97 research outputs found

    Composition of the collection of primitive cultivated species within the Solanum L. section Petota Dumort. and contemporary trends in their research

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    The diversity of potato genetic resources in the VIR genebank harbors one of the world’s first collections of primitive cultivated species. These accessions are native potato varieties cultivated by the indigenous population of South America. The oldest accessions in the collection are traced back to 1927. Approximately one fifth of the collection (106 accessions out of 573) is the unique material procured by VIR’s collecting missions to Bolivia, Colombia, Ecuador, and Peru. According to S. Bukasov’s potato classification, the diversity of South American highland potatoes explored by VIR’s collectors belongs to spp. Solanum ajanhuiri Juz. et Buk., S. × chaucha Juz. et Buk., S. mammilliferum Juz. et Buk., S. phureja Juz. et Buk., S. rybinii Juz. et Buk., S. goniocalyx Juz. et Buk., S. stenotomum Juz. et Buk., S. tenuifilamentum Juz. et Buk., S.× juzepczukii Buk., and S. × curtilobum Juz. et Buk. Within this group of species, S. × ajanhuiri, S. phureja and S. stenostomum are the closest in their characteristics to ancient domesticated forms of tuber-bearing Solanum spp. This publication is an analytical review of the current composition of the primitive cultivated potato species collection and the results of its earlier studies. Ecogeographic descriptions of the sites native for cultivated potatoes and information on the sources of the accessions are presented. A large-scale evaluation of primitive cultivated potato accessions by a set of characters, carried out in field and laboratory experiments, uncovers their breeding potential and serves as the primary information platform for further indepth research. Studying S. phureja and closely related cultivated potato species is important for finding solutions of fundamental problems in plant biology. The data arrays accumulated today would facilitate targeted selection among accessions to identify most promising ones for molecular genetic studies into the gene pool diversity of potato species

    Distribution of potato mosaic viruses on plants of the <i>Petota</i> Dumort. section of <i>Solanum</i> L. in the VIR collection

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    Background. Potato due to its vegetative propagation is affected by viruses, among which potato viruses Y (PVY), S (PVS) and M (PVM) are spread across all Russia’s territory. The VIR collection presents the diversity of the potato gene pool, including potato cultivars and related tuber-forming species. Diagnostics of viral infections in plants saved for several years by obtaining tuber reproductions is an important part of the work on the conservation and sustainable utilization of the potato gene pool.  The purpose of the work was to evaluate the distribution of PVX, PVY, PVS and PVM on plants of potato cultivars and related Solanum spp. in the VIR field collection.   Material and methods. Evaluation covered 315 accessions representing all groups of the potato gene pool. Diagnosis by enzyme-linked immunosorbent assay (ELISA) was carried out on plants that did not display symptoms of a virus infection. The Russian test system of RPA “BioTechnologies” and foreign one of Bioreba AG (Switzerland) were used. Statistical data processing was performed by the Statistica StatSoft 13 program.   Results. Mosaic viruses are distributed with different frequencies on potato plants in the field collection: PVM dominates, detected in 64% of potato accessions; PVY is found in 41 %, PVX on 24 %, and PVS in 18 % of accessions. The connection between the botanical and taxonomic origin of potato accessions and their infection with viruses has been confirmed. Among wild species, more than half of accessions, while among cultivated species, only 5% are affected by XBK. PVM, on the contrary, was detected in a significant part (77–91%) of cultivated potato accessions. and much less frequently (16%) in accessions of wild species. Cvs, ‘Grand’, ‘Krasa Meshchery’, ‘Yantar’ and ‘Nur-Alem’, hybrids 99-1-3, 952-35 and 914-5-2018, accessions of wild species from North America, and cultivated species Solanum goniocalyx Juz. et Buk. (k-9922) are not affected by viruses

    Late Pleistocene insects from the Dubrovino site at Ob River (West Siberia, Russia) and their paleoenvironmental significance

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    A blue-grey clay loam lens with plant and insect remains was found in an expo-sure of the Ob River, 2 km upper Dubrovino village in Novosibirskaya Oblast of Russia.Conventional radiocarbon dating of the Dubrovino deposit is ca 19,444±159 14C BP(23,234±338 cal yr BP) and coincides with Sartan glaciation period (MIS 2). Ninety-twoColeoptera species, dominated by fragments of Curculionidae and Carabidae are rep-resented in the Dubrovino deposit. Species of the tundra-steppe fauna are dominant,followed by meadow-dwelling taxa and coniferous forest taxa. A comparison of theDubrovino assemblage with the previously studied late Pleistocene Kalistratikha andBunkovo fossil assemblages showed that tundra-steppe landscapes with coniferousgroves and sparse meadow vegetation were typical for this area from the end of Kargininterglacial (MIS 3) through the end of the Sartan glaciation (MIS 2)

    Комплексы жесткокрылых из четвертичных отложений р. Кизиха - самые южные позднеплейстоценовые насекомые Западно-Сибирской равнины

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    Two sites with insect remains were found in an exposure on the bank of Kizikha river, in the Rubtsovskii District of the Altaiskii Krai of Russia, Kizikha-1 with radiocarbon age 13455±150 14C BP (SPb-1347), and Kizikha-2 with the age 26094±400 14C BP (SPb-1418). This period is coincides with Sartan stadial and Kargin interstadial (MIS 2 and MIS 3). This is the southernmost late Pleistocene insect bearing deposit found in West Siberia. The fragments in both sites are represented mainly by Coleoptera. Beetle fauna from the site Kizikha-1 is represented by 34 species from 9 families. The majority of fragments belong to weevils and ground beetles. 28 species from 8 families are found in Kizikha-2 site, the majority of fragments belong to Carabidae. 7 species found in the sites, Dyschiriodes rufimanus, Cymindis cf. rostowtzowi (Carabidae), Cidnopus cf. parallelus, Pristilophus punctatissimus (Elateridae), Hemitrichapion alexsandri (Brentidae), Paophilus albilaterus and Otiorhynchus sushkini (Curculionidae), are recorded in Pleistocene deposits for the first time. Sub-fossil insect assemblages of the two sites coincides with the late Pleistocene “Otiorhynchus-type” sub-fossil insect fauna from southeastern part of West-Siberian Plain (Zinovyev, 2011; Legalov et al., 2016) with characteristics as follows: dominance of steppe species, presence of halophile species, lack of forest species. Most of these species are absent in the contemporary regional fauna. The complex of eastern species and presence of endemics of Altai-Sayan Mountain system is also characteristic to the both studied sites. Specifics of the deposit assemblages in comparison with the other late Pleistocene fauna of West Siberian Plain is in high share of meadow species that could be explained by taphonomic condition of sedimentation or microclimatic conditions caused by close location to Altai mountains. Analysis of sub-fossil insect fragments showed that open landscapes with zonal steppe and sparse meadow vegetation near rivers and in depressions were typical for this area. In comparison to contemporary conditions climate was dry and cold, but Kizikha-2 (end of MIS 3) was formed in more mild climate conditions than Kizikha-1 (end of MIS 2). Results gained from Kizikha-1 and Kizikha-2 sites are complementing data on latitudinal-zonal distribution of beetles found in late Pleistocene deposits in West Siberian Plain

    Combination Breeding and Marker-Assisted Selection to Develop Late Blight Resistant Potato Cultivars

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    (1) Background: Although resistance to pathogens and pests has been researched in many potato cultivars and breeding lines with DNA markers, there is scarce evidence as to the efficiency of the marker-assisted selection (MAS) for these traits when applied at the early stages of breeding. A goal of this study was to estimate the potential of affordable DNA markers to track resistance genes that are effective against the pathogen Phytophthora infestans (Rpi genes), as a practical breeding tool on a progeny of 68 clones derived from a cross between the cultivar Sudarynya and the hybrid 13/11-09. (2) Methods: this population was studied for four years to elucidate the distribution of late blight (LB) resistance and other agronomical desirable or simple to phenotype traits such as tuber and flower pigmentation, yield capacity and structure. LB resistance was phenotypically evaluated following natural and artificial infection and the presence/absence of nine Rpi genes was assessed with 11 sequence-characterized amplified region (SCAR) markers. To validate this analysis, the profile of Rpi genes in the 13/11-09 parent was established using diagnostic resistance gene enrichment sequencing (dRenSeq) as a gold standard. (3) Results: at the early stages of a breeding program, when screening the segregation of F1 offspring, MAS can halve the workload and selected SCAR markers for Rpi genes provide useful tools

    Wild relatives and interspecific hybrids of potato as source materials in breeding for resistance to golden nematode

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    Background. Predominant use of the H1 and Gro1-4 genes of resistance to golden nematode (PGN) in potato breeding requires widening the gene pool of resistance to this pathogen.Materials and methods. Thirty-four genotypes of wild potatoes from North and South Americas, 14 interspecific hybrids, and 10 Russian potato cultivars were studied for PGN resistance. Screening for resistance to PGN pathotype Ro1 and molecular screening for the presence of H1 and Gro1-4 gene markers were performed. Amplification products of the Gro1-4 gene marker were sequenced.Results. Only seven among the studied 34 potato genotypes (two of S. brachystotrichum (Bitt.) Rydb., four of S. lesteri Hawkes et Hjerting, and one of S. kurtzianum Bitt. et Wittm.) were susceptible to PGN, while the rest demonstrated high or medium resistance. Molecular screening for the presence of H1 and Gro1-4 gene markers allowed us to identify Gro1-4 in 13 South American genotypes of S. alandiae Cárd., S. × doddsii Corr., S. kurtzianum, S. leptophyes Bitt., and S. yungasense Hawkes. The remaining 14 genotypes may supposedly contain resistance genes non-identical to H1 or Gro1-4. Hybrids of S. tuberosum L. with medium-resistant wild accessions of S. kurtzianum, S. leptophyes, S. sparsipilum (Bitt.) Juz. et Buk., S. alandiae, and S. × doddsii inherited PGN resistance determined either by the Gro1-4 gene or genes non-identical to H1 or Gro1-4. Sequencing a fragment of the Gro1-4 gene showed that changes in the structure of this fragment in orthologous genes did not affect the feature of resistance to PGN pathotype Ro1.Conclusion. For the first time, sources of resistance to PGN were found among the North American species S. brachystotrichum (k-23201) and S. lesteri (k-24475). Among the wild South American Solanum spp., sources of resistance determined by genes different from H1 or Gro1-4 were identified. Resistant interspecific hybrids can serve as donors of the Gro1-4 resistance gene or new resistance genes

    Polymorphism of CLE gene sequences in potato

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    CLE (CLV3/ESR) is one of the most important groups of peptide phytohormones: its members regulate the development of various plant organs and tissues, as well as interaction with some parasites and symbionts and response to environmental factors. In this regard, the identification and study of the CLE genes encoding the peptides of this group in cultivated plants are of great practical interest. Relatively little is known about the functions of CLE peptides in potato, since the CLE genes of the potato Solanum phureja Juz. et Buk. were characterized only in 2021. At the same time, potato includes plenty of tuberous species of the genus Solanum L., both wild and cultivated, and the diversity of its forms may depend on differences in the sequences of CLE genes. In this work, we performed a search for and analysis of the CLE gene sequences in three wild potato species (S. bukasovii Juz., S. verrucosum Schltdl., S. commersonii Dunal) and four cultivated species (S. chaucha Juz. et Buk., S. curtilobum Juz. et Buk., S. juzepczukii Juz. et Buk., S. ajanhuiri Juz. et Buk.). In total, we identified 332 CLE genes in the analyzed potato species: from 40 to 43 genes of this family for each potato species. All potato species taken for analysis had homologues of previously identified S. phureja CLE genes; at the same time, the CLE42 gene, which is absent from the S. phureja genome, is present in all other analyzed potato species. Polymorphism of CLE proteins of S. commersonii is significantly higher than that of other analyzed potato species, due to the fact that S. commersonii grows in places outside the growing areas of other potato species and this potato is probably not one of the ancestors of cultivated potato. We also found examples of polymorphism of domains of CLE proteins that carried different functions. Further study of potato CLE proteins will reveal their role in development, including regulation of productivity in this important agricultural crop

    Everolimus in patients with metastatic renal cell carcinoma previously treated with bevacizumab: a prospective multicenter study CRAD001LRU02T⃰

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    Everolimus is an orally administered inhibitor of the mammalian target of rapamycin (mTOR) recommended for patients with metastatic renal cell carcinoma (mRCC) who progressed on previous vascular endothelial growth factor (VEGF) receptor-tyrosine kinase inhibitor therapy. Efficacy of everolimus in patients who progressed on anti-VEGF monoclonal antibody bevacizumab is unknown. We did a multicenter prospective trial of everolimus in patients with mRCC whose disease had progressed on bevacizumab ± interferon alpha (IFN). Patients with clear-cell mRCC which had progressed on bevacizumab ± IFN received everolimus 10 mg once daily. The primary end point was the proportion of patients remaining progression-free for 56 days, and a two-stage Simon design was used, with 80 % power and an alpha risk of 5 %. This study is registered with ClinicalTrials.gov, number NCT02056587. From December 2011 to October 2013, a total of 37 patients (28 M, 9 F) were enrolled. Median age was 60.5 years (range 41-66), 11 % had Eastern Cooperative Oncology Group Performance Status (ECOG PS) &gt; 2, and Memorial Sloan-Kettering Cancer Center (MSKCC) favorable/intermediate risk was 38/62 %. Five (14 %) patients had a confirmed partial response and 26 (70 %) patients had a stable disease. Median progression-free survival was 11.5 months (95 % CI, 8.8–14.2). Median overall survival was not reached. No grade 3 or 4 treatment-related toxicities were observed. The most common grade 2 adverse events were fatigue (19 %) and pneumonitis (8 %). Everolimus demonstrated a favorable toxicity profile and promising anti-tumor activity as a second-line therapy in metastatic renal cell carcinoma (RCC) patients previously treated with bevacizumab ± IFN
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