Leveillula, G. Arnaud, 1921

Khodaparast, Seyed Akbar, Takamatsu, Susumu, Shadlou, Adel, Damadi, Mohsen, Pirnia, Mahdi & Jahani, Mahdi, 2016, Notes on the genus Leveillula (Erysiphaceae): a new unrecorded species and notes on Leveillula infecting Ficus, Cucurbita and Tropaeolum in Iran, Phytotaxa 260 (3), pp. 267-275 : 271

Leveillula on Ficus

There is no record of the genes Leveillula on Moraceae in Braun and Cook’s taxonomic manual. The only report of this fungus on Moraceae belongs to L. taurica ( Salari et al. 2010) . According to the drawing provided by the author, conidium morphology of the fungus is different from those of L. taurica . Hence, morphology of the fungus was reexamined. According to our observation primary conidium are broadly ellipsoid, ovoid, to lanceolate, secondary conidia ellipsoid-cylindric to ovoid ( Fig. 6). Such characteristics more or less resemble Leveillula contractirostris V.P. Heluta & Simonyan. Moreover , during this study rDNA ITS of herbarium material was sequenced.

Fig.5 compares the nucleotide sequences of the rDNA ITS region from Ficus and some related specimens. As shown in Fig. 5 , three substitutions have been occurred in Ficus isolates at position 139, 368 and 400, when compared to ITS sequences of L. taurica on Zygophyllum fabago , type host of the species. Such substitutions are similar to L. contractirostris on Alcea spp. However, two deletion sites were found at positions 170–175 and 182–184, that are found in some Leveillula isolates such as Leveillula on Medicago and Tropaeolum .

In ME and NJ trees the Ficus isolate clustered with L. contractirostris ( Fig. 1 ). However, in MP tree Ficus powdery mildew clustered with Medicago powdery mildew group with high bootstrap value (96%). As a result we suggest that Ficus powdery mildew is closely related to L. contractirostris .

Specimen examined. IRAN, Sistan and Bluchestan Province, Zabol, on Ficus carica L., 6 Nov 2007, J. Abkhoo (GUM 718).

Figures

FIGURE 1. A minimum-evolution (ME) tree (length = 0.28600863) based on ITS data for 38 Leveillula and one outgroup taxa. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the Kimura 2-parameter method and are in the units of the number of base substitutions per site. The ME tree was searched using the Close-Neighbor-Interchange (CNI) algorithm at a search level of 1 (level = 1). The Neighborjoining algorithm was used to generate the initial tree.All ambiguous positions were removed for each sequence pair. The numbers above the branches represent branch support using 1000 bootstrap replications (Bootstrap values below 50 % are not shown). GenBank database accession numbers of the nucleotide sequence data are shown after each taxon name.

FIGURE 5. Sequence alignment of parts of the rDNA ITS region of selected Leveillula isolates from some plant species studied in this paper. The most similar parts deleted from the alignment.