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Pseudosasa subsolida belongs to the Pseudosasa genus within the Poaceae family. Due to its unique flowering cycle and the physiological traits associated with asexual reproduction, acquiring floral material from P . subsolida is particularly challenging. To investigate the causes of the low seed set rate in P. subsolida, floral organs and the development of male and female gametes were examined using conventional paraffin sectioning. The results revealed that the spikelet of P . subsolida exhibited the characteristics of a pseudospikelet with a latent bud, while the inflorescence displayed traits of an infinite inflorescence. Each spikelet contained approximately 10–16 florets and was accompanied by two bracts at its base. The fundamental structure of the florets comprised one lemma, one palea, three lodicules, three stamens, and one pistil. At the later stages of anther development, some abnormalities were observed, including the failure of pollen grains to form, deformation and shrinkage of the cells in the anther sac and tapetum, loss of the cells in the middle layer, cavitation of the microspores, and no identifiable contents The study concluded that the primary factor contributing to the low seed setting rate of P . subsolida was the aberrant development of male gametophytes. The significance of this study lay in its pioneering exploration of the reproductive structure of P . subsolida , and provide a theoretical reference for the fundamental examination of flower structure.

Key message Not only the first systematic characterization of CAO gene in bamboo species, but also the first attempt to study the relationship between CAO gene expression and bamboo leaf color variation. Chlorophyllide a oxygenase (CAO) converts chlorophyllide (Chlide) a to Chlide b and hence plays an important role in chlorophyll (Chl) b biosynthesis. In this study, a cDNA of a CAO homologue designated PjCAO was isolated from Pseudosasa japonica cv. Akebonosuji that is a cultivar of high ornamental value in landscape due to its unique green-white striped leaf phenotype. The full-length cDNA of PjCAO was 2070 bp long with a 1626 bp open reading frame that encoded 541 amino acids. Multiple sequence alignment for amino acid showed that the putative PjCAO protein shared a high sequence similarity with CAO homologues from other plant species and consisted of four conserved parts, an amino-terminal transit peptide and three individual domains, namely, A, B, and C domain. Further, PjCAO was overexpressed in Arabidopsis thaliana ; and the Chl b contents of these PjCAO -overexpressed plants were much higher than that of wild-type plants, thereby indicating its important role in Chl b synthesis. Reverse transcription real time quantitative polymerase chain reaction revealed that PjCAO was ubiquitously expressed in all the 14 tissue samples collected from P. japonica cv. Akebonosuji. Specifically, it was expressed at higher levels in 12 leaf samples than in culms and roots. Moreover, the expression of PjCAO kept increasing during the development of white, striped, and green leaf samples, thus indicating its potential role in leaf development. In addition, the expression levels of PjCAO in leaf samples within almost the same developmental stages fell into two distinct classes: high expression levels in green, and almost green with some white stripes samples; and low expression levels in white, and almost white with some green stripes samples. Collectively, these expression data suggest that PjCAO may be involved in the leaf color variation for P. japonica cv. Akebonosuji.

Bamboo forest healthcare tourism is a practical and sustainable management model that utilizes the medicinal functions of bamboo. However, the mechanism and potential functions of bamboo’s healthcare functions are still unclear. In this study, the volatile organic compounds (VOCs) that are the core factor of bamboo forest healthcare were analyzed. The foliar VOCs of eight bamboo species, including Pleioblastus amarus (Keng) P. C. Keng, Pleioblastus maculatus (McClure) C. D. Chu et C. S. Chao, Pleioblastus juxianensis T. H. Wen, C. Y. Yao et S. Y. Chen, Acidosasa chienouensis (T. H. Wen) C. S. Chao et T. H. Wen, Pseudosasa amabilis (McClure) P. C. Keng ex S. L. Chen et al., Pseudosasa amabilis (McClure) Keng f., Phyllostachys rubromarginata McClure, and Phyllostachys hirtivagina G. H. Lai were qualitatively and semi-quantitatively analyzed by headspace solid-phase microextraction (HS-SPME)–gas chromatography–mass spectrometry (GC-MS). Screening compounds by aroma vitality value (OAV) determined the key aromas. The results showed that a total of 40 VOCs were identified from the leaves of the eight bamboo species. The compounds with relatively high content were (Z)-3-Hexen-1-ol, (E)-2-Hexen-1-ol, 1-Hexanol, (E, E)-2,4-Hexadienal, Limonene, and so on. The commonality of different bamboo species was that the dominant groups consisted of alcohols and aldehydes. The significant differences in leaf VOCs among species presented classification. Pleioblastus amarus, Acidosasa chienouensis, Pseudosasa amabilis, and Phyllostachys rubromarginata were noticeably clustered together. The aroma of bamboo leaves is a combination of grassy, fruity, and piney notes by 24 VOCs. The key aroma from Pleioblastus amarus is leaf alcohol, which contributes to the grassy scent, while the piney aroma is dominant in Pseudosasa amabilis and Phyllostachys rubromarginata. The study provides a reference value for enriching the chemical information of subtropical bamboo and developing the functional potential of bamboo forest healthcare tourism.

Sasa oblongula was described in 1987 based on a cultivated plant at the bamboo garden of Sun Yat-sen University. This species has two or three branches at the upper nodes, which differ from the rest of Sasa species that have a single branch per node. During the field trip to Baishi Town, Yunfu City, Guangdong Province in July 2021, one bamboo species with oblong foliage leaves was collected and matches the isotype. Then, our question was to test the identity of S. oblongula concerning other Sasa species based on morphology and molecular data. To do that, we sequenced the whole chloroplast genome of S. oblongula and did a phylogenetic analysis. Our morphological results indicate that the new collection is S. oblongula . The phylogenetic tree showed that S. oblongula is close to Pseudosasa , instead of Sasa species. Therefore, we transferred it to the genus Pseudosasa , and a revised description of P. oblongula is provided here.

Pseudosasa usawae is an endemic species in Taiwan, and grows at an altitude of 600-1200 m. In this study, we fully characterized the complete chloroplast genome of P. usawae. The complete chloroplast sequence was 139,660 bp, including large single-copy (LSC), small single-copy (SSC), and a pair of invert repeats (IR) region of 83,271, 12,803, and 21,793 bp. Besides, the plastid genome comprised a total of 129 genes, including protein-coding, tRNA, and rRNA genes as 83, 38, and 8 genes. Phylogenetic analysis reveals that P. usawae is closely associated with Phyllostachys genus clade, sister to the lineage of Phyllostachys.

Summary Pith cavity formation is critical for bamboo to overcome the bending force during its fast growth; however, the underlying molecular mechanisms remain largely unknown. Multiple approaches, including anatomical dissection, mathematical modelling and transcriptome profiling, were employed in this study to investigate the biology of pith cavity formation in bamboo Pseudosasa japonica. We found that the corruption of pith tissue occurred sequentially and asymmetrically from the top‐centre of the internode down to the bottom, which might be caused by the combined effects of asymmetrical radial and axial tensile forces during shoot‐wall cell elongation and spiral growth of bamboo internodes. Programmed cell death (PCD) in pitch manifested by TUNEL positive nuclei, DNA cleavage and degraded organelles, and potentially regulated by ethylene and calcium signalling pathway, ROS burst, cell wall modification, proteolysis and nutrient recycle genes, might be responsible for pith tissue corruption of Ps. japonica. Although similar physiological changes and transcriptome profiles were found in different bamboo species, different formation rates of pith cavity were observed, which might be caused by different pith cells across the internode that were negatively correlated with the culm diameter. These findings provided a systematical view on the formation of bamboo pith cavity and revealed that PCD plays an important role in the bamboo pith cavity formation.

Pseudosasa nanunica , a bamboo endemic to Guangdong and Hunan provinces, China, has a complicated taxonomic history due to lack of information on its floral morphology. It was initially described as a member of Indocalamus , and later successively transferred to Pseudosasa , Arundinaria and Acidosasa by different researchers. With the newly collected reproductive materials, we confirmed that this species is characterized by having branch complement with 1–3 branches per node, branch base appressed to the culm, narrowly trullate culm bud, panicle-like unit of inflorescence of the synflorescence and each floret with three stamens and three stigmas, which match well with the diagnostic characters of Pseudosasa . After comparison with similar congeneric species, we concluded that it is a distinct species of Pseudosasa . A supplementary description on its floral morphology as well as two color plates and a diagram of its synflorescence is also provided.

In angiosperms, NADPH: protochlorophyllide oxidoreductase (POR) catalyzes the photoreduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), the only light-dependent step in chlorophyll biosynthesis. There is a wide variety of gene organization and light- and development-dependent regulatory mechanisms for the POR genes. In this study, a POR homologue, designated PjPORB , was isolated from Pseudosasa japonica cv. Akebonosuji, which is a cultivar of high ornamental value in landscape due to its unique green-white striped leaf phenotype. The full-length PjPORB cDNA was 1567 bp long with a 1185 bp ORF that encoded 394 amino acids. Multiple amino acid sequence alignment showed that the putative PjPORB shared a high similarity to POR homologues from other plant species, and that the cofactor (NADPH)-binding motif and active site motif in particular were highly conserved among all the PORs. Further, PjPORB was overexpressed in Arabidopsis thaliana ; and the Pchlide contents of the genetically modified plants were reduced to a larger extent than that of wild type plants, thereby indicating its important role in Pchlide photoreduction. In real-time quantitative RT-PCR analysis, PjPORB was expressed at higher levels in leaf samples than in culms and roots, and showed a first increasing-then decreasing expression pattern during the development of white, stripe, and green leaf samples, thus indicating its essential role in leaf development. Although the mRNA levels for PjPORB did not differ considerably among white, stripe, and green leaf samples within the two almost same earlier developmental stages, its expression levels in the late leaf developmental stage fell into two distinct classes: high expression levels in strip and green leaf samples, and low expression levels in white leaf. Collectively, these expression data suggested that PjPORB may be involved in the leaf color variation for P. japonica cv. Akebonosuji.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions of taxa in the genera Bunias , Calocedrus , Calycanthus , Celosia , Clerodendrum , Convolvulus , Crassula , Cyclamen , Datura , Dicliptera , Eragrostis , Erigeron , Gamochaeta , Gazania , Impatiens , Kolkwitzia , Leucaena , Ludwigia , Medicago , Muscari , Nigella , Oenothera , Opuntia , Paulownia , Petroselinum , Phyllostachys , Physalis , Pseudosasa , Quercus , Reynoutria , Roldana , Saccharum , Sedum , Semiarundinaria , Senecio , Sisyrinchium , Solanum , Sporobolus , Tulipa , Vachellia , Verbena , and Youngia . Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Urban greening is the most effective way to regulate the microclimate environment and thermal discomfort. However, despite being an important type of vegetation, relatively few studies have investigated the effect of bamboo on microclimate characteristics and thermal comfort. In this study, the microclimate characteristics and the differences in the thermal comfort provided by common bamboo communities in East China were investigated in summer and winter, and the effects of canopy structure characteristics on microclimate and thermal comfort were analyzed. The results showed that there were significant differences in microclimate between bamboo communities and the control check in summer, but the differences in air temperature in winter were not obvious. In the daytime during summer, the maximum daily average temperature of the bamboo community decreased by 2.6 °C, and the maximum temperature–humidity index (THI) decreased by 1.1 °C. In the daytime during winter, the maximum daily average temperature increased by 0.5 °C and the maximum THI increased by 0.8 °C. Among the different bamboo communities, Sinobambusa tootsik var. laeta and Pseudosasa amabilis had better effects on improving microclimate and thermal comfort, while the effects of Phyllostachys nigra and Phyllostachys heterocycla ‘Pubescens’ were relatively small. Aspects of canopy structure, especially leaf area index and canopy coverage, had the greatest influence on the microclimate environment, while air temperature made the greatest contribution to thermal comfort. The goal of our study is to quantify the data to confirm the role of bamboo in improving urban climate problems and human comfort and to further select the appropriate bamboo species for urban green spaces and to utilize the ecological benefits of bamboo to optimize the human living environment.