Молекулярная диагностика заражения некоторых молдавских сортов томата фитоплазмой.

Relevance. The use of molecular methods allows reliable and fast determination of the resistance of genotypes (varieties) to pathogens, thereby reducing possible product losses and, at the same time, maintaining its environmental safety. It is very important in conditions of increasing demand for high-quality agricultural production. Aim: Using molecular diagnosis of ʹCandidatus Phytoplasma solaniʹ to compare the degree of infection in some Moldavian tomato varieties at different stages of plant development.Material and methods. The molecular analysis (nested-PCR) of plants of the four Moldavian tomato varieties (Elvira, Cerasus, Mary Gratefully, Desteptarea) created at the Institute of Genetics, Physiology and Plant Protection, and the wild formSolanum habrochaites, was carried out for the presence of the phytopathogen ʹCa. P. solaniʹ. Researches were made during two growing seasons. Results. The distribution of infection between the studied varieties was different in the process of plants development. The spread of infection in the tomato field was recorded under the climatic conditions of two growing seasons: the season of 2018, which was hot but with normal rains in the middle of summer, and the season of 2019, in conditions of a very hot and dry summer. During both seasons, Cerasus variety manifested the highest resistance to ʹCa. P. solaniʹ infection.  A little more than half of plants of this variety were affected by stolbur only at the end of the growing season, after harvesting most of the crop. Varieties Elvira and Desteptarea had similar levels of infection of plants with phytoplasma during two years of research. These varieties manifested a higher sensitivity to phytoplasma infection compared with Cerasus. Mary Gratefully was the genotype with the highest dependence of the sensitivity toʹCa. P. solaniʹ infection from the climatic conditions of the growing season. Plants of the wild form Solanum habrochaites demonstrated complete immunity to phytoplasma infection during the growing season. Conclusion.The Cerasus variety, as well as the wild form Solanum habrochaites, can be recommended for including in breeding programs for the creating tomato varieties or hybrids resistant to phytoplasma. Thus, molecular diagnosis may be a useful tool for the breeding resistant genotypes. Актуальность. Применение молекулярных методов позволяет более надежно и быстро определять устойчивые к патогенам генотипы (сорта), сокращая, таким образом, возможные потери продукции и, при этом, сохраняя её экологическую безопасность. Это очень важно в условиях возрастающего спроса на качественные сельскохозяйственные продукты. Цель: использование молекулярной диагностики ʹCandidatus Phytoplasma solaniʹ для сравнения степени заражения некоторых молдавских сортов томата на разных стадиях развития растений. Материалы и методика. В течение двух сезонов вегетации был проведен молекулярный анализ (нестед-ПЦР) растений четырех молдавских сортов томата (Elvira, Cerasus, Mary Gratefully, Desteptarea), созданных в Институте Генетики, Физиологии и Зашиты Растений, и дикой формы Solanum habrochaites, на присутствие фитопатогена ʹCa. P. solaniʹ. Результаты. Обнаружено, что распределение инфекции между изученными сортами было различным в процессе развития растений. Учет распространения инфекции на томатном поле проводили в климатических условиях двух сезонов вегетации: сезона 2018 года, который был жарким, но с нормальным количеством осадков в середине лета, и сезона 2019 года, в условиях очень жаркого и засушливого лета. В течение обоих сезонов сорт Cerasus проявил наибольшую устойчивость к инфекции ʹCa. P. solaniʹ, немногим более половины растений этого сорта были поражены столбуром только в конце периода вегетации, после сбора основной части урожая. Сорта Elvira и Desteptarea имели сходные показатели уровня зараженности растений фитоплазмой в течение двух лет исследований. Эти сорта проявили гораздо большую чувствительность к фитоплазменной инфекции по сравнению с сортом Cerasus. Единственным генотипом, чувствительность которого к инфекцииʹCa. P. solaniʹсильно зависела от климатических условий сезона вегетации, оказался сорт Mary Gratefully. Растения дикой формы Solanum habrochaites проявили полную невосприимчивость к фитоплазменной инфекции в течение всего периода вегетации. Выводы.Сорт Cerasus, наряду с дикой формой Solanum habrochaites, может быть рекомендован для включения в селекционные программы по созданию устойчивых к фитоплазме сортов или гибридов томата. Молекулярная диагностика может служить полезным инструментом в процессе селекции устойчивых генотипов.

Simple sequence repeats in Neurospora crassa: distribution, polymorphism and evolutionary inference

<p>Abstract</p> <p>Background</p> <p>Simple sequence repeats (SSRs) have been successfully used for various genetic and evolutionary studies in eukaryotic systems. The eukaryotic model organism <it>Neurospora crassa </it>is an excellent system to study evolution and biological function of SSRs.</p> <p>Results</p> <p>We identified and characterized 2749 SSRs of 963 SSR types in the genome of <it>N. crassa</it>. The distribution of tri-nucleotide (nt) SSRs, the most common SSRs in <it>N. crassa</it>, was significantly biased in exons. We further characterized the distribution of 19 abundant SSR types (AST), which account for 71% of total SSRs in the <it>N. crassa </it>genome, using a Poisson log-linear model. We also characterized the size variation of SSRs among natural accessions using Polymorphic Index Content (PIC) and ANOVA analyses and found that there are genome-wide, chromosome-dependent and local-specific variations. Using polymorphic SSRs, we have built linkage maps from three line-cross populations.</p> <p>Conclusion</p> <p>Taking our computational, statistical and experimental data together, we conclude that 1) the distributions of the SSRs in the sequenced N. crassa genome differ systematically between chromosomes as well as between SSR types, 2) the size variation of tri-nt SSRs in exons might be an important mechanism in generating functional variation of proteins in <it>N. crassa</it>, 3) there are different levels of evolutionary forces in variation of amino acid repeats, and 4) SSRs are stable molecular markers for genetic studies in <it>N. crassa</it>.</p

Molecular diagnosis of phytoplasma infection in some Moldavian tomato varieties

Relevance. The use of molecular methods allows reliable and fast determination of the resistance of genotypes (varieties) to pathogens, thereby reducing possible product losses and, at the same time, maintaining its environmental safety. It is very important in conditions of increasing demand for high-quality agricultural production. Aim: Using molecular diagnosis of ʹCandidatus Phytoplasma solaniʹ to compare the degree of infection in some Moldavian tomato varieties at different stages of plant development.Material and methods. The molecular analysis (nested-PCR) of plants of the four Moldavian tomato varieties (Elvira, Cerasus, Mary Gratefully, Desteptarea) created at the Institute of Genetics, Physiology and Plant Protection, and the wild formSolanum habrochaites, was carried out for the presence of the phytopathogen ʹCa. P. solaniʹ. Researches were made during two growing seasons. Results. The distribution of infection between the studied varieties was different in the process of plants development. The spread of infection in the tomato field was recorded under the climatic conditions of two growing seasons: the season of 2018, which was hot but with normal rains in the middle of summer, and the season of 2019, in conditions of a very hot and dry summer. During both seasons, Cerasus variety manifested the highest resistance to ʹCa. P. solaniʹ infection.  A little more than half of plants of this variety were affected by stolbur only at the end of the growing season, after harvesting most of the crop. Varieties Elvira and Desteptarea had similar levels of infection of plants with phytoplasma during two years of research. These varieties manifested a higher sensitivity to phytoplasma infection compared with Cerasus. Mary Gratefully was the genotype with the highest dependence of the sensitivity toʹCa. P. solaniʹ infection from the climatic conditions of the growing season. Plants of the wild form Solanum habrochaites demonstrated complete immunity to phytoplasma infection during the growing season. Conclusion.The Cerasus variety, as well as the wild form Solanum habrochaites, can be recommended for including in breeding programs for the creating tomato varieties or hybrids resistant to phytoplasma. Thus, molecular diagnosis may be a useful tool for the breeding resistant genotypes