Based on the importance and sensitivity of microbial communities to changes in the forest ecosystem, soil microorganisms can be used to indicate the health of the forest system. The metagenome sequencing was used to analyze the changes of microbial communities between natural and plantation Castanea henryi forests for understanding the effect of forest types on soil microbial communities. Our result showed the soil microbial diversity and richness were higher in the natural forests than in the plantation. Proteobacteria, Actinobacteria, and Acidobacteria are the dominant categories in the C. henryi rhizosphere, and Proteobacteria and Actinobacteria were significantly enriched in the natural forest while Acidobacteria was significantly enriched in the plantation. Meanwhile, the functional gene diversity and the abundance of functions in the natural forest were higher than that of the plantation. Furthermore, we found that the microbial network in the natural forests had more complex than in the plantation. We also emphasized the low-abundance taxa may play an important role in the network structure. These results clearly showed that microbial communities, in response to different forest types, provide valuable information to manipulate microbiomes to improve soil conditions of plantation.

Advancement of the oil tea industry requires the development of high-yielding and superior-quality varieties of Camellia oleifera, a major oilseed crop. However, traditional breeding methods, hampered by lengthy cycles and low selection accuracy, significantly constrain the breeding process. Identifying single nucleotide polymorphisms (SNPs) associated with target traits, and applying molecular marker-assisted selection (MAS) for these traits, can thereby shorten the breeding cycles and amplify the breeding efficiency. In this study, we utilized the hexaploid C. oleifera as the reference genome to identify high-quality SNPs and constructed a high-density genetic linkage map of C. oleifera that spanned 1566.733 cM, included 3097 SNPs, and was anchored to 15 linkage groups. Using interval mapping, we localized quantitative trait loci (QTLs) for 11 juvenile traits in C. oleifera, identifying 15 QTLs for growth traits and 24 QTLs for leaf traits, including 4 stable QTLs. The logarithm of odds (LOD) scores for individual QTLs ranged from 3.48 to 14.62, explaining 9.86–48.61% of the phenotypic variance. We further identified 2 SNPs associated with growth traits (marker11-951 and marker12-68) and 10 SNPs associated with leaf traits (marker11-276, marker11-410, marker11-560, marker13-16, marker13-39, marker13-110, marker13-731, marker14-701, marker14-910, and marker14-1331). These results provide valuable insights into the genetic mapping of key traits in C. oleifera and will contribute to the development of new varieties with high yield and superior quality in the future.

Glyptostrobus pensilis is an endangered tree species, and detecting its genetic diversity can reveal the mechanisms of endangerment, providing references for the conservation of genetic resources. Samples of 137 trees across seven populations within Fujian Province were collected and sequenced using double-digest restriction site-associated DNA (ddRAD-seq). A total of 3,687,189 single-nucleotide polymorphisms (SNPs) were identified, and 15,158 high-quality SNPs were obtained after filtering. The genetic diversity in the populations was found to be low (H_o = 0.08630, H_e = 0.03475, π = 0.07239), with a high genetic differentiation coefficient (F_st). When K = 4, the coefficient of variation (CV) error value was minimized, suggesting that the 137 individuals could be divided into four groups, with frequent gene flow between them. Principal component analysis (PCA) divided the seven populations into two major categories based on their north–south geographic location. The clustering was consistent with those obtained from the PCA. The main reasons for the endangerment of G. pensilis are likely to be poor natural regeneration, human disturbances, and climatic factors. It is recommended that methods such as in situ conservation, ex situ conservation, and the establishment of germplasm banks be implemented to maintain the genetic diversity of G. pensilis populations.

Castanea henryi is an important economic tree species in China. Its nutrient-rich nuts play a key role in raising farmers’ income in mountainous areas, promoting forestry industry development, and maintaining ecological balance, thereby providing significant economic and ecological value. To systematically elucidate the genetic characteristics of major C. henryi cultivars in China, this study conducted phenotypic trait measurements on 42 cultivars collected from Taining and Jian’ou in Fujian Province. Combined with whole-genome resequencing technology and using the C. henryi genome as a reference, systematic analyses were carried out. The results indicated that the Jian’ou group (HJO) generally exhibited superior performance in key fruit phenotypic traits compared to the Taining group (HTNC), with greater phenotypic diversity observed within the HJO group. Clustering analysis of phenotypic traits further revealed a cross-geographic convergent clustering pattern among the 42 C. henryi cultivars. Further analysis revealed that the overall genetic diversity of the 42 C. henryi cultivars was relatively low (observed heterozygosity: HJO = 0.0275, HTNC = 0.0194). Notably, parameters such as heterozygosity, minor allele frequency, nucleotide polymorphism, and polymorphic information content were slightly higher in the Jian’ou group compared to the Taining group. Divergent selection signal analysis (Fst top 5%) identified 3129 genomic regions under divergent selection. Genes within these regions showed homology to 1205 Arabidopsis thaliana genes, reflecting adaptive divergence driven by differential historical selection pressures between the two groups. Population genetic structure analysis indicated that the two regional groups exhibit high genetic similarity and low differentiation. This study reveals low genetic diversity and high genetic background homogeneity among C. henryi cultivars, findings that could inform the design of future breeding strategies.

Camellia oleifera Abel, recognized as a woody oil-producing tree species, possesses considerable economic significance. To improve the breeding efficiency of C. oleifera, it is crucial to elucidate the genetic foundation underlying the mechanisms regulating fruit traits. In this study, a total of 6,252,197 high-quality single-nucleotide polymorphisms (SNPs) were identified from 109 germplasm accessions. Through genetic structure analysis, these accessions were categorized into two distinct populations. The average fixation index (Fst) was found to be 0.0153, indicating weak population differentiation. The genome-wide association analysis (GWAS) identified 157 significant loci. From these loci, 110 candidate genes were selected, which were associated with disease resistance, reproduction, development, and RNA biosynthesis. Twenty-three genes were involved in metabolic pathways, including genetic information-processing protein families, metabolic protein families, terpenoids, and polyketides. The identification of gene loci closely related to fruit traits not only provides genetic data for studying the molecular mechanisms of fruit traits but also offers new research avenues for molecular breeding of C. oleifera.

Camellia oleifera Abel, recognized as a woody oil-producing tree species, possesses considerable economic significance. To improve the breeding efficiency of C. oleifera, it is crucial to elucidate the genetic foundation underlying the mechanisms regulating fruit traits. In this study, a total of 6,252,197 high-quality single nucleotide polymorphisms (SNPs) were identified from 109 germplasm accessions. Through genetic structure analysis, these accessions were categorized into two distinct populations. The average fixation index (Fst) was found to be 0.0153, indicating weak population differentiation. The genome-wide association analysis (GWAS) identified 157 significant loci. From these loci, 110 candidate genes were selected, which were associated with disease resistance, reproduction, development, and RNA biosynthesis. Twenty-three genes were involved in metabolic pathways, including genetic information processing protein families, metabolic protein families, terpenoids and polyketides. The identification of gene loci closely related to fruit traits not only provides genetic data for studying the molecular mechanisms of fruit traits but also offers new research avenues for molecular breeding of C. oleifera.