Calophoma clematidina

Last updated

Calophoma clematidina
Scientific classification
Kingdom:
Fungi
Division:
Ascomycota
Class:
Dothideomycetes
Order:
Pleosporales
Family:
Didymellaceae
Genus:
Calophoma
Species:
C. clematidina
Binomial name
Calophoma clematidina
(Thüm.) Q. Chen & L. Cai (2015) [1]
Synonyms [2]

Ascochyta clematidinaThüm. (1880)
Phyllosticta clematisBrunaud (1889)
Phyllosticta clematis Ellis & Dearn. (1893)
Ascochyta indusiata Bres. & Hedwigia (1896)
Ascochyta davidiana Kabát & Bubák (1904)
Phoma clematidina Boerema (1978)

Contents

Calophoma clematidina is a fungal plant pathogen and the most common cause of the disease clematis wilt affecting large-flowered varieties of Clematis . Symptoms of infection include leaf spotting, wilting of leaves, stems or the whole plant and internal blackening of the stem, often at soil level. [3] [4] Infected plants growing in containers may also develop root rot. [5]

Taxonomy

The asexual stage (anamorph) of the fungus was first described by the German botanist and mycologist Felix von Thümen in 1880 as Ascochyta clematidina. Based on new scientific insights into the differences in spore formation between species, [6] it was reclassified as Phoma clematidina by the Dutch mycologist Gerhard Boerema in 1978. [7] More recently, multi-locus phylogenetic analyses led to the fungus being reclassified again as Calophoma clematidina. [1]

Genetic sequencing has suggested that Calophoma clematidina is heterothallic which means that two compatible strains (mating types) of the fungus would need to come together under the right environmental conditions to produce a sexual stage (teleomorph). [8] Both mating types of Calophoma clematidina are known to occur in Europe, and yet no sexual stage (which is most likely to be a Didymella species) has ever been described. [2] [8]

Molecular phylogenetic analyses have revealed that some fungal isolates recovered from wild Clematis species, previously identified as Calophoma/Phoma clematidina, are in fact two closely related species of Phoma and Ascochyta with sexual stages in Didymella. [2] Didymella clematidi has been successfully used as a biological control agent of Clematis vitalba , which is seen as an invasive plant in New Zealand. [9] [10] Unlike Calophoma clematidina, the two closely related Didymella species (and their anamorphs) have not been found on large-flowered Clematis varieties. [2]

The previous misidentification of these species means that some literature referring to Calophoma clematidina or Phoma clematidina, particularly that on the biological control of C. vitalba , [9] [10] is actually describing work on Didymella clematidis and its Ascochyta anamorph. [2]

The situation is further complicated by the existence of another Calophoma species known to infect Clematis: Calophoma clematidis-rectae (syn. Coniothyrium clematidis-rectae). This species is closely related to C. clematidina [1] [2] [11] and has in the past been implicated in cases of clematis wilt in the Netherlands. [12]

Biology

The biology of Calophoma clematidina is now reasonably well understood thanks to research into clematis wilt at the University of Canterbury in New Zealand [13] [14] [15] and the University of Derby and ADAS in the UK. [3] [4] [5] [16] [17] [18]

A full overview of its life cycle was first produced in 1999. [3] [4] Within a nursery or garden, the fungus is mainly spread through splash dispersal of its asexual spores (conidia) which are formed in bulbous fruiting bodies called pycnidia. Pycnidia can be formed on any infected part of the plant showing symptoms, including leaves, stems and roots. The pycnidia exude the spores in a sticky mass which is splash dispersed to other plants nearby during rain or irrigation. Contact, such as with pruning tools, may also spread the spores and, in addition, it is suspected that certain insect species may act as contact vectors. Movement of infected plant material forms an important method of spread to previously unaffected nurseries or gardens. [3] [4]

Unlike many other plant pathogens, Calophoma clematidina is not a biotroph which means that it can infect plants but does not need them to survive. The fungus can live saprophytically on dead plant material or organic matter as well. In addition, it forms thick-walled resting spores (chlamydospores) which increase its survival in plant debris and soil during unfavourable conditions. [3] [4]

Disease development

Many publications report Calophoma clematidina to be a wound pathogen. However, although wounding may aid infection, scientific trials have shown that, in susceptible Clematis varieties, the fungus can cause extensive leaf spotting and wilt without any previous damage to plant tissues. [3] [4]

When spores of Calophoma clematidina land on a leaf of a susceptible plant under the right environmental conditions (moisture, temperature 15 to 25 °C (59 to 77 °F)), they will germinate within 6 hours and infect leaf tissues directly or via leaf hairs (but never via stomata). [17] Initial symptoms are small brown lesions which then rapidly spread, eventually killing the whole leaf. Unless the plant abcises the leaf in reaction to the infection, the fungus will spread via the leaf stalk to the node of the stem. [3] [4] [14]

Infection may also occur directly into the stem. This is particularly common at or below soil level where the right amounts of moisture are more likely to persist. Once in the stem, Calophoma clematidina destroys the internal tissues causing a distinctive, localised black discolouration. Such stem infections can be hugely destructive as they block the plant's vascular system and will lead to the wilting and death of all plant mass above the site of entry, no matter how substantial. [3] [4] [19]

Relatively recently, it was discovered that Calophoma clematidina can also infect the roots of Clematis and be a cause of black root rot. In practice, this has been found to be a particular issue in containerised plants. [3] [4] [5]

Host susceptibility

Many gardening publications express a view on the susceptibility of different Clematis varieties and species to clematis wilt based on observations in practice, but very few comment on their susceptibility to disease caused by Calophoma clematidina in particular compared with other causes of wilt.

Scientific trials have shown that large-flowered varieties are especially susceptible to disease caused by Calophoma clematidina in line with their vulnerability to wilt observed in practice. It is believed that hybrids which have Clematis lanuginosa in their ancestry are most susceptible to wilt. Such hybrids include many cultivars in the early flowering, large-flowered group (such as C. 'Nelly Moser' and C. 'Elsa Späth') and, to a lesser extent, cultivars in the late flowering, large-flowered group (such as C. 'Jackmanii' and C. 'Perle d'Azur'). [16] [20]

Clematis viticella and related varieties are also susceptible to infection with Calophoma clematidina, yet are reported to wilt less often than large-flowered varieties, possibly because they are very vigorous and outgrow infections quite rapidly. Most other cultivated Clematis species and their varieties are largely resistant to both infection with Calophoma clematidina and wilt in general. [16]

Calophoma clematidina has sporadically been reported from species of Clematis growing in the wild, including Clematis orientalis in Russia [2] and Clematis pubescens in Australia. [21] Reported isolations from wild C. vitalba in Europe have proven to be an unnamed Didymella species rather than Calophoma clematidina. [2] [22]

As biological control

This fungus has been reported as having been successfully used as a biological control agent of Clematis vitalba , which is seen as an invasive plant in New Zealand. [9] However, further genetic studies of the isolates used in those trials have revealed that the fungus released as biocontrol agent had been misidentified and was not Calophoma clematidina, which thus far has never been found on Clematis vitalba . [2] [22]

Management

Benzimidazole fungicides are used. [23] Benzimidazole resistance has occurred. [23]

Related Research Articles

<span class="mw-page-title-main">Fusarium wilt</span> Fungal plant disease

Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. This disease has been investigated extensively since the early years of this century. The pathogen that causes Fusarium wilt is Fusarium oxysporum. The species is further divided into formae speciales based on host plant.

Phytophthora sojae is an oomycete and a soil-borne plant pathogen that causes stem and root rot of soybean. This is a prevalent disease in most soybean growing regions, and a major cause of crop loss. In wet conditions the pathogen produces zoospores that move in water and are attracted to soybean roots. Zoospores can attach to roots, germinate, and infect the plant tissues. Diseased roots develop lesions that may spread up the stem and eventually kill the entire plant. Phytophthora sojae also produces oospores that can remain dormant in the soil over the winter, or longer, and germinate when conditions are favourable. Oospores may also be spread by animals or machinery.

Leptosphaeria maculans is a fungal pathogen of the phylum Ascomycota that is the causal agent of blackleg disease on Brassica crops. Its genome has been sequenced, and L. maculans is a well-studied model phytopathogenic fungus. Symptoms of blackleg generally include basal stem cankers, small grey lesions on leaves, and root rot. The major yield loss is due to stem canker. The fungus is dispersed by the wind as ascospores or rain splash in the case of the conidia. L. maculans grows best in wet conditions and a temperature range of 5–20 degrees Celsius. Rotation of crops, removal of stubble, application of fungicide, and crop resistance are all used to manage blackleg. The fungus is an important pathogen of Brassica napus (canola) crops.

Ascochyta tarda or Phoma tarda is a fungal plant pathogen that causes dieback and leafspot on coffee and was first observed in Ethiopia in 1954. It poses a potentially serious threat to coffee crops, but climate change may reduce the prevalence of environmental conditions favorable to its spread.

<i>Podosphaera leucotricha</i> Species of fungus

Podosphaera leucotricha is a plant pathogen that can cause powdery mildew of apples and pears.

<i>Diaporthe helianthi</i> Species of fungus

Diaporthe helianthi is a fungal pathogen that causes Phomopsis stem canker of sunflowers. In sunflowers, Phomopsis helianthi is the causative agent behind stem canker. Its primary symptom is the production of large canker lesions on the stems of sunflower plants. These lesions can eventually lead to lodging and plant death. This disease has been shown to be particularly devastating in southern and eastern regions of Europe, although it can also be found in the United States and Australia. While cultural control practices are the primary method of controlling for Stem Canker, there have been a few resistant cultivars developed in regions of Europe where the disease is most severe.

<i>Ascochyta</i> Genus of fungi

Ascochyta is a genus of ascomycete fungi, containing several species that are pathogenic to plants, particularly cereal crops. The taxonomy of this genus is still incomplete. The genus was first described in 1830 by Marie-Anne Libert, who regarded the spores as minute asci and the cell contents as spherical spores. Numerous revisions to the members of the genus and its description were made for the next several years. Species that are plant pathogenic on cereals include, A. hordei, A. graminea, A. sorghi, A. tritici. Symptoms are usually elliptical spots that are initially chlorotic and later become a necrotic brown. Management includes fungicide applications and sanitation of diseased plant tissue debris.

<i>Albugo</i> Genus of plant-parasitic oomycetes

Albugo is a genus of plant-parasitic oomycetes. Those are not true fungi (Eumycota), although many discussions of this organism still treat it as a fungus. The taxonomy of this genus is incomplete, but several species are plant pathogens. Albugo is one of three genera currently described in the family Albuginaceae, the taxonomy of many species is still in flux.

<i>Didymella pinodes</i> Species of fungus

Didymella pinodes is a hemibiotrophic fungal plant pathogen and the causal agent of ascochyta blight on pea plants. It is infective on several species such as Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Vicia sativa, and Vicia articulata, and is thus defined as broadrange pathogen.

<i>Didymella rabiei</i> Species of fungus

Didymella rabiei, commonly called chickpea ascochyta blight fungus, is a fungal plant pathogen of chickpea. Didymella rabiei is the teleomorph of Ascochyta rabiei, which is the anamorph, but both names are the same species.

<i>Ascochyta pisi</i> Species of fungus

Ascochyta pisi is a fungal plant pathogen that causes ascochyta blight on pea, causing lesions of stems, leaves, and pods. These same symptoms can also be caused by Ascochyta pinodes, and the two fungi are not easily distinguishable.

<i>Didymella bryoniae</i> Species of fungus

Didymella bryoniae, syn. Mycosphaerella melonis, is an ascomycete fungal plant pathogen that causes gummy stem blight on the family Cucurbitaceae, which includes cantaloupe, cucumber, muskmelon and watermelon plants. The anamorph/asexual stage for this fungus is called Phoma cucurbitacearum. When this pathogen infects the fruit of cucurbits it is called black rot.

Phoma macdonaldii is a plant pathogenic fungus that is a major causal force for the disease Phoma Black Stem.

Mal secco is a disease caused by the conidia-producing fungal plant pathogen Phoma tracheiphila. It mainly causes disease to citrus trees in the Mediterranean. In particular it causes damage to lemon trees in the Mediterranean basin. The plant pathogen, Phoma tracheiphila, is rain- and wind-disseminated.

<span class="mw-page-title-main">Raspberry spur blight</span> Species of fungus

Raspberry spur blight is caused by the fungus Didymella applanata. This plant pathogen is more problematic on red raspberries (Rubus idaeus) than on black or purple raspberries. The fungus infects the leaves first and then spreads to the cane. It causes necrotic spots on the cane near the base of the petiole attachment. Raspberry spur blight can cause a significant reduction in yield, fruit blight, premature leaf drop, and weak bud and cane growth. The magnitude of damage is not clearly understood in the United States, however, studies from Scotland suggest damage to the cane itself is limited. The disease has minor economic impacts by reducing leaves in the summer or killing buds. Major economic damage occurs if the disease manages to kill the entire cane. In the United States, this disease is found in Oregon and Washington.

<span class="mw-page-title-main">Ascochyta diseases of pea</span>

Ascochyta blights occur throughout the world and can be of significant economic importance. Three fungi contribute to the ascochyta blight disease complex of pea. Ascochyta pinodes causes Mycosphaerella blight. Ascochyta pinodella causes Ascochyta foot rot, and Ascochyta pisi causes Ascochyta blight and pod spot. Of the three fungi, Ascochyta pinodes is of the most importance. These diseases are conducive under wet and humid conditions and can cause a yield loss of up to fifty percent if left uncontrolled. The best method to control ascochyta blights of pea is to reduce the amount of primary inoculum through sanitation, crop-rotation, and altering the sowing date. Other methods—chemical control, biological control, and development of resistant varieties—may also be used to effectively control ascochyta diseases.

<span class="mw-page-title-main">Spring black stem</span> Plant fungal disease

Spring Black Stem is a common fungal, foliar disease caused by Ascochyta medicaginicola. Spring Black Stem is most commonly found in alfalfa, but also attacks certain clovers. The fungus survives in stubble from previous cuttings and spreads easily by rain splash, running water, and equipment. The disease is present in numerous alfalfa fields throughout the Northeast United States.

Gummy stem blight is a cucurbit-rot disease caused by the fungal plant pathogen Didymella bryoniae. Gummy stem blight can affect a host at any stage of growth in its development and affects all parts of the host including leaves, stems and fruits. Symptoms generally consist of circular dark tan lesions that blight the leaf, water soaked leaves, stem cankers, and gummy brown ooze that exudes from cankers, giving it the name gummy stem blight. Gummy stem blight reduces yields of edible cucurbits by devastating the vines and leaves and rotting the fruits. There are various methods to control gummy stem blight, including use of treated seed, crop rotation, using preventative fungicides, eradication of diseased material, and deep plowing previous debris.

References

  1. 1 2 3 Chen, Q.; Jiang, J.R.; Zhang, G.Z.; Cai, L.; Crous, P.W. (2015). "Resolving the Phoma enigma". Studies in Mycology. 82: 137–217. doi:10.1016/j.simyco.2015.10.003. PMC   4774273 . PMID   26955202.
  2. 1 2 3 4 5 6 7 8 9 Woudenberg, J.H.C.; Aveskamp, M.M.; de Gruyter, J.; Spiers, A.G.; Crous, P.W. (2009). "Multiple Didymella teleomorphs are linked to the Phoma clematidina morphotype". Persoonia. 22: 56–62. doi:10.3767/003158509X427808. PMC   2789541 . PMID   20198138.
  3. 1 2 3 4 5 6 7 8 9 van de Graaf P. (1999). Biology and Control of Phoma clematidina, causal Agent of Clematis Wilt. PhD thesis, University of Derby, Derby, UK.
  4. 1 2 3 4 5 6 7 8 9 van de Graaf, P. (1999). "Biology and control of clematis wilt" (PDF) (Final project report). Horticultural Development Council, UK. Archived from the original (PDF) on 2016-03-04.
  5. 1 2 3 van de Graaf, P.; Joseph, M.E.; Chartier-Hollis, J.M.; O’Neill, T.M. (1998). Root infection of cultivated clematis by Phoma clematidina, causal agent of clematis wilt. Proceedings 7th International Congress of Plant Pathology. Edinburgh, UK: British Society for Plant Pathology/International Society for Plant Pathology. Archived from the original on 2016-03-04. 3, 3·7·67.
  6. ↑ Boerema, G.H.; Bollen, G.J. (1975). "Conidiogenesis and conidial septation as differentiating criteria between Phoma and Ascochyta". Persoonia. 8: 111–144.
  7. ↑ Boerema G.H. and Dorenbosch M.M.J. (1979). "Mycologisch taxonomisch onderzoek". Verslagen en Mededelingen Plantenziektenkundige Dienst Wageningen 153 (Jaarboek 1978): 17-21.
  8. 1 2 Woudenberg, J.H.C. (2011). "Analysis of the mating-type loci of co-occurring and phylogenetically related species of Ascochyta and Phoma". Molecular Plant Pathology. 13 (4): 350–362. doi:10.1111/j.1364-3703.2011.00751.x. PMC   6638728 . PMID   22014305.
  9. 1 2 3 Gourlay, A. H.; Wittenberg, R.; Hill, R. L.; Spiers, A. G.; Fowler, S. V. (4–14 July 1999). Spencer, Neal R. (ed.). The Biological Control Programme against Clematis vitalba in New Zealand (PDF). X International Symposium on Biological Control of Weeds. Montana State University Bozeman, Montana, USA (published 2000). pp. 799–806. CiteSeerX   10.1.1.589.6666 . S2CID   82909885. bugwoodcloud.org/ibiocontrol/proceedings/pdf/10_709-718.pdf .
  10. 1 2 Paynter, Quentin; Waipara, Nick; Peterson, Paul; Hona, Shane; Fowler, Simon; Gianotti, Alison; Wilkie, Paula (2006). "The impact of two introduced biocontrol agents, Phytomyza vitalbae and Phoma clematidina, on Clematis vitalba in New Zealand". Biological Control. 36 (3): 350–357. doi:10.1016/j.biocontrol.2005.09.011. S2CID   55137731.
  11. ↑ Aveskamp, M.M.; de Gruyter, J.; Woudenberg, J.H.C.; Verkley, G.J.M.; Crous, P.W. (2010). "Highlights of the Didymellaceae: A polyphasic approach to characterise Phoma and related pleosporalean genera". Studies in Mycology. 65: 1–60. doi:10.3114/sim.2010.65.01. PMC   2836210 . PMID   20502538.
  12. ↑ Blok I. (1965). "Verwelkingsziekte in clematis". Jaarboek Proefstation voor de Boomkwekerij te Boskoop 1964: 82-87.
  13. ↑ Smith G.R. (1987). Leaf Spot and Wilt of Clematis caused by Phoma clematidina (Thum.) Boerema. PhD thesis, University of Canterbury, Christchurch, New Zealand
  14. 1 2 Smith, G.R.; Cole, A.L.J. (1991). "Phoma clematidina, causal agent of leafspot and wilt of Clematis in New Zealand". Australasian Plant Pathology. 20 (2): 67–72. doi:10.1071/app9910067. S2CID   44476448.
  15. ↑ Smith, G.R.; Munro, M.H.G.; Fineran, B.A.; Cole, A.L.J. (1994). "Evidence for the involvement of ascochitine in phoma leafspot-wilt disease of Clematis". Physiological & Molecular Plant Pathology. 45 (5): 333–348. doi:10.1016/s0885-5765(05)80063-3.
  16. 1 2 3 van de Graaf, P.; O'Neill, T.M.; Chartier-Hollis, J.M.; Joseph, M.E. (2001). "Susceptibility of clematis varieties and species to stem infection by Phoma clematidina as an indicator for resistance to wilt". European Journal of Plant Pathology. 107 (6): 607–614. doi:10.1023/A:1017902331872. S2CID   20130388.
  17. 1 2 van de Graaf, P.; Joseph, M.E.; Chartier-Hollis, J.M.; O'Neill, T.M. (2002). "Pre-penetration stages in infection of clematis by Phoma clematidina". Plant Pathology. 51 (3): 331–337. doi: 10.1046/j.1365-3059.2002.00727.x .
  18. ↑ van de Graaf, P. (2003). "Aspects of the Biology and Control of Benzimidazole Resistant Isolates of Phoma clematidina, cause of Leaf Spot and Wilt in Clematis". Journal of Phytopathology. 151 (7–8): 442–450. doi:10.1046/j.1439-0434.2003.00748.x.
  19. ↑ RHS Clematis wilt
  20. ↑ Howells J. (1994). "Vulnerability to clematis wilt in large flowered clematis". The Clematis, p. 51.
  21. ↑ Golzar, H.; Wang, C.; Willyams, D. (2011). "First report of Phoma clematidina the cause of leaf spot-wilt disease of Clematis pubescens in Australia". Australasian Plant Disease Notes. 6 (1): 87–90. doi: 10.1007/s13314-011-0030-x .
  22. 1 2 Johnston, P.R.; Park, D.; Ho, W.W.H.; Alexander, B.J.R. (2017). "Genetic validation of historical plant pathology records – a case study based on the fungal genus "Phoma" from the ICMP culture collection". Plant Pathology. 66 (9): 1424–1431. doi: 10.1111/ppa.12728 .
  23. 1 2 FRAC (Fungicide Resistance Action Committee (May 2020). "List of First Confirmed Cases of Plant Pathogenic Organisms Resistant to Disease Control Agents" (PDF).
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.