1a.Objectives (from AD-416):
The major objective of this cooperative research project is to develop potato germplasm with resistance to multiple pathotypes of the golden nematode.
1b.Approach (from AD-416):
1) Crosses of potato clones will be made to generate populations that are segregating for resistance to multiple pathotypes of the golden nematode and improved horticultural and marketing characteristics.. 2)Potato clones will be evaluated for resistance to golden nematode pathotypes of Ro1 and Ro2.
The overall objective is to develop potato germplasm with resistance to multiple pathotypes of the golden nematode (GN). The potato breeding program at Cornell University continued to make crosses to generate populations that are segregating for resistance to the two pathotypes of GN. In 2011-2012, ARS research produced over 244,000 seeds (N generation) of 57 progenies. ARS 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. Also planted were approximately 20,000 clones at the 4-hill plots stage (L generation) and saved 1,590 clones. Researchers 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. In 2011-2012, ARS researchers screened 566 Cornell potato clones for GN resistance. Among the 365 clones screened for Ro1 resistance, 266 were found to be resistant to Ro1. Among the 201 clones screened for Ro2 resistance, 136 were identified to be resistant to Ro2. Of these confirmed resistant clones, some are advanced clones including NY140, which may be released as named varieties in the near future.