Ciborinia gentianae sp. nov., the causal organism of sclerotial flower blight of cut-flower gentians

Abstract

A new Ciborinia causing sclerotial flower blight of cut-flower gentians (Gentiana triflora var. japonica and interspecific hybrids between related species or varieties) is described as Ciborinia gentianae on the morphological basis of sclerotia and apothecia. The characteristics of Ciborinia gentianae are (1) an abundant production of spermodochia in the hollow cavity of host stems; (2) flat and thin sclerotia produced beneath the epidermis and the inclusion of host vascular remnants within their medulla; (3) globose cells composed of ectal excipulum of apothecia; (4) elongated cells with a slight apical swelling in ectal excipulum at the apothecial margin; and (5) tetra nucleate ascospores. Asci and ascospores mounted in Melzer's reagent measured 156-208 × 8-12 µm and 11.8-15 × 5.5-7.1 µm, respectively.

The Host Stomatal Density Determines Resistance to Septoria gentianae in Japanese Gentian

“…), and their interspecific hybrids are mainly used as cultivars or lines in Japan (Nishihara et al 2018;Yoshiike 1992). Several gentian fungal diseases, including gentian leaf blight, gentian brown leaf spot, and gentian sclerotial flower blight, have been reported (Nekoduka et al 2013;Ohno et al 1996;Saito and Kaji 2006). Septoria gentianae, an ascomycete fungal pathogen of gentian, causes the gentian leaf blight disease that typically shows necrotic leaves with black spots (pycnidia formation of Septoria) on the adaxial side of the leaf surface (Ohno et al 1996;Saccardo 1884).…”