Increasing the sucrose content of sugarcane, a major sugar crop, is a key breeding objective. However, the complex genetic background of sugarcane affects development of sugarcane hybrids. In this study, we sequenced 292 sugarcane germplasm accessions and identified 2,542,965 single nucleotide polymorphisms (SNPs) and insertions/deletions (InDels). We performed a genome-wide association study (GWAS) for two important sugarcane traits: sucrose content and stem diameter. Both traits followed a normal distribution and showed typical characteristics of quantitative traits. Population structure analysis revealed four subpopulations with an average genetic distance of 0.236. GWAS of the sucrose content detected 27 SNPs. After annotating genes at or near significant loci, 17 candidate genes were screened. For stem diameter, GWAS revealed 19 SNPs, from which 9 candidate genes were identified. These results improve our understanding of genetic mechanisms affecting sucrose content in sugarcane, and identify important genetic resources to accelerate breeding of new sugarcane varieties with high sucrose content.

Michelia alba DC is a highly valuable ornamental plant of the Magnoliaceae family. This evergreen tropical tree commonly grows in Southeast Asia and is adored for its delightful fragrance. Our study assembled the M. alba haplotype genome MC and MM by utilizing Nanopore ultralong reads, Pacbio Hifi long reads and parental second-generation data. Moreover, the first methylation map of Magnoliaceae was constructed based on the methylation site data obtained using Nanopore data. Metabolomic datasets were generated from the flowers of three different species to assess variations in pigment and volatile compound accumulation. Finally, transcriptome data were generated to link genomic, methylation, and morphological patterns to reveal the reasons underlying the differences between M. alba and its parental lines in petal color, flower shape, and fragrance. We found that the AP1 and AP2 genes are crucial in M. alba petal formation, while the 4CL, PAL, and C4H genes control petal color. The data generated in this study serve as a foundation for future physiological and biochemical research on M. alba, facilitate the targeted improvement of M. alba varieties, and offer a theoretical basis for molecular research on Michelia L.