Phaeoseptum aquaticum (Halotthiaceae): new record for American continent in a new host for science

Abstract

Phaeoseptum aquaticum (Ascomycota: Halotthiaceae) described for France, Haute Garonne, Palaminy, in a swamp, on submerged branch of Robinia pseudoacacia and at Martres Tolosane, e Moulin, banks of Garonne River, on driftwood of Salix sp., is reported as a new record for American continent in Juá village, municipality of Paulo Afonso, Bahia state, northeastern Brazil, colonizing a new host, Syagrus coronate, palm tree well suited to dry and arid regions from the Caatinga biome.

Key words:
Arecaceae; Ascomycota; Caatinga bioma; taxonomy

Resumo

Phaeoseptum aquaticum (Ascomycota: Halotthiaceae) descrito para a França, Haute Garonne, Palaminy, em um pântano, no ramo submerso de Robinia pseudoacacia e em Martres Tolosane, e Moulin, bancos do rio Garonne, em troncos de Salix sp., é relatado como um novo registro para o continente americano no Povoado Juá, município de Paulo Afonso, estado da Bahia, nordeste do Brasil, colonizando um novo hospedeiro, Syagrus coronata, palmeira bem adaptada às regiões áridas e secas do bioma Caatinga.

Palavras-chave:
Arecaceae; Ascomycota; bioma da Caatinga; taxonomia

Syagrus coronata (Mart.) Becc., licuri or ouricury palm tree, is a species typical of the semi-arid northeast that has a clear preference for the dry and arid regions of the caatingas (Noblick 1986). Several parts of S. coronata are exploited by people in the semi-arid of Bahia for the manufacture of objects that are sold, playing an important role in the local subsistence economy (Crepaldi et al. 2004).

The palm tree S. coronata also presents great ecological value, representing a source of resources for the native fauna, especially in the Caatinga domain. The licuri is the main food for the maintenance and growth of the native population of the bird Anodorhynchus leari Bonaparte 1858, the blue-eared macaw. Endemic bird of the Caatinga that is extremely endangered (Rocha 2005).

Systematic surveys of the mycota colonizing S. coronata (licuri) are still scarce. In the Brazilian northeast, stand out the works of Santos et al. (2016) that registered some species of Ascomycota on licuri in areas of Caatinga in the semi-arid region of Bahia and Cruz and Gusmão (2009) where three conidial fungi are documented on the same host.

Phaeoseptum Y. Zhang, J. Fourn. & K.D. Hyde is a genus monotypic with ascomata immersed under pseudoclypeus, scattered to gregarious, depressed globose, papillate, ostiolate. Pseudoparaphyses narrowly cellular, belonging to Halotthiaceae family. Asci 8-spored, bitunicate, cylindrical-clavate, with a small ocular chamber and apical ring best seen in immature asci. Ascospores fusiform, slightly curved, dictyosporous with thickened septa. This genera was introduced to accommodate a freshwater taxon (Zhang et al. 2013), Phaeoseptum aquaticum Y. Zhang, J. Fourn. & K.D. Hyde.

Halotthiaceae was described to accommodate four aquatic genera: Phaeoseptum, Halotthia Kohlm., Mauritiana Poonyth, K.D. Hyde, Aptroot & Peerally, and Pontoporeia Kohlm. Phaeoseptum aquaticum was described for France in this work it was found on dried petioles in decomposition of S. coronata still attached to the plant, during a recent mycological search of Pezizomycotina (Ascomycota) on palms tree in Caatinga biome, Brazil.

Dried petioles in decomposition of S. coronata attached to the plant were collected in March 2016 in the Juá village, municipality of Paulo Afonso, Bahia (BA) states. Identification work was carried out in the Science Laboratory of the State University of Bahia (UNEB), Campus VIII. The signs of the fungi on surface of the host were examined under a stereoscopic microscope (Carl Zeiss). Posteriorly the fungal structures were mounted with lacto-glycerol cotton blue, Melzer reagent and water. Furthermore, permanent slides with PVL resin (polyvinyl alcohol + lactophenol) were made. Slides and the specimens were deposited in the URM Herbarium of the Federal University of Pernambuco (UFPE), Recife, Brazil. Examination of the microscopic preparations allowed the morphological characterization of the fungal structures which were measured with the aid of an ocular micrometer. Photomicrographs were taken using a digital camera (Sony W830), adjusted to the eyepieces of the microscope and the stereoscope.

Phaeoseptum aquaticum Ying Zhang, J. Fourn. & K.D. Hyde, in Zhang, Fournier, Phookamsak, Bahkali & Hyde, Mycologia 105(3): 606 (2013). Fig. 1a-i

Figure 1
Phaeoseptum aquaticum - a. ascomas na superfície do hospedeiro; b. ascoma em section vertical; c-d. asci mature; e. asci immature; f. pseudoparaphises; g-i. ascospores. Source: Santos MAL.

Ascomata immersed, scattered to gregarious, developing beneath black, raised, soft, papillate dome shaped areas on the host surface. Ascomata 300-395 × 422,5-425 µm in section, subglobose, ostiolate; peridium 20-27.5 µm thick, pseudoparenchymatous. Hamathecium of cellular pseudoparaphyses, 2.5-3 µm broad, septate, anastomosing. Asci 112.5-137.5 × 20-22.5 µm, 8-spored, bitunicate, cylindrical-clavate, pedicel well defined; ocular chamber small and truncate, ascus apex thickened. Ascospores 25-32.5 × 10-12.5 µm, dictyosporous, initially pale-brown, becoming heavily pigmented at maturity, smooth walled, uniseriate at base and overlapping triseriate at apex, broadly fusoid with broadly rounded ends, slightly curved, 9-12-transversally septate, end cells usually larger than others, with a vertical septum in nearly all cells.

The species distribution are France (Zhang et al. 2013), and Brazil (this paper).

The known hosts are Robinia pseudoacacia L. (Fabaceae), Salix sp. (Flacourtiaceae) and Syagrus coronata (Arecaceae, this paper).

Material examined: BRAZIL. BAHIA: Juá village, Paulo Afonso, on dried petiole in decomposition of S. coronata attached to the plant, 9º25.893’S, 38º25.449’W, 380 m, 31.III.2016, Maiara A.L.S. (URM 90190).

The specimen found is similar in ascomata, ascus and ascospores morphology to P. aquaticum (Zhang et al. 2013) and the material examined is compared with the original description in Table 1. Phaeoseptum aquaticum was collected once during this study. It was not possible to perform the isolation of the fungus due to the scarcity of the material. Additional collections are necessary to isolate this species in pure culture and make the molecular characterization of it. In this work, P. aquaticum on a new host for science is described and illustrated.

Table 1
Morphology comparison of Phaeoseptum aquaticum (Zhang et al. 2013) with material this study.

	(Zhang et al. 2013)		(This study)
	Shaped	Measurements	Shaped	Measurements
Ascomata	depressedspherical, immersed	300-400 × 400-600 µm	subglobose to depressedspherical, immersed	300-395 × 422,5-425 µm
Ascus	cylindrical-clavate	135-190 × 19-25 µm	cylindrical-clavate	112.5-137.5 × 20-22.5 µm
Ascospores	broadly fusoid and broadly rounded	30.5-38 × 9.5-12 µm	broadly fusoid and broadly rounded	25-32.5 × 10-12.5 µm
Number of transversalsepta	9-13(-16)		9-12

• Area Editor: Dr. Anibal de Carvalho Junior

Acknowledgments

Thanks are due to the Foundation for Research Support of the State of Bahia - FAPESB and the National Council of Research - CNPq for scholarships granted to first and second authors, respectively, the University of the State of Bahia - UNEB for providing facilities and laboratories to carry out this research and the resource provided for publication by Internal Program of Financial Aid for Publication in Qualified National and International Periodicals (PROPUBLIC).

References

• Crepaldi IC, Muradian LBA, Rios MDG, Camargo Penteado MVC & Salatino A (2001) Composição nutricional do fruto de licuri (Sysgrus coronata (Martius) Beccari). São Paulo. Revista Brasileira de Botânica 24: 155-159.
• Cruz ACR & Gusmão LFP (2009) Fungos conidiais na Caatinga: espécies associadas ao folhedo. Acta Botanica Brasilica 23: 999-1012.
• Noblick LR (1986) Palmeiras das caatingas da Bahia e as potencialidades econômicas. Simpósio sobre a Caatinga e sua Exploração Racional. EMBRAPA, Brasília. Pp. 99-115.
• Rocha KMR (2005) O Raso da Catarina. São Paulo. Revista Phoenix Magazine 6: 30-32.
• Santos MAL, Vitória NS & Bezerra JL (2016) Fungos colonizando palmeiras em áreas de caatinga do Sertão da Bahia. Agrotrópica 28: 37-46.
• Zhang Y, Fournir J, Phookamsak R, Bahkali AH & Hyde KD (2013) Halotthiaceae fam. nov. (Pleosporales) accommodates the new genus Phaeoseptum and several other aquatic genera. Mycologia 105: 603-609.

Publication Dates

• Publication in this collection
  20 Dec 2019
• Date of issue
  2019

History

• Received
  26 Jan 2018
• Accepted
  09 July 2018