Genetic diversity is crucial for determining the evolutionary potential of a species and is essential for developing optimal conservation strategies. The impact of habitat fragmentation on the genetic diversity of food-deceptive orchids seems to be unpredictable because of their specialized seed and pollen dispersal mechanisms. The habitat of deceptive Cypripedium flavum was severely fragmented during the past half century. This study investigated the genetic diversity and structure of seven fragmented Cypripedium flavum populations in Shangrila County using AFLP markers. A total of 376 alleles were identified, with a range of 70 to 81 alleles per locus. The species exhibited considerable genetic diversity, as evidenced by an average Nei’s gene diversity (H) of 0.339 and a Shannon’s information index (I) of 0.505, with all loci being polymorphic. Based on Molecular Variance (AMOVA), 8.75% of the genetic differentiation was found among populations, while the remaining 91.25% of genetic variation occurred within populations. Population structure analysis revealed that the C. flavum germplasm can be categorized into 2 distinct groups, among which there was significant gene flow. Despite habitat fragmentation, C. flavum still retained a high level of genetic diversity, and the substantial gene flow (5.0826) is a key factor in maintaining the genetic diversity. These findings offer valuable insights for the conservation and potential use of C. flavum genetic resources.

Salvia leucantha is a perennial herb of the genus Salvia in the family Labiatae, which has a wide range of biological activities, mainly including inhibition of acetylcholinesterase, antibacterial, and anti-inflammatory activity. To explore the protective effects and mechanism of action of S. leucantha on Alzheimer’s disease (AD), the anti-AD activity of SLE (extracts of S. leucantha) was determined by using a transgenic Caenorhabditis elegans (C. elegans) model (CL4176). Analyses included paralysis assay, phenotypic experiments, transcriptome sequencing, RNA interference (RNAi), heat shock assays, and gas chromatography-mass spectrometry (GC-MS). SLPE (S. leucantha petroleum ether extract) could significantly delay CL4176 paralysis and extend the longevity of C. elegans N2 without harmful effects. A total of 927 genes were significantly changed by SLPE treatment in C. elegans, mainly involving longevity regulatory pathways—nematodes, drug metabolism—cytochrome P450, and glutathione metabolic pathways. RNAi showed that SLPE exerted its anti-AD activity through up-regulation of the gene gst-5; the most abundant compound in SLPE analyzed by GC-MS was 2,4-Di-tert-butylphenol (2,4-DTBP), and the compound delayed nematode paralysis. The present study suggests that active components in S. leucantha may serve as new-type anti-AD candidates and provide some insights into their biological functions.

Ageratina adenophora is an invasive plant with bioactive essential oils. This study analyzed the chemical composition, antimicrobial and antioxidant activity of essential oils from three developmen...