication. The results achieved over the 11-year period (2009–2019) are analysed. Many true seed populations containing multiple resistance genes are produced and selected, and a constant flow of breeding clones is entering the evaluation and positioning trials of companies. However, it will still take a considerable amount of time before varieties with stacked resistance genes will replace the new resistant single gene varieties entering the market in the next few years. Five out of six new sources ofR-genes need more years of backcrossing before they are ready for commercial use. Bioimpuls successfully introduced a training course for farmer breeders, and published a manual for potato breeding.

Antioxidant Activity, Polyphenolic Profiles and Antibacterial Properties of Leaf Extract of Various Paulownia spp. Clones

Paulownia spp. are widely distributed ornamental trees with leaves abundant in secondary metabolites of high medicinal potential. Eighteen breeding clones of Paulownia spp. were tested in terms of their antioxidant activity and total polyphenolic contents. The 50% ethanolic extracts (2 g/30 mL) of leaves and petioles were compared in the screening step. Eight paulownia clones were selected for detailed analyses including HPTLC polyphenolic profile, verbascoside content and antibacterial activity against five bacteria species (S. aureus, B. cereus, E. coli, Y. enterocolitica, S. enterica). The species-specific differences in terms of antioxidant activity correlated with phenolic compounds were found mainly in the case of leaf blade extracts, the highest for P. tomentosa × P. fortunei and the lowest for P. elongata × P. fortunei clones. The P. tomentosa clones varied greatly in this regard. In the HPTLC polyphenolic profile, the occurrence of some polyphenols was proved and the specific verbascoside content was quantified (70 to 225 mg/g DW). The P. tomentosa × P. fortunei hybrids had the highest inhibitory activity, mainly against Gram-positive bacteria, whereas only slight inhibition of S. aureus growth was observed for P. elongata × P. fortunei clones. The obtained results indicate diverse suitability of paulownia clones as a source of active ingredients.

Nomenclatural standards and genetic passports of potato cultivars bred by the Tatar Research Institute of Agriculture «Kazan Scientific Center of the Russian Academy of Sciences»

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.