Gain of an autoregulatory site in one paralog led to the divergence of two duplicate genes in the time, space, and level of expression and regulation of one par

Gelidocalamus xunwuensis W.G.Zhang & G.Y.Yang, a new species collected from Xunwu County of Jiangxi Province in China, is described and illustrated. The new species is similar to G. stellatus in the habit, but differs by internodes sparsely hairy with granuliferous warts, culm sheath stiffly hairy, culm sheath blade broadly lanceolate to narrowly triangular, each node with a ring of appressed trichomes below, foliage leaves broadly lanceolate to narrowly oblong, and new shoots occurring in late October. Gelidocalamus xunwuensis W.G.Zhang & G.Y.Yang, a new species collected from Xunwu County of Jiangxi Province in China, is described and illustrated. The new species is similar to G. stellatus in the habit, but differs by internodes sparsely hairy with granuliferous warts, culm sheath stiffly hairy, culm sheath blade broadly lanceolate to narrowly triangular, each node with a ring of appressed trichomes below, foliage leaves broadly lanceolate to narrowly oblong, and new shoots occurring in late October.

The genus Gelidocalamus T. H. Wen, endemic to southern China, is a small but taxonomically problematic genus of Arundinarieae (Poaceae, Bambusoideae). During field work, a population of Gelidocalamus from Zixing, Hunan, was discovered, appearing to be distinct from our previously identified collection. Comparisons of the population of Zixing were performed by using scanning electron microscopy (SEM) and a plastid genome-based phylogeny. Morphologically, it was mostly similar to G. multifolius, but differed by culm leaf erect with densely white pubescence, apical branch sheath much longer than the internodes and foliage leaf larger. Phylogenetically, the new species was well-supported as a sister to the clade of G. multifolius + G. tessellatus, and the above three taxa were clustered in the Shibataea clade (IV) of Arundinarieae. Thus, the new species, formally named as Gelidocalamus zixingensis W.G.Zhang, G.Y.Yang & C.K.Wang, was described and illustrated herein.

Summary: Bamboo with its remarkable growth rate and economic significance, offers an ideal system to investigate the molecular basis of organogenesis in rapidly growing plants, particular in monocots, where gene regulatory networks governing the maintenance and differentiation of shoot apical and intercalary meristems remain a subject of controversy. We employed both spatial and single‐nucleus transcriptome sequencing on 10× platform to precisely dissect the gene functions in various tissues and early developmental stages of bamboo shoots. Our comprehensive analysis reveals distinct cell trajectories during shoot development, uncovering critical genes and pathways involved in procambium differentiation, intercalary meristem formation, and vascular tissue development. Spatial and temporal expression patterns of key regulatory genes, particularly those related to hormone signaling and lipid metabolism, strongly support the hypothesis that intercalary meristem origin from surrounded parenchyma cells. Specific gene expressions in intercalary meristem exhibit regular and dispersed distribution pattern, offering clues for understanding the intricate molecular mechanisms that drive the rapid growth of bamboo shoots. The single‐nucleus and spatial transcriptome analysis reveal a comprehensive landscape of gene activity, enhancing the understanding of the molecular architecture of organogenesis and providing valuable resources for future genomic and genetic studies relying on identities of specific cell types.

Five taxa of Delphinium subg. Anthriscifolium have been karyologically studied through chromosome counting, chromosomal measurement, and karyotype symmetry. Each taxon that we investigated has a basic chromosome number of x = 8, D. anthriscifolium var. savatieri, D. anthriscifolium var. majus, D. ecalcaratum, and D. callichromum were diploid with 2n = 16, while D. anthriscifolium var. anthriscifolium was tetraploid with 2n = 32. Monoploid chromosome sets of the investigated diploid taxa contained 1 metacentric chromosome, 3 submetacentric chromosomes, and 4 subtelocentric chromosomes. Higher interchromosomal asymmetry (CVCL) was present in D. ecalcaratum and D. callichromum than in other taxa. The highest levels of intrachromosomal asymmetry (MCA) and heterogeneity in centromere position (CVCI) were found in D. anthriscifolium var. majus. Diploid and tetraploid genome sizes varied by 3.02–3.92 pg and 6.04–6.60 pg, respectively. Karyotype and genome size of D. anthriscifolium var. savatieri, D. anthriscifolium var. majus, D. callichromum, and D. ecalcaratum were reported for the first time. Finally, based on cytological and morphological data, the classification of Delphinium anthriscifolium was revised.