ARS | Publication request: RESISTANCE TO FUSARIUM WILT RACE 2 IN THE PISUM CORE COLLECTION

Submitted to: American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 24, 1998
Publication Date: N/A

Interpretive Summary: Fusarium wilt caused by Fusarium oxysporum Schl. f. sp. pisi Snyd. & Hans. is a fungal disease that affects peas and is important worldwide. Four economically important races (races 1, 2, 5, and 6) are present in North America. Four hundred fifty-two accessions from the core collection of pea germplasm were artificially inoculated with Fusarium wilt race 2 under greenhouse conditions and tested for resistance. Sixty-two accessions collected from nearly every region of the world were identified as resistant. Thirty-nine of the accessions resistant to race 2 were also resistant to race 1. Although a specific region of the world could not be identified as a source of the resistance, those accessions identified as resistant will be valuable in breeding programs to introduce resistance to races 1 and 2 of Fusarium wilt into new varieties.

Technical Abstract: Plant breeders must be aware of sources of resistance to pathogens that affect their crops. Fusarium wilt caused by Fusarium oxysporum Schl. f. sp. pisi Snyd. & Hans. is a fungal disease that affects peas and is important worldwide. Resistance to the different races of the pathogen has been identified in adapted germplasm and from specific accessions in the United States World Collection of peas (Pisum sativum L.). The goal of this study was to evaluate the resistance to fusarium wilt race 2 in the Pisum core collection. Sixty-two of the 452 accessions screened (14%) were resistant. The resistant accessions included accessions from P.s. ssp. elatius that were collected from 24 different countries. The wide distribution of resistance around the world precludes the identification of any single country or region as a source of resistance. Thirty-nine of the sixty-two accessions resistant to race 2 are also resistant to race 1 based on data obtained from GRIN. One of the wild progenitors, PI 344012, possessed resistance to both races 1 and 2.