Morphology of Puccinia horiana Henn., the causal agent of chrysanthemum white rust occurred in West Bengal

Abstract

Chrysanthemum is one of the most important flower crops in India. The chrysanthemum white rust (CWR) disease caused by Puccinia horiana (Henn.) was observed on chrysanthemum (cv. Meri Gold) in West Bengal for the first time. Initial symptoms was appeared light green to yellow, slightly raised spots mostly on the lower surface of leaves, which later, turned into pinkish brown to dark brown necrotic lesion surrounded with light green to yellow hallo. The fungus produced only two spore stages, teliospores and basidiospores. Studies under the microscopes revealed that the telial pustules were found mostly on the lower side of the leaves. The teliospores were thin walled, bicelled, pedicellate, pale yellow, oblong to oblong-clavate. The average size of teliospores was 47.85μm X 13.48μm. The teliospores could germinate frequently into a promycelium in situ, from the apical telial cell and were tubular, mostly segmented, club shaped. The basidiospores were oval in shape.