The diversity and biology of the moss and leaf litter-inhabiting flea beetles are still poorly known. In this study, three new species of Benedictus are described from China: Benedictus fuanensis Ruan & Konstantinov, sp. nov., Benedictus quadrimaculatus Ruan & Konstantinov, sp. nov., and Benedictus wangi Ruan & Konstantinov, sp. nov. Comments on their biology are given. Benedictus quadrimaculatus has a highly unusual morphological feature not reported before in flea beetles: black spots on the abdominal tergites that are visible through the elytra. Traditional and modified ethanol traps were tested and proven useful for collecting leaf litter- and moss-inhabiting flea beetles. Based on our tests, eight traps could collect one specimen each day in the testing sites in Fujian Province; three traps could collect one specimen each day in the testing sites in Guangdong Province.

Tartary buckwheat (Fagopyrum tataricum) is an important plant, utilized for both medicine and food. It has become a current research hotspot due to its rich content of flavonoids, which are beneficial for human health. Anthocyanins (ATs) and proanthocyanidins (PAs) are the two main kinds of flavonoid compounds in Tartary buckwheat, which participate in the pigmentation of some tissue as well as rendering resistance to many biotic and abiotic stresses. Additionally, Tartary buckwheat anthocyanins and PAs have many health benefits for humans and the plant itself. However, little is known about the regulation mechanism of the biosynthesis of anthocyanin and PA in Tartary buckwheat. In the present study, a bHLH transcription factor (TF) FtTT8 was characterized to be homologous with AtTT8 and phylogenetically close to bHLH proteins from other plant species. Subcellular location and yeast two-hybrid assays suggested that FtTT8 locates in the nucleus and plays a role as a transcription factor. Complementation analysis in Arabidopsis tt8 mutant showed that FtTT8 could not recover anthocyanin deficiency but could promote PAs accumulation. Overexpression of FtTT8 in red-flowering tobacco showed that FtTT8 inhibits anthocyanin biosynthesis and accelerates proanthocyanidin biosynthesis. QRT-PCR and yeast one-hybrid assay revealed that FtTT8 might bind to the promoter of NtUFGT and suppress its expression, while binding to the promoter of NtLAR and upregulating its expression in K326 tobacco. This displayed the bidirectional regulating function of FtTT8 that negatively regulates anthocyanin biosynthesis and positively regulates proanthocyanidin biosynthesis. The results provide new insights on TT8 in Tartary buckwheat, which is inconsistent with TT8 from other plant species, and FtTT8 might be a high-quality gene resource for Tartary buckwheat breeding.

Starch is the main component that determines the yield and quality of Tartary buckwheat. As a quantitative trait, using quantitative trait locus (QTL) mapping to excavate genes associated with starch-related traits is crucial for understanding the genetic mechanisms involved in starch synthesis and molecular breeding of Tartary buckwheat varieties with high-quality starch. Employing a recombinant inbred line population as research material, this study used QTL mapping to investigate the amylose, amylopectin, and total starch contents across four distinct environments. The results identified a total of 20 QTLs spanning six chromosomes, which explained 4.07% to 14.41% of the phenotypic variation. One major QTL cluster containing three stable QTLs governing both amylose and amylopectin content, qClu-4-1, was identified and located in the physical interval of 39.85–43.34 Mbp on chromosome Ft4. Within this cluster, we predicted 239 candidate genes and analyzed their SNP/InDel mutations, expression patterns, and enriched KEGG pathways. Ultimately, five key candidate genes, namely FtPinG0004897100.01, FtPinG0002636200.01, FtPinG0009329200.01, FtPinG0007371600.01, and FtPinG0005109900.01, were highlighted, which are potentially involved in starch synthesis and regulation, paving the way for further investigative studies. This study, for the first time, utilized QTL mapping to detect major QTLs controlling amylose, amylopectin, and total starch contents in Tartary buckwheat. The QTLs and candidate genes would provide valuable insights into the genetic mechanisms underlying starch synthesis and improving starch-related traits of Tartary buckwheat.

Due to the requirements for quality testing and breeding Tartary buckwheat (Fagopyrum tartaricum Gaerth), it is necessary to find a method for the rapid detection of starch content in Tartary buckwheat. To obtain samples with a continuously distributed chemical value, stable Tartary buckwheat recombinant inbred lines were used. After scanning the near-infrared spectra of whole grains, we employed conventional methods to analyze the contents of Tartary buckwheat. The results showed that the contents of total starch, amylose, amylopectin, and resistant starch were 532.1–741.5 mg/g, 176.8–280.2 mg/g, 318.8–497.0 mg/g, and 45.1–105.2 mg/g, respectively. The prediction model for the different starch contents in Tartary buckwheat was established using near-infrared spectroscopy (NIRS) in combination with chemometrics. The Kennard–Stone algorithm was used to split the training set and the test set. Six different methods were used to preprocess the spectra in the wavenumber range of 4000–12,000 cm⁻¹. The Competitive Adaptive Reweighted Sampling algorithm was then used to extract the characteristic spectra, and the prediction model was built using the partial least squares method. Through a comprehensive analysis of each parameter of the model, the best model for the prediction of each nutrient was determined. The correlation coefficient of calibration (Rc) and the correlation coefficient of prediction (Rp) of the best models for total starch and amylose were greater than 0.95, and the Rc and Rp of the best models for amylopectin and resistant starch were also greater than 0.93. The results showed that the NIRS-based prediction model fulfilled the requirement for the rapid determination of Tartary buckwheat starch, thus providing an effective technical approach for the rapid and non-destructive testing of starch content in the food science and agricultural industry.

In taxonomy, qualitative methods are commonly used to analyze morphological characters, which can lead to dramatic changes in higher taxa. Geometric morphometrics (GM) has proven to be useful for discriminating species in various taxonomy groups. However, the application of geometric morphometrics in supraspecies classification is relatively scarce. In this study, we tested the controversial two subgenera classification of Chaetocnema with geometric morphometrics; a total of 203 Chaetocnema species representing 50% of all known species from around the world were selected for the analysis. We analyzed the shape of the pronotum, elytron, head, aedeagus, and spermatheca. The results showed that the two traditional subgenera distinctly differed from each other; therefore, we propose using two subgenera arrangements to facilitate the understanding and taxonomy of the Chaetocnema species (especially in the Oriental, Palearctic, and Nearctic regions). Additionally, the morphological diversity of the abovementioned structures of Chaetocnema was analyzed, and it was found that the highest morphological diversity was in the spermatheca, which was greater than that in the aedeagus. Our research demonstrated that GM could be useful for detecting morphological delimitation of the supraspecies taxa. It also showed that GM methods are applicable to insects as small as 2 mm in body size.

Tartary buckwheat (Fagopyrum tataricum Gaertn.) belongs to the family of Polygonaceae and is used as a multi-functional plant. R2R3-MYB transcription factors play a crucial part in plant growth and are involved in many biological processes where they regulate their internal environment. To date, there is no documented systematic research on the R2R3-MYB gene family in Tartary buckwheat. Here, domain features, chromosomal location, motif prediction, gene structure, cis-acting elements, as well as the expression pattern of R2R3-MYB transcription factors were analyzed comprehensively in Tartary buckwheat using a bioinformatic approach. Additionally, one R2R3-MYB gene was verified by transgenic Arabidopsis. Results indicate that a total of 152 R2R3-MYB genes were identified with special R2R3 domains and were distributed on 8 chromosomes of Tartary buckwheat. They were further classified into 25 sub-categories via phylogenetic analysis in terms of the R2R3-MYB gene family classification principles of Arabidopsis thaliana. This classification was further supported by analysis of exon–intron structure, motif, and cis-elements. Tandem and segmental duplication existed among the R2R3-MYB gene family of Tartary buckwheat, and there were 5, 8, 27, and 36 FtR2R3-MYB homologous genes, respectively, when comparing with Zea mays, Oryza sativa, Arabidopsis thaliana, and Solanum melongena by synteny analysis. The expression pattern of FtR2R3-MYB genes in different tissue and under salt stress and different light condition showed that members had tissue-specific expression levels and that these members may play diverse functions in plant growth and adaptation to varying environments. In addition, one of the FtR2R3-MYB gene families, FtMYB43, a homologue of AtTT2, clustered with R2R3-MYB from other plant species, which were reported to be involved in the regulation of anthocyanin or proanthocyanidin biosynthesis. This gene was located in the nucleus, and had transcriptional activation activity, indicating that FtMYB43 may be a positive transcript factor of anthocyanin or proanthocyadin biosynthesis. Moreover, the function of FtMYB43 was further verified to improve the production of anthocyanin in transgenic Arabidopsis by overexpression, and qRT-PCR assay implied that FtMYB43 may regulate the expression levels of most structural genes of the anthocyanin biosynthesis pathway in Arabidopsis seedlings. These results provide more insights into the structure and function of the R2R3-MYB gene family and may accelerate the breeding of ornamental buckwheat cultivars.