In Brno, at St Thomas Abbey where he worked, Mendel cultivated a grapevine. In 1913, cuttings of the grapevine were given to Prof Manabu Miyoshi of the University of Tokyo in thanks for financial contribution from Japanese botanists towards the construction of a monument honoring Mendel at Brno. Ever since, Mendel’s grapevine has been thriving at the Koishikawa Botanical Garden of the University of Tokyo. During the Soviet Union domination of Czechoslovakia after WW II, the grapevine was lost from the Abbey. After democratization, cuttings from the grapevine were sent back to the Botanical Garden of Mendel University at Brno, following a request from residents. I confirmed the growth of Mendel’s grapevine when I visited Brno in 1999. The story of Mendel’s grapevine has attracted attention from around the world.

This study conducted a comprehensive karyotype analysis of Cirsium (Compositae) species in Taiwan to elucidate their taxonomic relationships. This study investigated 12 known Cirsium taxa indigenous to Taiwan. Notably, detailed karyotype analyses of all Taiwanese taxa are reported for the first time, with the karyotypes of four taxa, C. ferum, C. japonicum var. fukienense, C. suzukii, and C. arisanense f. purpurescens, documented for the first time in this study. The chromosome numbers of Taiwanese Cirsium species mostly had a configuration of 2n=34, although instances of 2n=30 and 2n=32 were also observed. The karyotype analysis revealed differences in karyotype structures, asymmetry, and presence of satellite chromosomes between the taxa; these three characteristics are thus of considerable taxonomic import. To further explore karyotypic diversity among Taiwanese Cirsium species, this study used the unweighted pair group method with the arithmetic mean method in a cluster analysis and implemented principal component analysis. Our findings offer novel insights into the classification of Cirsium species and emphasize the critical role of satellite chromosomes in taxonomy, particularly for C. suzukii, C. taiwanense, and C. ferum.

Tradescantia spathacea (2n=2x=12) and T. pallida (2n=4x=24), two species of Tradescantia L., were the subjects of a comprehensive meiotic investigation. The genus appears highly interesting as a tool for studying complex chromosomal rearrangements. During meiosis, both species showed diverse multivalent arrangements with two distinct orientations—adjacent and alternating. Some meiotic anomalies, including chromosome stickiness, unequal distribution during anaphase, lagging chromosomes, chromosomal fragments, and chromosomal bridges, were observed as a result of adjacent orientation, inappropriate spindle apparatus functioning, and paracentric inversions. Despite these irregularities, over 95% of pollen fertility was recorded in both species. This is most likely due to the evolution of permanent translocation heterozygosity (PTH) in Tradescantia. Our study contributes to the knowledge of intricate chromosomal arrangements in the genus Tradescantia for further cytogenetic research.

Quinoa (Chenopodium quinoa Willd.) is gaining attention as both a promising food resource and a genetic model for stress-resilient crops; however, its substantial genetic diversity remains largely untapped. In this study, we identified a novel genomic region associated with betalain pigmentation that may contribute to stress tolerance and environmental adaptation in quinoa, using bulked segregant analysis and a fully de novo assembled chromosome-scale genome of quinoa line J131. We identified the first 2 Mb of the chromosome 1B pseudomolecule of J131 as a candidate region associated with pigmentation. Within this region, 35 predicted functional genes were identified, including a tandem gene cluster comprising CqCYP76AD1 and CqDODA1, key genes involved in betalain biosynthesis. A PCR marker adjacent to this cluster completely co-segregated with the pigmentation phenotype in an F₂ population. This gene cluster is embedded within rRNA gene repeats and is absent from three previously published chromosome-scale quinoa genomes—QQ74, J075, and J100. We identified additional homologs of CqCYP76AD1 and CqDODA1 in other genomic regions that may contribute to variation in pigmentation intensity and tissue-specific patterns. Our results underscore the importance of structural variation in lineage-specific trait evolution and demonstrate how high-quality chromosome-scale assemblies enable the detection of hidden genomic features. This is the first study to link visible phenotypic traits in quinoa to differences in genome structure through direct comparison of multiple chromosome-level assemblies. Our findings highlight the potential of graph-based pan-genome approaches for systematically exploring structural diversity and its phenotypic consequences.

Chromatin remodeling complexes regulate gene expression through nucleosome repositioning, thereby controlling plant development and stress responses. Among these, the SWI/SNF ATPase BRAHMA (BRM) plays a pivotal role in transcriptional regulation and hormone signaling, yet its spatial localization across organs has remained unclear. Here, we investigated the expression and subcellular localization of BRM using a translational reporter line (pBRM::BRM-GFP) in Arabidopsis thaliana. Confocal imaging revealed that BRM-GFP accumulates in the nuclei of all root cell layers, with strong enrichment at the base of lateral root primordia. In leaves, BRM-GFP was detected in mesophyll, guard, and petiole epidermal cells after tissue clearing. Co-localization with EdU staining showed that BRM distribution is independent of the cell-cycle phase or endoreduplication. These findings provide a comprehensive view of BRM localization patterns and suggest that SWI/SNF remodeling contributes to transcriptional and developmental regulation in plants.

This report focuses on the meiotic process during microsporogenesis in wild populations of Hordeum bulbosum L. (Poaceae), which were sampled in Algeria. This species is known for its natural vegetative propagation via bulbs. Pollen mother cells (PMCs) at various stages were treated with basic fuchsin to study meiotic behavior, and mature pollen was stained with a aniline blue dye to assess viability. The analyzed samples were confirmed to be diploid (2n=2x=14, based on x=7) and exhibited regular-looking meiosis with seven bivalents at metaphase and four microspores at the end of division. The pollen was also found to be relatively viable (85.55% and 89.7%). The presence of univalents in some pollen mother cells (0.58% and 0.31%) may indicate a genetic isolation mechanism in the species. Conversely, the presence of tetravalents (0.17% and 4.81%) suggests heterozygosity for a reciprocal translocation. The analyses revealed several abnormalities at low frequencies (with cumulative rates ranging from 5.71 to 6.63%). These abnormalities included laggards, chromatin bridges, micronuclei, unoriented bivalents, asynchronous divisions, syncytia, triads, and cytomixis. However, these cytogenetic findings alone do not appear to explain the species’ low caryopsis production (ranging from 46.62 to 49.3%) or its reliance on asexual reproduction through bulbs. The report discusses other potential biological mechanisms that may contribute to this reduced fertility.

Aneuploidy, characterized by an alteration in the normal chromosomal number, disrupts genomic stability and can negatively affect organismal fitness by reducing fertility and causing developmental abnormalities. In the genus Impatiens L. (Balsaminaceae), aneuploidy is relatively common and may contribute to genetic diversity and reproductive variation. Somatic chromosome counts ranged from 2n=12 to 2n=20, indicating the occurrence of both aneuploid and diploid cytotypes. In this study, cytomorphological observations were conducted on 18 accessions representing seven species of Impatiens L., collected from riparian habitats along the Beas River, Himachal Pradesh, India, at altitudes ranging from 1,000 to 3,000 m. Among these, seven new aneuploid cytotypes were documented for the first time worldwide in the following species: I. amphorata (2n=12, 16), I. balsamina (2n=16), I. brachycentra (2n=18, 20), I. glandulifera (2n=14), and I. laxiflora (2n=12). Intraspecific cytotypic variation was evident, suggesting chromosomal instability and potential hybridization. Meiotic irregularities—such as laggards, chromosomal stickiness, bridges, and abnormal microsporogenesis—were frequently observed, contributing to reduced pollen viability, which ranged from 65.47 to 97.84%. These findings underscore the importance of aneuploidy and meiotic irregularities in shaping genetic diversity, adaptation, and speciation in Impatiens L., and provide valuable cytogenetic data to support taxonomic classification and conservation strategies in the Himalayan biodiversity hotspot.

The present work uses mitotic and meiotic studies to validate the cytotype of Diplazium esculentum (Retz.) Sw found in Kerala, India. Emerging crozier tips at various developmental stages were used for observing the mitotic chromosomes, pretreated with paradichlorobenzene, and stained with acetoorcein. The chromosome count from the young crozier tip is a novel report in this plant, confirming the occurrence of 82 chromosomes in its diploid state. Meiotic studies on sporophyll from various plant samples verified that the haploid number, n=41. Using a modified protocol, the mitotic chromosomal number from the crozier tip is a new report and it confirms the previous reports of cytological data.

Chromosome numbers and karyotypes of four species of Aspiditra endemic to Guangxi, China, are reported here for the first time. A. alternativa and A. jingxiensis share the same karyotype formula of 2n=38=22m+4sm+12st. The karyotype of A. punctatoides is formulated as 2n=38=20m+6sm+12st, and A. sinensis also has the same karyotype.