Susceptibility of safflower lines to head rot and leaf spot disease

Abstract

Ten safflower (Carthamus tinctorius L.) genotypes were evaluated for susceptibility to head rot (caused by Botrytis cinerea Pers. : Fr.) and leaf spot disease (caused by Alternaria and Stemphylium species) in three locations in the Manawatu district. Leaf spot disease had not previously been recorded in New Zealand. Genotypic variance components were significant, with broad sense heritability values for susceptibility to head rot and leaf spot disease being 0.20 and 0.46 respectively. The local cuItivar 0-22 showed some resistance to head rot disease, whereas the low hull lines, VFstp-I and Partial-hull, were highly susceptible. Two genotypes, PI 262437 and PI 306684, which exhibited high resistance to leaf spot disease could be useful for the incorporation of disease resistance into commercial cuItivars.