Screening of chrysanthemum (Dendranthema grandiflora) genotypes for resistance to white rust (Puccinia horiana Henn.)

Puccinia horiana is the causal agent of chrysanthemum white rust. This microcyclic autoecious rust has a quarantine status and cause major damage in the commercial production of Dendranthema grandiflora. The experiment was carried out to identify genetic resources of chrysanthemum that are resistant/susceptible to white rust disease. A total 20 chrysanthemum genotypes were screened for resistance to P. horiana isolates collected from ICAR-IIHR, Bengaluru. By combing the observation methods without and with optical microscope, we established the identification standards for chrysanthemum white rust. The results showed that out of 20 genotypes screened for white rust, eleven genotypes/lines viz., Sweta Singar, Punjab Gold, Garden Beauty, Red Stone, Punjab Anuradha, Lal Pari, White Dolly, White Andaman, IIHR6-32, IIHR9-3 and IIHR6-41 were determined to be resistant. The use of white rust resistant genotypes will be useful for breeding programs in developing varieties with novel flower quality coupled with resistant to white rust for safe cultivation of chrysanthemum.