Neofusicoccum brasiliense

Coutinho, Ingrid B. L., Cardoso, José E., Lima, Cristiano S., Lima, Joilson S., Gonçalves, Francisco J. T., Silva, Abigail. M. S. & Freire, Francisco C. O., 2018, An emended description of Neofusicoccum brasiliense and characterization of Neoscytalidium and Pseudofusicoccum species associated with tropical fruit plants in northeastern Brazil, Phytotaxa 358 (3), pp. 251-264 : 258-260

Neofusicoccum brasiliense

Phylogenetic description:— M.W. Marques, A.J.L. Phillips & M.P.S. Câmara MycoBank MB80473 (Marques et al. 2013).

Morphological description:— I.B.L. Coutinho, C. S. Lima & J.E. Cardoso. MycoLibrary:— CMM 4576.

Sexual morph: not observed. Asexual morph.: Production of pycnidia after 8 days in pine needles embedded in PCA and sporulation after 17 days under the same conditions. Conidia hyaline, fusiform, base subtruncate to bluntly rounded, non-septate, smooth with granular contents. Dimensions: 10.7– 25.6 × 8.3–11.9 μm (mean = 21.3 × 10.2 μm; L:W = 2.1, n = 50). Mycelium abundant, cotonous and dark in BDA, malt extract, oats and V8. Production of red pigment in BDA at 35ºC. Habitat: Necrotic cankers in branches and trunks of Psidium guajava .

Geographic distribution:— Ceará State, Brazil.

Specimens examined:— BRAZIL. Ceará State: Cruz city (latitude: -2.91941, longitude: -40.1703 2° 55′ 10″ S, 40° 10′ 13″ E), October 2013, collected by I.B.L Coutinho & J. S. Lima , culture ex-holotype CMM 4576, NCBI GenBank access codes KT247455 (ITS) and KT247457 (EF1-α).

Pathogenicity characterization

All species were virulent when the mango fruits and young plants of cashew and “caja-umbu” were inoculated, but to different degrees of severity depending on the host ( Fig. 3 ). N. kwambonambiense , N. brasiliense and P. stromaticum (IBL36) were highly aggressive when inoculated into mango fruit, cashew and “caja-umbu” seedlings, causing the greatest lesion length ( Fig. 3 ). In cashew, Ne. hyalinum (IBL272) and P. stromaticum (IBL500) were the least aggressive, while in mango fruit, Ne. hyalinum (IBL272) was moderately aggressive, followed by Ne. hyalinum (IBL89) and P. stromaticum (IBL500), which were the least aggressive.

In “caja-umbu” seedlings, Ne. hyalinum (IBL272) and Ne. hyalinum (IBL89) were moderately virulent without significant differences, followed by P. stromaticum (IBL500), which was the least virulent isolate among all inoculated hosts ( Fig. 3 ).

The symptoms in mango fruits were seen 3 days after inoculation by any isolate, but N. brasiliense was the most virulent species, reaching a maximum growth rate of 18.4 mm day-1. Symptoms in mango fruit were necrotic and watery lesions that grew towards the peduncle and were mummified at the end. The most virulent species stimulated gum exudation by both cashew and “caja-umbu” seedlings, causing superficial cankers in their stem tissues that later progressed to large, necrotic lesions.

Figures

FIGURE 3. Mean lesion length (mm) caused by Botryosphaeriaceae species associated with dieback and stem-end rot in several tropical fruit trees from Northeast Brazil: 45 days after inoculation in stems of young plants of caja-umbu, 15 days after inoculation in stems of young cashew plants and four days after inoculation in injured mango fruits. Bars above columns represent the standard error of the mean. For each host, columns with the same letter do not differ significantly according to Scott–Knott’s test at a = 0.05.