Morphological and Phylogenetic Analyses Reveal Two New Species of Sporocadaceae From Hainan, China

Species of Sporocadaceae have often been reported as plant pathogens, endophytes or saprobic, commonly isolated from a wide range of plant hosts. The isolated fungi were studied through a complete examination based on multi-locus phylogeny of a combined dataset of ITS/TUB2/TEF1-α, in conjunction with morphological characteristics. Nine strains isolated from Schima superba, Ficus microcarpa and Ilex chinensis in Hainan Province, China, represented four species, viz, Monochaetia schimae sp. nov., Neopestalotiopsis haikouensis sp. nov., Neopestalotiopsis piceana and Pestalotiopsis licualacola.

Three new species of the family Eriophyidae (Acari: Eriophyoidea) from South China

In this paper, three new species of eriophyoid mites of the family Eriophyidae from South China are described and illustrated. They are: Stenacis cryptomeris sp. nov. infesting Cryptomeria japonica (Thunb. Ex L.f.) D.Don (Cupressaceae), Tetra guizhouensis sp. nov. infesting Caesalpinia sp. (Leguminosae), and Nothopoda schimae sp. nov. infesting Schima superba Gardner & Champ. (Theaceae). All of these three new species are vagrants on lower leaf surface and causing no apparent damages to their host plants.

Identification and Validation of Reference Genes for Gene Expression Analysis in Schima superba

Real-time quantitative PCR (RT-qPCR) is a reliable and high-throughput technique for gene expression studies, but its accuracy depends on the expression stability of reference genes. Schima superba is a fast-growing timber species with strong resistance. However, thus far, reliable reference gene identifications have not been reported in S. superba. In this study, 19 candidate reference genes were selected and evaluated for their expression stability in different tissues of S. superba. Three software programs (geNorm, NormFinder, and BestKeeper) were used to evaluate the reference gene transcript stabilities, and comprehensive stability ranking was generated by the geometric mean method. Our results show that SsuACT was the most stable reference gene and that SsuACT + SsuRIB was the best reference gene combination for different tissues. Finally, the stable and less stable reference genes were verified using SsuSND1 expression in different tissues. To our knowledge, this is the first report to verify appropriate reference genes for normalizing gene expression in S. superba for different tissues, which will facilitate the future elucidation of gene regulations in this species and useful references for relative species.

Radial Variation of Wood Anatomical Properties Determines the Demarcation of Juvenile-Mature Wood in Schima superba

Schima superba is a precious broadleaf tree species that produces excellent timber. Analyzing the radial variation of wood anatomical properties within stems and determining the boundary between the juvenile and mature wood can provide a theoretical basis for the breeding and cultivation of S. superba. Herein, 30 54-year-old trees were used to analyze the radial variation of wood anatomical properties qualitatively. The correlation among wood properties was analyzed. On this basis, four types of model were used to predict the wood properties quantitatively, and the optimal segmentation model was used to determine the boundary between juvenile and mature wood. The results showed that the variation of the early stage (before the 20th year) was larger than that of the later stage (after the 20th year); moreover, the variation of the vessel features (9.56%) was greater than that of the fiber features (7.42%), the vessel lumen diameter (11.94%) and the fiber length (8.00%) had the most variation. There were three radial variation patterns in the wood properties. In the early stage, there was a significant positive correlation between the ring width and wood air-dry density (0.78) and wood basic density (0.89), and a significant negative correlation between the ring width and the fiber characters (−0.79~−0.93) and vessel characters (−0.64~−0.90). The growth models of Logistic and Richards were more suitable (R2 = 84.2%~95.2%) for the radial variation of wood anatomical properties than the nonlinear least square model (R2 = 67.7%~90.9%). The transition wood between juvenile and mature wood of S. superba was from the 11th to the 16th year based on aggregative indicators from the pith to bark at breast height. Finally, when taken together, the wood anatomical properties of S. superba had regular radial variation. Breeding programs need to consider both growth and wood anatomical properties in the early stage, but they can be neglected in the mature stage. The formation of mature wood of S. superba occurred after the 16th year.

Identification and validation of appropriate reference genes for gene expression analysis in Schima superba

Background: Real-time quantitative PCR (RT-qPCR) is a reliable and high-throughput technique for gene expression studies, but its accuracy depends on the expression stability of reference genes. Schima superba is a strong resistance and fast-growing timber specie. However, so far, reliable reference gene identifications have not been reported in S. superba. In this study, we screened and verified the stably expressed reference genes in different tissues of S. superba.Results: Nineteen candidate reference genes were selected and evaluated for their expression stability in different tissues. Three software programs (geNorm, NormFinder, and BestKeeper) were used to evaluate the reference gene transcript stabilities, and comprehensive stability ranking was generated by the geometric mean method. Our results identified that SsuACT was the most stable reference gene, SsuACT + SsuRIB was the best reference genes combination for different tissues. Finally, the stable and less stable reference genes were verified using the SsuSND1 expression in different tissues.Conclusions: This is the first report to verify the appropriate reference genes for normalizing gene expression in S. superba, which will facilitate future elucidation of gene regulations in this species, and useful references for relative species.

PacBio Single-Molecule Long-Read Sequencing Reveals Genes Tolerating Manganese Stress in Schima superba Saplings

Schima superba (Theaceae) is a subtropical evergreen tree and is used widely for forest firebreaks and gardening. It is a plant that tolerates salt and typically accumulates elevated amounts of manganese in the leaves. With large ecological amplitude, this tree species grows quickly. Due to its substantial biomass, it has a great potential for soil remediation. To evaluate the thorough framework of the mRNA, we employed PacBio sequencing technology for the first time to generate S. Superba transcriptome. In this analysis, overall, 511,759 full length non-chimeric reads were acquired, and 163,834 high-quality full-length reads were obtained. Overall, 93,362 open reading frames were obtained, of which 78,255 were complete. In gene annotation analyses, the Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Genes (COG), Gene Ontology (GO), and Non-Redundant (Nr) databases were allocated 91,082, 71,839, 38,914, and 38,376 transcripts, respectively. To identify long non-coding RNAs (lncRNAs), we utilized four computational methods associated with protein families (Pfam), Cooperative Data Classification (CPC), Coding Assessing Potential Tool (CPAT), and Coding Non-Coding Index (CNCI) databases and observed 8,551, 9,174, 20,720, and 18,669 lncRNAs, respectively. Moreover, nine genes were randomly selected for the expression analysis, which showed the highest expression of Gene 6 (Na_Ca_ex gene), and CAX (CAX-interacting protein 4) was higher in manganese (Mn)-treated group. This work provided significant number of full-length transcripts and refined the annotation of the reference genome, which will ease advanced genetic analyses of S. superba.

Nitrogen Fertilization Modified the Responses of Schima superba Seedlings to Elevated CO2 in Subtropical China

There are very few studies about the effects of relatively higher CO2 concentration (e.g., 1000 μmol·mol−1) or plus N fertilization on woody plants. In this study, Schima superba seedings were exposed to ambient or eCO2 (550, 750, and 1000 μmol·mol−1) and N fertilization (0 and 10 g·m−2·yr−1, hereafter: low N, high N, respectively) for one growth season to explore the potential responses in a subtropical site with low soil N availability. N fertilization strongly increased leaf mass-based N by 118.38%, 116.68%, 106.78%, and 138.95%, respectively, in different CO2 treatments and decreased starch, with a half reduction in leaf C:N ratio. Leaf N was significantly decreased by eCO2 in both low N and high N treatments, and N fertilization stimulated the decrease of leaf N and mitigated the increase of leaf C:N by eCO2. In low N treatments, photosynthetic rate (Pn) was maximized at 733 μmol·mol−1 CO2 in August and September, while, in high N treatments, Pn was continuously increased with elevation of CO2. N fertilization significantly increased plant biomass especially at highly elevated CO2, although no response of biomass to eCO2 alone. These findings indicated that N fertilization would modify the response of S. superba to eCO2.

Selection and Validation of Appropriate Reference Genes for Gene Expression Studies in Schima Superba

Background Quantitative real-time PCR (qRT-PCR) is a reliable and high-throughput technique for gene expression studies, but its accuracy depends on the expression stability of reference genes. Schima superba is a strong resistance and fast-growing timber specie. However, so far, reliable reference gene identifications have not been reported in S. superba. In this study, we screened and verified the stably expressed reference genes in different tissues of S. superba.Results Nineteen candidate reference genes were selected and evaluated for their expression stability in different tissues. Three software programs (geNorm, NormFinder, and BestKeeper) were used to evaluate the reference gene transcript stabilities, and comprehensive stability ranking was generated by the geometric mean method. Our results identified that SsuACT was the most stable reference gene, SsuACT + SsuRIB was the best reference genes combination for different tissues. Finally, the stable and less stable reference genes were verified using the SsuSND1 expression in different tissues.Conclusions This is the first report to verify the appropriate reference genes for normalizing gene expression in S. superba for different tissues, which will facilitate future elucidation of gene regulations in this species, and useful references for relative species.