The fungal community in Qu plays a key role in the formation of turbid rice wine (TRW) style. The Sichuan Basin and its surrounding areas have become one of the main TRW production regions in China; however, the fungal community in Qu and how they affect the characteristics of TRW remain unknown. Therefore, this study provided insight into the fungal biomarkers in Qu from Guang’an (GQ), Dazhou (DQ), Aba (AQ), and Liangshan (LQ), as well as their relationships with compounds in TRW. The main biomarkers in GQ were Rhizopus arrhizus, Candida glabrata, Rhizomucor pusillus, Thermomyces lanuginosus and Wallemia sebi. However, they changed to Saccharomycopsis fibuligera and Mucor indicus in DQ, Lichtheimia ramose in AQ, and Rhizopus microsporus and Saccharomyces cerevisiae in LQ. As a response to fungal biomarkers, the reducing sugar, ethanol, organic acids, and volatile compounds were also changed markedly in TRWs. Among important volatile compounds (VIP > 1.00), phenethyl alcohol (14.1–29.4%) was dominant in TRWs. Meanwhile, 3-methyl-1-butanol (20.6–56.5%) was dominant in all TRWs except that fermented by GQ (GW). Acetic acid (29.4%) and ethyl palmitate (10.1%) were dominant in GW and LW, respectively. Moreover, GQ biomarkers were positively correlated with acetic acid and all unique important volatile compounds in GW. DQ biomarkers had positive correlations with unique compounds of acetoin and ethyl 5-chloro-1,3,4-thiadiazole-2-carboxylate in DW. Meanwhile, the AQ biomarkers were positively correlated with all AW unique, important, and volatile compounds. Although there were not any unique volatile compounds in LW, 16 important volatile compounds in LW were positively related to LQ biomarkers. Obviously, biomarkers in different geographic Qu played vital roles in the formation of important volatile compounds, which could contribute specific flavor to TRWs. This study provided a scientific understanding for future efforts to promote the excellent characteristics of TRW by regulating beneficial fungal communities.

Terrestrialization is an important evolutionary process that plants experienced. However, little is known about how land plants acquired aquatic growth behaviors. Here, we integrate multiproxy evidence to elucidate the evolution of the aquatic plant duckweed. Three genera of duckweeds show chronologically gradual degeneration in root structure and stomatal function and a decrease in lignocellulose content, accompanied by the contraction of relevant gene families and/or a decline in their transcription levels. The number of genes in main phytohormone pathways is also gradually decreased. The coordinated action of genes involved in auxin signaling and rhizoid development causes a gradual decrease in adventitious roots. Additionally, the significant expansion of the flavonoid pathway is related to the adaptation of duckweeds to floating growth. This study reconstructs the evolutionary history of duckweeds, tracing its journey from land back to water — a reverse trajectory of early land plants.