Sphaerophragmium acaciae (Cooke) Magnus, Ber. Deutsch. Bot. Ges.

Tabe, Affoussatou, Aime, M. Catherine, Yorou, Nourou Soulemane & Piepenbring, Meike, 2022, New records and data on rust fungi (Pucciniales, Basidiomycota) in Benin, Phytotaxa 548 (2), pp. 127-145 : 139

Sphaerophragmium acaciae (Cooke) Magnus, Ber. Deutsch. Bot. Ges. 9: 121 (1891)

Figure 11

Uredinia hypophyllous, scattered, individual or grouped, circular, subepidermal, erumpent, brown. Urediniospores ovoid, ellipsoidal to broadly ellipsoidal, or reniform, (18–)22–26(–27) × (15–)16–18(–20) µm (n = 30), pale yellow, wall 1–2 µm thick, echinulate, with 4–5 inconspicuous, more or less equatorial germ pores. Telia not observed.

The 28S rDNA sequence of the specimen of S. acaciae from Benin shares 99.9% (875/876 bp) sequence identity with a sequence deposited as Sphaerophragmium sp. on Albizia sp. ( KJ862350 , specimen BRIP 56910 from Australia; McTaggart et al. 2015) as well as 100% with two specimens deposited in BPI and identified as S. acaciae (BPI863973 from Puerto Rico; BPI878100 from Nigeria; C. Aime, unpublished). Here, we publish the first completely annotated LSU rDNA sequence for S. acaciae .

Host and distribution within the studied area: —Uredinia on Albizia lebbeck (L.) Benth. ( Fabaceae ), Central Benin.

Specimen examined: — Uredinia on Albizia lebbeck : BENIN. Collines: Glazoué , elev. 192 m, 7°58’ N, 2°14’ E, 22 September 2019, A . Tabé , Y . Meswaet , M . Piepenbring , N. S . Yorou , M. U . Schmidt , TA432 ( UNIPAR), GenBank Acc. no. LSU: OL 437039 .

Host species:—Primary host species: Albizia acle (Blanco) Merr. , A. coriaria Welw. ex Oliv. , A. corniculata (Lour.) Druce , A. falcataria (L.) Fosberg, A. julibrissin Durazz. , A. kalkora (Roxb.) Prain , A. lebbeck , A. mollis (Wall.) Boivin , A. myriantha Merr. , A. odoratissima (L.f.) Benth., A. procera (Roxb.) Benth. , A. saponaria (Lour.) Blume , Albizia sp. ; Fabaceae (Farr & Rossman 2021) . Secondary host species: not known ( Beenken & Berndt 2010).

Distribution: —Africa [ Ghana ( Wakefield & Hansford 1949), Madagascar ( Spaulding 1961), Malawi ( Corbett 1964), Mauritius ( Spaulding 1961), Nigeria ( Eboh 1978), Reunion ( Boa & Lenné 1994), Sierra Leone, Somalia ( Castellani & Ciferri 1937), Sudan ( Tarr 1963), Uganda ( Boa & Lenné 1994), Benin (this study)], Asia, North America, Oceania, Southern America, Caribbean (Farr & Rossman 2020).

Comments: —The 28S rDNA sequence of the specimen on A. lebbeck from Benin indicates that it represents a species of Sphaerophragmium . Three species of Sphaerophragmium are known on Albizia spp. , namely S. acaciae (Cooke) Magnus , S. albiziae Lohsomb., Kakish. & Y. Ono , and S. clemensiae Syd. ( Lohsomboon et al. 1994) . S. acaciae is reported from many countries with warm to hot climate, while S. albiziae and S. clemensiae are only known from East Asia. S. albiziae forms amphigenous uredinia and urediniospores that are longer than those of the specimen from Benin, i.e., 24–39 µm ( Lohsomboon et al. 1994) vs. 22–26 µm (specimen from Benin). The urediniospores of S. clemensiae are as long as those of the present specimen, but they are slenderer than those from Benin (16–18 µm) by being 12–17 µm wide ( Lohsomboon et al. 1994). With a size of (18–)22–26(–27) × (15–)16–18(–20) µm, the urediniospores of the present specimen are within the size range of those of S. acaciae (20–33 × 14–25 µm; Lohsomboon et al. 1994). Further similarities are the exclusively hypophyllous position of the uredinia and 4 to 5 germ pores on each urediniospore which are however difficult to see. Based on these similarities, the specimen from Benin is identified as S. acaciae and represents the first report for Benin.

Figures

FIGURE 11. Sphaerophragmium acaciae on Albizia lebbeck (TA432). A Hypophyllous uredinia B urediniospores drawn in optical sections except one spore. Scale bar: 10 µm.