Cultivar Resistance to Anthracnose Disease of Cowpea (Vigna unguiculata (L.) Walp.) caused by Colletotrichum destructivum O'Gara

The infection process of Colletotrichum destructivum, a hemibiotrophic anthracnose fungus, was studied by light microscopy in two cowpea (Vigna unguiculata) cultivars which differ in disease reaction type. Large, multilobed, intracellular infection vesicles, followed by necrotrophic, radiating, secondary hyphae were produced in tissues of the susceptible cv. IT82E-60. In the resistant cv. TVx3236, both the production of appressoria and their melanisation were impaired, resulting in reduced penetration. Where penetration occurred, the initially-infected epidermal cells underwent a hypersensitive response, restricting the growth of multilobed vesicles and thereby blocking the destructive necrotrophic phase of disease development. The phytoalexins kievitone and phaseollidin accumulated earlier and more rapidly in stem tissues of the resistant cultivar, associated with the appearance of delimited, necrotic spots on inoculated surfaces. In contrast, delayed and slower accumulation of these compounds occurred in the compatible interaction, together with the development of typical spreading, water-soaked, anthracnose lesions.     

Anthracnose of Japanese radish caused by Colletotrichum dematium

Anthracnose of Japanese radish found in Kagoshima and Miyazaki prefectures was demonstrated to be caused by Colletotrichum dematium based on inoculation experiments and morphological and molecular identification of the pathogenic fungus. Although symptoms of Japanese radish anthracnose caused by Colletotrichum higginsianum were similar to those caused by C. dematium, damage by the latter pathogen was more severe than that by C. higginsianum.     

Anthracnose of centipede grass caused by Colletotrichum caudatum

Anthracnose disease was found on centipede grass [Eremochloa ophiuroides (Munro) Hack.] planted as a ground cover on paddy field levees in Shiga Prefecture in 2004. The symptoms were ear blight, stalk blight, and leaf spots. The causal fungus was morphologically identified as Colletotrichum caudatum (Sacc.) Peck. This is the first report of centipede grass anthracnose caused by C. caudatum.     

Anthracnose of sweet pepper caused by Colletotrichum scovillei in Japan

Severe fruit rot of sweet pepper was found in Shimane, Hyogo, Chiba, Toyama, and Nagano prefectures, Japan from 2005 to 2011. Dark, sunken spots with concentric rings of orange conidial masses appeared on fruits. Pathogenic isolates from diseased fruits in the prefectures were identified as Colletotrichum scovillei. This species was added to the pathogens of sweet pepper anthracnose in Japan. The representative isolate was pathogenic to sweet pepper, tomato and chili pepper fruits, kidney bean pod, azuki bean, pea and strawberry leaves, but a caused no symptoms on cucumber or carrot in inoculation tests.     

Anthracnose disease of Amomum villosum caused by Colletotrichum fructicola in China

In May 2019, leaf spots were found on Amomum villosum in Guangxi Province, China. Light yellow-green spots first appeared at the tips or edges of leaves. A fungus was isolated from the leaves and identified as Colletotrichum fructicola based on morphological characteristics and molecular identification using the DNA sequences from ITS, TUB2, ACT, and GAPDH sequences. Similar leaf spots developed after leaves were inoculated with the isolate. This is the first report that C. fructicola causes leaf spots on A. villosum.

     

Anthracnose of Sansevieria trifasciata caused by Colletotrichum sansevieriae sp. nov.

A Colletotrichum sp. was isolated from water-soaked lesions on sansevieria (Sansevieria trifasciata Prain cv. Laurentii) in Japan. Classifying the species only from the morphology of the fungus was difficult; therefore, host range was tested and the ribosomal DNA ITS2 region was phylogenetically analyzed. The fungus was pathogenic only on sansevieria among 20 test plants belonging to 11 families. In a phylogenetic analysis with the neighbor-joining method, the two isolates used formed a single-isolate clade. The fungus is thus proposed to be a new species, Colletotrichum sansevieriae. This report is the first of anthracnose on sansevieria.     

Anthracnose of Madagascar periwinkle caused by species belonging to the Colletotrichum gloeosporioides species complex

Severe blight of stems was found on Madagascar periwinkle (Catharanthus roseus) in Shizuoka and Okinawa prefectures, Japan, in July 2003 and September 2004, respectively. Similar fungi were isolated from the diseased plants. The isolated fungi caused the disease after inoculation and subsequently were reisolated from diseased tissues. The fungi were identified as species closely related to C. siamense or C. tropicale according to sequences of the β-tubulin-2 gene, indicating that they belong to the Colletotrichum gloeosporioides species complex. This is the first report specifying the genetic relationships of the pathogens of Madagascar periwinkle anthracnose in the complex.     

Anthracnose of Nemesia strumosa Caused by Colletotrichum fuscum

Severe wilt with spots and/or leaf and stem blight were found on a scrophulariaceous flowering plant, Nemesia strumosa, grown in Kagawa Prefecture, Japan, in February 1999. Wilted plants had numerous lesions and died early. A mitosporic fungus isolated repeatedly from the diseased plants was identified as Colletotrichum fuscum and was demonstrated to cause the disease. N. strumosa is a new host for C. fuscum, which has been known to attack foxglove (Digitalis spp.). The present disease was named “anthracnose of N. strumosa” as a new disease. Received 10 October 2000/ Accepted in revised form 11 January 2001     

Anthracnose of snapdragon caused by <Emphasis Type="Italic">Colletotrichum destructivum</Emphasis>

Severe spotting and blight of leaves caused by Colletotrichum destructivum were found on snapdragon (Antirrhinum majus L.), a scrophulariaceous ornamental, in open fields in Shizuoka Prefecture, Japan, from June through September 2004. The fungus is added to the group of the pathogens causing anthracnose of snapdragon.     

Infection process of Colletotrichum destructivum O'Gara from lucerne (Medicago sativa L.)

The infection process of Colletotrichum destructivum, a cause of anthracnose in lucerne (= alfalfa, Medicago sativa) was studied by light microscopy. At the onset of the host-pathogen interaction, the fungus produced large, multilobed, multiseptate infection vesicles with elongated neck regions. Each infection structure packed the lumen of the initially-infected epidermal cell and remained confined within its walls for 48 h. Subsequently, narrow, invasive secondary hyphae radiated from the multilobed vesicles, grew through the walls of host cells and rapidly colonized the surrounding tissues. Acervuli emerged on the surface of colonized leaves 96 h after inoculation. These observations are discussed in relation to the infection process and specificity of a genetically closely-related isolate of Colletotrichum destructivum causing anthracnose in cowpea (Vigna unguiculata).     

Effect of Strawberry Density on the Spread of Anthracnose Caused by Colletotrichum acutatum

ABSTRACT Spread of strawberry anthracnose, resulting from the rain splash dispersal of Colletotrichum acutatum conidia, was determined in field plots by assessing fruit disease incidence at a range of distances from an introduced point source of infected fruit with sporulating lesions. Four within-row plant densities were established in replicated plots in each of 2 years. A generalized linear model with a logit link function and binomial distribution for incidence was used to quantify the effects of distance and side of the row relative to the inoculum source, plant density treatment, and their interactions on disease incidence. At all assessment times, there was a significant (P 相似文献   

Colletotrichum dematium Produces Phytotoxins in Anthracnose Lesions of Mulberry Leaves

ABSTRACT Colletotrichum dematium, the causal agent of mulberry anthracnose, was examined to produce phytotoxins in vitro and in planta. Raw and autoclaved mulberry leaves infected with the fungus, as well as the fungus incubated with several solid or liquid media, were extracted with acetone. Extracts obtained from the fungus grown on raw and autoclaved mulberry leaves caused brown necrotic lesions on susceptible mulberry leaves when they were placed (10 mul) on the wounded adaxial surface. Whereas, no extracts obtained from media, except inoculated medium containing homogenized mulberry leaves, induced the necrosis, suggesting that the fungus produced phytotoxins in planta and that some components in mulberry leaves may be indispensable substrates for producing the toxins. The phytotoxins obtained from the diseased leaves induced necrosis on nonhost plants leaves as well as on mulberry leaves. The toxins were present in the border of anthracnose lesions on the leaves, and the sensitivity to the toxin correlated with that to the fungus infection in each susceptible or resistant mulberry cultivar. These results suggest that the phytotoxins are host nonspecific and play a role in fungal pathogenesis in the development of the lesions. Four toxic compounds were isolated and purified from anthracnose lesions. However, due to the low yield, the chemical structure of the compounds could not be identified.     

Biotin Induces Sporulation of Mulberry Anthracnose Fungus, Colletotrichum dematium

Compounds in mulberry leaves inducing sporulation of C. dematium, mulberry anthracnose fungus, were detected. Dissolved or suspended aqueous solutions (1%) of 16 amino acids and 10 vitamins occurring in mulberry leaves were applied individually at the margin of the fungal colony growing on PSA plate. Sporulation was induced only where a biotin solution was applied on the mycelium at a concentration of at least 0.01 ppm. This result suggests that biotin, which occurs in mulberry leaves (ca. 0.6 mg/kg of dried leaves), has a role in inducing sporulation of C. dematium. Received 20 August 1999/ Accepted in revised form 16 November 1999     

黄瓜炭疽病拮抗细菌的筛选及其抑制效果

从连作多年的黄瓜根际土样中筛选得到1株对黄瓜炭疽病菌Colletotrichum orbiculare具有较强拮抗活性的菌株WF-3。通过菌落形态观察、生理生化特性及16S rDNA序列分析,该菌株鉴定为甲基营养型芽孢杆菌Bacillus methylotrophicus。活体盆栽条件下,该菌株对黄瓜炭疽病的防治效果为66.48%。两年的田间试验表明拮抗菌株WF-3培养物对黄瓜炭疽病具有良好的防治效果,防效分别为68.14%和73.70%。     

Genetic and Morphological Characterization of Colletotrichum acutatum Causing Anthracnose of Lupins

ABSTRACT Anthracnose, caused by Colletotrichum sp., is a serious problem of lupins (Lupinus spp.) worldwide. Morphological characters and molecular markers were used to characterize 43 Colletotrichum isolates from lupins, 8 isolates from other hosts, and 18 reference isolates representing related Colletotrichum spp., to assess the pathogen diversity and resolve its taxonomy. All lupin Colletotrichum isolates tested positive with C. acutatum-specific polymerase chain reaction (PCR) and did not test positive with C. gloeosporioides-specific PCR. Spore shape and colony diameter as well as insensitivity to benomyl grouped the lupin anthracnose isolates closer to C. acutatum than to C. gloeosporioides. Analysis of internal transcribed spacer (ITS) sequences of 57 Colletotrichum isolates grouped all lupin isolates with C. acutatum and distinct from C. gloeosporioides. Further, tub2 and his4 sequences revealed groups concordant with ITS, reducing the excessive dependence on the latter. Arbitrarily primed-PCR and amplified fragment length polymorphism analyses revealed intraspecific subgroups, but neither was useful to decipher species level relationships. ITS, tub2, and his4 results strongly support designating lupin anthracnose pathogen as C. acutatum or its subspecies. Most Colletotrichum isolates from lupins from worldwide locations are genetically homogeneous and form a distinct subgroup within C. acutatum. Present results also underline the potential of the C. acutatum-specific PCR for routine pathogen diagnosis.     

Colletotrichum acutatum and C. gloeosporioides Cause Anthracnose on Olives

Morphological and cultural features and restriction fragment length polymorphism analysis of ITS regions, including 5.8S rDNA, from 26 isolates of Colletotrichum species revealed that isolates from olive fruits, previously identified as C. gloeosporioides, belong to two taxa: C. acutatum and C. gloeosporioides. Comparison of both ITS sequence data with reference isolates confirmed the presence of both species in olives affected by anthracnose disease.     

Strawberry Anthracnose: Histopathology of Colletotrichum acutatum and C. fragariae

ABSTRACT Ontogeny of the invasion process by Colletotrichum acutatum and C. fragariae was studied on petioles and stolons of the strawberry cultivar Chandler using light and electron microscopy. The invasion of host tissue by each fungal species was similar; however, each invasion event occurred more rapidly with C. fragariae than with C. acutatum. Following cuticular penetration via an appressorium, subsequent steps of invasion involved hyphal growth within the cuticle and within the cell walls of epidermal, subepidermal, and subtending cells. Both species of fungi began invasion with a brief biotrophic phase before entering an extended necrotrophic phase. Acervuli formed once the cortical tissue had been moderately disrupted and began with the development of a stroma just beneath the outer periclinal epidermal walls. Acervuli erupted through the cuticle and released conidia. Invasion of the vascular tissue typically occurred after acervulus maturation and remained minimal. Chitin distribution in walls of C. fragariae was visualized with gold-labeled wheat germ agglutinin. The outer layer of bilayered walls of conidia, germ tubes, and appressoria contained less chitin than unilayered hyphae in planta.     

First report of anthracnose on Spigelia anthelmia caused by Colletotrichum karstii and Colletotrichum siamense in Brazil

Journal of Plant Diseases and Protection - In Brazil, Spigelia anthelmia is an herbaceous weedy plant normally used for the treatment of helminths in humans and animals. Leaves and stems of S....