Fungi infecting Escobaria cubensis and Melocactus holguinensis (Cactaceae) in northeastern Cuba

• Published in: Acta ecologica Sinica Vol. 39; no. 2; pp. 117 - 124
• Main Authors: Reyes-Fornet, Alena, Fornet Hernández, Elena Balbina, Martínez Ondaro, Yania Raquel
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2019
• Subjects: Endangered species; Fungus; Holguin; Natural heritage; Fungus; Endangered species; Holguin; Natural heritage
• ISSN: 1872-2032; 1872-2032
• DOI: 10.1016/j.chnaes.2018.08.009

Escobaria cubensis (Britton & Rose) D.R. Hunt and Melocactus holguinensis Areces (Cactaceae) are valuable Cuban natural heritage plants from ophiolite (serpentine) soils that are in Critical Danger of extinction. The in situ study on E. cubensis was conducted in Matamoros and that of M. holguinensis in La Ceja between May 2017 and July 2017, both in Holguín province. Samples in ex situ collections were also taken. The appearance of fungi somatic and reproductive structures was induced through wet chamber technique and isolation. Fungi were identified using taxonomic keys. Symptoms in E. cubensis consist of rotten soft roots, while M. holguinensis displays yellow spots followed by brown to blackish lesions with brown centers. Cacti death is the result of those infections. Pathogenicity tests showed that in E. cubensis, the fungi responsible for the symptoms are Fusarium oxysporum Schltdl. (or a complex), Colletotrichum gloeosporioides (Penz.) Penz. & Sacc and Penicillium sp. In M. holguinensis, C. gloeosporioides causes the witnessed anthracnose in stems in both habitats. These fungi constitute a severe threat in natural habitat more for M. holguinensis than for E. cubensis. Results suggest that roots are the most vulnerable part of E. cubensis and stems appear to be more sensitive in M. holguinensis. C. lunata can infect both cacti, but no symptoms of illness have been seen either in situ or ex situ. Infection similarities seen both in nature and in collections could be because of inappropriate horticultural practices. Other fungi found are Aspergillus fumigatus Fresenius, A. niger van Tieghem, Cephalosporium sp., Cladosporium sp., Rhizopus sp. and Trichoderma sp. All fungi found in this study are new records for both hosts in Cuba. The results of this research allow to solve problems found in natural habitat and in ex situ collections. In addition, results suggest to collectors not to remove and use soil from the natural habitat, unless it is properly sterilized.