Location: Crop Genetics Research Unit
2012 Annual Report
Isolates of homopsis longicolla have been collected from seed harvested in Stoneville, MS, in the past years, and from seedlings at the Southeast Research Station, Rohwer, AR. Additional isolates will be collected from northeast Arkansas for inoculation studies. Four isolates from Mississippi have been sequenced at the internal transcribed spacer (ITS) region to confirm the pathogen identity. For breeding and genetics studies, the following plant populations are being advanced in Fayetteville, AR, for breeding/mapping purposes: F3: 5002T x PI 417050, 5002T x PI 417479, R03-984 x PI 417050 F2: R07-10231 x PI 235335, R07-10244 x PI 424324B, R04-1268RR x PI 594858A F1: PI 458130 x R05-3239, PI 506647 x UA 5612, PI 567635 x R01-976 The Phomopsis resistant parents are PI 417050, PI 417479, PI 235335, PI 424324B, PI 594858A, PI 458130, PI 506647, and PI 567635.
The following Phomopsis resistant PI’s also were planted in the crossing block for making new crosses this summer in Fayetteville, AR: PI 424324B, PI 458130, PI 506647, PI 567381B, PI 567635, PI 594858A, PI 567102B.
In Illinois’ location, PI 567381B plants grown in the greenhouse to be crossed with agronomically elite lines adapted to the midwest could not be used due to severe virus infections. Seeds of this accession, carefully chosen for their lack of virus symptoms, have been planted in the greenhouse for crossing this summer to generate agronomically competitive breeding lines with PSD resistance derived from PI 567381B.