Populus is an effective model for genetic studies in trees. The genus Populus includes dioecious species, and the differences exhibited in males and females have been intensively studied. This review focused on the distinctions between male and female poplar and aspen plants under stress conditions, such as drought, salinity, heavy metals, and nutrient deficiency on morphological, physiological, proteome, and gene expression levels. In most studies, males of Populus species were more adaptive to the majority of the stress conditions and showed less damage, better growth, and higher photosynthetic capacity and antioxidant activity than that of the females. However, in two recent studies, no differences in non-reproductive traits were revealed for male and female trees. This discrepancy of the results could be associated with experimental design: different species and genotypes, stress conditions, types of plant materials, sampling sizes. Knowledge of sex-specific differences is crucial for basic and applied research in Populus species.

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Flax is grown worldwide for seed and fiber production. Linseed varieties differ in their oil composition and are used in pharmaceutical, food, feed, and industrial production. The field of application primarily depends on the content of linolenic (LIN) and linoleic (LIO) fatty acids. Inactivating mutations in the FAD3A and FAD3B genes lead to a decrease in the LIN content and an increase in the LIO content. For the identification of the three most common low-LIN mutations in flax varieties (G-to-A in exon 1 of FAD3A substituting tryptophan with a stop codon, C-to-T in exon 5 of FAD3A leading to arginine to a stop codon substitution, and C-to-T in exon 2 of FAD3B resulting in histidine to tyrosine substitution), three approaches were proposed: (1) targeted deep sequencing, (2) high resolution melting (HRM) analysis, (3) cleaved amplified polymorphic sequences (CAPS) markers. They were tested on more than a thousand flax samples of various types and showed promising results. The proposed approaches can be used in marker-assisted selection to choose parent pairs for crosses, separate heterogeneous varieties into biotypes, and select genotypes with desired homozygous alleles of the FAD3A and FAD3B genes at the early stages of breeding for the effective development of varieties with a particular LIN and LIO content, as well as in basic studies of the molecular mechanisms of fatty acid synthesis in flax seeds to select genotypes adequate to the tasks.

1 Институт молекулярной биологии им. В.А. Энгельгардта Российской академии наук, Москва, Россия 2 Российский университет дружбы народов, Москва, Россия Тополь широко используется в озеленении Москвы благо-даря способности эффективно очищать воздух от вредных примесей и выделять большое количество кислорода. Роду Тополь (Populus) свойствен высокий уровень внутривидо-вого полиморфизма, а также наличие естественных меж-видовых гибридов. Целью на стоящей работы была оценка генетического разнообразия тополей, растущих на терри-тории города Москвы, с использованием высокопроизво-дительного секвенирования внутренних транскрибируе-мых спейсеров генов 45S рРНК (ITS-последовательностей). На платформе Illumina (MiSeq) проведено секвенирование ITS-по следовательностей 40 растений тополя и в среднем получено около 3 000 прочтений для каждого образца. Биоинформатиче ская обработка данных проведена с использованием программы CLC Genomics Workbench. Исследованная выборка тополей имела высокий уровень генетического разнообразия: число выявленных в каждом генотипе однонуклеотидных полиморфизмов (SNP) от-носительно референсных последовательностей ITS1 и ITS2 P. trichocarpa варьировало от 4 до 44. Показано, что даже деревья, посаженные на одной территории и, вероятно, в одно время, зна чительно различаются генетически. Можно предположить, что при посадке тополей в Москве исполь-зовался крайне полиморфный растительный материал. Для некоторых сайтов c SNP у одного и того же индивидуума выявлено несколько вариантов нуклеотидов, соотношение которых было различным. Мы предполагаем, что соот-ношение, близкое к 50/50, наблюдается в межвидовых гибридах и является следствием генетических различий в ITS-по следовательностях между материнским и отцовским Poplars are widely used in landscaping of Moscow due to the ability to effectively purify the air from harmful impurities and to release a large amount of oxygen. The genus Populus is characterized by a high level of intraspecies polymorphism, as well as the presence of natural interspecies hybrids. The aim of our work was to evaluate the genetic diversity of poplars, which are growing on the territory of Moscow city by high-throughput sequencing of internal transcribed spacers of 45S rRNA genes (ITS sequences). Sequencing of ITS of 40 poplar plants was performed on Illumina platform (MiSeq) and about 3 000 reads were obtained for each sample in average. Bioinformatics analysis was performed using CLC Genomics Workbench tool. The involved set of poplars had a high level of genetic diversity -the number of single nucleotide polymorphisms (SNPs) detected in each genotype relative to the reference ITS1 and ITS2 sequences of P. trichocarpa varying from 4 to 44. We showed that even trees which had been planted on the same territory and, probably, at the same time had significant genetic differences. It can be speculated that highly polymorphic plant material was used for planting poplars in Moscow. For some sites with SNPs, several variants of nucleotides were found in the same individual and the ...

Flax (Linum usitatissimum L.) is attacked by numerous devastating fungal pathogens, including Colletotrichum lini, Aureobasidium pullulans, and Fusarium verticillioides (Fusarium moniliforme). The effective control of flax diseases follows the paradigm of extensive molecular research on pathogenicity. However, such studies require quality genome sequences of the studied organisms. This article reports on the approaches to assembling a high-quality fungal genome from the Oxford Nanopore Technologies data. We sequenced the genomes of C. lini, A. pullulans, and F. verticillioides (F. moniliforme) and received different volumes of sequencing data: 1.7 Gb, 3.9 Gb, and 11.1 Gb, respectively. To obtain the optimal genome sequences, we studied the effect of input data quality and genome coverage on assembly statistics and tested the performance of different assembling and polishing software. For C. lini, the most contiguous and complete assembly was obtained by the Flye assembler and the Homopolish polisher. The genome coverage had more effect than data quality on assembly statistics, likely due to the relatively low amount of sequencing data obtained for C. lini. The final assembly was 53.4 Mb long and 96.4% complete (according to the glomerellales_odb10 BUSCO dataset), consisted of 42 contigs, and had an N50 of 4.4 Mb. For A. pullulans and F. verticillioides (F. moniliforme), the best assemblies were produced by Canu–Medaka and Canu–Homopolish, respectively. The final assembly of A. pullulans had a length of 29.5 Mb, 99.4% completeness (dothideomycetes_odb10), an N50 of 2.4 Mb and consisted of 32 contigs. F. verticillioides (F. moniliforme) assembly was 44.1 Mb long, 97.8% complete (hypocreales_odb10), consisted of 54 contigs, and had an N50 of 4.4 Mb. The obtained results can serve as a guideline for assembling a de novo genome of a fungus. In addition, our data can be used in genomic studies of fungal pathogens or plant–pathogen interactions and assist in the management of flax diseases.