First Report of the A2 Mating Type of Phytophthora capsici Infecting Peppers (Capsicum annuum) in Taiwan

Phytophthora capsici Leonion was first identified on pepper (Capsicum annuum L) in Taiwan in 1976. At that time, only the A1 mating type was present (2). In 2007, the A2 mating type of P. capsici was identified on tomato and eggplant in the central part of the country (1). During an excessively rainy period in mid-2008, many chili and sweet pepper fields in Taiwan suffered severe losses due to P. capsici. Symptoms included a foliar blight and stem, root, and fruit rot. Plants eventually wilted and died. Symptomatic plants were collected from chili- and sweet pepper-production areas in central, southern, and eastern Taiwan. Fifty-three isolates from single zoospores were identified by PCR using species-specific primers CAPFW/CAPRV2 (4). Mating type was determined by co-inoculating rape seed agar plates (3) with mycelial plugs of the tester and a known isolate. Pc134, maintained by the mycology unit at The World Vegetable Center, and 27220, provided by P. J. Ann at the Taiwan Agricultural Research Institute, were used as reference isolates of A1 and A2 mating types, respectively. Plates were examined microscopically for oospores after 5 to 7 days of incubation at 24°C in the dark. Of the 53 isolates, 15 were identified as the A2 mating type and the remaining 38 isolates were identified as A1. The A2 mating type was found in the central and southern regions while the A1 mating type was widely distributed across all three regions. The sporangia of the A2 mating type were 60.4 to 73.4 × 40.9 to 51.8 μm (average 69.2 × 44.7 μm), whereas sporangia of the A1 mating type were 50.1 to 73.9 × 37.9 to 48.1 μm (average 61.4 × 44.1 μm). In general, the A2 mating type produced longer sporangia and only a few isolates produced chlamydospores in V8 broth and on agar. To our knowledge, this is the first report of the A2 mating type of P. capsici infecting peppers in Taiwan. The presence of both mating types in the same field has been observed. References: (1) P. J. Ann et al. Plant Pathol. Bull. 17:69, 2008. (2) L. S. Leu and C. W. Kao. Plant Prot. Bull. (Taiwan) 23:59, 1981. (3) M. M. Sautor. Mycologia 59:161, 1967. (4) C. Silvar et al. Eur. J. Plant Pathol. 112:43, 2005.

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First Report of Blight of Field Peppers Caused by Phytophthora capsici in Ontario

Plant Disease ◽

10.1094/pdis.2000.84.6.705b ◽

2000 ◽

Vol 84 (6) ◽

pp. 705-705 ◽

Cited By ~ 8

Author(s):

T. R. Anderson ◽

R. Garton

Keyword(s):

Phytophthora Capsici ◽

Sweet Pepper ◽

Fluorescent Light ◽

Mating Types ◽

Phytophthora Blight ◽

Essex County ◽

First Report ◽

Diameter Range ◽

Run Off ◽

Internal Surfaces

In August 1994, a disease of sweet peppers (Capsicum annuum L.) and butternut squash (Cucurbita pepo L.) was observed in a 2-ha field near Harrow, Essex County, ON, Canada. In 1995, a similar disease was noted on peppers at two locations 30 km apart in Essex County. In 1997, the disease occurred on peppers in a 20-ha field in the vicinity of the 1994 outbreak. Yield loss was estimated at 40 to 60% in pepper fields and 20% in the affected squash field. Brown, necrotic lesions were more prevalent on pepper fruits and upper stems and lateral branches than basal stems. Affected plants occurred in lower areas of fields that had been flooded by rain or irrigation. Gray, floccose masses of sporangia were evident on fruits and stems under humid conditions and on the internal surfaces of infected fruits. Symptoms were similar to those described for Phytophthora blight of pepper (1). Squash infections occurred where fruits contacted soil. Isolations were made from sections of fruit, stems, and leaves of pepper and squash plants with symptoms of disease on lima beans (Difco Laboratories, Detroit) or 20% V8 agar medium and incubated at 22°C. Phytophthora capsici was readily isolated from all plants with disease symptoms. Observations of colony morphology and growth were made on cultures on 20% V8 agar at 25°C under continuous fluorescent light. Sporangia were papillate and averaged 45 ± 5.9 × 27 ± 3.5 μm in size (range 28 to 58 × 21 × 39 μm). Oospores were spherical and 23 ± 2.9 μm in diameter (range 16 to 28 μm) and, when the external wall was included, were 28 ±2.7 μm in diameter (range 23 to 37 μm). Pedicels varied in length, averaging 63 ± 30.9 μm (range 9 to 129 μm). These observations are similar to those described for P. capsici (2). Mating type was determined by coculture with isolates obtained from A. F. Schmitthenner (OARDC, Wooster, OH) designated A1 and A2. Oospore development was determined after 10 days growth at 25°C on 20% V8 agar. Mating types A1 and A2 occurred among Ontario isolates from pepper and squash. In 1995, 13 of 15 isolates tested were A1, and in 1997, 1 of 5 was A1. Both mating types were found in the same field. Pathogenicity of pepper and squash isolates was tested by inoculating greenhouse-grown pepper cvs. Merlin and North Star at the 5-leaf stage by adding 5 ml of a spore suspension (1,000 sporangia per ml) to the crown and adjacent soil or sprayed on the foliage until run off. Plants were covered in plastic bags for 24 h. Wilting and plant death occurred at 4 and 10 days, respectively, with both cultivars. Crown-inoculated plants wilted prior to development of brown lesions on lower stems at the soil line. Symptoms on foliar-inoculated plants were first observed on young tissue at growing points and stem nodes. P. capsici was reisolated from affected tissue. This is the first report of Phytophthora blight of sweet pepper in Ontario. References: (1) L. H. Leonian. Phytopathology 12:401, 1922. (2) P. H. Tsao and A. Alizadeh. 1988. Proceedings of the 10th International Cocoa Research Conference. Santo Domingo, Dominican Republic, pp. 441–445.

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First Report of Fusarium solani Causing Fruit Rot of Sweet Pepper in Trinidad

Plant Disease ◽

10.1094/pdis-06-10-0433 ◽

2010 ◽

Vol 94 (11) ◽

pp. 1375-1375 ◽

Cited By ~ 1

Author(s):

H. A. Ramdial ◽

S. N. Rampersad

Keyword(s):

Fusarium Solani ◽

Disease Incidence ◽

Sweet Pepper ◽

Fruit Rot ◽

Universal Primers ◽

Distilled Water ◽

Sequence Comparisons ◽

Agar Block ◽

First Report ◽

Plant Pathol

In Trinidad, sweet pepper (Capsicum annuum L.) is an important crop that is produced for local markets and regional export. From February to April 2010, severe fruit rot was observed in 9 of 11 commercial fields located in North Trinidad in the major production areas of North and South Aranguez. All fields were in the late harvesting stage and the most commonly grown cultivars were Aristotle and Canape. Disease incidence for each field was estimated to be 80% with a yield loss of 40 to 60%. Symptoms appeared on mature red fruits but growers reported that disease can also occur on green fruit. Symptoms began as soft lesions that turned dark brown to black. Lesions usually originated at the calyx end of the fruit and extended down the sides. Fruits were surface sterilized by rinsing with 70% ethanol for 2 min, followed by three rinses with sterile distilled water. Two 4-mm3 blocks of tissue from the opposite sides of fruit lesions were transferred to water agar and incubated for 5 to 7 days at 25 ± 1°C. A 4-mm3 agar block consisting of the leading mycelial edge was then transferred to potato dextrose agar (PDA) and incubated under the same conditions. Colonies on PDA were fast growing with white, fluffy, aerial mycelia; hyphae were septate and hyaline; conidiophores were unbranched; microconidia were abundant, thin walled, hyaline, ovoid, one to two celled, and measured 6 to 10 × 2 to 4 μm. Macroconidia were hyaline, three to four celled, curved, thick walled, and measured 20 to 30 × 4 to 6 μm. PCR amplification was carried out utilizing universal primers ITS4/5 and translation elongation factor primers EF1/2 (2). Sequence comparisons of the internal transcribed spacer (ITS) region (HM157262) and EF-1α gene (HQ014854) with cognate sequences available in GenBank and the FUSARIUM-ID databases revealed 100 and 99.6% sequence identity, respectively, to Fusarium solani (Mart.) Sacc. Pathogenicity tests were conducted by drop inoculating 10-μl of spore suspension (106 spores/ml) of each of four isolates on wounded and unwounded sites of mature sweet pepper fruits (five per isolate of cvs. Aristotle, Canape, Century, Destra, and Paladin). Control fruits were inoculated with sterile distilled water. Inoculated fruits were kept at 25 ± 1°C in loosely sealed plastic containers and monitored for the onset of symptoms for 6 days. The experiment was conducted twice. Lesions (8.0 to 15.2 mm in diameter) developed on wounded fruit of Aristotle, Canape, and Century. No symptoms were seen on Destra, Paladin, or the water controls. No symptoms developed on nonwounded fruits. Koch's postulates were fulfilled by reisolating the pathogen from infected tissues. Fruit rot caused by F. solani has been reported to be a serious constraint to sweet pepper production in Canada (4), the United Kingdom (1), and New Zealand (3). To our knowledge, this is the first report of Fusarium fruit rot of sweet pepper in Trinidad. References: (1) J. T. Fletcher. Plant Pathol. 43:225, 1994. (2) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (3) J. L. Tyson. Aust. Plant Pathol. 30:375, 2001. (4) R. Utkhede and S. Mathur. Plant Dis. 87:100, 2003.

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A PCR-based Assay for Distinguishing between A1 and A2 Mating Types of Phytophthora capsici

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04013-17 ◽

2017 ◽

Vol 142 (4) ◽

pp. 260-264

Author(s):

Ping Li ◽

Dong Liu ◽

Min Guo ◽

Yuemin Pan ◽

Fangxin Chen ◽

...

Keyword(s):

Genetic Diversity ◽

Mating Type ◽

Phytophthora Capsici ◽

Mating Types ◽

Sequence Repeat ◽

Chain Reaction ◽

Plant Parasite ◽

Dna Fragment ◽

Polymerase Chain ◽

Microsatellite Diversity

Sexual reproduction in the plant parasite Phytophthora capsici Leonian requires the interaction of two distinct mating types, A1 and A2. Co-occurrence of these mating types can enhance the genetic diversity of P. capsici and alter its virulence or resistance characteristics. Using an intersimple sequence repeat (ISSR) screen of microsatellite diversity, we identified, cloned, and sequenced a novel 1121-base pair (bp) fragment specific to the A1 mating type of P. capsici. Primers Pcap-1 and Pcap-2 were designed from this DNA fragment to specifically detect the A1 mating type. Polymerase chain reaction (PCR) using these primers amplified an expected 997-bp fragment from known A1 mating types, but yielded a 508-bp fragment from known A2 mating types. This PCR-based assay could be adapted to accurately and rapidly detect the co-occurrence of A1 and A2 P. capsici mating types from field material.

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Caractérisation ultrastructurale d'une résistance induite par un éliciteur d'origine fongique, chez un cultivar sensible de Piment

Canadian Journal of Botany ◽

10.1139/b90-050 ◽

1990 ◽

Vol 68 (2) ◽

pp. 381-390 ◽

Cited By ~ 2

Author(s):

C. Coulomb ◽

P. J. Coulomb ◽

I. Saimmaime ◽

Y. Lizzi ◽

C. Polian

Keyword(s):

Endoplasmic Reticulum ◽

Capsicum Annuum ◽

Defense Response ◽

Culture Medium ◽

Phytophthora Capsici ◽

Physiological State ◽

Sweet Pepper ◽

Host Cells ◽

Lytic Function ◽

Wall Appositions

Elicitation of a sensitive sweet pepper (Capsicum annuum) cultivar roots by immersion in the culture medium of Trichoderma album induces resistance in leaves infected by Phytophthora capsici. In infected tissues, host cells are intact and develop wall formations that look like typical wall appositions, but differ from them by the presence of a substance of cytoplasmic origin, which is phagocytized and degraded, conferring a lytic function and unusual dynamics to these structures. The involvement of the endoplasmic reticulum and peroxysomes in eventual detoxification processes is discussed. The resistance induced by this elicitor seems to be programmed by the establishment of a reactive physiological state, which produces the defense response.

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Occurrence and distribution of mating types A1 and A2 of Phytophthora infestans (Mont.) de Bary in the Czech Republic

Plant Protection Science ◽

10.17221/2697-pps ◽

2010 ◽

Vol 42 (No. 2) ◽

pp. 41-48 ◽

Cited By ~ 7

Author(s):

J. Mazáková ◽

V. Táborský ◽

M. Zouhar ◽

P. Ryšánek ◽

E. Hausvater ◽

...

Keyword(s):

Czech Republic ◽

Phytophthora Infestans ◽

Mating Type ◽

Mating Types ◽

Pcr Markers ◽

The Czech Republic ◽

First Report

A total of 199 <i>Phytophthora infestans</i> isolates were obtained from leaves, tubers and fruits of infected crops of potato and tomato in different regions of the Czech Republic in 2003, 2004 and 2005. They were analysed for mating type using the conventional pairing assay and PCR markers; 107 isolates were of A1 and 92 of A2 mating type. No self-fertile isolate was found. Our study is the first report of the presence and distribution of the A2 mating type of <i>P. infestans</i> in the Czech Republic. The co-existence of the two mating types may enable the pathogen to reproduce sexually, thus enhancing the diversity of its population countrywide.

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Phosphite effect on hot and sweet pepper reaction to Phytophthora capsici

Scientia Agricola ◽

10.1590/s0103-90162004000500005 ◽

2004 ◽

Vol 61 (5) ◽

pp. 492-495 ◽

Cited By ~ 3

Author(s):

Fernando Cesar Sala ◽

Cyro Paulino da Costa ◽

Márcia de Moraes Echer ◽

Marise Cagnin Martins ◽

Sally Ferreira Blat

Keyword(s):

Capsicum Annuum ◽

Plant Resistance ◽

Adult Stage ◽

Phytophthora Capsici ◽

Sweet Pepper ◽

Hot Pepper ◽

Heterozygous Genotype ◽

Capsicum Annuum L ◽

Fruiting Stage ◽

Resistant Lines

Phosphite has been recommended to enhance plant resistance against Phytophthora. This work evaluated the response of hot and sweet pepper (Capsicum annuum L.) to Phytophthora capsici from juvenile up to the adult stage following treatment with phosphite. Sweet pepper hybrids considered to be resistant to P. capsici, like Reinger, Nathalie and Athenas, were evaluated. The susceptible checks were hybrid Magali R and cvs. Myr 10 and Ikeda. Hot pepper Criollo de Morelos 328, CM 334, BGH 3756, BGH 5122, CNPH 294 and Locorte were used as referential resistant lines. Phosphite did not have an effect on the hot pepper resistant lines because of their genetic homozygozity, while no protection was observed for the Athenas hybrid claimed to be resistant. Heterozygous hybrids recognized as resistant, like Reinger and Nathalie, showed higher survival following phosphite treatment, and their reaction was equivalent to the resistant cvs. CM 328 and CM 334, except for the fruiting stage. Depending of the hybrid heterozygous genotype, phosphite possibly acts through indirect phytoalexin induction through the inhibited pathogen.

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Evidence for mitochondrial gene control of mating types in Phytophthora

Canadian Journal of Microbiology ◽

10.1139/w05-073 ◽

2005 ◽

Vol 51 (11) ◽

pp. 934-940 ◽

Cited By ~ 5

Author(s):

Yu-Huan Gu ◽

Wen-Hsiung Ko

Keyword(s):

Mating Type ◽

Mitochondrial Gene ◽

Phytophthora Capsici ◽

Nuclear Genes ◽

Gene Control ◽

Mating Types ◽

Phytophthora Parasitica ◽

Decisive Effect ◽

Mating Type Genes ◽

Fusion Products

When protoplasts carrying metalaxyl-resistant (Mr) nuclei from the A1 isolate of Phytophthora parasitica were fused with protoplasts carrying chloroneb-resistant (Cnr) nuclei from the A2 isolate of the same species, fusion products carrying Mr nuclei were either the A2 or A1A2 type, while those carrying Cnr nuclei were the A1, A2, or A1A2 type. Fusion products carrying Mr and Cnr nuclei also behaved as the A1, A2, or A1A2 type. The result refutes the hypothesis that mating types in Phytophthora are controlled by nuclear genes. When nuclei from the A1 isolate of P. parasitica were fused with protoplasts from the A2 isolate of the same species and vice versa, all of the nuclear hybrids expressed the mating type characteristics of the protoplast parent. The same was true when the nuclei from the A1 isolate of P. parasitica were fused with the protoplasts from the A0 isolate of Phytophthora capsici and vice versa. These results confirm the observation that mating type genes are not located in the nuclei and suggest the presence of mating type genes in the cytoplasms of the recipient protoplasts. When mitochondria from the A1 isolate of P. parasitica were fused with protoplasts from the A2 isolate of the same species, the mating type of three out of five regenerated protoplasts was changed to the A1 type. The result demonstrated the decisive effect of mitochondrial donor sexuality on mating type characteristics of mitochondrial hybrids and suggested the presence of mating type genes in mitochondria. All of the mitochondrial hybrids resulting from the transfer of mitochondria from the A0 isolate of P. capsici into protoplasts from the A1 isolate of P. parasitica were all of the A0 type. The result supports the hypothesis of the presence of mating type genes in mitochondria in Phytophthora.Key words: mating type, mitochondrial gene, Phytophthora parasitica, Phytophthora capsici.

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Karakteristik morfologi dan sebaran tipe kawin Phytophthora capsici asal lada di Pulau Jawa

Jurnal Fitopatologi Indonesia ◽

10.14692/jfi.14.5.166 ◽

2019 ◽

Vol 14 (5) ◽

pp. 166

Author(s):

Bahru Rohmah ◽

Bambang Hadisutrisno ◽

Dyah Manohara ◽

Achmadi Priyatmojo

Keyword(s):

Mating Type ◽

Phytophthora Capsici ◽

Morphological Characteristics ◽

Black Pepper ◽

Piper Nigrum ◽

Mating Types ◽

Foot Rot ◽

Distribution Map ◽

Rot Disease ◽

Special Region

Morphology characters and mating types distribution of Phytophthora capsici from black pepper in Java IslandPepper (Piper nigrum) is one of the most important spice crops in Indonesia. Recently its production declining due to infection of foot rot disease caused by Phytophthora capsici. This pathogen has two different mating types, namely A1 and A2, in which the presence of opposite two mating types is important for sexual reproduction and formation of oospores. The movement of pepper seedling from one area to another is highly facilitated alteration of mating type distribution map of P. capsici. The objectives of this research were to determine the morphological characteristics and the spread of mating types of P. capsici in Java. Morphology characters of P. capsici isolates were indicated by variation in sporangial size and shape, as well as types of colony appearance. The length (l) and width (w) of sporangium were in the range of 15.1–76.2 µm and 9.8–44.8 µm, respectively; while the l/w ratio was 1.12–2.27. Mating type assay showed that A2 type was more dominantly found than A1 type. This study found two different mating types present in the same area, i.e. Regency of Pacitan (East Java) and Regency of Sleman (Special Region of Yogyakarta). The findings of this research suggested that it is required more strict control strategy on the mobilization of black pepper seedling particularly in the area where the certain mating type is not found yet so that the emergence of new more virulent genotype of pathogen can be prevented.

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esponse of Sweet pepper (Capsicum annuum L.) in saline region of Bangladesh

Asian Journal of Crop, Soil Science and Plant Nutrition ◽

10.18801/ajcsp.040220.19 ◽

2020 ◽

Vol 4 (2) ◽

pp. 150-156

Author(s):

M. R. I. Suhel ◽

N. J. Methela ◽

R. A. Ruhi ◽

B. Hossain

Keyword(s):

Capsicum Annuum ◽

Growth And Development ◽

Agricultural Research ◽

Saline Soil ◽

Crop Productivity ◽

Sweet Pepper ◽

Fruit Weight ◽

Research Field ◽

Capsicum Annuum L ◽

Red Army

Salinity is one of the major issues that lead to a reduction in crop productivity. This study aimed to investigate the response of sweet pepper (Capsicum annuum L.) to saline soil. The research was conducted in Agricultural Research Field at Noakhali Science and Technology University during 2018-19 with two sweet pepper varieties as treatment named Red Army (V1) and California Wonder (V2). The results indicated that there were significant variations between the two varieties in different parameters of growth as well as yield performance. The result showed that between the treatments V2 (California Wonder) gave the higher yield ie., 10.65 ton/ha while V1(Red Army) produced 9.61 ton/ha. Moreover, the taller plants and longer fruit were obtained from the V2 which were 32.43 cm and 8.23 cm respectively. Even among the other parameters, V2 gave higher growth and development than V1. Furthermore, average single fruit weight/plant was recorded 76.33 g in California Wonder (V2) whereas Red Army (V1) provided 74.16 g. The finding of the experiment indicated that the overall better performance could be obtained from V2 California Wonder variety of sweet pepper. This study evaluated the varietal performance of two varieties and it can be said from the experiment that the California Wonder is the best variety for cultivation in saline region in Bangladesh.

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