Mission Statement:
“To exercise the tools of plant breeding and related sciences to develop commercial potato varieties that bring Wisconsin growers a competitive advantage in the market place.”

Breeding Strategies

Potato variety development through the UW Potato Breeding program continues to work on the many levels required to substantiate a comprehensive effort. Breeding goals are continuously evaluated in light of both long standing and recent needs of the potato industry. Significant adjustments made in 2006 are the following. 1) Crossing strategies based on improved pedigree analysis, 2) Reduction of years within the selection scheme, 3) Earlier selection exposure to Central WI and 4) Initiation of two new projects are all examples of adjustments made in 2006.

We continue to build collaboration with in state and out of state researchers to achieve the agronomic and disease screening tools. These efforts will confirm if value added characteristics are being captured in advanced selections. Germplasm with key traits are sought as a means of building parents as varieties derived from such parents.

Breeder’s Seed multiplication is an ongoing emphasis that has allowed for extensive exposure to variety trials and on-farm testing. Our efforts in coordinating systematic testing is improving and beginning to yield a more complete picture of Elite lines promoted from the program. This again is related to the input of many cooperating parties. Finally, SPUDPRO, our potato variety promotion mechanism and the Wisconsin Alumni Research Foundation (WARF) are each contributing to make possible the protection of new releases of the breeding program and defining licensing agreements that benefit the potato industry in general and facilitate continued research the University. The following is a summary of our effort in 2006.

Seed Production and Greenhouse Tubers Production and Exchange: One hundred and fifty lines were planted in the greenhouses and the field for crossing and true seed production. Also, 48,000 greenhouse tubers were produced that will be planted in the field as single hills or field year 1 of selection (FY-1) in 2007. In a similar experience in 2006, of the 93,004 single hills planted in FY-1, 56,285 corresponded to 398 families coming from WI crosses. The remaining 36,789 single hills were planted with seedling tubers obtained through interchanges with the breeding programs from CO, ME, ID, ND, and Canada. For 2007, the targeted number of single hills (FY-1) is 80,000, 48,000 from WI and the remaining 32,000 will be obtained from CO, ME, ID, ND, NY and Canada. Tuber exchange with out of state sources is important to strengthen selections for Colorado Potato Beatle, viruses (PVY, PVX and others), scab, late, blight, fresh market red and russets, processing ability in russets and round whites (chippers). Enhanced germplasm is currently used to derive varieties of better processing quality (e.g. cold chipping and long storability), disease resistance (scab, late blight, early blight and early dying), and resistance to environmental stresses including cold tolerance and improved tuber quality (enhanced tuber calcium). Germplasm with key traits continues to be sought as a means of building parents as varieties derived from such parents. In the last 11 years the number of single hill plots has grown from 20,000 to 93,000 in an effort to have a greater probability to select lines with cultivar potential (Fig.1).

Field Year 2 (4 Hills Plots): 2653 lines corresponding to 489 families (crosses) were planted (33% russet, 55% chipping and 12% red) as FY2. Of these 546 lines were selected to be evaluated in FY-3. Early evaluation of processing traits (specific gravity and chipping) will occur thanks to collaboration with the USDA East Grand Forks potato processing facility.

Field Year 3: FY-3 was composed of 756 lines that were planted as unreplicated 8 hills plot at the Hancock, WI A.R.S. and simultaneously, 20 hills plots were planted at the Rhinelander, WI A.R.S for evaluation and seed multiplication. Of 756 lines, the goal is to select 100-120 lines to be included in the replicated trials-1 of 2007. Line performance for early blight, early dying and tuber aspect were recorded. Evaluation of processing traits (specific gravity and chipping) will occur thanks to collaboration with the USDA East Grand Forks potato facility. A special project initiated in Dr. Palta’s potato physiology lab included the evaluation of a population of 534 clones from the crosses of Superior to Atlantic and Snowden. An evaluation of these 534 clones was conducted in two unreplicated locations (Hancock and Rhinelander) using 8 hills plots. Preliminary data from this population indicates that important variability for tuber Calcium intake ability. Breeding and genetic studies are proposed for the use and understanding of Calcium intake ability since this may have a significant impact on tuber health and quality. Weights, tuber appearance, specific gravity and frying quality are being evaluated. Tuber appearance indicates a high probability of obtaining competitive lines from these lines. A subset of these lines will be included in the replicated trials-1 of 2007 and 2008.

Field Year 4 and Beyond: Advanced selection trials are conducted at Hancock and Rhinelander, WI. We continue to build collaboration with WI and out of state researchers to achieve the agronomic and disease screening tools. These efforts will confirm if value added characteristics of importance are being captured in advanced selections.

Modifications in Potato Breeding Strategies Implemented in 2006

Important modifications to the breeding scheme were introduced in 2006. Basically these modifications consist of the following:

1. A two year reduction within the breeding scheme used to identify Advanced Selections (Fig. 2).
2. Use of the Hancock Agricultural Research Station at earlier stages, targeting adaptation to environment of Central Wisconsin.
3. Testing at earlier stages for field performance, processing quality (gravity and frying at 45ºF) in collaboration with the USDA facility at East Grand Forks.
4. A bigger emphasis on internal and external tuber quality.
5. Selection at earlier stages for disease resistance (late blight, scab and early dying) through in-State evaluation and collaboration with out of state programs located in OR, MI and ON.
6. A small, but significant component of marker assisted selection in early generations for late blight resistance is carried out in collaboration with Dr. Jiming Jiang’s lab at UW-Madison.

The objectives of these modifications, including crossing strategy and early generation selection, are to facilitate a more efficient use of resources. This will be achieved through evaluating a larger number of potential varieties under the environments and stresses of Hancock, which represent the WI Central Sands, our main production region. This will result in a larger number of selectable lines. This approach will increase the opportunities of finding a winner earlier in the selection process. Unless line selection is performed, the genetic make-up of a potato line is not expected to change by year of selection; the earlier their value is known the better for a breeding program. In 2007, implementation of a crossing and early generation strategies similar to 2006 are proposed. The parents to be used will be derived from analysis of 2006 and earlier data, and from recommendations from breeders and potato growers.

Fig. 1. Number of single hill plots planted by the breeding program from 1996 to 2006