Extreme Resistance to Potato Virus A in Potato Cultivar Barbara is Independently Mediated by and .

Potato virus A (PVA) and potato virus Y (PVY) are two members of genus infecting potato crops worldwide. Host resistance offers an economical and effective means for the control or management of these viruses. In this study, 20 potato clones were screened for their resistance against PVA and PVY by mechanical or graft inoculation assay, and were explored for the relationship between extreme resistance genes and by the detection of molecular markers linked to , , and .

Tuber transcriptome profiling of eight potato cultivars with different cold-induced sweetening responses to cold storage.

Tubers are vegetative reproduction organs formed from underground extensions of the plant stem. Potato tubers are harvested and stored for months. Storage under cold temperatures of 2-4 °C is advantageous for supressing sprouting and diseases.

High Resolution DNA Melting Assays for Detection of Rx1 and Rx2 for High-Throughput Marker-Assisted Selection for Extreme Resistance to Potato virus X in Tetraploid Potato.

Assessment of the existing PCR-gel electrophoresis-based methods for detection of Rx1 and Rx2, the genes that independently control extreme resistance (ER) to Potato virus X (PVX), indicated that the 5Rx1F/5Rx1R primer pair led to reliable detection of Rx1, whereas the 106Rx2F/106Rx2R primer pair detected Rx2 despite some nonspecific reactions in potato clones/cultivars without Rx2. However, the methodology is time consuming and does not differentiate the absence of Rx1/Rx2 from a failed PCR reaction. A newly designed primer pair that targets Rx1 and Rx2 as well as rx1 and rx2 produced an amplicon for all alleles.

Disease Resistance and the Regulatory Pathway for Maturity and Tuberization in Potato.

Kleb. is a pathogenic fungus causing wilting, chlorosis, and early dying in potato ( L.).

Development and Validation of High-Resolution Melting Markers Derived from Ry STS Markers for High-Throughput Marker-Assisted Selection of Potato Carrying Ry.

Sequence analysis of the chromosome region harboring the sequence-tagged site (STS) markers YES3-3A and YES3-3B for Ry, a gene responsible for extreme resistance to Potato virus Y (PVY) in potato, was performed in tetraploid potato 'Barbara' (Rrrr) and 'AC Chaleur' (rrrr) as well as their progeny selections. Three and two sequence variants were identified in Barbara resistant (R) selections and AC Chaleur susceptible (S) selections, respectively. Further analysis indicates that the variant with a 21-nucleotide (nt) deletion is likely the chromosome copy harboring the STS markers.

Differences between the Bud End and Stem End of Potatoes in Dry Matter Content, Starch Granule Size, and Carbohydrate Metabolic Gene Expression at the Growing and Sprouting Stages.

Potatoes usually have the tuber bud end dominance in growth during tuber bulking and in tuber sprouting, likely using carbohydrates from the tuber stem end. We hypothesized that the tuber bud end and tuber stem end coordination in carbohydrate metabolism gene expression is different between the bulking dominance and sprouting dominance of the tuber bud end. After comparing the growing tubers at harvest from a green vine and the stage that sprouts just started to emerge after storage of tubers at room temperature, we found the following: (1) Dry matter content was higher in the tuber stem end than the tuber bud end at both stages.

Quantitative resistance in potato leaves to late blight associated with induced hydroxycinnamic acid amides.

Late blight is a serious economic threat to potato crop, sometimes leading to complete crop loss. The resistance in potato to late blight can be qualitative or quantitative in nature. Qualitative resistance is not durable.

Decreased defense gene expression in tolerance versus resistance to Verticillium dahliae in potato.

Verticillium dahliae Kleb., a soil-borne fungus that colonizes vascular tissues, induces wilting, chlorosis and early senescence in potato. Difference in senescence timing found in two diploid potato clones, 07506-01 and 12120-03, was studied and genetic variation in response to V.

Response of Potato Cultivars to Five Isolates Belonging to Four Strains of Potato virus Y.

The responses of 14 potato cultivars to five Potato virus Y (PVY) isolates belonging to four strains (ordinary [PVY], tobacco veinal necrosis [PVY], N:O group [PVY], and nonrecombinant potato tuber necrotic [PVY]) were studied in primary and secondary infections. For the primary infection experiments, foliage symptoms were monitored daily after mechanical inoculation with a PVY isolate until harvest; and, for the secondary infection experiments, foliage symptoms were monitored regularly from plant emergence until harvest. Tuber symptoms (namely, tuber necrotic ringspots) were checked at harvest and monthly postharvest for up to 4 months.

Effect of preparation method on the glycaemic index of novel potato clones.

The purpose of this study was to investigate whether the effects of cooling and reheating on the glycaemic index (GI) of novel potato clones (selections) differed depending on selection and whether cooling altered starch absorption in vivo. We conducted 3 experiments using 4 novel potato clones in healthy subjects. Experiment 1: the GI of 4 selections each prepared in 3 ways (freshly boiled, cooled, or cooled and reheated) was measured in 2 groups of 10 subjects (each group tested 2 selections).