Development of new primers based on gapdh gene for Cercospora species and new host and fungus records for Iran

Document Type : Original Article

Authors

Department of Botany, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

Abstract

ITS region and protein coding genes such as actA, cmdA, gapdh, his3, rpb2, tef1 and tub2 have been applied to investigate the molecular phylogeny of Cercospora species in recent years. Although gapdh is an informative gene for species delimitation in the genus, difficult amplification of this locuswith available primers limits its use for Cercospora. Therefore, in this study novel primers including GpdF-Cer (5’-TTC ATY GAG CCM CAC TAC GCT-3’) and GpdR-Cer (5’-RTC GGT GAC KRC GAG VAC-3’) were developed to supplement previously published primers for the amplification of gapdh. Besides, in a taxonomic survey on the genus Cercospora in Iran based on consolidated species concept, leaf samples with leaf spot symptoms were collected and Cercospora isolates were characterized based on a combination of morphological features and sequence data from the ITS, actA, cmdA, gapdh, his3 and tef1 loci. Seventeenspeciesof the genus Cercospora were recognized of which C. mercurialis on Mercurialis annua is confirmed for the first time, for Iran (Asia) mycobiota using sequence data of six genomic loci.Several new hosts are recorded for C. apii (one), C. beticola (one), C. cf. flagellaris (10), C. gamsiana (one), C. iranica (one), Cercospora sp. G (three) and Cercospora sp. T (four). Thus, new host families were added to the host range of C. beticola (Brassicaceae), C. cf. flagellaris (Lamiaceae, Polygonaceae, Vitaceae), and Cercospora sp. T (Lamiaceae, Plantaginaceae, Rosaceae) in the world.
 

Keywords


INTRODUCTION

 

Fungi in the genus Cercospora (Mycosphaerellaceae, Capnodiales) are known as serious plant pathogens, causing major losses on a wide range of crop plants worldwide including sugar beet (Weiland & Koch 2004; Bakhshi et al. 2011; Vaghefi et al. 2018), beans (Chand et al. 2015; Duangsong et al. 2016), faba beans (Kimber & Paull 2011), corn (Crous et al. 2006), carrots (Kushalappa et al. 1989), sesame (Bakhshi & Zare 2020) and soybean (Soares et al. 2015; Bakhshi & Zare 2020) as well as many vegetable and ornamental species. Several taxa are also considered potential biocontrol agents of weeds (Tessmann et al. 2001; Praveena & Naseema 2004).

Correct identification of Cercospora species has a crucial role in order to understand the epidemiology of the diseases caused by these taxa and to develop effective control measures. Due to the lack of useful morphological characters and high levels of intraspecific variation, morphology does not provide sufficient and informative characters for an accurate identification of Cercospora species (Groenewald et al. 2013; Bakhshi et al. 2012b, 2015a, 2015b). Therefore, traditional identification systems in Cercospora relied heavily on host plant association (Crous & Braun 2003). Molecular studies of Cercospora spp. in recent years revealed that many taxa have broader host ranges (Groenewald et al. 2013; Bakhshi et al. 2015a, 2018), consequently reliance on host data in Cercospora taxonomy has proven problematic.

Phylogenetic analyses based on DNA sequences have led to momentous progress in the systematics of the genus. In this regard, phylogenetic performance of sequence data of eight genomic loci including ITS, actA, cmdA, gapdh, his3, rpb2, tef1 and tub2, were assessed for Cercospora species based on the inter-/intraspecific distance ratio and clade recovery (Groenewald et al. 2013; Bakhshi et al.2015a, 2018; Bakhshi 2019). According to these results, none of the genes analyzed provides an effective barcode on its own across the entire genus. However, Bakhshi et al. (2018) showed that, gapdh is a strong candidate for improved species delimitation in Cercospora and this gene provided better insight, especially into species complexes. The amplification of gapdh with available primers (Berbee et al. 1999; Myllys et al. 2002) was, however, not easy and indicated the need of new primer designation for gapdh in Cercospora.

Therefor our primary aim was to designate an additional primer set for amplification of gapdh in Cercospora. In addition, our secondary aim was to characterize Cercospora species gained from the infected leaves of several plant species collected from different provinces of Iran, based on morphology, cultural characteristics and phylogenetic analyses of the DNA sequence data.

 

MATERIALS AND METHODS

 

Samples and morphology

Plant samples with Cercospora leaf spot symptoms were collected from seven provinces of Iran including Ardabil, Golestan, Guilan, Hormozgan, Khuzestan, Mazandaran and North Khorasan during the growing seasons 2017–2019, taken to the laboratory, and examined under a Nikon SMZ 445 stereo-microscope to observe sporulation. Fungal strains were isolated in pure culture by direct transfer of spores from a single leaf spot onto plates containing 2% malt extract agar (MEA; Fluka, Hamburg, Germany) with a sterile fine pointed needle as explained in Bakhshi et al. (2011). Representative samples of diseased specimens were dried in a plant press and deposited in the Fungal Herbarium of the Iranian Research Institute of Plant Protection (IRAN F). Representative isolates of the fungi were deposited in the Culture Collection of the Iranian Research Institute of Plant Protection (IRAN C), Tehran, Iran.

Morphological descriptions are based on structures from dried material. Diseased leaf tissues were examined under a Nikon SMZ 445 stereo-microscope and taxonomically informative morphological structures (stromata, conidiophores and conidia) were picked up from lesions with a sterile dissecting needle and mounted on glass slides in clear lactic acid. Structures were examined under an Olympus-BX51 (Olympus, Tokyo, Japan) light microscope, and photographed using a mounted Olympus DP 25 high definition color camera. Thirty measurements were made at ×1000 for each microscopic structure, and 95% confidence intervals were derived for the measurements with extreme values given in brackets.

 

DNA isolation, PCR amplification and sequencing

Mycelium from actively growing fungal cultures was scraped from the surface of MEA using a sterile scalpel blade and DNA was isolated using the protocol of Möller et al. (1992). The DNA samples were subsequently diluted 50–100 times in preparation for further DNA amplification reactions. The primers V9G (de Hoog & Gerrits van den Ende 1998) and ITS4 (White et al. 1990) were used to amplify part of the nuclear rRNA operon (ITS) spanning the 3’ end of 18S rRNA gene, the first internal transcribed spacer, the 5.8S rRNA gene, the second ITS region and the 5’ end of the 28S rRNA gene. Part of the actin gene (actA) was amplified using the primer set ACT-512F (Carbone & Kohn 1999) and ACT2Rd (Groenewald et al. 2013), whereas the primer set EF1-728F (Carbone & Kohn 1999) and EF-2 was used to amplify part of the translation elongation factor 1-alpha (tef1) gene. Primers employed for the amplification of calmodulin gene (cmdA) included CAL-228F and CAL-737R (Carbone & Kohn 1999) or CAL-2Rd (Groenewald et al. 2013), while the primer set CylH3F and CylH3R (Crous et al. 2004) was used to amplify part of the histone H3 gene (his3). The PCR amplifications were performed in a total volume of 25 µL on a GeneAmp PCR System 9700 (Applied Biosystems, Foster City, California). The protocols, and conditions for standard PCR amplification of the loci followed Bakhshi & Arzanlou (2017) and subsequent sequencing was performed in both directions using the PCR primers by Microsynth company (Balgach, Switzerland).

To amplify part of the gapdh, new primer set was designated here. For this purpose, the available sequences of gapdh for Cercospora spp. were retrieved from National Center for Biotechnology Information (NCBI) GenBank sequence database and were aligned with the MEGA v.7 (Molecular Evolutionary Genetics Analysis) software (Kumar et al. 2016). The forward and reverse primers were designed in regions showing similarity between different sequences using the OligoCalc (Oligonucleotide Properties Calculator) online software (http://biotools.nubic.northwestern.edu/OligoCalc.html) (Kibbe 2007). Synthesis of primers was carried out by Microsynth company. The different PCR mixtures and conditions were tested using the new primers to set the best condition and PCR mixture for amplification of part of the gapdh. Finally, the resulting fragments were sequenced in both directions using the PCR primers.

 

Sequence alignment and phylogenetic inference

The raw trace files were inspected and edited with MEGA v.7 software (Kumar et al. 2016), and consensus sequences were manually generated from the forward and reverse sequences. The newly generated sequences were blasted against the NCBI’s GenBank sequence database using MegaBLAST to identify related taxa. The obtained sequences from GenBank together with the novel sequences generated during this study were initially aligned with the MAFFT v.7 online interface using default settings (http://mafft.cbrc.jp/alignment/server/) (Katoh & Standley 2013) for each gene and, whenever necessary, manually improved in MEGA v.7.

For phylogenetic comparison, Bayesian inference (BI) analyses on individual gapdh gene and concatenated ITS, actA, cmdA, gapdh, his3 and tef1 loci were performed with MrBayes 3.2.6 (Ronquist et al. 2012). The best evolutionary model for each data partition was obtained using the software MrModelTest v. 2.3 (Nylander 2004). The heating parameter was set at 0.15 and the Markov Chain Monte Carlo (MCMC) analysis of four chains was started in parallel from a random tree topology and lasted until the average standard deviation of split frequencies came below 0.01. Trees were saved each 1 000 generations and the first 25% of saved trees were discarded as the ‘burn-in’ phase and posterior probabilities (PP) determined from the remaining trees. The resulting phylogenetic tree was printed with Geneious v. 5.6.7 (Drummond et al.2012). Sequences derived from this study were lodged at NCBI’s GenBank nucleotide database (http://www. ncbi.nlm.nih.gov; Table 1).

 

RESULTS AND DISCUSSION

 

Field survey

During the field survey of this study, leaf spot symptoms of various species of Cercospora were associated with different plant species including important crops and vegetables such as sugar beet (Beta vulgaris), celery (Apium graveolens), alfalfa (Medicago sativa), kohlrabi (Brassica oleracea), radish (Raphanus sativus), basil (Ocimum basilicum) and mint (Mentha longifolia), ornamentals such as Gazania sp. and Boston ivy (Parthenocissus tricuspidata), medical plants and or weeds such as mallow (Malva sp.), camel thorn (Alhagi maurorum), hemp-agrimony (Eupatorium cannabinum), sticky nightshade (Solanum sisymbriifolium), creeping cinquefoil (Potentilla reptans) etc. (Fig. 1).

 

 

Fig. 1. Disease symptoms associated with Cercospora spp. in the field. a. C. althaeina on Malva sp.; b. C. beticola and C. gamsiana on Beta vulgaris; c. C. beticola on Raphanus sativus; d–i. C. cf. flagellaris on d. Brassica oleracea, e. Ocimum basilicum, f.Mentha longifolia, g.Parthenocissus tricuspidata, h. Lapsana sp., i. Solanum sisymbriifolium;j. C. rumicis on Rumex sp.;k, l. Cercospora sp. G on k. Eupatorium cannabinum, l. Gazania sp.; m. Cercospora sp. T on Potentilla reptans; n. C. mercurialis onMercurialis annua; o.C. violae onViola sp.; p.C. zebrina on Alhagi maurorum.

 

Table 1. Collection details and GenBank accession numbers of Cercospora isolates included in this study.

Species 

Culture accession number  

Host 

Host Family 

Origin 

GenBank accession numbers

ITS

tef1

actA

cmdA

his3

gapdh

C. althaeina

IRAN 3920C

Malva sp.

Malvaceae

Mazandaran, Amol**

_

MT843584

MT843607

MT843631

MT843658

MT843686

C. apii

IRAN 3921C

Apium graveolens

Apiaceae

Guilan, Paresar, Pilembra

MT804377

MT843585

MT843608

MT843632

MT843659

MT843687

 

IRAN 3922C

Ipomoea hederacea*

Convolvulaceae

Golestan, Galikesh

MT804378

MT843586

MT843609

MT843633

MT843660

MT843688

C. beticola

P 631 I2

Beta vulgaris

Amaranthaceae

Ardabil, Moghan

_

_

_

MT843634

MT843661

MT843689

 

IRAN 3923C

Beta vulgaris

Amaranthaceae

Ardabil, Moghan

_

_

_

MT843635

MT843662

MT843690

 

IRAN 3924C

Beta vulgaris

Amaranthaceae

Mazandaran, Kelardasht, Goharkela

_

_

MT843610

MT843636

MT843663

MT843691

 

P 656 R2

Beta vulgaris

Amaranthaceae

Mazandaran, Marzanabad, Foshkour

_

_

MT843611

MT843637

MT843664

MT843692

 

IRAN 3925C

Raphanus sativus*

Brassicaceae*

Khuzestan, Shush-Dezful

_

MT843587

MT843612

MT843638

MT843665

MT843693

C. bizzozeriana

IRAN 3926C

Cardaria draba

Brassicaceae

North Khorasan, Bojnourd

_

MT843588

MT843613

MT843639

MT843666

MT843694

C. conyzae-canadensis

IRAN 3927C

Conyza canadensis

Asteraceae

Mazandaran, Sangdeh**

_

_

_

_

_

MT843695

 

IRAN 3928C

Conyza canadensis

Asteraceae

Mazandaran, Amol, Baudeh

_

_

_

_

_

MT843696

C. cylindracea

IRAN 3929C

Cichorium intybus

Asteraceae

Mazandaran, Galugah-Sefidchah**

_

MT843589

MT843614

MT843640

MT843667

MT843697

 

IRAN 3930C

Cichorium intybus

Asteraceae

North Khorasan, Eshghabad, Raz**

MT804379

MT843590

MT843615

MT843641

MT843668

MT843698

C. cf. flagellaris

IRAN 3931C

Conyza canadensis*

Asteraceae

Guilan, Rasht

_

_

_

MT843642

_

_

 

IRAN 3932C

Ocimum basilicum*

Lamiaceae*

Golestan, Gorgan**

MT804380

MT843591

MT843616

MT843643

MT843669

_

 

IRAN 3933C

Plantago major*

Plantaginaceae

Mazandaran, Tonekabon, Sehezar Road

_

_

_

MT843644

_

_

 

IRAN 3934C

Abutilon theophrasti

Malvaceae

Mazandaran, Babol, Tazehabad

_

_

_

_

_

MT843699

 

IRAN 3935C

Brassica oleracea*

Brassicaceae

Guilan, Shaft, Siahmazgi

_

_

_

_

_

MT843700

 

IRAN 3936C

Brassica oleracea

Brassicaceae

Guilan, Shaft, Siahmazgi

_

_

_

_

_

MT843701

 

IRAN 3937C

Calendula sp.

Asteraceae

Mazandaran, Tonekabon, Sehezar Road

_

_

_

_

_

MT843702

 

IRAN 3938C

Fallopia convolvulus*

Polygonaceae*

Guilan, Talesh, Jokandan

_

_

_

_

_

MT843703

 

Table 1. Continue…

Species

Culture accession number

Host

Host Family

Origin

GenBank accession numbers

ITS

tef1

actA

cmdA

his3

gapdh

 

IRAN 3939C

Fallopia convolvulus

Polygonaceae

Guilan, Astara, Havigh

_

_

_

_

_

MT843704

 

IRAN 3940C

Lapsana sp.*

Asteraceae

Guilan, Shaft, Siahmazgi

_

_

_

_

_

MT843705

 

IRAN 3941C

Mentha longifolia*

Lamiaceae

Mazandaran, Tonekabon, Sehezar Road

_

_

_

_

_

MT843706

 

P 682 I2

Mentha longifolia

Lamiaceae

Mazandaran, Tonekabon, Sehezar Road

_

_

_

_

_

MT843707

 

IRAN 3942C

Parthenocissus tricuspidata*

Vitaceae*

Guilan, Paresar, Pilembra

_

_

_

_

_

MT843708

 

IRAN 3943C

Solanum sisymbriifolium*

Solanaceae

Guilan, Rasht, Saravan

_

_

_

_

_

MT843709

 

IRAN 3944C

Sonchus sp.*

Asteraceae 

Mazandaran, Babol, Tazehabad

_

_

_

_

_

MT843710

 

IRAN 3945C

Unknown

Unknown

Mazandaran, Tonekabon, Dohezar Road

_

_

_

_

_

MT843711

C. gamsiana

IRAN 3946C

Beta vulgaris*

Amaranthaceae

Mazandaran, Kelardasht, Goharkela

_

_

MT843617

MT843645

MT843670

MT843712

 

IRAN 3947C

Malva sp.

Malvaceae

Hormozgan, Minab**

_

_

MT843618

MT843646

MT843671

MT843713

C. iranica

IRAN 3948C

Bidens tripartita*

Asteraceae

Guilan, Siahkal

_

MT843592

MT843619

MT843647

MT843672

MT843714

C. mercurialis

IRAN 3949C

Mercurialis annua

Euphorbiaceae

Golestan, Gorgan

MT804381

MT843593

MT843620

MT843648

MT843673

MT843715

 

IRAN 3950C

Mercurialis annua

Euphorbiaceae

Golestan, Gorgan

_

MT843594

MT843621

MT843649

MT843674

_

C. plantaginis

IRAN 3951C

Plantago lanceolata

Plantaginaceae

North Khorasan, Eshghabad, Raz**

_

MT843595

_

MT843650

MT843675

MT843716

 

IRAN 3952C

Plantago lanceolata

Plantaginaceae

Azerbaijan-Iran border, Ardabil, Mil-Mughan Water Reservoir

_

MT843596

_

MT843651

MT843676

MT843717

C. rumicis

IRAN 3953C

Rumex sp.

Polygonaceae

Mazandaran, Amol, Najarmahalleh**

_

_

_

_

_

MT843718

Cercospora sp. G

IRAN 3954C

Eupatorium cannabinum*

Asteraceae

Guilan, Shaft, Siahmazgi

_

_

_

_

_

MT843719

 

IRAN 3955C

Gazania sp.*

Asteraceae

Guilan, Rasht

_

_

_

_

_

MT843720

 

IRAN 3956C

Lapsana sp.*

Asteraceae

Mazandaran, Tonekabon, Dohezar**

_

_

_

_

_

MT843721

 

IRAN 3957C

Lapsana sp.

Asteraceae

Mazandaran, Tonekabon, Dohezar

_

_

_

_

_

MT843722

Cercospora sp. T

IRAN 3958C

Helianthus tuberosus*

Asteraceae

Mazandaran, Salmanshahr**

_

MT843597

MT843622

MT843652

MT843677

MT843723

 

IRAN 3959C

Mentha longifolia*

Lamiaceae*

Guilan, Sowme’eh Sara, Lifshagard

_

_

MT843623

_

_

MT843724

 

P 686 I1

Plantago major*

Plantaginaceae*

Mazandaran, Tonekabon, Sehezar

_

MT843598

MT843624

MT843653

MT843678

MT843725

 

IRAN 3960C

Potentilla reptans*

Rosaceae*

Mazandaran, Salmanshahr

_

MT843599

MT843625

_

_

MT843726

 

Table 1. Continue …

Species

Culture accession number

Host

Host Family

Origin

GenBank accession numbers

ITS

ITS

ITS

ITS

ITS

ITS

C. uwebrauniana

IRAN 3961C

Heliotropium europaeum

Boraginaceae

Golestan, Gorgan-Aghghala**

MT804382

MT843600

MT843626

_

MT843679

MT843727

 

IRAN 3962C

Heliotropium europaeum

Boraginaceae

Mazandaran, Amol, Ejbarkola**

MT804383

MT843601

MT843627

_

MT843680

MT843728

C. violae

IRAN 3963C

Viola sp.

Violaceae

Golestan, Gorgan, Shastkola

_

_

_

_

_

MT843729

 

IRAN 3964C

Viola sp.

Violaceae

Golestan, Gorgan, Shastkola

_

_

_

_

_

MT843730

C. zebrina

IRAN 3965C

Medicago sativa

Fabaceae

Golestan, Gorgan

_

MT843602

MT843628

MT843654

MT843681

MT843731

 

IRAN 3966C

Medicago sativa

Fabaceae

North Khorasan, Ashkhaneh**

_

MT843603

_

MT843655

MT843682

MT843732

 

IRAN 3967C

Medicago sativa

Fabaceae

Mazandaran, Galugah-Sefidchah

MT804384

MT843604

MT843629

MT843656

MT843683

MT843733

 

IRAN 3968C

Oxalis sp.

Fabaceae

Golestan, Gorgan, Ghorogh Forest Park**

_

MT843605

MT843630

MT843657

MT843684

MT843734

 

IRAN 3969C

Alhagi maurorum 

Fabaceae

Golestan, Aghghala-Incheboroun, Agh Ghabr

MT804385

MT843606

_

_

MT843685

MT843735

* new host species and family records. ** new locality (province) record

 

Primer design and experimental setup for gapdh gene amplification

Recently eight-gene (ITS, actA, cmdA, gapdh, his3, rpb2, tef1 and tub2) molecular phylogenetic study on the genus Cercospora have revealed that gapdh is strong candidate for improved species delimitation in this genus, however the amplification of the locus using the available primers was not easy (Bakhshi et al. 2018; Bakhshi 2019). Therefore, during the course of this study, we developed two new primers namely GpdF-Cer and GpdR-Cer to amplify fragments of the protein-coding gene gapdh in Cercospora species. Primer sequences and annealing conditions are presented in Table 2. The primers successfully amplified the target in Cercospora species, however, based on their degenerate design, they may also be applied to a broader fungal community.

To obtain the partial gapdh sequences, using the novel primer set, we found that the best PCR mixture consisted of 5–10 ng genomic DNA, 1× PCR buffer, 2 mM MgCl2, 56 μM of each dNTP, 0.7 μL DMSO, 0.28 μM of each primer and 0.5 unit Taq DNA polymerase in a total volume of 25 μL. As multiple bands were sometimes present, we adapted a touchdown PCR protocol: initial denaturation (94 °C, 5 min), five amplification cycles (94 °C, 45 s; 59 °C, 45 s; 72 °C, 2 min), five amplification cycles (94 °C, 45 s; 57 °C, 45 s; 72 °C, 2 min), 30 amplification cycles (94 °C, 45 s; 52 °C, 45 s; 72 °C,2 min) and a final extension (72 °C, 8 min).

 

Phylogenetic analysis

gapdh phylogeny: The final aligned gapdh dataset contained 125 ingroup taxa with a total of 889 characters, containing 302 unique site patterns and Septoria provencialis (GenBank accession JX142538) as the outgroup taxon and a heating parameter set at 0.15. The results of MrModeltest recommended a general time reversible (GTR) substitution model with inverse gamma rates for gapdh and dirichlet base frequencies. During the generation of the tree (Fig. 2), a total of 5152 trees were saved, and consensus trees and posterior probabilities were calculated from the remaining 3864 (75%) trees. The isolates of some Cercospora species could be identified based on the results of the gapdh phylogeny, therefore there was no need to do multi-gene phylogeny (Fig. 2).

 

Multi-gene phylogeny: In the multi-gene analyses (gene boundaries of ITS: 1–481, tef1: 482–817, actA: 818–1033, cmdA: 1034–1303, his3: 1304–1672 and gapdh: 1673–2568) of 199 isolates of Cercospora (including 145 taxa from NCBI, and 54 taxa from this study), 2568 characters including the alignment gaps were used and these characters contained 1044 unique site patterns (86, 239, 141, 136, 141 and 301 for ITS, tef1, actA, cmdA, his3 and gapdh respectively). Septoria provencialis (CBS 118910) was used as outgroup in the phylogenetic analyses. The results of MrModeltest recommended a HKY+G with gamma distributed rate variation for ITS, tef1, actA, cmdA and his3; while, a GTR+I+G with inverse gamma-distributed rate variation for gapdh. All partitions had dirichlet base frequencies. The Bayesian analysis lasted 90175000 generations and generated 180352 trees from which the first 45088 trees (25%), representing the burn-in phase of the analyses, were discarded, and the remaining trees (135264) were used for calculating posterior probability (PP) values in the phylogenetic tree (50% majority rule consensus tree) (Fig. 3).

 

Taxonomy

During the course of the present research, the Consolidated Species Concept (Quaedvlieg et al. 2014) using a polyphasic approach based on multilocus DNA sequences, host taxonomy, and morphological data, was employed to distinguish species. Seventeenspecies of Cercosporaincluding C. althaeina, C. apii, C. beticola, C. bizzozeriana, C. conyzae-canadensis, C. cylindracea, C. cf. flagellaris, C. gamsiana, C. iranica, C. mercurialis, C. plantaginis, C. rumicis, Cercospora sp. G & T, C. uwebrauniana, C. violae and C. zebrina were resolved based on the clustering and support in the Bayesian trees obtained from the single gapdh phylogeny (Fig. 2) and the combined six-gene (ITS, actA, cmdA, gapdh, his3 and tef1) phylogeny (Fig. 3). Data are alphabetically summarized in Table 1.


 

Table 2. Details of primers developed for gapdh in this study.

Primer name

Primer sequence (5’ to 3’)

Orientation

Tm (oC)

%GC

Annealing temperature

GpdF-Cer

TTCATYGAGCCMCACTACGCT

Forward

59.5

48–57

59→57→52

GpdR-Cer

RTCGGTGACKRCGAGVAC

Reverse

53.8

50–72

59→57→52

 

Cercospora mercurialis was confirmed for the first time in Iran (Asia) using multi-gene molecular data. In addition, several new host species and families were recognized for the previously known Cercospora species including C. apii, C. beticola, C. cf. flagellaris, C. gamsiana, C. iranica, Cercospora sp. G & T in the world, and some species were recorded for the first time in some provinces of Iran. The species are treated as follows.

Fig. 2. part 2. Phylogenetic tree inferred by Bayesian analysis of the gapdh sequence alignment using MrBayes v.3.2.6. The scale bar indicates 0.01 expected changes per site. Cercospora species could be identified based on the results of the gapdh phylogeny, are indicated in colored blocks.

Fig. 3. Part 3. Phylogenetic tree inferred by Bayesian analysis of the combined 6-gene (ITS, tef1, actA, cmdA, his3 and gapdh) sequencealignment using MrBayes v.3.2.6. The scale bar indicates 0.01 expected changes per site. Cercospora species could be identified based on the results of the 6-gene phylogeny, are indicated in colored blocks.

Fig. 4. Cercospora althaeina. a, b. Fasciculate conidiophores; c–f. Conidia. Scale bars = 10 µm.

 

Cercospora althaeina Sacc., Michelia 1: 269 (1878) (Fig. 4)

Description.Leaf spots distinct, angular to irregular, mostly vein-limited, olivaceous-brown, sometimes grey-brown with dark brown margin, center becoming pale grey with black dots (= stroma with conidiophores). Caespituli amphigenous, mostly epiphyllous. Mycelium internal. Stromata well-developed, emerging through stomatal openings or erumpent through the cuticle. Conidiophores in divergent fascicles (6–18), pale olivaceous-brown at the base, paler upwards, 2–8-septate, straight to mildly curved, (50–)130–170(–250) × 3.5–6 µm, conically narrowed at the apex; loci conspicuous, apical or on shoulders formed by geniculation, 1.5–2 µm. Conidia solitary, obclavate-cylindrical to filiform, not acicular, straight to mildly curved, hyaline, 4–12-septate, obtuse at the apex, subtruncate or obconically truncate at the base, (40–)70–95(–145) × 3–5 µm. 

Specimen examined. IRAN, Mazandaran province, Amol, 36°28'31.21'' N, 52°27'56.69''E, on leaves of Malva sp. (Malvaceae), 2 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3920C, IRAN 17716F). Notes: Based on available literature (Ershad 2009; Bakhshi et al. 2012a, 2015a, 2018, Ershad et al. 2018), C. althaeina is reported here for the first time from Mazandaran Province.

 

Cercospora apii Fresen., emend. Groenewald et al., Phytopathology 95: 954 (2005)

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, Guilan province, Paresar, Pilembra, 37°35'43.51''N, 49°04'51.62''E, on leaves of Apium graveolens (Apiaceae), 17 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3921C, IRAN 17717F); Golestan province, Galikesh, 37°16'28.9"N 55°25'33.2"E, on leaves of Ipomoea hederacea (Convolvulaceae), 3 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3922C, IRAN 17718F). Notes. In this investigation, Cercospora apii was found for the first time on Ipomoea hederacea in the world based on multi-gene phylogeny and morphological data.

 

Cercospora beticola Sacc., emend. Groenewald et al., Phytopathology 95: 954 (2005)

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, Ardabil province, Moghan, 39°30'08.27''N, 48°02'38.62''E, on leaves of Beta vulgaris, 14 May 2018, M. Bakhshi (IRAN 3923C, IRAN 17720F) (P 631 I2, IRAN 17719F); Mazandaran province, Kelardasht, Goharkela, 36°28'59.04''N, 51°14'58.68''E, on leaves of B. vulgaris, 12 Aug. 2018, M. Bakhshi & A. Bahramishad  (IRAN 3924C, IRAN 17721F); Mazandaran province, Marzanabad, Foshkour, 36°21'29.2"N 51°11'43.0"E, on leaves of B. vulgaris, 12 Aug. 2018, M. Bakhshi & A. Bahramishad (P 656 R2, IRAN 17722F); IRAN, Khuzestan province, Shush-Dezful, 32°15'14.5"N 48°22'46.9"E, on leaves of Raphanus sativus (Brassicaceae), 22 Feb. 2018, M. Bakhshi & F. Ghamghami (IRAN 3925C, IRAN 17723F).

Notes. In the present research, C. beticolais found for the first time on Raphanus sativus in the world, thus a further family, Brassicaceae was added to the host range of this species.

 

Cercospora bizzozeriana Sacc. & Berl., Malpighia 2: 248 (1888)

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, North Khorasan province, Bojnourd, 37°28'35.27''N, 57°19'01.47''E, on leaves of Cardaria draba (Brassicaceae), 6 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3926C, IRAN 17724F).

 

Cercospora conyzae-canadensisM. Bakhshi, Arzanlou, Babai-ahari, Crous & U. Braun, Persoonia 34: 77 (2015a)

Description and illustration: Bakhshi et al. (2015a).

Specimens examined. IRAN, Mazandaran province, Sangdeh, 36°08'05.72''N, 53°12'49.12''E, on leaves of Conyza canadensis (Asteraceae), 31 Oct. 2017, M. Bakhshi & A. Bahramishad (IRAN 3927C, IRAN 17725F); Mazandaran province, Amol, Baudeh, 36°34'52.46''N, 52°20'59.88''E, on leaves of Conyza canadensis, 3 May 2018, M. Bakhshi & A. Bahramishad (IRAN 3928C, IRAN 17726F).

Notes: Cercospora conyzae-canadensiswas described recently by Bakhshi et al. (2015a) from Guilan and Zanjan provinces as host-specific to Conyza canadensis. Here the species recorded on this host, for the first time from Mazandaran Province.

 

Cercospora cylindracea M. Bakhshi, Arzanlou, Babai-ahari, Crous & U. Braun, Persoonia 34: 78 (2015a)

Description and illustration: Bakhshi et al. (2015a).

Specimens examined. IRAN, Mazandaran province, Galugah-Sefidchah, 36°41'50.38''N, 53°47'58.84''E, on leaves of Cichorium intybus (Asteraceae), 8 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3929C, IRAN 17727F); North Khorasan province, Eshghabad, Raz, 37°41'47.6"N 56°55'08.7"E, on leaves of Cichorium intybus, 7 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3930C, IRAN 17728F).

Notes: Cercospora cylindracea was described by Bakhshi et al. (2015a) from Ardabil, West Azerbaijan and Zanjan provinces on the host plants,Cichorium intybus and Lactuca serriola (Asteraceae) based on multi-gene phylogeny and morphological data. The species recorded here for the first time from North Khorasan and Mazandaran Provinces.

 

Cercospora cf. flagellaris

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, Guilan province, Rasht, 37°11'04.66''N, 49°39'34.09''E, on leaves of Conyza canadensis, 14 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3931C, IRAN 17729F); Golestan province, Gorgan, 36°50'26.22''N, 54°27'24.98''E, on leaves of Ocimum basilicum (Lamiaceae), 5 July 2017, M. Bakhshi & F. Ghamghami (IRAN 3932C, IRAN 17730F); Mazandaran province, Tonekabon, Sehezar Road, 36°36'14.26''N, 50°50'20.64''E, on leaves of Plantago major (Plantaginaceae), 13 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3933C, IRAN 17731F); Mazandaran province, Babol, Tazehabad, 36°33'01.58''N, 52°47'39.56''E, on leaves of Abutilon theophrasti (Malvaceae), 11 Oct. 2017, M. Bakhshi & F. Ghamghami (IRAN 3934C, IRAN 17732F); Guilan province, Shaft, Siahmazgi, Livandan, 37°01'19.13''N, 49°16'25.45''E, on leaves of Brassica oleracea (Brassicaceae), 16 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3935C, IRAN 17733F) (IRAN 3936C, IRAN 17734F); Mazandaran province, Tonekabon, Sehezar Road, 36°36'14.26''N, 50°50'20.64''E, on leaves of Calendula sp. (Asteraceae), 13 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3937C, IRAN 17735F); Guilan province, Talesh, Jokandan, on leaves of Fallopia convolvulus (Polygonaceae), 25 Aug. 2019, M. Kermanian (IRAN 3938C, IRAN 17736F); Guilan province, Havigh, Eshikaghasi, on leaves of Fallopia convolvulus, 25 Aug. 2019, M. Kermanian (IRAN 3939C); Guilan province, Shaft, Siahmazgi, Doudvazan Waterfall, 37°01'02.61''N, 49°15'01.21''E, on leaves of Lapsana sp. (Asteraceae), 16 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3940C, IRAN 17737F); Mazandaran province, Tonekabon, Sehezar Road, 36°36'14.26''N, 50°50'20.64''E, on leaves of Mentha longifolia (Lamiaceae), 13 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3941C, P 682I2, IRAN 17738F); Guilan province, Paresar, Pilembra, 37°35'43.51''N, 49°04'51.62''E, on leaves of Parthenocissus tricuspidata (Vitaceae), 17 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3942C, IRAN 17739F); Guilan province, Rasht, Saravan, 37°10'34.52''N, 49°35'50.17''E, on leaves of Solanum sisymbriifolium (Solanaceae), 16 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3943C, IRAN 17740F); Mazandaran province, Babol, Tazehabad, 36°33'01.58''N, 52° 47'39.56''E, on leaves of Sonchus sp. (Asteraceae ), 11 Oct. 2017, M. Bakhshi & F. Ghamghami (IRAN 3944C, IRAN 17741F). Mazandaran province, Tonekabon, Dohezar Road, Barseh, 36°38'28.1"N, 50°43'48.5"E, Unknown, 13 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3945C, IRAN 17742F).

Notes: Recently based on the combination of morphological and multi-gene phylogenetic analysis, it has been demonstrated that, C. cf. flagellaris is a plurivorous species with multiple family-associations in different groups of plants viz. agricultural crops, ornamentals, forest trees and weeds including Acerceae, Amaranthaceae, Araceae, Asteraceae, Balsaminaceae, Brassicaceae, Buxaceae, Caesalpinaceae, Campanulaceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, Geraniaceae, Hydrangeaceae, Malvaceae, Oleaceae, Onagraceae, Phytolaccaceae, Poaceae, Pontederiaceae, Rutaceae, Salicaceae, Solanaceae and Urticaceae, and is geographically distributed worldwide (Groenewald et al. 2013; Bakhshi et al. 2015a, 2018; Farr & Rossman 2020). Similar to Bakhshi et al. (2015a, 2018), in the present study, C. cf. flagellaris was the most common species in the country. Additionally, C. cf. flagellaris is newly recorded here on 10 new hosts, Brassica oleracea, Conyza canadensis, Fallopia convolvulus, Lapsana sp., Mentha longifolia, Ocimum basilicum, Parthenocissus tricuspidata, Plantago major, Solanum sisymbriifolium and Sonchus sp. in the world. Thus, three more plant families including Lamiaceae, Polygonaceae and Vitaceae were added to the host range of this species. In addition, it is reported for the first time from Golestan province.

 

Cercospora gamsiana M. Bakhshi & Crous, IMA Fungus 9: 321 (2018)

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, Mazandaran province, Kelardasht, Goharkela, 36°28'59.04''N, 51°14'58.68''E, on leaves of B. vulgaris, 12 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3946C, IRAN 17743F); Hormozgan province, Minab, 27°06'29.9"N 57°05'28.4"E, on leaves of Malva sp. (Malvaceae), 9 March 2018, M. Bakhshi (IRAN 3947C, IRAN 17744F).

Notes: Cercospora gamsiana was described recently by Bakhshi et al. (2018) on Malva spp., Rumex crispus, Sesamum indicum and Sonchus sp. from north and north-west of Iran. The species reported here for the first time from the south of the Iran (Hormozgan province). Furthermore, the report of this species on Beta vulgaris is new for the world.

 

Cercospora iranica M. Bakhshi, Arzanlou, Babai-ahari, Crous & U. Braun, Persoonia 34: 79 (2015a)

Description and illustration: Bakhshi et al. (2015a).

Specimens examined. IRAN, Guilan province, Siahkal, 37°11'58.61''N, 49°55'20.78''E, on leaves of Bidens tripartite (Asteraceae), 14 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3948C, IRAN 17745F).

Notes: Cercospora iranica was described by Bakhshi et al. (2015a) on Vicia faba (Fabaceae)and Hydrangea sp. (Hydrangeaceae). The report of this species on Bidens tripartita is new for the world.

 

Cercospora mercurialis Pass., in Thüm., Mycoth. Univ., No. 783. (1877) (Fig. 5)

Description. Leaf spots amphigenous, circular to subcircular, 1–5 mm, grey-brown, with dark brown border. Mycelium internal. Caespituli amphigenous, brown. Conidiophores aggregated in moderately loose fascicles (3–15), arising from a moderately-developed, erumpent, brown stroma, up to 25 μm diam; conidiophores pale to medium brown, aseptate or sparingly septate, straight to geniculate-sinuous due to sympodial proliferation, simple, uniform in width, sometimes constricted at the proliferating point, (15–)30–40(–55) × 3.5–4(–5) μm. Conidiogenous cells intercalary and terminal, sometimes conidiophores reduced to conidiogenous cells, pale brown, proliferating sympodially, 15–30 × 3.5–5 μm, multi-local; loci distinctly thickened, darkened and somewhat refractive, apical, lateral or formed on shoulders caused by geniculation, 2–3 μm diam. Conidia solitary, cylindrical to acicular, straight to slightly curved, hyaline, (25–)55–80(–120) × 2.5–5 μm, (3–)6–9(–15)-septate, with subobtusely rounded apices and subtruncate or obconically truncate bases; hila thickened, darkened, refractive, 1–2 μm diam.

Specimens examined. IRAN, Golestan province, Gorgan, 36°50'26.22''N, 54°27'24.98''E, on leaves of Mercurialis annua (Euphorbiaceae), 1 Nov. 2017, M. Bakhshi (IRAN 3949C, IRAN 17746F); on leaves of M. annua, 5 May 2018, M. Bakhshi (IRAN 3950C, IRAN 17747F)

Notes: Cercospora mercurialis was reported from Iran based on morphological data (Pirnia et al. 2010). To our knowledge, this study is the first molecular confirmation of C. mercurialis in Asia. Furthermore, part of the gapdh is sequenced for the first time in this species.

 

Cercospora plantaginis Sacc., Michelia 1: 267 (1878).

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, North Khorasan province, Eshghabad, Raz, 37°41'47.58''N, 56°55'08.65''E, on leaves of Plantago lanceolata (Plantaginaceae), 7 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3951C, IRAN 17748F); Azerbaijan-Iran border, Ardabil province, Mil-Mughan Water Reservoir, 39°25'55.7"N, 47°22'16.8"E, on leaves of Plantago lanceolata, 15 may 2018, M. Bakhshi (IRAN 3952C, IRAN 17749F).

Notes: Recently Bakhshi et al. (2018) have designated an epitype for C. plantaginis based on the combination of morphological and molecular data, and have shown that the species ishost-specific toPlantago lanceolata. This is the first report of this species from North Khorasan Province.

 

Cercospora rumicis Pavgi & U.P. Singh, Mycopathol. Mycol. Appl. 23: 191 (1964) (Fig. 6)

Description. Leaf spots circular to subcircular, with grey center and purple-brown margin, 2–8 mm diam. Mycelium internal. Caespituli amphigenous, brown. Conidiophores in divergent fascicles, arising from the upper cells of a moderately to well-developed, intraepidermal and substomatal, brown stroma; conidiophores pale brown to brown, 1–6-septate, straight, sinuous to distinctly geniculate, (40–)58–70 × 4– 5 μm, irregular in width, constricted at the parts of proliferation or at the septa. Conidiogenous cells terminal or intercalary, unbranched, pale brown, smooth, proliferating sympodially, multi-local; loci thickened, darkened, refractive, apical or formed on the shoulders caused by geniculation. Conidia solitary, subcylindrical to filiform, straight to mildly curved, hyaline, distinctly 2–15-septate, subobtuse at the apex, truncate at the base, (37–)80–110(–160) × 2.5–5 μm; hila thickened, darkened, refractive, 1.5–2.5 μm diam.

Specimen examined. IRAN, Mazandaran province, Amol, Najarmahalleh, 36°26'39.88''N, 52°27'11.02''E, on leaves of Rumex sp. (Polygonaceae), 3 May 2018, M. Bakhshi & A. Bahramishad (IRAN 3953C, IRAN 17750F).

Notes: Cercospora rumicisrecorded here for the first time from Mazandaran Province.

 

Cercospora sp. G sensu Groenewald et al. (2013)

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, Guilan province, Shaft, Siahmazgi, Doudvazan Waterfall, 37°01'02.61''N, 49°15'01.21''E, on leaves of Eupatorium cannabinum (Asteraceae), 16 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3954C, IRAN 17751F); Guilan province, Rasht, 37°11'04.66''N, 49°39'34.09''E, on leaves of Gazania sp.(Asteraceae), 14 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3955C, IRAN 17752F); Mazandaran province, Tonekabon, Dohezar Road, Barseh, 36°38'28.1"N, 50°43'48.5"E, on leaves of Lapsana sp., 13 Aug. 2018, M. Bakhshi & A. Bahramishad (IRAN 3956C, IRAN 17753F) (IRAN 3957C, IRAN 17754F).

Notes: Cercospora sp. G occurs on a wide host range such as Amaranthaceae, Asteraceae, Cucurbitaceae, Lamiaceae, Malvaceae, Plantaginaceae, Poaceae (Groenewald et al. 2013, Bakhshi et al. 2015a). Cercospora sp. G is found in this research, on three new hosts, Eupatorium cannabinumGazania sp. and Lapsana sp. in the world, and additionally for the first time from Mazandaran province.

 

Cercospora sp. T sensu Bakhshi et al. (2015a)

Description and illustration: Bakhshi et al. (2015a).

Specimens examined. IRAN, Mazandaran province, Salmanshahr, 36°42'22.4"N, 51°12'44.6"E, on leaves of Helianthus tuberosus (Asteraceae), 13 Aug 2018, M. Bakhshi & A. Bahramishad (IRAN 3958C, IRAN 17755F); Guilan province, Sowme’eh Sara, Lifshagard, 37°19'49.0"N, 49°25'12.6"E, on leaves of Mentha longifolia, 17 Aug 2018, M. Bakhshi & A. Bahramishad (IRAN 3959C, IRAN 17756F); Mazandaran province, Tonekabon, Sehezar Road, 36°36'14.26''N, 50°50'20.64''E, on leaves of Plantago major, 13 Aug 2018, M. Bakhshi & A. Bahramishad (P 686 I1); Mazandaran province, Salmanshahr, 36°42'22.4"N, 51°12'44.6"E, on leaves of Potentilla reptans (Rosaceae), 13 Aug 2018, M. Bakhshi & A. Bahramishad (IRAN 3960C, IRAN 17757F).

Notes: Cercospora sp. T was reported on Coreopsis sp. (Asteraceae) (Bakhshi et al. 2015a). In this research, Cercospora sp. T, is found on four new hosts, Helianthus tuberosus, Mentha longifolia, Plantago major and Potentilla reptans, therefore three more plant families including Lamiaceae, Plantaginaceae and Rosaceae were added to the host range of this species in the world. Inaddition, it is reported for the first time from Mazandaran province.

 

Cercospora uwebrauniana M. Bakhshi & Crous, IMA Fungus 9: 317 (2018)

Description and illustration: Bakhshi et al. (2018).

Specimens examined. IRAN, Golestan province, Gorgan-Aghghala, 36°52'15.4"N, 54°25'49.4"E, on leaves of Heliotropium europaeum (Boraginaceae), 1 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3961C, IRAN 17758F); Mazandaran province, Amol, Ejbarkola, 36°28'31.2"N 52°27'56.7"E, on leaves of Heliotropium europaeum, 14 Oct. 2017, M. Bakhshi & A. Bahramishad (IRAN 3962C).

Notes: Cercospora uwebraunianawas described recently by Bakhshi et al. (2018) and appears to be host specific to Heliotropium europaeum. Here we report this species for the first time from Golestan and Mazandaran provinces.

 

Cercospora violae Sacc., Nuovo Giron. Bot. Ital. 8: 187 (1876) (Fig. 7)

Description.Leaf spots circular to irregular, mostly vein-limited, dark brown, with concentric rings (= stroma with conidiophores), 2–8 mm diam. Mycelium internal. Caespituli amphigenous. Stromata lacking to moderately developed, dark brown, intraepidermal, and substomatal. Conidiophores in moderately dense fascicles, irregular in width, slightly attenuated at the upper portion, straight or mildly sinuous-geniculate, straight, simple, rarely branched, pale brown to brown, short conically truncate at the apex, wider at the base, 45–70(–90) × 3.5–4.5 µm, 2–12-septate. Conidiogenous cells integrated, terminal, rarely intercalary, proliferating sympodially, multilocal; loci distinct, thickened, apical or formed on shoulders caused by geniculation, 2–3.5 µm diam. Conidia solitary, hyaline, subcylindrical to obclavate or acicular, straight to slightly curved, truncate at the base, subobtuse at the apex, 44–95(–132) × 2.5–3.5 µm, 3–14-septate, smooth.

Specimen examined. IRAN, Golestan province,

Gorgan, Shastkola, 36°46'59.0"N, 54°21'58.0"E, on leaves of Viola sp.(Violaceae), 6 July 2017, M. Bakhshi & F. Ghamghami (IRAN 3963C, IRAN 17759F) (IRAN 3964C, IRAN 17760F).

 

Cercospora zebrina Pass., Hedwigia 16: 124 (1877) (Fig. 8)

Description.Leaf spots distinct, circular to irregular, brown to dark grey, without definite borders. Caespituli amphigenous. Mycelium internal. Stromata well-developed, intraepidermal or substomatal. Conidiophores in moderately dense fascicles (4–18), brown at the base, paler upwards, 1–6-septate, straight to mildly curved, (30–)50–65(–98) × 3.5–5 µm. Conidiogenous cells mostly terminal, pale brown, proliferating sympodially, uni-local to multi-local; loci conspicuous, thickened, darkened, refractive, apical, 2–3 µm. Conidia solitary, rarely catenate, cylindrical to obclavate-subcylindrical, straight to mildly curved, hyaline, 3–14-septate, obtuse at the apex, subtruncate or obconically truncate at the base, (30–)50–85(–135) × 3–5 µm.

Specimens examined. IRAN, Golestan province, Gorgan, 36°50'26.2"N 54°27'25.0"E, on leaves of Medicago sativa (Fabaceae), 5 July 2017, M. Bakhshi & F. Ghamghami (IRAN 3965C, IRAN 17761F); North Khorasan province, Ashkhaneh, 37°35'13.2"N 56°52'13.7"E, on leaves of Medicago sativa, 7 Nov. 2017, M. Bakhshi & A. Bahramishad (IRAN 3966C, IRAN 17762F); Mazandaran province, Galugah-Sefidchah, 36°41'50.38''N, 53°47'58.84''E, on leaves of Medicago sativa, 4 May 2018, M. Bakhshi & A. Bahramishad (IRAN 3967C, IRAN 17763F); Golestan province, Gorgan, Ghorogh Forest Park, 36°52'58.5"N, 54°40'47.2"E, on leaves of Oxalis sp. (Fabaceae), 7 May 2018, M. Bakhshi & A. Bahramishad (IRAN 3968C, IRAN 17764F); Golestan province, Aghghala_Incheboroun, Agh Ghabr, 37°00'42.6"N 54°23'43.1"E, on leaves of Alhagi maurorum (Fabaceae), 11 Nov. 2019, M. Bakhshi & A. Torabi (IRAN 3969C, IRAN 17765F).

Notes: To our knowledge, here, we report C. zebrina for the first time from Golestan and North Khorasan Provinces.

 

Fig. 5. Cercospora mercurialisa. Leaf spot; b–e. Fasciculate conidiophores; f–h. Conidia. Scale bars = 10 µm.

Fig. 6. Cercospora rumicisa–c. Fasciculate conidiophores; d–f. Conidia. Scale bars = 10 µm.

Fig. 7. Cercospora violae. a. Fasciculate conidiophores; b–c. Conidia. Scale bars = 10 µm.

Fig. 8. Cercospora zebrina. a. Fasciculate conidiophores; b–c. Conidia. Scale bars = 10 µm.

 

ACKNOWLEDGEMENTS

We gratefully acknowledge the Iran National Science Foundation (INSF), Research Deputy of the Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO) for financial support.

 

  

 

 

Bakhshi M, Arzanlou M, Babai-Ahari A, Groenewald JZ, Braun U, Crous PW. 2015a. Application of the consolidated species concept to Cercospora spp. from Iran. Persoonia 34: 65–86.
Bakhshi M, Arzanlou M, Babai-Ahari A, Groenewald JZ, Crous PW. 2015b. Is morphology in Cercospora a reliable reflection of generic affinity? Persoonia 34: 65–86.
Bakhshi M, Arzanlou M, Babai-Ahari A, Groenewald JZ, Crous PW. 2018. Novel primers improve species delimitation in Cercospora. IMA Fungus 9(2): 299–332.
Bakhshi M, Arzanlou M, Babai-Ahari A. 2011. Uneven distribution of mating type alleles in Iranian populations of Cercospora beticola, the causal agent of Cercospora leaf spot disease of sugar beet. Phytopathologia Mediterranea 50: 101–109.
Bakhshi M, Arzanlou M, Babai-Ahari A. 2012a. Comprehensive checklist of Cercosporoid fungi from Iran. Plant Pathology and Quarantine 2: 44–55.
Bakhshi M, Arzanlou M, Babai-Ahari A. 2012b. Morphological and molecular characterization of Cercospora zebrina from black bindweed in Iran. Plant Pathology and Quarantine 2: 125–130.
Bakhshi M, Arzanlou M. 2017. Multigene phylogeny reveals a new species and novel records and hosts in the genus Ramularia from Iran. Mycological Progress16: 703–712.
Bakhshi M, Zare R. 2020. Polyphasic identification of Cercospora cf. sigesbeckiae as causal agent of cercospora leaf spot of oilseed plants soybean, sesame and rapeseed in Golestan and Mazandaran provinces.Iranian Journal of Plant Pathology. In press.
Bakhshi M. 2019. Epitypification of Cercospora rautensis, the causal agent of leaf spot disease on Securigera varia, and its first report from Iran. Fungal Systematics and Evolution 3: 157–163.
Berbee ML, Pirseyedi M, Hubbard S. 1999. Cochliobolus phylogenetics and the origin of known, highly virulent pathogens, inferred from ITS and glyceraldehyde-3-phosphate dehydrogenase gene sequences. Mycologia 91: 964–977.
Carbone I, Kohn LM. 1999. A method for designing primer sets for speciation studies in filamentous ascomycetes. Mycologia 91: 553–556.
Chand R, Pal C, Singh V, Kumar M, Singh V, Chowdappa P. 2015. Draft genome sequence of Cercospora canescens: a leaf spot causing pathogen. Current Science 109: 2103–2110.
Crous PW, Braun U. 2003. Mycosphaerella and its anamorphs: 1. Names published in Cercospora and Passalora. CBS Biodiversity Series 1: 1–571.
Crous PW, Groenewald JZ, Groenewald M, Caldwell P, Braun U, Harrington TC. 2006. Species of Cercospora associated with grey leaf spot of maize. Studies in Mycology 55: 189–197.
Crous PW, Groenewald JZ, Mansilla JP, Hunter GC, Wingfield MJ. 2004. Phylogenetic reassessment of Mycosphaerella spp. and their anamorphs occurring on Eucalyptus. Studies in Mycology 50: 195–214.
de Hoog GS, Gerrits van den Ende AHG. 1998. Molecular diagnostics of clinical strains of filamentous Basidiomycetes. Mycoses 41: 183–189.
Drummond A, Ashton B, Buxton S, Cheung M, Cooper A, et al. (2012) Geneious. Version 5.6, http://www.geneious.com.
Duangsong U, Laosatit K, Somta P, Srinives P. 2018. Genetics of resistance to Cercospora leaf spot disease caused by Cercospora canescens and Psuedocercospora cruenta in yardlong bean (Vigna unguiculata ssp. sesquipedalis) x grain cowpea (V. unguiculata ssp. unguiculata) populations. Journal of Genetics 97: 1451–1456.
Ershad D, Asef MR, Bakhshi M, Javadi A, Zangeneh S, Asgari B, Aliabadi F, Mehrabi M. 2018. Genera of Fungi and Fungal Analogues of Iran. Ministry of Jihad-e-Agriculture. Agricultural Research, Education and Extension Organization, Tehran, Iran. (in Persian)
Ershad D. 2009. Fungi of Iran. Ministry of Jihad-e-Agriculture. Agricultural Research, Education and Extension Organization, Tehran, Iran.
Farr DF, Rossman AY. 2020. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. [cited 2019 Jun 9]. Available from: https://nt.ars-grin.gov/ fungaldatabases
Groenewald JZ, Nakashima C, Nishikawa J, Shin HD, Park JH, Jama AN, Groenewald M, Braun U, Crous PW. 2013. Species concepts in Cercospora: spotting the weeds among the roses. Studies in Mycology 75: 115–170.
Katoh K, Standley DM. 2013. MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Molecular Biology and Evolution 30: 772–780.
Kibbe WA. 2007. OligoCalc: an online oligonucleotide properties calculator. Nucleic Acids Research 35.
Kimber RBE, Paull JG. 2011. Identification and genetics of resistance to cercospora leaf spot (Cercospora zonata) in faba bean (Vicia faba). Euphytica 177: 419–429.
Kumar S, Stecher G, Tamura K. 2016. MEGA v.7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. Molecular Biology and Evolution 33(7): 1870–1874.
Kushalappa AC, Boivin G, Brodeur L. 1989. Forecasting incidence thresholds of Cercospora blight in carrots to initiate fungicide application. Plant Disease 73: 979–983.
Möller EM, Bahnweg G, Sandermann H, Geiger H. 1992. A simple and efficient protocol for isolation of high molecular weight DNA from filamentous fungi, fruit bodies, and infected plant tissues. Nucleic Acids Research 20: 6115–6116.
Myllys L, Stenroos S, Thell A. 2002. New genes for phylogenetic studies of lichenized fungi: glyceraldehyde-3-phosphate dehydrogenase and beta-tubulin genes. Lichenologist 34: 237–246.
Nylander JAA. 2004. MrModeltest. Version 2.0. Program distributed by the author. Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
Pirnia M, Zare R, Zamanizadeh HR, Khodaparast A. 2010. Contribution to the identification of Cercospora species in Iran. Rostaniha 11(2). 183–189.
Praveena R, Naseema A. 2004. Fungi occurring on water hyacinth (Eichhornia crassipes (Mart.) Solms) in Kerala. Journal of Tropical Agriculture 42: 21–23.
Quaedvlieg W, Binder M, Groenewald JZ, Summerell BA, Carnegie AJ, Burgess TI, Crous PW. 2014. Introducing the consolidated species concept to resolve species in the Teratosphaeriaceae. Persoonia 33: 1–40.
Ronquist F, Teslenko M, Van der Mark P, Ayres DL, Darling A, Höhna S, Larget B, Liu L, Suchard MA, Huelsenbeck JP. 2012. MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542.
Soares APG, Guillin EA, Borges LL, Da Silva AC, De Almeida ÁM, Grijalba PE, Gottlieb AM, Bluhm BH, De Oliveira LO 2015. More Cercospora species infect soybeans across the Americas than meets the eye. PloS One 10: e0133495.
Tessmann DJ, Charudattan R, Kistler HC, Rosskopf EN. 2001. A molecular characterization of Cercospora species pathogenic to water hyacinth and emendation of C. piaropi. Mycologia 93: 323–334.
Vaghefi N, Kikkert JR, Hay FS, Carver GD, Koenick LB, Bolton MD, Hanson LE, Secor GA, Pethybridge SJ. 2018. Cryptic diversity, pathogenicity, and evolutionary species boundaries in Cercospora populations associated with Cercospora leaf spot of Beta vulgaris. Fungal Biology 122(4): 264–282.
Weiland J, Eide J, Rivera-Varas V, Secor G. 2001. Genetic diversity of Cercospora beticola in the US and association of molecular markers with tolerance to the fungicide triphenyltin hydroxide. Phytopathology 91: 94.
White TJ, Bruns T, Taylor J. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, et al. (eds), A guide to molecular methods and applications: 315–322. Academic Press, New York.