Exploitable variation for fusarium wilt resistance in advanced safflower lines

Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. carthami is a significant constraint to safflower (Carthamus tinctorius L.) production in India. Identifying resistant sources is the most economical and sustainable approach for managing soil and seed-borne diseases. The present investigation was conducted during Rabi 2022-23 at the safflower Fusarium wilt-sick plot of the Agricultural Research Station, Tandur, Telangana, to evaluate safflower breeding lines for wilt resistance. Ninety-one entries, comprising 88 advanced breeding lines and three checks, were screened. Wilt incidence was recorded at 15-day intervals from 30 to 120 days after sowing and genotypes were classified based on standard disease rating scales. Analysis of variance revealed highly significant treatment effects, indicating considerable genetic variability for wilt resistance. Wilt incidence in breeding lines ranged from 0 to 100 per cent. Five genotypes were immune, nine resistant, and eighteen moderately resistant, whereas most genotypes exhibited susceptible or highly susceptible reactions. The susceptible checks recorded high wilt incidence, confirming uniform disease pressure. The immune and resistant entries identified in this study can serve as valuable sources for breeding Fusarium wilt-resistant safflower cultivars.