RNA-seq and phytohormone analysis reveals the culm color variation of Bambusa oldhamii Munro

Background The clumping bamboo Bambusa oldhamii Munro, known as “green bamboo”, is famous for its edible bamboo shoots and fast-growing timber. The green and yellow striped-culm B. oldhamii variety, named B. oldhamii f. revoluta W.T. Lin & J. Y. Lin, is an attractive system for researching the culm color variation of B. oldhamii. Methods Millions of clean reads were generated and assembled into 604,900 transcripts, and 383,278 unigenes were acquired with RNA-seq technology. The quantification of ABA, IAA, JA, GA1, GA3, GA4, and GA7 was performed using HPLC–MS/MS platforms. Results Differential expression analysis showed that 449 unigenes were differentially expressed genes (DEGs), among which 190 DEGs were downregulated and 259 DEGs were upregulated in B. oldhamii f. revoluta. Phytohormone contents, especially GA1 and GA7, were higher in B. oldhamii. Approximately 21 transcription factors (TFs) were differentially expressed between the two groups: the bZIP, MYB, and NF-YA transcription factor families had the most DEGs, indicating that those TFs play important roles in B. oldhamii culm color variation. RNA-seq data were confirmed by quantitative RT-PCR analysis of the selected genes; moreover, phytohormone contents, especially those of ABA, GA1 and GA7, were differentially accumulated between the groups. Our study provides a basal gene expression and phytohormone analysis of B. oldhamii culm color variation, which could provide a solid fundamental theory for investigating bamboo culm color variation.

A new genus of bamboo culm tarantula from Thailand (Araneae, Mygalomorphae, Theraphosidae)

Bamboo plays an important role in the animal world, including providing a nutritious food source, shelter, and habitat. Inside of bamboo culm, we discovered a new genus of tarantula, which we describe here as Taksinusgen. nov. (♂♀). Specimens of this new tarantula were collected from Mae Tho, Mueang Tak district, Tak province, in Thailand, making it geographically distant from any other arboreal genera. Genital morphology was used to diagnose its genus, which is supported by distributional data, natural history, morphological characters, and photographic illustrations of the male and female. Diagnosis of the new genus was determined by distinguishing its different characters from those of other arboreal theraphosid spiders distributed throughout Southeast Asia. This tarantula’s specialization is that it lives in the stalks of the Asian bamboo Gigantochloa sp.

Effect of Rosin Modification on the Visual Characteristics of Round Bamboo Culm

Rosin was used to treat round bamboo culm using the impregnation method. The quantitative color and gloss measurements combined with a qualitative eye tracking experiment were used to evaluate the effect of rosin treatment under different temperatures on the visual characteristics of the bamboo surface. Surface morphology analysis was also used to explore the mechanism of modification. The results showed that proper heating of the modified system was conducive to the formation of a continuous rosin film, which increased the gloss value. The maximum gloss value of 19.6 achieved at 50 °C was 122.7% higher than the gloss value of the control group. Heating decreased the brightness of the bamboo culm and changed the color from the green and yellow tones to red and blue. Additionally, at temperatures higher than 60 °C, the bamboo epidermal layer was damaged or shed, and stripes formed on the culm surface. The density of these stripes increased with an increase in treatment temperature. Eye movement experiment and subjective evaluation showed that high gloss would produce dazzling feeling, such as at 50 °C, while low gloss will appear dim, such as at 80 °C, while the gloss at 40 °C and 60 °C were appropriate. Additionally, the solid color surface below 60 °C had a large audience of about 73%, and the striped surface above 60 °C was preferred by 27% of the subjects.

Veronaea aquatica sp. nov. (Herpotrichiellaceae, Chaetothyriales, Eurotiomycetes) from submerged bamboo in China

Freshwater fungi are highly diverse and ecologically important in freshwater systems. In China, more than 1000 species of freshwater fungi are known. Here, we present a brown-spored hyphomycetes that was collected on a submerged decaying bamboo culm in a forest stream in China. Phylogenetic analyses of combined LSU, ITS and TUB2 sequences confirm the placement of our new strain in Veronaea (Herpotrichiellaceae), sister to V. japonica. Veronaea aquatica sp. nov. differs from related taxa V. compacta and V. japonica in having longer conidiophores and cylindrical to pyriform or subclavate conidia with 0–2 septa. Veronaea aquatica also has darker brown hyphae compared to V. japonica. A morphological description and detailed illustrations of V. aquatica are provided.

Bamboo as a Sustainable Building Material—Culm Characteristics and Properties

Bamboo culm is a renewable and lightweight material with high strength, particularly tensile strength. It is well accepted that bamboo culms have played a significant role in architecture because of their sustainable contribution. The culm characteristics and properties of three-year-old bamboo from five species (Dendrocalamus asper, Dendrocalamus sericeus, Dendrocalamus membranaceus, Thyrsostachys oliveri, and Phyllostachys makinoi) were investigated. The results show that each bamboo species has different culm characteristics along with culm length. Culm size, particularly the outer culm diameter and culm wall thickness, affects the ultimate load. These results confirm that a bigger culm with a thicker wall could receive more load. D. asper received the highest ultimate load, while T. oliveri received the lowest ultimate load. However, when calculating the test results for stress (load per cross-section area), P. Makinoi showed excellent mechanical properties, while D. asper showed the worst mechanical properties. This research promotes bamboo’s appropriate use for building applications and as a more sustainable material for architecture.