American Journal of Potato Research最新文献

With a rising global population and looming water shortages in the U.S., there is a pressing need for water-efficient farming methods. The water needs of potato plants decrease in the late season due to foliage aging and tuber maturation. Therefore, proper late-season irrigation is vital in preventing water waste and maximizing potato profits. This study assessed the feasibility of reducing late-season irrigation to improve crop water productivity (WPc), tuber quality, and economic return. Field trials were planted near Othello, WA, across three years (2018–20). Treatments included five irrigation levels (ILs), 40%, 60%, 80%, 100%, and 120% of modeled evapotranspiration (ET), and five potato cultivars: Alturas, Clearwater Russet, Ranger Russet, Russet Burbank, and Umatilla Russet. Treatments started 100 to 105 days after planting (DAP), approximately 1500 day degrees (at or near peak canopy growth), and ended at vine kill, 150 to 155 DAP. Water from reduced ILs of 40% to 80% ET was more efficiently converted into yield (WPc) for Alturas than higher ILs; however, economic return for all cultivars typically peaked when irrigation was supplied at or above 80% ET. Tuber quality generally improved with a reduction in irrigation level, occasionally at the expense of yield and economic value.

Potato production is being affected by high temperature stresses worldwide due to global warming. The biological basis of carbohydrate metabolism and reactive oxygen species (ROS) activity in potato tubers under high temperature stress is yet to be clearly understood. We evaluated the activities of two of the most important primary ROS members: superoxide (O₂.⁻) and hydrogen peroxide (H₂O₂) and their scavengers to understand the effects of heat stress on the changes of carbohydrates in growing tubers of five potato varieties including heat-tolerant and heat‐susceptible check varieties. The enzymatic ROS-scavengers were found to be differentially activated in these genotypes. The detoxification mechanism was more efficient in dual-stress (heat and salt) tolerant variety compared to single-stress tolerant variety. The antioxidant activity was increased by several folds in the tolerant variety compared to the susceptible variety. Storage starch accumulation and its composition was affected by O₂.⁻ and H₂O₂ metabolisms in potato tuber. The findings will be helpful in understanding the biological basis of the effect of ROS-detoxification on starch accumulation in growing tubers under heat stress.

Potato virus Y (PVY) is a common and devastating pathogen of potato worldwide and insecticide control alone for aphid vectors is not effective due to the rapid transmission of the virus by aphids following probing. Three Ry genes for extreme resistance to PVY have been identified and are used in potato breeding programs for the development of PVY-resistant varieties. Tightly linked molecular markers have been developed for all three genes and are used for marker-assisted selection (MAS). However, some varieties with known extreme resistance to PVY do not amplify any molecular markers for these resistance genes. Sante and its progeny Bistra are examples of two varieties with extreme resistance to PVY and yet have no amplification of Ry associated molecular markers. The source of PVY resistance in Bistra was mapped using SNP genotyping of 190 of its progeny which had been characterized for response to PVY infection using a N-Wilga strain. A major QTL was found on the proximal end of chromosome 11, in close proximity to Ry_adg, one of the three known extreme resistance genes for PVY. However, no known markers which detect Ry_adg amplify in Sante or Bistra which indicates they may possess a currently unidentified resistance gene, or the genetic linkages of molecular markers typically associated with the presence of Ry_adg no longer exist due to recombination between the gene and its associated molecular marker primer annealing sites.

Recombinant inbred line (RIL) populations are powerful mapping tools in many crops but have not yet been created using cultivated potato germplasm. We crossed the doubled monoploid cultivated clone DM 1–3 with the self-compatible diploid inbred wild clone M6 to create a diploid F1 hybrid. One F1 plant was self- pollinated to generate a phenotypically diverse F2 population, which was selfed to create 87 RILs. This is the first report of a RIL population developed from a cultivated x wild hybrid in potato. Poor fertility was a significant challenge in creating RILs. Nevertheless, we generated inbred lines that ranged from high to low fertility, vigor, and tuber production. F6 RILs ranged from 98 to 68% homozygosity, based on 2884 SNP markers. Considering the phenotypic variability between the two parents and among the RILs, we expect the RIL population to be valuable for mapping traits important to the potato industry.

Handling potatoes individually or collectively in packages can create opportunities for potatoes to develop quality defects including blackspot and shatter bruise. Three trials were conducted to examine how handling packaged potatoes can influence the risk for physical damage including shatter and blackspot bruise. An impact recording device was used to record peak acceleration (max g-force) in common fresh market packaging options (boxes or bales) at four drop heights (15 to 91 cm) on to three different surface types. When boxed potatoes were dropped onto concrete or a plastic slip, the potatoes on the bottom of the box had the highest risk of damage (greater than 100 g-force). When drop heights were lowered, or when cushioning material was added to hard surfaces (e.g., wooden pallet on top of concrete floor), the risk for impact damage was decreased throughout the box. When palletizing boxed potatoes, the risk of bruise decreased after the first layer was stacked on the pallet. Drop heights need to be below 15 cm, especially when making the first layer in a palletized stack of packaged potatoes to reduce potential bruising. The risk of high peak accelerations was not seen in the dropped or stationary bales for any of the drop heights examined. This study provided information for educating personnel on handling packaged potatoes and determining situations in which robotic stacking equipment needs to be adjusted to lower drop heights of packaged potatoes.

Potato virus Y is the most important potato virus worldwide, affecting tuber yield and quality. The resistance gene Ry_chc, derived from the potato wild relative Solanum chacoense, provides broad spectrum and durable resistance to the virus and has been used to develop resistant cultivars. Several DNA markers have been developed and have contributed to the efficient selection of resistant individuals. In this study, we developed Kompetitive Allele Specific PCR markers for Ry_chc using whole-genome resequencing data for a diverse set of 25 PVY susceptible cultivars and a Ry_chc-positive clone. Marker Ry_4099 targets two variants in the 3ʹ-UTR and was able to discriminate all five allele dosages in a tetraploid test population. Marker Ry_3331 targets two variants in Exon 4 and, although it only provides presence/absence information, it discriminates between the two known resistant alleles of Ry_chc. These markers will greatly contribute to efficient development of resistant cultivars.