1a. Objectives (from AD-416)
1. Define and Select Resistance to Powdery Scab and Black Dot in Potato. a) Evaluate genetic materials for resistance to powdery scab, emphasizing resistance to root colonization and impairment by the fungus. b) Screen advanced breeding lines and germplasm for black dot resistance emphasizing establishment of screening protocols. Define the triggering factors that result in damaging outbreaks of black dot. c) Evaluate resistance to combined inoculation with black dot and powdery scab. 2. Determining foliar and tuber symptoms and yield impact due to planting seed infected by different Potato Virus Y strains in eight different potato cultivars. a) Determine the foliar and tuber symptoms produced and yield loss in eight different cultivars when seed infected with three PVY strain are planted. 3. Develop high-phytonutrient Washington potatoes. a) Plant breeding lines or cultivars to assess their potential to produce high-phytonutrient potatoes. b) Analyze phytonutrient content of new potatoes grown. c) Select three genotypes that will be harvested at the new potato stage and at full maturity. d) Conduct taste tests of new potato lines that merit additional testing – namely those lines that perform well in terms of yields and phytonutrient content. e) Use some of the same seed from 3-5 varieties grown in Eastern Washington and plant them in Western Washington. Plants will be grown to maturity and small and large tubers harvest from the same plant and analyzed for phytonutrient content. The results will be compared to the levels seen in baby potatoes from young plants. 4. Breed for Resistance to Columbia Root-Knot Nematode and Corky Ringspot Disease (Toward Pesticide-Reduced Potato Production). a) Identify a molecular marker for tuber resistance to CRKN. b) Screen advanced breeding lines and germplasm for CRKN and CRS resistance in the field and in the greenhouse. c) Make crosses, produce tuber families and select new materials with resistance and improved horticultural and culinary traits.
1b. Approach (from AD-416)
Analyze phytonutrients in developmentally young potatoes (baby potatoes) using LCMS and GCMS. Evaluate phytonutrients in over 80 cultivars and breeding lines grown in the same field. Other key traits that will influence market success will be measured, including taste, appearance and yield of small tubers. Screen germplasm in the field and greenhouse for Powdery Scab and Black Dot resistance. Use field inoculation and greenhouse inoculation methods. Determine the relationship of field and greenhouse studies. Search for molecular markers associated with resistance. Use polymerase chain reaction methodology to screen segregating progeny. Tissue samples will be tested in this laboratory by reverse transcription polymerase chain reaction (RT-PCR) for strains of PVY. Documents Trust with Washington State Potato Commission. Log 41804.
3. Progress Report
About 90 genotypes were planted at Othello Washington to evaluate their suitability for baby potato production. Small tubers have been harvested from all of these lines and will be evaluated for phytonutrient content. We planted trials of advanced breeding lines and named varieties in a field in the North Columbia Basin to study resistance to black dot and powdery scab. Yield traits and direct measurements of pathogen presence and damage were also measured. Total yield and yield of large tuber sizes are the most important outcome of resistance or tolerance to the complex of the two pathogens. Several varieties and breeding lines were characterized for the first time as being resistance candidates. Among these were Sage Russet and Premier Russet. Resistance to Columbia root-knot nematode (CRN) was tested in grower's and experiment station fields. The advanced breeding line PA99N82-4 showed a high level of resistance to CRN and to Corky Ringspot Disease. Fry tests performed at Conagrafoods labs indicated that this clone did not result in cullage of finished product out of infested and unfumigated fields, in contrast to Russet Burbank from the same field, which resulted 100 percent cullage. This resistance was extracted from a Mexican wild species and backcrossed into the cultivated gene pool using traditional breeding aided by molecular markers. This project supports objective 1: Identify superior germplasm for potato disease- and pest-resistance, phytonutrients, minerals, and determine the extent of natural variation in diverse potato germplasm of select phytonutrients/metabolites and objective 2: Determine host resistance options, epidemiological parameters and develop diagnostic tests for emerging pests and pathogens of potato. Work was monitored by meetings, phone and email.