The rare plant Primula esquirolii, a karst cave species in the family Primulaceae, endemic to Guizhou, China, and with a presumed extremely small population, had not previously been observed since 1910. It is categorized as Endangered on the China Species Red List. In surveys during 2018–2022, we were unable to locate the species in its type location in Pingba county, but we discovered a previously unrecorded population of 44 mature individuals, 37 of which were long homostylous and seven of which were heterostylous. These individuals were discovered in Xiuwen county in February 2022, in an area of c. 50 m2, c. 40 km from the type location. All seven heterostylous individuals showed the short-styled morph. The almost homostylous P. esquirolii potentially faces the same high genetic load as other homostylous plants, and this may have led to its small population size and potential sensitivity to habitat destruction. Field surveys and informal interviews with local people indicated that the main threats to this species are its small population size and the loss of suitable habitat as a result of human activities. The most urgent requirement for the conservation of this species is to protect the habitat of this single known extant population and to carry out ex situ conservation. Further field surveys and research are also required to improve our understanding of the status of this species.

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Indigofera stachyodes Lindl. is a traditional medicinal plant in southwestern China. In this study, we report the complete chloroplast genome sequence of I. stachyodes , using next-generation sequencing technology. The complete chloroplast genome of I. stachyodes was 158,039 bp in length with an overall GC content 35.80%, containing a large single-copy (LSC) region of 88,772 bp, a small single-copy (SSC) region of 18,733 bp, and a pair of inverted repeats (IRs) regions of 25,267 bp. In total, there are 128 genes (83 protein-coding genes (PCGs), eight ribosomal RNA (rRNA) genes, and 37 tRNA genes) in the whole chloroplast genome, including 113 unique genes (78 unique PCGs, 31 unique tRNAs, and four unique rRNAs). The phylogenetic analysis indicated that I. stachyodes formed a monophyletic clade with I. tinctoria and I. linifolia , showing that they have close relationship. The complete chloroplast genome of I. stachyodes provides valuable genomic information for the phylogeny, molecular identification and sustainable utilization of this species.

Water-soluble polyethylenimine (PEI) was grafted onto the surface of nano-SiO2 particles through the intermedium effect of 4-bromobutyryl chloride, and the water-insoluble SiO2 containing macromolecular quaternary ammonium salts (MQAS/SiO2) was prepared followed by the N-alkylation of coated PEI with 1-bromohexane and idomethane. The results of FT-IR analysis testified that PEI is successfully immobilized on the surface of SiO2 nanoparticles. The minimum inhibitory concentrations of MQAS/SiO2 against Gram-positive bacterium, Staphylococcus aureus, and Gram-negative bacterium, Escherichia coli, are 100ug/ml and 1200ug/ml, respectively. The bactericidal efficiency of exhaustively washed MQAS/SiO2 did not decline significantly compared to the MQAS/SiO2without washing.

Primula jiaozishanensis Z.K.Wu, W.H.Yang & Yuan Wu, a new species of Primulaceae is described and illustrated from Jiaozi Snow Mountain of Dongchuan District, Yunnan, China. Morphological evidence supports P. jiaozishanensis as a member of P. sect. Petiolares subsect. Davidii, which is characterized by firmly papery or leathery leaves, with veins impressed adaxially, often prominently raised and alveolate abaxially. The new species is characterized by having long and stout rhizomes, smaller leaves with short petioles, short or almost obsolete scape, and larger flowers. The distribution, phenology and conservation status of the new species are also provided.