Dyes derived from plants have an extensive history of use for coloring food and clothing in Dong communities and other indigenous areas in the uplands of China. In addition to use as coloring agents, Dong communities have historically utilized dye plants for their value for enhancing the nutritive, medicinal and preservative properties of foods. However, the persistence of plant-derived dyes and associated cultural practices and traditional knowledge is threatened with rapid socio-economic change in China. Research is needed to document the ethnobotany of dye plants in indigenous communities towards their conservation and potential commercialization as a sustainable means of supporting local development initiatives. Semi-structured surveys on plants used for coloring agents and associated traditional knowledge were conducted in fifteen Dong villages of Tongdao County in Hunan Province of South Central China during 2011–2012. Transect walks were carried out with key informants identified from semi-structured surveys to collect samples and voucher specimens for each documented plant species for taxonomic identification. Dong households at the study sites utilize the flowers, bark, stems, tubers and roots of 13 plant species from 9 families as dyes to color their customary clothing and food. Out of the documented plants, a total of 7 are used for coloring food, 3 for coloring clothing and 3 for both food and clothing. Documented plants consist of 3 species that yield black pigments, 3 for brownish red/russet pigments, 3 for red pigments, 2 for dark blue pigments and 2 for yellow pigments. In addition to dyes, the plants have multiple uses including medicinal, ornamental, sacrificial, edible, and for timber. The use of dyes derived from plants persists at the study sites for their important role in expressing Dong cultural identity through customary clothing and food. Further research is needed to evaluate the safety of dye plants, their efficacy in enhancing food items and their commercial potential. Conservation policies and management plans are called for to preserve these ethnobotanical resources in a sustainable manner that supports local livelihoods while maintaining cultural practices.

Polygonatum cyrtonema Hua is a perennial herb of the Asparagaceae family that is used for both dietary and medicinal purposes in China. In September 2019, a new leaf spot disease on Polygonatum cyrtonema was detected and is currently widespread in Huaihua, Hunan Province, China. Pathogenic fungi were isolated and purified from samples of diseased tissue that were collected for morphological and molecular phylogenetic studies. The pathogen was identified using multilocus (ITS, TEF-1, and TUB2) phylogenies, as well as morphological characters, and was found to be clustered but separately divergent from species of Pestalotiopsis. However, there were significant morphological differences between the pathogen and similar species. The pathogen was finally identified as a new species that was designated Pestalotiopsis xuefengensis. This is the first report of Pestalotiopsis xuefengensis serving as the causal agent of gray leaf spot on Polygonatum cyrtonema. This study will provide useful information for the diagnosis and management of this disease.

The immunoassay based on the integrated detection antibody, comprising GOx and anti-CEA in ZnCPs, allows for amplified colorimetric detection of CEA through a self-supplying oxygen cascade reaction involving GOx and MnO ₂ .