Location: Emerging Pests and Pathogens Research2012 Annual Report
1a. Objectives (from AD-416):
The objectives of this cooperative research project are to develop and release improved potato cultivars with resistance to multiple races of the golden nematode, effect more efficient protocols to screen segregating potato populations for resistance to the golden nematode, develop profiles of new resistant cultivars to aid grower acceptance, provide for nuclear disease-free seed of resistant cultivars.
1b. Approach (from AD-416):
1) Crosses of potato clones will be made to generate populations that are segregating for resistance to multiple races of the golden nematode and improved horticultural and marketing characteristics. 2) Potato clones will be evaluated for nematode resistance. 3) Resistant potato clones will be subjected to an extensive evaluation scheme and selected for improved yield, desired marketing characteristics, and disease resistance. 4) Production and storage profiles for advanced clones will be developed through field testing. 5) Disease-free seed stocks will be maintained and multiplied as necessary to meet grower demands.
3. Progress Report:
The overall objective is to develop and release new potato varieties resistant to the golden potato cyst nematode (GN). In 2011, researchers produced over 244,000 seeds (N generation) of 57 progenies. All of the crosses segregate for resistance to Ro1 or Ro2. Researchers transplanted 7,961 seedlings (M generation) into 72 hole seedling trays for hardening in the greenhouse, then to six inch pots in outdoor beds. Among the 6,300 saved clones, all segregate for resistance to GN Ro1. Researchers also planted approximately 20,000 clones at the 4-hill plots stage (L generation) and saved 1,590 clones and also planted 942 white clones and 110 colored clones at the 20-hill plots stage (K generation). All clones segregate for resistance to Ro1 and/or Ro2. Two hundred and forty-six clones were saved after postharvest analyses. The 265 clones at the 100-hill plots stage (J generation) were also planted in 2 x 15 foot observation plots and 66 clones with resistance to Ro1 were saved. Seventeen clones (H generation) were planted in replicated trials at two locations and in a seed plot. Six clones survived post-harvest selection based on yield, appearance, and specific gravity. In addition, 12 advanced round white and 3 round red clones (G, F, E, NY generations) were tested at three locations around Ithaca and also distributed seed for several other trials. One of the white clones (NY140) is resistant to both Ro1 and Ro2. ARS continued to screen potato clones and varieties for GN resistance. A total of 642 and 201 clones were evaluated for Ro1 and Ro2 resistance, respectively. Among these, three hundred and thirty-three clones were identified to be resistant to Ro1 and one hundred and thirty-six clones were resistant to Ro2. Extension potato variety yield trials were conducted with growers in upstate New York. Marketable yield, tuber quality and appearance, maturity, storage life and processing potential are among the important characteristics that were evaluated. Foundation seed of advanced GN-resistant potato clones and varieties continue to be produced. In the 2011 growing season, 69% of the acreage at the Uihlein Farm was planted to 29 GN resistant varieties. The total estimated cwt (hundredweight) of GN resistant varieties sold and/or distributed was 6,647 cwt.