Neofusicoccum luteum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, Studies

Pereira, Diana S. & Phillips, Alan J. L., 2023, Botryosphaeriaceae on palms-a new species of Neodeightonia, N. chamaeropicola, and new records from diseased foliage of ornamental palms in Portugal, Phytotaxa 627 (1), pp. 1921-1935 : 1921-1935

Neofusicoccum luteum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, Studies in Mycology 55: 248 (2006), MycoBank MB500876

( Figure 14 )

Type: NEW ZEALAND, Bay of Plenty, Te Puke, No 1 Road, DSIR Research Orchard, from lesions on ripe fruit of Actinidia deliciosa ( Actinidiaceae ), 6 Oct 1982, M. J. Wingfield (holotype PREM 57589, culture ex-type CBS 562.92). S. R. Pennycook (holotype of asexual morph PDD 45400, culture ex-type of asexual morph PDDCC 8004). PORTUGAL, Estremadura, Oeiras, Quinta do Marquês, on cane of Vitis vinifera cv. Galego Dourado ( Vitaceae ), Mar 1996, A. J. L. Phillips (holotype of sexual morph LISE 94070, culture ex-type of sexual morph CBS 110299).

Sexual morph and asexual morph reported. See Phillips et al. (2013) for illustrations and descriptions.

Isolate CDP 0038. Sexual morph: Undetermined. Asexual morph: Conidiomata on palm leaflets in culture pycnidial, globose to subglobose, non-stromatic, uniloculate, black, solitary, occasionally aggregated in small groups, semi-immersed to superficial, densely covered by greyish to olivaceous mycelial hairs, exuding a creamy, pale mucoid mass or cirrus of conidia. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth- and thin-walled, simple, discrete, determinate, cylindrical, often tapering towards the apex, straight or curved, aseptate, enteroblastic, proliferating at the same level giving rise to conspicuous periclinal thickenings, rarely proliferating percurrently to form 1–2 annellations, (6.33–)8.45–12.76(–14.62) × 2.34–4.21 μm, 95 % confidence limits = 9.49– 10.64 × 3.18–3.45 μm (mean ± SD = 10.02 ± 1.97 × 3.31 ± 0.43 μm, n = 30). Conidia ellipsoidal to cylindrical, or irregularly cylindrical, often widest in the middle or upper third, ends subobtuse, often base truncate or subtruncate, smooth- and thin-walled, hyaline and aseptate, rarely becoming 1–2(–3)-septate and pale brown before germination, 16.47–22.1 × 5.78–7.78 μm, 95 % confidence limits = 19.23–20.2 × 6.55–6.91 μm (mean ± SD = 19.71 ± 1.37 × 6.73 ± 0.51 μm), mean ± SD conidium length/width ratio = 2.95 ± 0.32 (n = 30).

Culture characteristics: Colonies on 1/2 PDA, reaching 85 mm diam. after 7 d at 20 ℃ in darkness. Surface flat, with appressed, moderately dense aerial mycelium, with filamentous margin, circular shape, whitish to pale, opaque. Reverse pale to yellowish. Turning entirely dirty white, greyish (surface) and orangish and dark brown (reverse) after about 2 w. Presence of yellowish diffusible pigment.

Material examined: PORTUGAL, Lisbon, Areeiro, Rua Sarmento de Beires, on foliar lesions of leaflets of Phoenix canariensis ( Arecaceae ), 6 October 2018, Diana S. Pereira (specimen HDP 014, new host record), living culture CDP 0033 ( ITS sequence OQ996216, tef1 sequence OR 233664); Areeiro, Rua Sarmento de Beires, on foliar lesions of segments of Washingtonia filifera ( Arecaceae ), 6 October 2018, Diana S. Pereira (specimen HDP 016, new host record), living culture CDP 0038 ( ITS sequence OQ996217, tef1 sequence OR 233665); Parque das Nações, on foliar lesions of segments of Chamaerops humilis ( Arecaceae ), 8 May 2021, Diana S. Pereira (specimen HDP 091, new host record), living culture CDP 1568 ( ITS sequence OQ996238, tef1 sequence OR 233675); Parque das Nações, on foliar lesions of segments of Chamaerops humilis ( Arecaceae ), 8 May 2021, Diana S. Pereira (specimen HDP 098), living culture CDP 1969 ( ITS sequence OQ996243, tef1 sequence OR 233677); Parque das Nações, on foliar lesions of segments of Chamaerops humilis ( Arecaceae ), 8 May 2021, Diana S. Pereira (specimen HDP 099), living culture CDP 2026 ( ITS sequence OQ996244, tef1 sequence OR 233678).

Hosts: Reported from 45 genera in 29 families, including Acanthaceae ( Avicennia marina ), Actinidiaceae ( Actinidia deliciosa ), Adoxaceae ( Viburnum sp. ), Anacardiaceae ( Mangifera indica ), Araucariaceae ( Araucaria angustifolia ), Arecaceae ( Chamaerops humilis , Phoenix canariensis , Washingtonia filifera ), Asteraceae ( Chrysanthemoides monilífera , Helianthus annuus ), Combretaceae ( Lumnitzera racemosa ), Cupressaceae ( Chamaecyparis lawsoniana , Cupressus lusitanica , C. sempervirens , Juniperus communis , Sequoia sp. , S. sempervirens , Thuja plicata , Thujopsis dolabrata ), Ebenaceae ( Diospyros kaki ), Ericaceae ( Erica arborea , Rhododendron sp. , Vaccinium sp. ), Fabaceae ( Styphnolobium japonicum ), Fagaceae ( Quercus robur ), Lauraceae ( Persea americana ), Malvaceae ( Tilia platyphyllos ), Meliaceae ( Melia azedarach ), Moraceae ( Ficus microcarpa ), Myrtaceae ( Eucalyptus globulus , Syzygium cordatum ), Oleaceae ( Fraxinus excelsior , F. ornus , Olea europaea ), Pinaceae ( Pinus pinea ), Proteaceae ( Banksia sp. ), Proteaceae ( Buckinghamia sp. , Macadamia integrifolia ), Rhizophoraceae ( Bruguiera gymnorhiza , Rhizophora mucronata ), Rosaceae ( Crataegus mexicana , Malus domestica ), Rutaceae ( Citrus sp. , C. limon , C. sinensis ), Salicaceae ( Populus alba , P. nigra , P. tremula , Salix fragilis ), Sapotaceae ( Mimusops caffra ), Tamaricaceae ( Tamarix sp. ) and Vitaceae ( Vitis sp. , V. riparia-rupestris , V. vinífera ) ( Farr & Rossman 2023, present study).

Distribution: Australia, Chile, France, Germany, Italy, New Zealand, Portugal, South Africa (including the Eastern Cape and KwaZulu-Natal provinces), Tunisia, Uruguay and USA (California) ( Farr & Rossman 2023).

Notes: Based on the phylogenetic analyses of the combined ITS- tef1-tub2 dataset, strains CDP 0033, CDP 0038, CDP 1568, CDP 1969 and CDP 2026 clustered with the ex-type and other strains of N. luteum with high ML-BS value ( Figure 5 ). Sequence comparisons with the ex-type strain of N. lutem ( CBS 562.92) for ITS and tef1 showed 99.58–100 % and 100 %, respectively, sequence similarity, and differences were represented by gaps on ITS 1 in strains CDP 1568 and CDP 1969. No tub2 sequence data is available for CDP 0033, CDP 0038, CDP 1568, CDP 1969 and CDP 2026. Morphologically, the strains isolated in this study are similar to the holotype of N. luteum from lesions on ripe fruit of Actinidia deliciosa in New Zealand ( Phillips et al. 2013) ( Figure 14 ). Considering the strain characterized here ( CDP 0038) and the ex-type strain of N. luteum ( CBS 562.92), both produce pycnidial conidiomata with ellipsoidal, hyaline and aseptate conidia of remarkably similar mean size, although conidia of CDP 0038 seem to be somewhat wider (19.71 × 6.73 μm and 19.7 × 5.6 μm, respectively) ( Phillips et al. 2013) ( Figure 14 ). Nonetheless, L / W ratio of CDP 0038 is lower than that reported for the ex-type strain of N. luteum ( CBS 562.92) (2.95 versus 3.6, respectively) ( Phillips et al. 2013). Based on these morpho-molecular analyses, strains CDP 0033, CDP 0038, CDP 1568, CDP 1969 and CDP 2026 are here reported as representing intraspecific variation of N. luteum . Neofusicoccum luteum has not previously been recorded on Arecaceae and thus three new host records are here reported, namely Chamaerops humilis , Phoenix canariensis and Washingtonia filifera ( Table 5). The isolates of N. luteum studied here were recorded from foliar lesions of palms, but pathogenicity has not been tested.

Figures

FIGURE 5. Phylogenetic tree of Neofusicoccum generated from BA inference based on combined ITS, tef1 and tub2 sequences. ML bootstrap support values (ML-BS ≥ 50 %) and Bayesian posterior probabilities (PP ≥ 0.85) are shown at the nodes. Strains with type status are indicated in bold font, the isolates from this study are presented in brown typeface and species are delimited with coloured blocks. Species names in N. parvum species complex are noted before the strain number. The scale bar represents the expected number of nucleotide changes per site. The tree was rooted to Botryosphaeria corticis (CBS 119047) and B. dothidea (CBS 115476).

FIGURE 14. Neofusicoccum luteum (CDP 0038). A. Conidiomata formed on palm leaf piece. B, C. Conidiogenous layer. D–G. Conidiogenous cells. H, I. Conidia. Scale bars: A = 200 μm, B,C = 5 μm, D–G = 2.5 μm, H, I = 10 μm.