卷 110, 编号 1 (2025)

The general ideas that determine the structure of the embryo are discussed. A comparative analysis of the classifications of the endospermogenesis and embryogenesis types has shown that the principles of their creation are similar. However, during the endosperm development, the process of separation of the types (cellular and helobial, the latter includes the nuclear endosperm) begins as early as after the second division, and during the formation of the embryo, only after the third division during the formation of the proembryo, i. e. the ontogenetic time of typing differs in both systems. Using these principles, we proposed an original classification of the embryo formation modes. It uses the concept of “megatypes of embryogenesis” and analyzes existing modes and systems of types of embryo development. The data on the Piperad-type have been revised, and a new Orchidad-type has been proposed for orchids, including 3 variations.

After the division of the zygote, patterns of clusters of future types of embryogenesis are outlined: transverse, inclined, irregular (features of the formation of the first and subsequent partitions during the formation of the early embryo), coenocytic (nuclear stage in the development of the early embryo). The main cluster is transverse, which is inherent in most flowering plants. It is accompanied by the formation of apical and basal cells, further divisions of which lead to the formation of two ways of development based on the T-shaped or linear tetrad of cells. In each way, the participation of derivatives of apical and basal cells is different, which leads to the emergence of autonomous types of embryogenesis — Asterad-type, Caryophyllad-type, Chenopodiad-type, Onagrad-type, Solanad-type. The oblique cluster of megatypes is characterized by inclined partitions during the formation of proembryo (Poad-type of embryogenesis), while the irregular cluster is characterized by a combination of longitudinal, oblique, and transverse partitions (Piperad-type of embryogenesis) or a variety of tetrad forms of proembryo and the lack of regularity in the division and fate of basal cell derivatives (Orchidad-type of embryogenesis). The coenocyte cluster is represented by Paeonad-type only.

In contrast to terrestrial species, epiphytic orchids possess water storage elements as an adaptation to dry habitats. Tracheoidal elements are present in roots and are involved in the interaction with mycorrhizal fungi, which colonize orchid roots obligately. Lignified water storage cells are located in the cortex and perform the functional role of water storage. Among the lignified exodermis cells, thin-walled passage cells are present. These elements are essential for the exchange of water between the root and the environment. This study supports existing data indicating that passage cells are the only exodermis cells through which fungal hyphae can pass. It also presents evidence of water storage cells being colonized by mycorrhizal fungi and shows that lignified elements of cortex are less conducive to peloton formation than thin-walled cortex cells.

The pollen morphology of 14 species of the tribe Solaneae (Solanaceae) was studied by light and scanning electron microscopy, of which the pollen of 10 species was described for the first time. The pollen morphology of previously described species is compared with our data. The validity of the inclusion of the previously isolated genera Lycopersicon and Cyphomandra in the genus Solanum, as well as the genus Hebecladus in the genus Jaltomata, is confirmed on the basis of the morphological structure of their pollen grains. Typical pollen grains of the studied species are 3-colporate, spheroidal, medium-sized, the equatorial diameter does not exceed 35 µm. Colpi are long, narrow, and the structure of endoaptures is different. The sculpture of the pollen grain surface is echinate. Pollen grains of genus Solanum are characterized by a 3-lobate outline in polar view, strongly elongated endoapertures with clear equatorial edges, and high density of spinules on pollen grain surface. Pollen grains of the genus Jaltomata are always characterized by a strictly rounded shape in polar view, endoapertures are rounded and weakly pronounced, pollen sizes, structure of apertures and sculpture of pollen grain surface are individualizing features for some of the studied species.

The article provides information on the state of cenopopulations of a rare species Lilium callosum in the vicinity of the villages of Nevelskoye and Argunskoye (Khabarovsk Territory). The characteristics of the phytocenoses in which the cenopopulations occur are given. Data are provided on the number of individuals in the cenopopulations, ecological density (individuals/m²), ontogenetic structure, vitality, as well as morphometric parameters of individuals to assess their condition. The measures for the protection of Lilium callosum are proposed, its cultivation in botanical gardens being considered the most effective one.

The VII All-Russian Scientific Conference with international participation “Algae: Issues on taxonomy and ecology, monitoring and biotechnology approaches” was held in Vladivostok and Primorye Territory from 16 to 20 September 2024. It was organized by the Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS and the A. V. Zhirmunsky National Scientific Center of Marine Biology FEB RAS. The conference was attended by 81 participants from 51 scientific institutions in three countries: Russia (76 participants), Belarus (one), and Iran (four). There were 15 Drs Sci., 63 PhDs, and 27 young scientists (including five postgraduates and four students) among the participants. The results of fundamental and applied research in the field of phycology were reflected in five reports, including one online, during the plenary session, 83 reports, including 21 online ones, during section sessions, and 24 poster presentations. The scientific program of the conference was represented by the following sections: 1) taxonomy and systematics of cyanobacteria and algae, the genetic structure of populations and species, life cycle, and reproduction features (14 reports); 2) biochemistry, physiology, and biotechnology (24 reports); 3) diversity and geography (17 reports); 4) ecology, community structure and functioning, use in environmental quality assessment (21 reports); 5) palaeoalgology and biostratigraphy (two reports).