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Potato Genotypes (potato + genotype)
Selected AbstractsInhibited Long-Distance Movement of Potato Leafroll Virus to Tubers in Potato Genotypes Expressing Combined Resistance to Infection, Virus Multiplication and AccumulationJOURNAL OF PHYTOPATHOLOGY, Issue 9 2003J. Syller Abstract Plants of two potato clones which, in preliminary greenhouse assessments, showed resistance to multiplication and accumulation of potato leafroll virus (PLRV) were graft or aphid inoculated with the virus and grown in the greenhouse; plants of a moderately susceptible cultivar were used for comparison in all experiments. A high concentration of aphid-borne inoculum was used to ensure strong infection pressure. Clone M62759 appeared to be highly resistant to PLRV infection, whereas clone PS1706 was more susceptible. Both clones expressed a high level of resistance to virus multiplication, when primary or secondary infection was assayed by enzyme-linked immunosorbent assay. Moreover, PLRV was detected in only few or none of the progeny plants of clone M62759, which thus strongly inhibited virus transport to tubers. The study on PLRV translocation from aphid-inoculated shoots to uninoculated shoots sprouted from the same tubers showed that no specific mechanisms are likely to impair PLRV movement through the tubers of the resistant genotypes. These results indicate that three valuable components of the resistance to PLRV are probably closely linked in the genotype, a combination that seems to occur rather rarely in potato clones. Nevertheless, selecting potato genotypes for the complex resistance to PLRV may prove to be a worthwhile part of breeding programmes, provided that the genetic mechanisms governing particular types of resistance are better recognized. [source] The influence of tuber mineral element composition as a function of geographical location on acrylamide formation in different Italian potato genotypesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2010Anne Whittaker Abstract BACKGROUND: The present study was aimed at examining the effect of tuber mineral composition, distinctive for geographical location, on the expression of acrylamide precursors in three potato genotypes (Arinda, Rossa di Cetica and Sieglinde) in three Italian potato cultivation regions (Puglia, Sicily and Tuscany). RESULTS: Sucrose and amino acids were not correlated with acrylamide formation. In contrast, reducing sugars, limiting with respect to the principal amino acid precursor asparagine, were positively correlated with acrylamide. From analysis of variance, both acrylamide and reducing sugars were not significant for variety but highly significant for location, with higher levels occurring in all three varieties cultivated in Tuscany, followed by Sicily and Puglia respectively. Reducing sugars were negatively correlated with K and Ca and positively correlated with Zn and Cu. Neither N nor P was correlated with reducing sugar content. Path analysis, a statistical technique distinguishing causation and correlation between variables, was implemented to provide additional insight on the interactions between mineral elements and reducing sugars under open field conditions. The variation in reducing sugars in all three varieties was shown to be attributable to Zn. CONCLUSION: Cultivation location has a significant impact on the composition of tuber mineral elements and, as a result, on genotype in the expression of reducing sugars. The negative correlation between Zn and K and the variation in reducing sugar content attributed to the element Zn, which is particularly available in acid soils, are important factors warranting future research aimed at reducing acrylamide formation from an agronomic perspective. Copyright © 2010 Society of Chemical Industry [source] First-generation SNP/InDel markers tagging loci for pathogen resistance in the potato genomePLANT BIOTECHNOLOGY JOURNAL, Issue 6 2003Andreas M. Rickert Summary A panel of 17 tetraploid and 11 diploid potato genotypes was screened by comparative sequence analysis of polymerase chain reaction (PCR) products for single nucleotide polymorphisms (SNPs) and insertion-deletion polymorphisms (InDels), in regions of the potato genome where genes for qualitative and/or quantitative resistance to different pathogens have been localized. Most SNP and InDel markers were derived from bacterial artificial chromosome (BAC) insertions that contain sequences similar to the family of plant genes for pathogen resistance having nucleotide-binding-site and leucine-rich-repeat domains (NBS-LRR-type genes). Forty-four such NBS-LRR-type genes containing BAC-insertions were mapped to 14 loci, which tag most known resistance quantitative trait loci (QTL) in potato. Resistance QTL not linked to known resistance-gene-like (RGL) sequences were tagged with other markers. In total, 78 genomic DNA fragments with an overall length of 31 kb were comparatively sequenced in the panel of 28 genotypes. 1498 SNPs and 127 InDels were identified, which corresponded, on average, to one SNP every 21 base pairs and one InDel every 243 base pairs. The nucleotide diversity of the tetraploid genotypes (, = 0.72 × 10,3) was lower when compared with diploid genotypes (, = 2.31 × 10,3). RGL sequences showed higher nucleotide diversity when compared with other sequences, suggesting evolution by divergent selection. Information on sequences, sequence similarities, SNPs and InDels is provided in a database that can be queried via the Internet. [source] Alteration of the genomic composition of Solanum nigrum (+) potato backcross derivatives by somatic hybridization: selection of fusion hybrids by DNA measurements and GISHPLANT BREEDING, Issue 3 2001K. Horsman Abstract Fusion experiments were performed with a first (BC1 -6738) and a second (BC2 -9017) generation backcross hybrid of 6x Solarium nigrum (+) 2x potato somatic hybrids with potato cultivars. Because no progeny was obtained from the BC2 genotypes, alternative approaches were sought to overcome the sexual crossing barrier. Five potato genotypes, one of which contains the hygromycin resistance gene, were used in the fusion experiments. All vigorous regenerants were used for the estimation of nuclear DNA content using flow cytometry. Plants with a DNA content higher than that of the BC1 -6738 or BC2 genotypes were considered potential somatic hybrids. Forty-nine potential somatic hybrids resulted from fusion experiments with BC1 -6738, from which 20 grew vigorously in the greenhouse and flowered. After pollination with several 4x potato cultivars, eight genotypes produced seeded berries and five genotypes gave seedless berries. In addition, 11 of these 13 somatic hybrids were selected for genomic in situ hybridization (GISH) analysis to determine their genomic composition. Nine had exactly or approximately the expected number of 36 S. nigrum and 60 potato chromosomes. In one genotype, only 22 instead of 36 S. nigrum chromosomes were found and one potato chromosome was possibly missing. Only five potential somatic hybrids were detected among the 79 regenerants from BC2 -9017 (+) 2x potato fusion experiments that were analysed by flow cytometry. Two of these hybrids were rather vigorous and did flower, but pollinations with potato have not yet set any berries. [source] Systemic Potato virus YNTN infection and levels of salicylic and gentisic acids in different potato genotypesPLANT PATHOLOGY, Issue 4 2005-Stres, H. Kre Endogenous levels of free and conjugated salicylic (SA) and gentisic (GA) acids, both putative signal molecules in plant defence, were analysed in order to investigate their involvement in the resistance of four potato (Solanum tuberosum) genotypes with different susceptibilities to Potato virus YNTN (PVYNTN) infection: the highly susceptible cv. Igor and its extremely resistant transgenic line, the extremely resistant cv. Sante and the tolerant cv. Pentland Squire. The lowest levels of free and conjugated SA were observed in the extremely resistant cv. Sante, while free GA, which was detected in all the other varieties, was absent. The extremely resistant transgenic cv. Igor contained the highest basal total SA level and the lowest level of total GA of all four cultivars. In susceptible cv. Igor, but not in resistant transgenic cv. Igor, a systemic increase of free SA was measured 1 day postinfection (dpi). Even more significant increases of free and conjugated SA and GA were detected 11 dpi when systemic symptoms appeared. In inoculated but not in upper noninoculated leaves of resistant transgenic cv. Igor, significant increase of SA conjugates occurred, but not before 11 dpi. The increase of SA and GA in susceptible cv. Igor could contribute to the general elevated levels of phenolic compounds as a response to stress caused by virus infection. It appears that basal levels of SA and GA do not correlate with resistance to PVYNTN in potato plants. [source] Factors underpinning the responsiveness and higher levels of virus resistance realised in potato genotypes carrying virus-specific R genesANNALS OF APPLIED BIOLOGY, Issue 2 2010A.L. Vuorinen Responses to Potato virus A (PVA, genus Potyvirus) segregate to three phenotypic groups in a diploid cross between Solanum tuberosum subsp. andigena and a highly interspecific potato hybrid. The aim of this study was to compare gene expression between the progeny genotypes which react with hypersensitive response (HR) to PVA, allow PVA accumulation in inoculated leaves but restrict PVA infection to the inoculated leaf by blocking systemic movement [non-necrotic resistance (nnr)], or are susceptible (S) and systemically infected with PVA. Expression levels of ca 10 000 genes were compared using probes arranged in a microarray format, and real-time RT-PCR was applied for quantitative comparison of the expression of selected defense-related genes (DRGs). Results showed that a few DRGs were autoactivated in HR genotypes at an early stage of plant growth in the absence of PVA infection, which was not observed in the two other phenotypic groups (nnr and S). More detailed studies on the DRGs encoding a beta-1,3-glucanase, a chitinase and a basic PR-1b protein showed that autoactivation of the genes was not evident in vitro and up to 2 weeks of growth in soil in a controlled growth cabinet but was apparent 2 weeks later. Hence, autoinduction of these DRGs in the HR genotypes could be associated with growth stage, environmental factors or both. Furthermore, a number of other DRGs were induced in the inoculated leaves of HR genotypes as a response to infection with PVA, which was not observed in nnr and S genotypes. These results provide some novel information about factors underpinning the higher levels of virus resistance realised in potato genotypes carrying virus-specific R genes and suggest that part of the resistance is attributable to additional ,minor' genes functioning simultaneously, hence adding to the overall responsiveness and level of resistance against infection. These results also imply that some genotypes might be more responsive to chemical induction of pathogen and pest resistance, which could be considered in screening of progenies in plant-breeding programs. [source] | ||||||||||