Venturia Sacc., Syll. fung. (Abellini) 1: 586 (1882)


The genus Venturia was introduced by Saccardo (1882), for V. inaequalis (Cooke) G. Winter. Most of the species in this genus are notable plant pathogens, e.g. apple scab (V. inaequalis), pear scab (V. pyrina Aderh.), poplar shoot blight (V. populina (Vuill.) Fabric.), and stone fruit scab or freckle (V. carpophil E.E. Fisher). The taxonomic concept of Venturia was adopted by Sivanesan (1977). Molecular evidence indicated that Venturia is a genus within Venturiales, Dothideomycetes (Zhang et al. 2011; Hyde et al. 2013).

ClassificationDothideomycetes, Pleosporomycetidae, Venturiales, Venturiaceae

Type speciesVenturia inaequalis (Cooke) G. Winter, in Thümen, Mycoth. Univ., cent. 3: no. 261 (1875)

Distribution – Worldwide

Disease Symptoms – Leaf blight/spot, Scab

            Symptoms are more noticeable on leaves and fruits. Nearly circular, velvety, olive-green spots on both sides of the leaves appear in early spring. The spots eventually turn dark green to brown and the leaves will turn yellow and fall. Lesions on the leaves and fruit are “scabby” in appearance, with a distinct margin. The earliest noticeable symptom on fruit is water-soaked areas which develop into velvety, green to olive-brown lesions (Vaillancourt and Hartman 2000).

Hosts – broad host range including genera Acer, Achilea, Alchemilla, Allium, Alnus, Betula, Epilobium, Malus, Pandanus, Persea, Pinus, Populus, Prunus, Quercus and Salix (Farr and Rossman 2018).

Morphological based identification and diversity

Species of Venturia are parasitic or endophytic on leaves, bark and wood, immersed and becoming erumpent, black, globose ascomata, with papillate, ostiolate, bitunicate, oblong to obclavate asci, with or without short and thick pedicel, with an ocular chamber, uniseriate, ellipsoidal, broadly rounded ends, hyaline to pale brown, 1-septate ascospores, with upper cell shorter than the lower one (Wu et al. 2011; Hyde et al. 2013). The asexual morph of this genus was found as two genera, Pollaccia E. Bald. & Cif. and Spilocaea Fr. (Barr 1968; Sivanesan 1984; Crous et al. 2007). Seifert and Gams (2011) synonymized Spilocaea under Fusicladium Bonord., however, Zhang et al. (2011) indicated that the type species of Spilocaea (S. pomi Fr.) is the asexual morph of Venturia based on molecular analyses. Therefore, Spilocaea was synonymized under Venturia based on the number of its epithets being higher than Spilocaea (Index Fungorum 2018). Currently, about 180 species are listed in Index Fungorum (2018), but many of them lack clear description and illustration. There ais little sequence data for Venturia available in GenBank when compared with the number of species listed in Index Fungorum (2018). Fresh collections and molecular data are needed to clarify relationships between species (Zhang et al. 2011; Hyde et al. 2013).

The species are distinguished by hosts, disease symptoms, the morphology of ascomata, number of ascospores in the ascus, and shape and colour of ascospores. However, most species have unclear descriptions. Thus, it is difficult to compare unknown/newly collected Venturia species with described species. Molecular analysis is an important method for identifying species in Venturia, but not many species have such data.

Molecular based identification and diversity

Sequence data has been provided from both sexual and asexual morphs (Crous et al. 2007; Zhang et al. 2011). In phylogenetic trees, Venturia was placed in a monophyletic clade of Venturiaceae, which is a sister group to Symphoventuriaceae (Zhang et al. 2011; Hyde et al. 2013). It is closely related to Microthyriales with Phaeotrichaceae as a sister clade (Schoch et al. 2009; Wu et al. 2011; Hyde et al. 2013, Liu et al. 2017). We update the phylogenetic relationship of Venturia species by analysing the concatenated alignment of SSU, LSU and ITS sequence data. Based on this phylogenetic tree, the placement of species within this genus are not different from previous studies. Only a few species are confidently identified and established due to little sequence data from Venturia species available in GenBank.

Recommended genetic markers (genus level) – LSU, SSU

Recommended genetic markers (species level) – ITS

Accepted number of species: There are 276 species epithets in Index Fungorum (2018) under this genus. However, only around 20 species are confirmed by sequence data (Hyde et al. 2013; Ibrahim et al. 2016; Zhang et al. 2016).

References: Crous et al. 2007, Zhang et al. 2011 (morphology, phylogeny), Carisse et al. 2010 (life cycle and disease management), Machouart et al. 2014 (Phylogeny), Zhang et al. 2016 (Phylogeny)


Table  Venturia. Details of the isolates used in the phylogenetic analyses. Ex-type (ex-epitype) strains are in bold and marked with an * and voucher strains are in bold

Species Isolate LSU ITS TEF Calmodulin TUB SSU
Fusicladium peltigericola CBS:128206 HQ599579 HQ599579
Sympoventuria capensis CPC 12840 DQ885904 DQ885904
V. anemones CBS 370.55 EU035447 EU035447 KF853965 KF808264
V. atriseda CBS 371.55 EU035448 EU035448
V. aucupariae CBS 363.35 EU035450 EU035450
V. catenospora BJFU 140822-1 KU220966 KU220964
V. catenospora CBS 447.91 EU035427 EU035427 KF853957 KF808256
V. chinensis BJFU 140826-17 KP689595 KP689596
V. chlorospora CBS 470.61 EU035454 EU035454
V. chlorospora CBS 466.61 EU035453 EU035453
V. ditricha CBS 118894 EU035456 EU035456 KF853970 KF808270
V. fraxini VE4 KT823548 KT823582 KT823616 KT823514
V. fuliginosa BJFU 140827.14 KU220967 KU220965
V. helvetica CBS 474.61 EU035458 EU035458 KF853974 KF808274
V. hystrioides CBS:117727 EU035459 EU035459 KF853975
V. inaequalis CBS 309.31 EU035437 EU035437
V. inaequalis CBS 476.61 GU456336 EU282478 GU456288
V. inopina MYA 2852 AY177406
V. lonicerae CBS 445.54 EU035461 EU035461
V. macularis CBS 477.61 EU035462 EU035462 KF853977 KF808277
V. martianoffianum BJFC 150828_1 KU985140 KU985131
V. minuta CBS 478.61 EU035464 EU035464 KF853980 KF808280
V. nashicola OYO-1 HQ434393 HQ434349 HQ434437
V. orni VO10 KT823564 KT823598 KT823632 KT823530
V. phaeosepta BJFC 140520_1 KU985142 KU985133
V. pirina 38995 EF114714 HQ434425 HQ434381 HQ434469 EF114739
V. polygoni-vivipari CBS:114207 EU035466 EU035466 KF853984 KF808284
V. populina CBS 256.38 GU323212 EU035467 GU296206
V. saliciperda CBS 480.61 EU035471 EU035471
V. tremulae CBS 112625 EU035438 EU035438
V. tremulae var. tremulae CBS 257.38 EU035475 EU035475
V. viennotii CBS 690.85 EU035476 EU035476

Fig.  Phylogenetic tree generated by maximum likelihood analysis of combined ITS and LSU sequence data of Venturia species. Sequences were obtained from GenBank. Thirty-two strains are included in the analyses, which comprise 1380 characters including gaps. Single gene analyses were carried out to compare the topology of the tree and clade stability. The tree was rooted with Sympoventuria capensis (CPC 12840). Tree topology of the Bayesian analysis was similar to the RAxML. The best scoring RAxML tree with a final likelihood value of -4376.419190 is presented. The matrix had 261 distinct alignment patterns, with 15.44% of undetermined characters or gaps. Estimated base frequencies were as follows; A = 0.237094, C = 0.259593, G = 0.296334, T = 0.206979; substitution rates AC = 1.996953, AG = 2.270150, AT = 1.867221, CG = 0.763559, CT = 10.363584, GT = 1.000000; gamma distribution shape parameter α = 0.419710. RAxML and Bayesian posterior probabilities value ≥70% (BT) and 0.9 (PP) are shown respectively near the nodes. The scale bar indicates 0.2 changes. The ex-type strains are in bold.

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