scholarly journals Preemergence Infection of Potato Sprouts by Phytophthora infestans in the Highland Tropics of Ecuador

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Peter Kromann ◽  
Arturo Taipe ◽  
Jorge L. Andrade-Piedra ◽  
Lisa Munk ◽  
Gregory A. Forbes
Keyword(s):  
Disease Management ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Seed Potato ◽  
Soil Surface ◽  
Potato Tubers ◽  
Potato Plants ◽  
Management Approaches

Experiments were conducted to determine whether preemergence infection of potato sprouts by Phytophthora infestans occurs in the highland tropics of Ecuador. In three separate experiments in the field, P. infestans was identified on the preemerged sprouts of 49, 5, and 43% of tubers, respectively, which had been removed from soil prior to emergence. Tubers had been planted within 10 m of approximately 300-m2 plots with mature potato plants severely infected with late blight. Infection potential of potato sprouts also was evaluated in the greenhouse by applying 10-ml sporangial suspensions (50 and 250 sporangia/ml) daily for 10 days to the soil surface of pots planted with sprouted seed potato tubers. The daily inoculation rate of 50 sporangia/ml (15.9 × 103 sporangia/m2) resulted in sprout infection in 100% of inoculated pots and roughly corresponded to the sporangial deposition accumulated over 24 h in the field. Deposition had been measured at 1 m from a severely infected potato plot. Our study demonstrated the potential for preemergence infection of potato sprouts by P. infestans in the highlands of Ecuador, where year-round aerial inoculum is present. Preemergence infection is consistent with high levels of disease sometimes seen in recently emerged potato fields. These experiments indicate a need to reconsider disease management approaches.

scholarly journals Sprinkling Irrigation Enhances Production of Oospores of Phytophthora Infestans in Field-Grown Crops of Potato

2000 ◽  
Vol 90 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Yigal Cohen ◽  
Sonja Farkash ◽  
Alexander Baider ◽  
David S. Shaw
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Field Experiments ◽  
Soil Surface ◽  
Field Trials ◽  
Detached Leaves ◽  
Oospore Formation ◽  
Potato Crops ◽  
Host Tissues

Two field experiments were conducted to study the effect of overhead sprinkling irrigation on oospore formation by the late blight fungus Phytophthora infestans in potato. Total rain (natural + sprinkling) accumulated in treatments of experiment 1 (winter 1997 to 1998) were 765, 287, and 219 mm and treatments of experiment 2 (winter 1999 to 2000) were 641, 193, and 129 mm. Sporangia from 11 isolates of P. infestans were combined in eight pairs, seven of A1 and A2 and one of A2 and A2 mating type, and were sprayed on field-grown potato crops (42 plants per plot at 7 m2 each) and examined for their ability to form oospores in the host tissues. In experiment 1, oospores were recorded in a total of 132 of 1,680 leaflets (7.9%), 24 of 105 stems, and 2 of 90 tubers. In experiment 2, oospores were recorded in 40 of 519 leaflets (7.7%), but not in any of the 90 stems or the 45 tubers examined. Both the proportion of leaflets containing oospores and the number of oospores per leaflet increased with time after inoculation and were dependent on the rain regime, the position of leaves on the plant, and the isolate pair combination. In both field trials, increasing the rainfall significantly enhanced oospore production in leaves. Leaf samples collected from the soil surface had significantly more oospores than those collected from the midcanopy. Two pairs in experiment 1 were more fertile than the others, whereas the pair used in experiment 2 was the least fertile. The total number of oospores per leaflet usually ranged from 10 to 100 in experiment 1, but only from 2 to 10 in experiment 2. Maximal oospore counts in the field were 200 and 50 in experiments 1 and 2, respectively, but ranged from ≈2,000 to 12,000 oospores per leaflet in detached leaves in the laboratory. We concluded that P. infestans can produce oospores in the foliage of field-grown potato crops, especially when kept wet by regular overhead sprinkling irrigation, but production was far below that in the laboratory.

scholarly journals Агробиологические аспекты производства семенного картофеля с многослойной мульчей из мискантуса

2020 ◽  
Author(s):  
V.A. Nikolaev ◽  
N.F. Khokhlov ◽  
A.A. Anisimov ◽  
I.G. Tarakanov
Keyword(s):  
Seed Potato ◽  
Soil Surface ◽  
Potato Yield ◽  
Potato Plants ◽  
Miscanthus Giganteus ◽  
Russian State ◽  
Russian Agriculture ◽  
Giant Miscanthus ◽  
Control Variant ◽  
Number Of Stems

Показаны результаты сравнительного анализа эффективности выращивания семенного картофеля при размещении клубней в нижнюю часть мульчирующего слоя биомассы мискантуса гигантского (Miscanthus giganteus) культуры, площади которой начали активно увеличиваться на территории Российской Федерации. Цель исследования поиск способов получения качественного посадочного материала семенного картофеля при возделывании в Центральном регионе РФ с применением мульчирования мискантусом, поскольку один из основных факторов низкой урожайности картофеля в отечественных хозяйствах использование собственного зараженного посадочного материала. Исследования проводили методом полевого эксперимента в 20182019 годах на Полевой опытной станции РГАУ МСХА имени К.А. Тимирязева. Изучали два способа посадки картофеля традиционная на гребни (контроль), и высадка в мульчу. Опыт заложен в четырехкратной повторности, учетная площадь 8 м2. Лучшее сочетание факторов для роста и развития растений при мульчировании мискантусом привело к увеличению урожайности наряду с повышением доли здоровых семенных клубней. Использование биомассы мискантуса в качестве мульчи для выращивания семенного картофеля привело к увеличению выхода здоровых кондиционных посадочных клубней. В контроле, без использования мульчи, 55 клубней оказались поражены серебристой паршой. Кроме того, мульчирование способствовало увеличению содержания влаги в верхнем слое почвы (010 см) в фазу бутонизации картофеля по сравнению с традиционным способом посадки почти в два раза. У растений картофеля, выращенных при мульчировании, число стеблей на 1 га увеличилось на 12,9 тыс. шт. по сравнению с контрольным вариантом. В среднем за два года прибавка урожайности картофеля от мульчирования составила 15,2 т/га. Кроме того, мульчирование привело к увеличению выхода семенных клубней, доля которых составила 41,6 от общей массы клубней при 30,5 в контроле. Таким образом, способ возделывания семенного картофеля с многослойной мульчей при полосном размещении мискантуса обладает высоким потенциалом к использованию в хозяйствах для получения собственного здорового посадочного материала.The results of the comparative analysis of the seed potato cultivation efficiency with the use of soil surface mulching with the above-ground biomass of giant miscanthus (Miscanthus giganteus) a rare crop for Russian agriculture, which is beginning to spread now. The aim of the research is the searching of the methods of the qualitative seed potato getting while growing it the central part of Russian Federation with the mulching by the miscanthus biomass. One of the main factors of low yields in Russia is the usage of own infested seed potato. The researches were conducted by the means of field experiment during the vegetation seasons of 2018 and 2019 years on the territory of the Field experimental station of Russian State Agrarian University Moscow Timiryazev Agricultural Academy. Two ways of potato planting traditional in the ranges (the control variant), and planting in the miscanthus mulch. The experiment was planned with the 4 recurrences, the registrative area was 8 m2. The usage of miscanthus biomass as a mulch for seed potato growing lead for obtaining of the healthy conditional planting tubers. In the control variant, without mulching, 55 of all tubers were affected by Helminthosporium solani. The use of miscanthus biomass mulching contributed the increase of the soil moisture in the upper layer of the soil (010 sm) comparing with the traditional way of potato planting almost in 2 times. The potato plants grown with the miscanthus biomass mulching the number of stems on 1 ha increased by 12,9 thousand comparing with the control variant. The maximum potato yield 40,7 t/ha was marked in the variant with the miscanthus biomass mulch usage. Mulching also lead to the increase of the number of seed tubers, the part of them was 40,4 from the whole biomass. Hereby the giant miscanthus biomass can be recommended as a mulching material for the plantations of seed potato, the use of it leads to the increase of the seed potato yield and decrease the growth of the number of diseases, which can contaminate the potato plantations in the traditional way of cultivation.

scholarly journals Development of Real-Time Isothermal Amplification Assays for On-Site Detection of Phytophthora infestans in Potato Leaves

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1269-1277 ◽  
Author(s):  
Mélissa Si Ammour ◽  
Guillaume J. Bilodeau ◽  
David Mathieu Tremblay ◽  
Hervé Van der Heyden ◽  
Thaer Yaseen ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Real Time ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Closely Related Species ◽  
Potato Plants ◽  
Crude Plant Extract ◽  
Time Loop ◽  
Potato Pathogens

Real-time loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) assays were developed targeting the internal transcribed spacer 2 region of the ribosomal DNA of Phytophthora infestans, the potato late blight causal agent. A rapid crude plant extract (CPE) preparation method from infected potato leaves was developed for on-site testing. The assay’s specificity was tested using several species of Phytophthora and other potato fungal and oomycete pathogens. Both LAMP and RPA assays showed specificity to P. infestans but also to the closely related species P. andina, P. mirabilis, P. phaseoli, and P. ipomoeae, although the latter are not reported as potato pathogen species. No cross-reaction occurred with P. capsici or with the potato pathogens tested, including P. nicotianae and P. erythroseptica. The sensitivity was determined using P. infestans pure genomic DNA added into healthy CPE samples. Both LAMP and RPA assays detected DNA at 50 fg/μl and were insensitive to CPE inhibition. The isothermal assays were tested with artificially inoculated and naturally infected potato plants using a Smart-DART platform. The LAMP assay effectively detected P. infestans in symptomless potato leaves as soon as 24 h postinoculation. A rapid and accurate on-site detection of P. infestans in plant material using the LAMP assay will contribute to improved late blight diagnosis and early detection of infections and facilitate prompt management decisions.

scholarly journals Arabidopsis late blight: Infection of a nonhost plant by Albugo laibachii enables full colonization by Phytophthora infestans

2015 ◽  
Author(s):  
Khaoula Belhaj ◽  
Liliana M. Cano ◽  
David C. Prince ◽  
Ariane Kemen ◽  
Kentaro Yoshida ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Molecular Mechanisms ◽  
Transcriptional Profiling ◽  
Unexpected Finding ◽  
Potato Plants ◽  
Nonhost Plant ◽  
Gene Expression Dynamics ◽  
Oomycete Pathogen ◽  
Arabidopsis Cells

AbstractThe oomycete pathogen Phytophthora infestans causes potato late blight, and as a potato and tomato specialist pathogen, is seemingly poorly adapted to infect plants outside the Solanaceae. Here, we report the unexpected finding that P. infestans can infect Arabidopsis thaliana when another oomycete pathogen, Albugo laibachii, has colonized the host plant. The behaviour and speed of P. infestans infection in Arabidopsis pre-infected with A. laibachii resemble P. infestans infection of susceptible potato plants. Transcriptional profiling of P. infestans genes during infection revealed a significant overlap in the sets of secreted-protein genes that are induced in P. infestans upon colonisation of potato and susceptible Arabidopsis, suggesting major similarities in P. infestans gene expression dynamics on the two plant species. Furthermore, we found haustoria of A. laibachii and P. infestans within the same Arabidopsis cells. This Arabidopsis - A. laibachii - P. infestans tripartite interaction opens up various possibilities to dissect the molecular mechanisms of P. infestans infection and the processes occurring in co-infected Arabidopsis cells.

scholarly journals Phomous rot is a dangerous disease of potato tubers

2019 ◽  
pp. 28-32
Author(s):  
V. Polozhenets ◽  
L. Nemerytska
Keyword(s):  
Seed Potato ◽  
Microbiological Diagnosis ◽  
Potato Tubers ◽  
Potato Varieties ◽  
Potato Plants ◽  
Flowering Phase ◽  
Development Cycle ◽  
Economically Valuable Traits ◽  
Dark Color ◽  
First Time

Goal. To establish the symptoms of pathogens of fomose rot on potato varieties of different resistance, to isolate pathogens from the genus Phoma, parasitizing on tubers and stems of plants. Methods. Symptoms of phomotic rot were determined visually by the determinant of diseases and the method of microbiological diagnosis was used. Pathogens were isolated from stems and tubers affected by fomose rot. Results. On the basis of psychopathological examination, it was experimentally proved for the first time in Ukraine that fomozna potato rot is widespread in commodity and seed potato plantings. The degree of harmfulness reaches 35%. Pathogens of the genus Phoma (Ph. Solanicola Prill. Et Del Ph tuberosa Malkomcon) affect potato stems and tubers. On the stems, the first symptoms appear as spots during the flowering phase of the plants, and on tubers the gangrene appears as round, depressed and hard spots, light or dark brown in color, on the top of which pycnids form. According to the harmfulness of the pathogen, the Polesye of Ukraine is divided into three zones: 1. The zone of strong development includes the Volyn and Zhytomyr regions, where the number of affected plants with phomosis exceeds 5%, affected tubers — 8—10%; 2. The zone of moderate development, it includes the Rivne and Khmelnitsky regions, where the number of plants affected by phomosis is 2—3%, and tubers during storage of the crop — 5—7%; 3. The zone of insignificant development of the disease includes Kiev and Chernihiv regions, where the number of plants affected by gangrene is up to 2%, and tubers after storage of the crop — up to 4%. Conclusions. According to the results of psychopathological surveys, three zones of development of fomose rot of potatoes (severe, moderate and minor damage to phomosis) were identified and a scheme for the development cycle of the infection of the genus Phoma (Solanicola Prill. et. Del. And Ph. Tuberosa Melh.) was established. Symptoms of fomose rot appear on the stems in the form of elongated blurry spots, on which pycnids form from light brown (Eurostar) to dark brown (Riviera) color. On potato tubers, fomosis appears in the form of round, hard, sunken spots of a dark color. It is proved that during the interaction of potato plants with pathogens of the genus Phoma complex physiological, biochemical and pathological processes occur that significantly reduce productivity, quality, taste and other economically valuable traits.

scholarly journals Effects of Tuber Depth and Soil Moisture on Infection of Potato Tubers in Soil by Phytophthora infestans

Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 146-152 ◽  
Author(s):  
L. D. Porter ◽  
N. Dasgupta ◽  
D. A. Johnson
Keyword(s):  
Soil Moisture ◽  
Phytophthora Infestans ◽  
Soil Type ◽  
Soil Depth ◽  
Soil Surface ◽  
Fine Sand ◽  
Silt Loam ◽  
Potato Plants ◽  
Tuber Infection ◽  
Zoospore Formation

The effects of tuber depth, soil type, and soil moisture on potato tuber infection due to Phytophthora infestans were assessed under greenhouse conditions in soil contained in large pots. Healthy tubers were used to assess infection and were either hand buried in soil at specific depths or naturally formed from potato plants growing in the soil. A spore suspension of P. infestans was chilled to induce zoospore formation and a suspension of resulting zoospores and sporangia were applied to the soil. Soil depth at which tubers became infected was used to determine the extent of spore movement in the soils. Tuber infection significantly decreased with increasing soil depth. Most infected tubers were found at the surface of soil; infection was rare on tubers at 5 cm or deeper in the soil. Amount of tuber infection varied among soil types. Significantly less tuber infection occurred in a Shano silt loam than in medium and fine sands. Only tubers on the soil surface were infected in the Shano silt loam. Depth in soil at which tubers became infected did not differ significantly among Quincy fine sand, Quincy loamy fine sand, and Quincy medium sand. Increased soil moisture did not significantly increase the soil depth at which tuber infection occurred, regardless of the soil type.

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