Camellia vietnamensis Huang is an important woody oil crop in China, which has attracted much attention because of its abundant nutritional components and pharmaceutical value. Its seeds undergo a complex series of physiological and biochemical changes during maturation, with consequent alterations in metabolites. In order to investigate the endogenous metabolism of C. vietnamensis on Hainan Island during seed development, in this study, ultra-high-performance liquid tandem chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) and multivariate statistical analysis (MSA) were used to analyze the differences in the chemical compounds of C. vietnamensis seeds among the four maturation stages. A total of 293 metabolites were identified from the methanol extract of the seeds of C. vietnamensis. Five metabolites, belonging to benzene and substituted derivatives, 5′-deoxyribonucleosides and linear 1,3-diarylpropanoids, were found in all three comparison groups, with consistently down-regulated trends. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that phloretin and 5′-methylthioadenosine were the differentially expressed metabolites when seeds were in the growth periods of S2 and S3, and indole and L-tryptophan were the differentially expressed metabolites when seeds were in the growth periods of S3 and S4. In addition, 34 flavonoid metabolites were detected, of which 4 were differentially expressed. It was indicated that flavonoids dynamically change during all the oil-tea camellia seed development stages. The findings provide data for the better understanding of endogenous metabolic pathways during C. vietnamensis seed development.

Objectives: Peduncle length (PL) is a critical agronomic trait in sorghum [Sorghum bicolor (L.) Moench], influencing mechanical harvesting efficiency. Exploration of the PL genetic mechanism and the PL major genes of sorghum can provide a reference for breeding of sorghum suitable for mechanization and PL genetic research of other graminaceous crops. Methods: Here, we conducted genetic analysis, transcriptome analysis, and candidate major gene screening of PL using long-peduncle (KY133B) and short-peduncle (KY123B) parents, as well as their constructed F2 segregated populations. Results: Genetic analysis revealed that PL trait may be controlled by two major genes with additive-dominant effects, showing a heritability of 69.638%. At the early stage of sorghum peduncle elongation, the young panicle of the parents was sampled and performed transcriptome analysis. DEGs 3603 genes were obtained. With the short peduncle parent (F) as the control, 2204 upregulated genes and 1399 downregulated genes were expressed in the long peduncle parent (M). We compared the 1161 genes obtained by BSA-seq from the laboratory in the early stage with the DEGs obtained by RNA-seq, and obtained 148 co-localized genes. Through the high DEGs screening criteria (|Log₂FC(M/F)| ≥ 5, p < 0.0001), we further identified 36 genes with highly significant expression differences between parents. Functional annotation identified four candidate major genes strongly associated with PL: LOC8056900 (MIZU-KUSSEI 1), LOC8065075 (ethylene-responsive transcription factor WIN1), LOC8083493 (GDSL esterase/lipase), and LOC8085367 (auxin-responsive protein IAA21). qPCR validated their expression trends, corroborating RNA-seq results. Conclusions: The comprehensive information presented here provides a reference for understanding the PL mechanism of sorghum and provides some important candidate major genes related to PL. This study laid the foundation for subsequent gene functional verification and mechanism analysis of sorghum peduncle length major genes.