Objective 1. Continue to develop and deploy DNA markers for SCN resistance
Details of the ongoing activities at the University of Minnesota can be found in the quarterly reports. As a summary, some metrics that describe our accomplishments towards breeding SCN resistant varieties and germplasm include: 1) 66 new crosses made in 2019 that specifically target incorporation of 88788-type rhg1 SCN resistance; 2) 4800 F4:5 families were genotyped for rhg1, and 1519 of these families were advanced to plant rows based on the marker results indicating resistance; 3) 555 breeding lines carrying 88788-type resistance were tested in preliminary yield trials in MGs ranging from late 00 to late I; 4) 106 breeding lines carrying 88788-type resistance were tested in advanced yield trials; 5) 42 breeding lines carrying 88788-type resistance were tested in the first year of regional trials; 6) 8 varieties were tested in advanced regional trials for the second or greater year; 7) Breeder’s seed was created for two new SCN resistant varieties, and release decisions are awaiting 2019 yield results; 8) 5 SCN-resistant varieties were released in the form of invention disclosures and transferred to two different private companies for licensing and crossing rights.; 9) One new variety with SCN resistance is slated to be released in 2020 pending Committee approval in the coming weeks (MN1901CN).
Objective 2. Advance and expand new sources of SCN resistance
Regarding breeding with novel sources of SCN resistance, our programs is aggressively creating breeding populations from which we plan on deriving new breeding lines starting this fall. In summary, we made 12 new crosses involving a novel SCN resistance source in 2019. We also advanced 11 F4 populations, and 22 F2 populations involving novel SCN sources.
Another activity we’ve assisted with is the creation of mapping populations involving early MG accessions. In 2018, we successfully created 5 such mapping populations by crossing these accessions identified to an early MG SCN susceptible variety, MN0095. These populations are currently in the F2 generation. In 2019, we made seven crosses between MN0095 and novel SCN resistance accessions. F1 seed will be sent to Chile for generational advancement. These materials will be important for the eventual identification of novel loci controlling SCN resistance.
Objective 3. Conduct SCN testing on commercial varieties entered into the UMN Variety Trials.
Forty-five commercial and public varieties were entered into the UMN SCN Variety Trials. These varieties were screened for SCN resistance using a greenhouse bioassay as described in the proposal. Results have been summarized and published at www.soybeans.umn.edu. As always, a few varieties were found to be susceptible yet their originator claimed that they had resistance. This is an important result that farmers can use to help select resistant varieties.