An evaluation of allium germplasm for resistance to white rot caused by sclerotium cepivorum berk

Abstract

Sixty-nine accessions, representing 30 species of Allium, were tested for resistance to Sclerotium cepivorum in a glasshouse. Allium seeds were sown in soil which had been inoculated with laboratory-grown sclerotia of S. cepivorum. Seedling mortality was assessed for 7 weeks beginning 3 weeks after sowing. After the final assessment 61 of the accessions tested had mortalities of 76-100%. A tel- avivense showed no evidence of infection to S. cepivorum. Five accessions which had mortalities ≤75% were tested again. A. tel-avivense still showed no evidence of infection; accessions of A cemuum, A. ledebourianum, A. lineare, and A galanthum were found to be significantly less susceptible than A. cepa. The A cepa cultivars ‘Pukekohe Longkeeper’ and ‘Early Longkeeper’ used as controls, were very susceptible. Lack of infection in A. tel-avivense is perhaps a result of the inability of the species to stimulate sclerotial germination. © 1992 The Royal Society of New Zealand.