Variation in aggressiveness is detected among Puccinia triticina isolates of the same pathotype and clonal lineage in the adult plant stage

Puccinia triticina reproduces asexually in France and thus individual genotype is the unit of selection. A strong link has been observed between genotype identities (as assessed by microsatellite markers) and pathotypes (pools of individuals with the same combination of qualitative virulence factors). Here, we tested whether differences in quantitative traits of aggressiveness could be detected within those clonal lineages by comparing isolates of identical pathotype and microsatellite profile. Pairs of isolates belonging to different pathotypes were compared for their latent period, lesion size and spore production capacity on adult plants under greenhouse conditions, with a high number of replicates. Isolates of the same pathotype showed remarkably similar values for the measured traits, except in three situations: differences were obtained within two pathotypes for latent period and within one pathotype for sporulation capacity. One of these differences was tested again and confirmed. This indicates that the average aggressiveness level of a leaf rust pathotype may increase without any change in its virulence factors or microsatellite profile

Emergence of Poplar Diseases or the “Arms Race” between Breeders and Diseases (Abstract)

Poplar cultivation is an example of highly artificialized and intensive woody plant production (clonal and evenaged cultivation) that resembles crop production more than it does forest production. Since the 19th century, breeders have created poplar varieties, especially interspecific hybrids selected on the basis of agronomic criteria (speed of growth, wood volume, straightness of stem, quality of wood). Because of the compromise between growth and resistance classically described for plants, the poplar cultivars have become a target of choice for many diseases (bacterial canker, scab, leaf blight, rust, Dothichiza, viral disease, etc.) and pests (borer, Saperda, wooly aphid, hornet moth, weevil, etc.). European poplar cultivation experienced several health crises in the 20th century that led breeders to select new varieties on the criterion of resistance to the main diseases. As a result, there were periods of massive use of certain varieties endowed with satisfactory resistance to a disease that were subsequently gradually abandoned as it became apparent that they were too susceptible to another emerging or re-emerging disease. In the particular case of poplar rust caused by the fungus Melampsora larici-populina, we have documented the existence of cycles in the use of certain varieties resistant to rust. Because the fungus is able to circumvent qualitative poplar resistance, a number of wholly resistant varieties became susceptible after just a few years of cultivation. We have shown that the implementation on a regional scale of certain poplar varieties that carry qualitative resistances had structured the M. larici-populina populations on the scale of France. In this way, the varietal distribution of poplar trees has influenced pathogen distribution. These feedback loops between host populations (poplar stands) and pathogen populations are similar to models of host/pathogen co-evolution with an “arms race” between the poplar tree (via breeders and poplar tree farmers) and the pathogens

Развитие мобильной учебной среды по высшей математике в подготовке инженеров-электромехаников

Дисертація на здобуття наукового ступеня кандидата педагогічних наук за спеціальністю 13.00.10 – інформаційно-комунікаційні технології в освіті. – Інститут інформаційних технологій та засобів навчання НАПН України. У роботі досліджено проблему розвитку та використання мобільного навчального середовища з вищої математики у підготовці інженерів-електромеханіків. Проведено комплексний аналіз підготовки бакалаврів електромеханіки у ВНЗ та зроблено висновок про те, що підвищення якості математичної підготовки бакалаврів електромеханіки забезпечується професійною спрямованістю навчання та використанням сучасних засобів ІКТ. Проведено аналіз сучасних засобів ІКТ, що використовуються в навчанні вищої математики бакалаврів електромеханіки. Уточнено поняття мобільного навчального середовища та розвитку мобільного навчального середовища з вищої математики. Удосконалено структуру мобільного навчального середовища з вищої математики та визначено напрями його розвитку. За допомогою сервісу Google Apps Education Edition сформовано мобільне навчальне середовище з вищої математики та розроблено методику його використання у підготовці інженерів-електромеханіків. Розроблено методичні рекомендації для викладачів щодо створення та використання мобільного навчального середовища з вищої математики та методичні вказівки для студентів з використання мобільного навчального середовища з вищої математики.Thesis for Candidate of Pedagogical Sciences Degree awarding on the speciality 13.00.10 – information and communication technologies in education. – Institute of Information Technologies and Learning Tools of NAPS of Ukraine. In this thesis, the problem of creating and developing a mobile learning environment in higher mathematics in the training of Electromechanics Engineers is analyzed. A complex research of conversion bachelors in electrical mechanics in Ukrainian universities is made, and it is concluded that improving the quality of mathematical training of bachelors in electrical mechanics is achieved by professional orientation of learning and usage of modern ICT tools. The analysis of modern ICT tools used in learning higher mathematics bachelors in electromechanics is made. The concept of mobile learning environment is clarified. The model of the mobile learning environment in higher mathematics and the ways of its development are made. A mobile learning environment in higher mathematics based on Google Apps Education Edition and methodic of its usage in training Electromechanics Engineers are created. Methodical recommendations in organization of the educational process with the usage of mobile learning environment in higher mathematics for teachers and students are made.Диссертация на соискание ученой степени кандидата педагогических наук по специальности 13.00.10 – информационно-коммуникационные технологии в образовании. – Институт информационных технологий и средств обучения НАПН Украины. В работе исследуется проблема развития и использования мобильной учебной среды по высшей математике в подготовке инженеров-электромехаников. Проведенный анализ дал возможность уточнить базовые понятия исследования: 1) мобильная учебная среда – это учебная среда, использование которой направлено на удовлетворение учебных потребностей субъектов обучения в любое время и в любом месте; 2) развитие мобильной учебной среды по высшей математике – прогрессивное, необратимое и закономерное изменение составляющих этой среды (содержания обучения высшей математики и средств поддержки учебной деятельности), направленное на учет особенностей развития сферы будущей профессиональной деятельности студентов. Под методикой использования мобильного учебной среды по высшей математике в подготовке инженеров-электромехаников будем понимать нормативную модель процесса использования среды, развитие которой направлено на удовлетворение учебных потребностей мобильных субъектов обучения на основе комплексного применения мобильных средств ИКТ обучения. Структурно методика использования мобильной учебной среды по высшей математике состоит из трех компонентов: целевого, содержательно-технологического и результатного. Формирование мобильной учебной среды по высшей математике осуществлялось с помощью Google Apps Education Edition, в котором можнао реализовать все выделенные направления использования ИКТ в обучении высшей математике: подача учебных ведомостей, выполнение вычислений и визуализации математических зависимостей, формирование умений и навыков проведения учебных математических исследований, автоматизация контроля и оценивание учебных достижений студентов по высшей математике, поддержка учебной деятельности студентов, организация самостоятельной работы студентов

Genetic diversity and origins of the homoploid type hybrid Phytophthora×alni

Assessing the process that gives rise to hybrid pathogens is central to understanding the evolution of emerging plant diseases. Phytophthora xalni, a pathogen of alder, results from the homoploid hybridization of two related species, Phytophthora uniformis and Phytophthora xmultiformis. Describing the genetic characteristics of P. xalni should help us understand how reproductive mechanisms and historical processes shaped the population structure of this emerging hybrid pathogen. The population genetic structure of P. xalni and the relationship with its parental species were investigated using 12 microsatellites and one mitochondrial DNA (mtDNA) marker on a European collection of 379 isolates. Populations of P. xalni were dominated by one multilocus genotype (MLG). The frequency of this dominant MLG increased after the disease emergence together with a decline in diversity, suggesting that it was favored by a genetic mechanism such as drift or selection. Combined microsatellite and mtDNA results confirmed that P. xalni originated from multiple hybridization events that involved different genotypes of the progenitors. Our detailed analyses point to a geographic structure that mirrors that observed for P. uniformis in Europe. The study provides more insights on the contribution of P. uniformis, an invasive species in Europe, to the emergence of Phytophthora-induced alder decline. IMPORTANCE Our study describes an original approach to assess the population genetics of polyploid organisms using microsatellite markers. By studying the parental subgenomes present in the interspecific hybrid P. xalni, we were able to assess the geographical and temporal structure of European populations of the hybrid, shedding new light on the evolution of an emerging plant pathogen. In turn, the study of the parental subgenomes permitted us to assess some genetic characteristics of the parental species of P. xalni, P. uniformis, and P. xmultiformis, which are seldom sampled in nature. The subgenomes found in P. xalni represent a picture of the "fossilized" diversity of the parental species