scholarly journals Бактерии в гифосфере Phytophthora infestans и Alternaria alternata на картофеле

2020 ◽  
Author(s):  
A.N. Smirnov ◽  
V.V. Vasilchenko ◽  
K.S. Vorobyeva
Keyword(s):  
Phytophthora Infestans ◽  
Alternaria Alternata ◽  
Early Blight ◽  
Plant Protection ◽  
Electronic Microscopy ◽  
Oatmeal Agar ◽  
Bacterial Development ◽  
Increased Temperature ◽  
Laboratory Investigations ◽  
Sarpo Mira

Фитофтороз и альтернариоз, вызываемые фитопатогенами Phytophthora infestans (Mont.) de Bary и Alternaria alternata (Fr.) Keissl., опаснейшие болезни картофеля и томата. Бактериозы картофеля другая опасная проблема как картофеля и томата, так и других с.-х. культур. Нередко возбудители бактериозов, особенно пектолитические бактерии, присутствуют на пораженных растениях вместе с фитопатогенными псевдогрибами и грибами, в том числе с Ph. infestans и A. alternata. Цель исследования оценить присутствие бактерий в гифосфере Phytophthora infestans и Alternaria alternata, а также влияние бактерий на характеристики Ph. infestans и A. alternata. Лабораторные исследования проводили в лаборатории сектора фитопатологии кафедры защиты растений в 2016-2019 годах. Использовали изоляты Ph. infestans T-9, IO-37, 161, A. alternatа Д12 из коллекций МГУ имени М. В. Ломоносова и РГАУ-МСХА имени К. А. Тимирязева. Заражение дисков клубней картофеля сортов Жуковский ранний, Ред Скарлетт, Сарпо Мира, Луговской, Удача проводили в марте 2016 года на фоне потепления погодных условий, температура в лаборатории достигала 25 С. Наличие бактерий в мицелиях исследуемых штаммов Ph. infestans, выращиваемых на овсяном агаре, проверялили посредством световой и электронной микроскопии, а также путем смывов с мицелиев и высевом на специальные питательные среды King B и YDS. В результате исследований доказано наличие пектолитических бактерий в гифосфере Ph. infestans и A. alternatа. При наличии бактерий доказаны лизис и изменения морфологии Ph. infestans и конкурентная экспрессия по локусам глюкозо-6 фосфат изомеразы (Gpi-1) и малатдегидрогеназы (Mdh-2). Инокуляция клубневых дисков четырех сортов картофеля Жуковский ранний, Ред Скарлетт, Сарпо Мира и Удача суспензиями патогенов на фоне повышенной температуры выявили значительное развитие бактериозов уже на первые сутки инкубации. Только на сорте Луговской развитие данные симптомов было в значительной степени подавлено. Мицелии Ph. infestans, A. alternata и пектолитические бактерии их гифосферы образуют на картофеле единый и достаточно стабильный патокомплекс с достаточно сложными взаимосвязями, которые предстоит изучать. Этот патокомплекс способен создать напряженный комбинированный инфекционный фон на картофеле, который в ряде случаев способен представлять для него существенную опасность.Late blight and early blight caused with phytopathogens Phytophthora infestans (Mont.) de Bary and Alternaria alternata (Fr.) Keissl. are the dangerous diseases of potato and tomato. Bacteria are connected to the other dangerous problems of both potato and tomato, and other crops. Often bacteria especially pectolytic bacteria occur on affected plants with phytopathogeneous pseudofungi and fungi with Ph. infestans и A. alternata as well. Objective of our investigation is an estimation of bacterial occurrence in Ph. infestans and A. alternata hyphosphaere as well as influence of bacteria on the Ph. infestans and A. alternate properties. Laboratory investigations were conducted at phytopathology branch of department of plant protection of RSAUMTAA in 2016-2019. Ph. infestans isolates T-9, IO-37, 161, A. alternatа isolate D12 of MSU and RSAUMTAA were investigated. Tuber disc inoculation of potato cultivars Zhukovskiy ranniy, Red Scarlett, Sarpo Mira, Lugovskoy and Udacha was done in 2016 at the temperature about 25 C. Checking bacterial occurrence was done in Ph. infestans mycelia grown at oatmeal agar by means of light and electronic microscopy as well as with transferring on special selective media King B and YDS. As a result, occurrence of pectolytic bacteria was proved to be in Ph. infestans and A. alternatа hyphosphaere. At bacterial occurrence Ph. infestans lysis and morphological deviations as well as competitive expression at the loci of Glucose 6 Phosphate Isomerase (Gpi-1) and Malate Dehydrogenase (Mdh-2) are proved to be developed. Inoculation of potato tuber discs of five cultivars Zhukovskiy ranniy, Red Scarlett, Sarpo Mira and Udacha with suspensions of pathogens at increased temperature revealed essential bacterial development at increased temperature during already first day of incubation. Manifestation of these symptoms was significantly suppressed only on cultivar Lugovskoy. Ph. infestans and A. alternata mycelia as well as pectolytic bacteria of their hyphosphaere form on potato unique and stable pathocomplex with complicated interconnections which should be studied as quickly as possible. This pathocomplex provides strong combined infective phone on potato which is able to be essentially dangerous for this crop.

Genetic defense analysis of tomatoes in response to early blight disease, Alternaria alternata

2019 ◽  
Vol 142 ◽  
pp. 500-509 ◽  
Author(s):  
Giti Alizadeh Moghaddam ◽  
Zahra Rezayatmand ◽  
Mehdi Nasr Esfahani ◽  
Mahdi Khozaei
Keyword(s):  
Alternaria Alternata ◽  
Early Blight ◽  
Blight Disease

Resistance to Phytophthora infestans Clonal Lineage US-23 in Potato Cultivars and Its Relationship with Early Blight Resistance and Tuber Yield

Plant Disease ◽  
2021 ◽  
Author(s):  
Weiya Xue ◽  
Kathleen G. Haynes ◽  
Xinshun Qu
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Early Blight ◽  
Tuber Yield ◽  
Late Blight Resistance ◽  
Field Trials ◽  
Potato Cultivars ◽  
Blight Resistance ◽  
Clonal Lineage ◽  
Progress Curve

Resistance to late blight, caused by Phytophthora infestans clonal lineage US-23, in 217 old and modern potato cultivars was evaluated in field trials in 2016 and 2017 in Pennsylvania. Significant differences in resistance were found among these cultivars (P < 0.0001). Significant interaction between cultivars and environments was found (P < 0.0001). The values of relative area under the disease progress curve ranged from 0 to 0.5841 in 2016 and from 0 to 0.5469 in 2017. Broad-sense heritability of late blight resistance was estimated to be 0.91 with a 95% confidence interval of 0.88 to 0.93. Cluster analysis classified the cultivars into 5 groups: resistant, moderately resistant, intermediate, moderately susceptible, and susceptible. Thirty cultivars showing resistance and 32 cultivars showing moderate resistance were identified. The 217 cultivars were also evaluated for foliar maturity, tuber yield and resistance to early blight, caused by Alternaria solani. A few cultivars with late blight resistance independent of late maturity were found. Late blight resistance and early blight resistance were positively correlated, and 17 cultivars possessed resistance to both diseases. Yield tradeoff associated with late blight resistance was not observed among the cultivars in the absence of disease pressure.

scholarly journals Environmental and Genetic Factors Influencing Self-Fertility in Phytophthora infestans

2000 ◽  
Vol 90 (9) ◽  
pp. 987-994 ◽  
Author(s):  
C. D. Smart ◽  
H. Mayton ◽  
E. S. G. Mizubuti ◽  
M. R. Willmann ◽  
W. E. Fry
Keyword(s):  
Phytophthora Infestans ◽  
Mating Type ◽  
Leaf Tissue ◽  
Single Individual ◽  
Oatmeal Agar ◽  
Physical Proximity ◽  
Type Isolate ◽  
In Vivo Tests

Phytophthora infestans is generally regarded as heterothallic-requiring physical proximity of two individuals of different mating type (A1 and A2) for oosporogenesis. Recent reports of limited selfing in young cultures of this oomycete stimulated us to investigate factors contributing to the phenomenon. The ability to produce oospores rapidly (within 2 weeks) in pure, single individual cultures (self-fertility) was tested in 116 individual isolates. The 116 isolates were from geographically diverse locations (16 countries) and were genetically diverse. Mating type and growth medium were the most prominent factors in determining if an isolate would be self-fertile. The majority of A2 isolates (45 of 47 tested) produced oospores when grown on a 50:50 mixture of V8 and rye B medium. In contrast, the majority of A1 isolates (65 of 69 tested) did not produce oospores on this medium. None of the 116 isolates produced oospores when grown on rye B medium (with no V8 juice). Further tests on representative A1 and A2 isolates revealed that oatmeal agar, tomato juice agar, and V8-juice agar all induced the A2 mating type isolate to produce oospores but did not induce the A1 mating type isolate to produce oospores. Calcium carbonate and pH did not alter the self-fertile oospore production in either A1 or A2 mating type isolates. For in vivo tests, the application of fungicide to potato or tomato leaf tissue either before or after inoculation did not stimulate any individual isolate (one A2 and one A1 isolate) to produce oospores in infected tissue. However, in all of the controls for all experiments (in vivo and in vitro), many oospores were produced rapidly if both strains grew in physical proximity.

scholarly journals First Report of Phoma strasseri as a Pathogen of Stachys officinalis in Bulgaria

Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 699-699
Author(s):  
S. G. Bobev ◽  
A. F. Margina ◽  
J. de Gruyter
Keyword(s):  
Plant Protection ◽  
Aerial Mycelium ◽  
Culture Collection ◽  
Leaf Spot Disease ◽  
Oatmeal Agar ◽  
First Report ◽  
Average Temperature ◽  
Leaf Spots ◽  
Monarda Didyma

For several years, a leaf spot disease has been observed on Betony, Stachys officinalis (synonym Betonica officinalis), in an experimental field in Kazanlak, Bulgaria. The round to somewhat angular spots (6 to 8 mm diameter) are dark brown with a pale center and have a chlorotic halo. A Phoma species isolated from the lesions formed regular to irregular, light brown colonies on potato dextrose agar (PDA). The isolate was studied as described by de Gruyter and Noordeloos (2). After 7 days, the growth rate was 43 mm on oatmeal agar and 33 mm on malt agar; the colonies were olivaceous gray-to-glauceous gray with a regular outline and with finely floccose, white-to-olivaceous gray aerial mycelium. Pycnidia, produced after 2 weeks, were ostiolate, globose to subglobose, 120 to 280 μm in diameter, citrine or honey, and later olivaceous to olivaceous black. The conidiogenous cells were globose to bottle shaped, 2 to 6 × 3 to 5 μm. The conidia were hyaline and unicellular, 5 to 7.5 × 2.5 to 4.2 μm, cylindrical to ellipsoidal with several small, scattered guttules. Chlamydospores were absent. According to these in vitro characters and after comparing the isolate with several Phoma isolates present in the culture collection of the Dutch Plant Protection Service, Wageningen, the Netherlands, the fungus has been identified as Phoma strasseri Moesz. The pathogenicity of the isolate was confirmed by artificial leaf inoculation of potted S. officinalis plants with a spore suspension (8 × 106 spores per ml) kept in a moist chamber for 48 h at a mean average temperature of 16°C. Leaf spots observed 4 to 5 days after inoculation were similar to those observed in the field. P. strasseri was subsequently reisolated from the spots. P. strasseri (synonym Phoma mentae Strasser) has been recorded as the cause of rhizome and stem rot on mint, Mentha spp., in Europe, Japan, and North America (3). In addition, this fungus has been found in New Zealand (strain identified at the Dutch Plant Protection Service, unpublished data). To our knowledge, this is the first report of P. strasseri on S. officinalis in Bulgaria. P. strasseri may produce septate conidia and, therefore, can be classified in Phoma section Phyllostictoides Zherbele ex Boerema (1). P. strasseri clearly differs from other Phoma species described on Lamiaceae: Phoma leonuri Letendre (Phoma section Plenodomus (Preuss) Boerema et al., pycnidia scleroplectenchymatous, conidia aseptate, 3.5 to 5.5 × 1.5 to 2.5 μm), Phoma dorenboschii Noordel. & de Gruyter (Phoma Sacc. section Phoma, conidia aseptate, 3 to 5.5 × 2 to 2.5 μm, producing dendritic crystals in vitro), and Phoma valerianae Henn. (Phoma Sacc. section Phoma, conidia aseptate, 2.5 to 4 × 1.5 to 2 μm). Occasionally P. strasseri has been isolated from other Lamiaceae, namely Monarda didyma (Dutch Plant Protection Service, unpublished data). There is also a report from Valeriana sp. (3). References: (1) G. H. Boerema. Mycotaxon 64:321, 1998. (2) J. de Gruyter and M. E. Noordeloos. Persoonia 15(1):71, 1992. (3) C. E. Horner. Plant Dis. Rep. 55:814, 1971.

Bio-genetic analysis of resistance in tomato to early blight disease, Alternaria alternata

2020 ◽  
Vol 179 ◽  
pp. 112486
Author(s):  
Giti Alizadeh-Moghaddam ◽  
Zahra Rezayatmand ◽  
Mehdi Nasr- Esfahani ◽  
Mahdi Khozaei
Keyword(s):  
Genetic Analysis ◽  
Alternaria Alternata ◽  
Early Blight ◽  
Blight Disease

scholarly journals Hyperspectral Measurements Enable Pre-Symptomatic Detection and Differentiation of Contrasting Physiological Effects of Late Blight and Early Blight in Potato

2020 ◽  
Vol 12 (2) ◽  
pp. 286 ◽  
Author(s):  
Kaitlin M. Gold ◽  
Philip A. Townsend ◽  
Adam Chlus ◽  
Ittai Herrmann ◽  
John J. Couture ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Precision Agriculture ◽  
Early Blight ◽  
Physiological Status ◽  
Disease Development ◽  
Spectral Features ◽  
Non Destructive ◽  
Non Destructive Characterization

In-vivo foliar spectroscopy, also known as contact hyperspectral reflectance, enables rapid and non-destructive characterization of plant physiological status. This can be used to assess pathogen impact on plant condition both prior to and after visual symptoms appear. Challenging this capacity is the fact that dead tissue yields relatively consistent changes in leaf optical properties, negatively impacting our ability to distinguish causal pathogen identity. Here, we used in-situ spectroscopy to detect and differentiate Phytophthora infestans (late blight) and Alternaria solani (early blight) on potato foliage over the course of disease development and explored non-destructive characterization of contrasting disease physiology. Phytophthora infestans, a hemibiotrophic pathogen, undergoes an obligate latent period of two–seven days before disease symptoms appear. In contrast, A. solani, a necrotrophic pathogen, causes symptoms to appear almost immediately when environmental conditions are conducive. We found that respective patterns of spectral change can be related to these differences in underlying disease physiology and their contrasting pathogen lifestyles. Hyperspectral measurements could distinguish both P. infestans-infected and A. solani-infected plants with greater than 80% accuracy two–four days before visible symptoms appeared. Individual disease development stages for each pathogen could be differentiated from respective controls with 89–95% accuracy. Notably, we could distinguish latent P. infestans infection from both latent and symptomatic A. solani infection with greater than 75% accuracy. Spectral features important for late blight detection shifted over the course of infection, whereas spectral features important for early blight detection remained consistent, reflecting their different respective pathogen biologies. Shortwave infrared wavelengths were important for differentiation between healthy and diseased, and between pathogen infections, both pre- and post-symptomatically. This proof-of-concept work supports the use of spectroscopic systems as precision agriculture tools for rapid and early disease detection and differentiation tools, and highlights the importance of careful consideration of underlying pathogen biology and disease physiology for crop disease remote sensing.

scholarly journals First Report of Alternaria alternata Causing Leaf Blight of Potatoes in South Africa

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 363-363 ◽  
Author(s):  
J. E. van der Waals ◽  
B. E. Pitsi ◽  
C. Marais ◽  
C. K. Wairuri
Keyword(s):  
South Africa ◽  
Alternaria Alternata ◽  
Early Blight ◽  
Leaf Blight ◽  
Morphological Identification ◽  
High Humidity ◽  
Surfactant Mixture ◽  
First Report ◽  
Potato Plants ◽  
Severe Infections

During recent growing seasons, a new leaf blight was observed on potatoes (Solanum tuberosum L.) in various production regions in South Africa. Symptoms were observed before early blight, from 50 to 60 days after emergence of the potato plants. Typical leaf symptoms were small, circular, brown lesions, first visible on the abaxial sides of leaves. Lesions resembled those of early blight, but were smaller and did not show concentric rings. During favorable environmental conditions, severe infections were seen as coalesced lesions and blighted leaves and stems. Such severe infections occurred in seasons when high humidity, leaf wetness, and warm temperatures were present. Yield losses as much as 40% were reported on approximately 50 20-ha pivots in various potato-growing regions, particularly Ceres, Eastern Free State, KwaZulu Natal, and Mpumalanga, due to this leaf blight because conventional fungicidal spray programs did not adequately control the disease. Isolations from leaf lesions were made on V8 juice agar under aseptic conditions. The fungus, Alternaria alternata (Fr.) Kreissler, was consistently isolated and preliminarily identified on the basis of morphological characteristics. Dark brown conidia were produced in chains on conidiophores. Conidia had short beaks and ranged from 20 to 60 × 9 to 18 μm. Morphological identification was confirmed by amplification of the internal transcribed spacer (ITS) region. Primers used were AAF2 (5′-TGCAATCAGCGTCAGTAACAAAT-3′) and AAR3 (5′-ATGGATGCTAGACCTTTGCTGAT-3′), specifically designed for identification of A. alternata (4). PCR products were sequenced and the identity of isolates confirmed by a BLAST search on the GenBank database. Koch's postulates were conducted by inoculation of healthy potato leaves of cv. BP1. Spores at a concentration of 106 spores per ml were suspended in an oil/surfactant mixture and sprayed onto leaves until runoff. Control plants were sprayed with a sterile oil/surfactant mixture until runoff. Plants were covered by polyethylene bags for 2 days to achieve high humidity levels and maintained in a greenhouse at 25 ± 2°C. Three days after inoculation, plants were exposed to a moisture regimen simulating that of in-field irrigation. Plants were placed in a fogging chamber twice a week for 1 h at a time. Leaf blight symptoms similar to those observed on diseased potato plants in the field began to develop 3 weeks after inoculation. Isolations made from these lesions consistently yielded A. alternata. Control plants did not develop any symptoms. Five plants were used for each treatment and the experiment was repeated twice. Leaf blight on potatoes caused by A. alternata has previously been reported in Israel, (2), Brazil (1), and North America (3). To our knowledge, this is the first report of A. alternata causing leaf blight on potatoes in South Africa. Future research will focus primarily on management of this disease. References: (1) L. S. Boiteux and F. J. B. Reifschneider. Plant Dis. 78:101. 1994. (2) S. Droby et al. Phytopathology 74:537, 1984. (3) W. W. Kirk et al. Plant Dis. Manage. Rep. 2:V065:1, 2007. (4) P. Konstantinova et al. Mycol. Res. 106:23, 2002.

scholarly journals Economic effectiveness of using fungicides in the protection of potato against Phytophthora infestans and Alternaria spp.

2021 ◽  
Vol 61 (3) ◽  
pp. 239-245
Keyword(s):  
Phytophthora Infestans ◽  
Tuber Yield ◽  
Plant Protection ◽  
Meteorological Conditions ◽  
Economic Effectiveness ◽  
Potato Blight ◽  
Chemical Treatments ◽  
Causative Agents ◽  
Protected Object ◽  
Orientation Index

The aim of the research carried out in 2014–2016 at the Plant Breeding and Acclimatization Institute in Jadwisin was to assess the economic effectiveness of the use of fungicides in combating the causative agents of potato blight and alternaria on plants of four edible potato varieties with different resistance to Phytophthora infestans. The experiment included two objects: control – without chemical protection and protection – in which from 3 to 5 chemical treatments were performed. In the protected object obtained increase of yield of tubers was 20.4%. The value of saved production amounted to an average of 4.181.8 zł/ha. In the years of research in which meteorological conditions favored the development of late blight and alternaria, high profitability of using fungicides was found. Orientation index of profitability (E2) was in the range of 2.5–4.0, which means that the performed plant protection treatment constituted from 2.5 to 4.0% of the value of the obtained tuber yield per 1 hectare.

Sign in / Sign up

Export Citation Format

Share Document