American Journal of Potato Research最新文献

The stubby root nematode, Paratrichodorus allius, is an important plant-parasitic nematode that feeds on plant roots and transmits Tobacco rattle virus to potato. Identification of P. allius based on morphometric measurements requires taxonomic knowledge, while previously developed molecular techniques require a well-equipped laboratory. A new recombinase polymerase amplification (RPA) assay was developed in this study, which requires minimal sample preparation, low temperature (37–42 °C), and short time duration (20–40 min) for detection of P. allius. RPA primers were designed targeting the internal transcribed spacer (ITS) region, and conditions were optimized to amplify DNA at 40 °C in 20 min. RPA products were visualized using agarose gel electrophoresis and SYBR Green I dye. In-silico analysis was conducted to predict the primer specificity. The RPA assay was specific to P. allius only. Detection sensitivity of the agarose gel electrophoresis-based RPA assay was 1/4th portion of a single nematode, and a single nematode by the SYBR Green I-based assay. This assay was validated with P. allius infested potato fields. The developed RPA assay can serve as an efficient tool for rapidly detecting P. allius from infested potato fields to help growers with their management decisions.

Brodie is a high-yielding white-fleshed potato cultivar with resistance to both pathotypes Ro1 and Ro2 of the golden cyst nematode (Globodera rostochiensis) and partial resistance to pathotype Pa2/3 of the pale cyst nematode (G. pallida). It was selected from a cross made at Cornell University in 1998 between Cornell breeding clones NY121 and NY115 and released by the New York Agricultural Experiment Station in 2018. The tubers are oval and slightly flattened, with shallow eyes and smooth attractive skin. In addition to its suitability for tablestock, Brodie also has merit for chipping as its chip color is good, comparable in lightness to the chipping cultivar Snowden when chipped out of two to four months of 6.7 °C storage. Specific gravity of Brodie averaged 1.078 across 63 Northeastern US trials, 0.010 less than Atlantic in the same locations, while marketable yield averaged 115% of Atlantic across 70 trials in New York and Pennsylvania. For growers affected by pathotypes Ro1 and Ro2 of the golden nematode, Brodie provides a means of producing a marketable crop while simultaneously decreasing infestation levels of both Ro1 and Ro2.

In potato, a classification system known as the endosperm balance number (EBN) hypothesis has been employed as a measure of effective ploidy. This classification system assigns an integer value to each species based on their ability to form normal endosperm when crossed to a species with a “known” EBN. This hypothesis then stipulates that only species with the same EBN number are able to form viable seeds. This is a widely accepted classification system in the potato breeding community and has some utility. However, research since its proposal has highlighted instances where this hypothesis is inconsistent or breaks down entirely. Nevertheless, the EBN hypothesis still directs many potato breeders away from utilizing some of the more valuable wild species that are deemed too difficult to access. Utilizing two experiments, we attempted to validate the accuracy of the EBN classification system. We found significant variation for normal seed development in interspecific crosses and between 11 1EBN species and three clones of the 2EBN wild species S. verrucosum that is not explained by the EBN hypothesis. As it stands, the EBN hypothesis does not have the capacity to fully capture and categorize the nuanced and complex postzygotic hybridization barriers that result in endosperm failure in potato. It is our recommendation that in the future the EBN hypothesis can only be used effectively as an indicator of where postzygotic incompatibility may occur, not a guide on which interspecific crosses are possible.

Potato mop top virus (PMTV) and Tobacco rattle virus (TRV) are significant soil borne pathogens of potato vectored by powdery scab and stubby-root nematodes, respectively. These viruses adversely impact tuber quality with infected tubers displaying brown streaks in the flesh and/or necrotic arcs on the surface contributing to the rejection of tubers in commercial settings. Currently, limited agricultural control methods for PMTV are available to farmers outside of planting resistant genotypes and avoiding fields with its vector; however, for TRV chemical control of the nematode vector is an option. Field screening for susceptibility to PMTV and TRV identified ‘Castle Russet’ to be resistant to both PMTV and TRV. In order to localize virus resistance genes for the development of marker assisted selection, a tetraploid mapping population (A15001) was developed by hybridizing ‘Castle Russet’ x A06084-1TE (susceptible to both viruses) and its progeny were subsequently trialed for two years in fields known to be infested with PMTV and TRV (two separate disease trial sites) near Larimore, ND. The population was phenotyped for PMTV and TRV incidence and severity of necrotic tubers at two time points post-harvest (approximately 19 days after harvest and 89 days after storage) with several genotypes in the population showing little or no virus induced necrosis over the years of evaluation, making them useful as parents in hybridizations by the potato breeding community. Tubers produced from the population were further assayed for PMTV and TRV infection by testing tuber core samples with a quantitative polymerase chain reaction (qPCR) assay. The A15001 population and the parents, 241 individuals, were genotyped with the Illumina Infinium SolCAP V2 12K Potato SNP Array yielding 6,704 quality-filtered, informative SNP markers. A genome wide association study (GWAS) analysis revealed SNP markers on multiple chromosomes (1, 2, 3, 5, and 11) that were significantly associated with PMTV incidence and negative qPCR suggesting polygenic inheritance. Conversely, GWAS revealed a significant QTL on chromosome 9 associated with all TRV phenotypes indicative of a major gene contributing to TRV resistance. These data can guide the development of molecular markers to select genotypes resistant to PMTV and TRV in potato breeding programs.

‘Rainier Russet’ was released in 2020 as a medium- to late-maturing selection with russeted tubers. Total yields are less, but similar to controls ‘Ranger Russet’ and ‘Russet Burbank’, and U.S. No. 1 yields are higher than Russet Burbank with increased tubers > 284 g. Compared to controls, it has high protein levels, high specific gravity, excellent fry color and flavor ratings, low acrylamide potential, good post-harvest merit scores for processing quality, and few internal and external tuber defects. Rainier Russet is susceptible to blight diseases, PVY, and Fusarium dry rot (F. solani var. sambucinum), but resistant to common scab (Streptomyces scabies) and Fusarium dry rot (F. solani var. coeruleum). Compared to Russet Burbank, tubers are less susceptible to hollow heart/brown center, secondary growth, growth cracks, and internal brown spot but higher tuber defects for net necrosis and shatter bruise with similar blackspot bruise potential. Rainier Russet is noted for its long tuber dormancy compared to Russet Burbank.

New, reliable strategies are needed to control Meloidogyne chitwoodi in potato; plant host resistance is central to this effort. While efforts to breed potato for resistance to M. chitwoodi are underway, a major bottleneck in this process is phenotyping plant genotypes for nematode resistance. Currently, time and resource consuming phenotyping takes place in the greenhouse or field. The objective of this study was to establish a high throughput methodology for screening potatoes against M. chitwoodi and quantify nematode egg densities at the end ofscreening using qPCR. Various parameters were evaluated for a canister assay where soil was added to a small container, planted with potato seed tuber, inoculated with nematode eggs, and incubated at a constant temperature in the dark. To obtain maximum reproduction factor (RF = final population density/initial population density) values, a minimum of 6 weeks after inoculation was required. Timing of inoculation was also important, with higher RF values when inoculation with eggs occurred at planting compared to 2 weeks after planting. The volume of water in which inoculum was delivered to soil did not impact RF values, nor did inoculation density (0.5, 1, or 5 eggs/g soil). The canister assay was evaluated using genotypes from a breeding population with varying levels of resistance to M. chitwoodi. Egg enumeration by qPCR was more sensitive than by microscopy, however, this increased sensitivity did not result in a significant difference in RF values nor the designation of a genotype being a good or poor host for M. chitwoodi. This method has the potential to greatly decrease the amount of time and resources needed to phenotype potato against M. chitwoodi and can allow for multiple screenings throughout the year, regardless of the season.

Nitrogen (N) fertilizer applied as polymer coated urea (PCU) may have the potential to improve potato (Solanum tuberosum L.) production. The objectives of this study were to determine the effects of PCU on potato yield and quality. ‘Russet Burbank’ potato was grown at three Idaho, USA locations. Five rates of N (0, 33, 67, 100, and 133% of the recommended rate) were applied in all combinations of: PCU applied at emergence, urea applied at emergence, or urea split-applied. The PCU-fertilized treatments produced 11%, 11%, and 10% higher US No. 1, marketable and total tuber yields, respectively, than urea-split applied. PCU trended toward increased tuber size. At equivalent rates, PCU was more efficient than urea N in providing N to potato. These results confirm findings from other researchers that a single application of PCU fertilizer, just prior to emergence, can efficiently meet seasonal N requirements for Russet Burbank potato.

Low soil moisture content and soil fertility are the major problems constraining productivity of potato (Solanum tuberosum L.) in the eastern highlands of Ethiopia. Therefore, a field experiment was conducted to investigate the effect of drip irrigation regimes and fertilizer rates on tuber yield, as well as nitrogen, phosphorus, and water use efficiencies of potato during the off-season of 2019/2020. The experiment was laid out as a split-plot design with three replications. Three levels of irrigation regimes, viz. 50%, 75% and 100% (full) of ETc were assigned to the main plots. Seven rates of fertilizer [control; 65 kg N + 242 kg NPS ha⁻¹(recommended rate); 50% of the recommended N + 75% of the recommended NPS along with 10 ton FYM ha⁻¹; 75% of the recommended N + 50% of the recommended NPS along with 10 ton FYM ha⁻¹; 75% of the recommended rate of N and NPS along with 5 ton FYM ha⁻¹; 75% of the recommended rate of N and NPS along with 10 ton FYM ha⁻¹ and 111 kg N + 92 kg P2O5 ha⁻¹] were assigned to the sub-plots. The results indicated that the optimum total tuber yield (48.38-ton ha⁻¹) and marketable tuber yield (47.80 ton ha⁻¹) were obtained in response to the application of 75% of the recommended rate of N and NPS along with 5 ton FYM ha⁻¹ together with 75% ETc. These total and marketable tuber yields exceeded the total and marketable tuber yield obtained in response to 50% ETc together with no fertilizer application by about four-fold. The above-mentioned treatment combination also resulted in the optimum agronomic nitrogen and phosphorus use efficiencies. Water use efficiency was improved by 3 kg m⁻³ in response to the application of 75% of the recommended rates of N and NPS along with 5-ton FYM ha⁻¹ together with 50% ETc compared to the same rate of the fertilizer treatment combined with 100% ETc. It is concluded that application of 75% ETc combined with 75% of the recommended rate of N and NPS along with 10 ton FYM ha⁻¹ increased potato yield, water productivity and N and P use efficiencies in Haramaya district.

Nitrogen (N) fertilization is a key factor in determining potato (Solanum tuberosum L.) yield, especially on sandy soils. A two-year field study was conducted in the Columbia Basin region of Oregon to determine the effect of N fertilizer rates (0, 157, 280, 404, and 527 kg ha^− 1) on tuber yield and quality. Elevated tuber yield and high tuber quality were associated with Castle Russet and Echo Russet, suggesting that the newly released cultivars suit the Columbia Basin region. Regardless of cultivars and years, the total and US No. 1 tuber yields increased when the N rate was 280 kg N ha^− 1. Increasing N supply further did not affect or even tended to decrease potato yield especially when N was at 527 kg N ha^− 1. The yield of tubers > 283 g and culls increased with increasing N rates up to 280 kg ha^− 1 but then decreased at 404 kg N ha^− 1 and at 527 kg N ha^− 1. Moreover, the specific gravity and the fry color of potatoes were not affected by the N rate. As the petiole nutrient concentrations were associated with tuber yields, their values at the N levels of 280 to 404 kg ha^− 1 might be used by producers in deciding fertilization, especially N. More data should be collected to create the critical petiole nutrient concentrations for developing management practices for these new cultivars.

The selective use of potato crop models is a key factor in increasing potato production. This requires a better understanding of the synergies and trade-off of crop management while accounting for the controlling effects of potato genetic and agro-climatic factors. Over the years, crop modeling for potato has relied on historical data and traditional management approaches. Improved modeling techniques have recently been exploited to target specific yield goals based on historical climatic records, future climate uncertainties and weather forecasts. However, climate change and new sources of information motivate better modeling strategies that might take advantage of the vast sources of information in the spectrum of actual, optimal and potential yield and potato management methodologies in a more systematic way. In this connection, two questions warrant interest: (i) how to deal with the variability of crop models relevant to their structure, data requirement and crop-soil-environmental factors, (ii) how to provide robustness to the selection process of a model for specific applications under unexpected change of their structure, data requirement and climatic factors. In this review, the different stages of potato model development are described. Thirty-three crop growth models are reviewed and their usage and characteristics are summarized. An overview of the literature is given, and a specific example is worked out for illustration purposes to identity key models suitable for potato management in the Atlantic provinces of Canada. Based on a categorical principal component analysis (CatPCA) procedure three potato models representing three principal components (PCs) were identified which will be useful for future potato production and yield simulation in this geographic area.