Biology subjects

KOSINA, R.

Publications and source records attributed to KOSINA, R..

5 recordsLinked to original sources

bioRxiv2026

Acellular starch domains in the endosperm of wheat and oat

The transformation of the free nuclear syncytium into cellular endosperm tissue with starch and protein accumulation is a well-established phenomenon, at least in the fruits of cereals of the Triticeae tribe. The present article demonstrates that there is considerable diversity inherent in this type of caryopsis morphogenesis. By examining various taxa (species, varieties, and cultivars) of wheat, oats, and some wild grasses, this research reveals significant deviations in endosperm morphogenesis from the typical state. A new developmental pattern of endosperm was identified, characterized by several distinctive features such as incomplete cellularization of the syncytium and starch accumulation within the acellular endosperm domains and the endosperm cavity. A large number of plastids were observed in the syncytium stage, which served as the basis for the later amyloplast stage. The acellular endosperm domains and the cavity domain exhibited connections at specific discontinuities in the modified aleurone layer surrounding the cavity. The peripheral parts of the caryopsis received fewer assimilates necessary for starch synthesis, which was attributed to their increased distance from the transfer system and a likely reduction in the efficiency of assimilate transport through the apoplast in these areas. The starch cavity volume constituted a few percent of the overall caryopsis volume, which could serve as a foundation for potential breeding improvements to enhance starch yields across different varieties.

plant biology↗

bioRxiv2024

Multi-character assessment of caryopsis in diverse common wheat germplasm,including high protein breeds

In 15 varieties and hybrids of common wheat, including high-protein, varieties such as Atlas 66, Nap Hal, and Lancota, the microstructural characters of the caryopsis were analysed. Among the wheats, a high variability in the correlation matrices of characters was observed. A variable relationship between the specific gravity of the caryopsis and the size of the endosperm cavity was demonstrated. Some principal components (I, II, IV and V) contained the majority of the information regarding the weight, quality, vitreousness, and aleurone layer of the caryopsis, respectively. In the ordination space of nonmetric multidimensional scaling (nmMDS), two groups of wheat were distinguished: high-protein and low-protein subaleurone layers. Endosperm morphotypes were characterised by the proportion of two types of starch tissue, cylindric and isodiametric. In the nmMDS ordination space, wheat was described by the frequency distributions of six endosperm cavity morphotypes, with more (leptokurtosis) or less (platykurtosis) cumulated variation. In the case of endosperm developmental anomalies, the intrusive growth of cell walls, particularly in the aleurone layer, was identified as playing a significant role in the formation of endosperm mosaic architecture and domains. Varietal developmental specificity was discovered in the development of acellular starch domains within the endosperm tissue and starch grain storage in the cavity (as observed in cv. Purdue).

plant biology↗

bioRxiv2022

Synanthropic flora in the vicinity of the mediaeval Castle Kolno, Stare Kolnie near Brzeg, southwestern Poland

The mediaeval castle Kolno situated near the village Stare Kolnie served as a custom house at the confluence of two rivers, Budkowiczanka and Stobrawa. Numerous diaspores of plants were obtained from the archaeological excavations, from the layers of the 14th-15th centuries A.D. The excavations were located near the former access road, where increased human activity has affected the composition of the fossil macroremains of plants. Two species of cabbage cultivated in small fields near the castle were recognised. Diaspores of weeds and ruderal plants were deposited at the site. The most frequent were: Solanum nigrum, Setaria pumila, Chenopodium album, Rumex acetosella, Polygonum lapathifolium and Urtica dioica. The botanical set of fossil diaspores was composed of plant species associated with anthropogenic habitats and showing the dispersion dynamics in various micro-niches within them.

plant biology↗

bioRxiv2021

Variability of pollen grains quality in oat amphiploids and their parental species

The reproductive potential of oat species and their hybrid progeny (amphiploids) was evaluated during three vegetation seasons. Morphotypes and viability of pollen grains were described by means of correlations and regression, while relationships between taxa were analysed with the use of numerical taxonomy methods. Size of pollen grains varied between the growing seasons, but the relations between the taxa appeared to be stable. Viability of pollen grains was environmentally modified and showed no correlation with pollen length. In an ordination space, amphiploids were discriminated from parental species. In both group of plants, a positive correlation between the pollen size and the level of ploidy was maintained; however, along a regression line, amphiploids were located among species with a high level of ploidy and were extreme units deviating from the regression line. Developmental anomalies of pollen grains had a low frequency, with the formation of micrograins being the most common event. Such a pattern of development can prove that some pollen grains were chromosomally unbalanced. Anomalous morphotypes of pollen were more common in hybrid types than in species, including pollens with many poruses, which were found only in amphiploids. Frequencies of multiporate grains and micropollens were strongly correlated. In an ordination space, monoporate types (species) were discriminated from multiporate types (amphiploids). In general, the high level of pollen viability in amphiploids can prove their genomic stabilisation through many generations of their reproduction.

plant biology↗

bioRxiv2021

Cytogenetic events in the endosperm of amphiploid Avena maroccana x A. longiglumis

This study analysed cytogenetic events occurring in the syncytial endosperm of the Avena maroccana Gand. x Avena longiglumis Dur. amphiploid, which is a product of two wild species having different genomes. Selection through the elimination of chromosomes and their fragments, including those translocated, decreased the level of ploidy in the endosperm below the expected 3n, leading to the modal number close to 2n. During intergenomic translocations, fragments of the heterochromatin-rich C-genome were transferred to the A and Al genomes. Terminal and non-reciprocal exchanges dominated, whereas other types of translocations, including microexchanges, were less common. Using two probes and by counterstaining with DAPI, the A. longiglumis and the rare exchanges between the A and Al genomes were detected by GISH. The large discontinuity in the probe labelling in the C chromosomes demonstrated inequality in the distribution of repetitive sequences along the chromosome and probable intragenomic rearrangements. In the nucleus, the spatial arrangement of genomes was non-random and showed a sectorial-concentric pattern, which can vary during the cell cycle, especially in the less stable tissue like the hybrid endosperm.

genetics↗