Short-term responses of soil enzyme activities and stoichiometry to litter input in Castanopsis carlesii and Cunninghamia lanceolata plantations.

Litter input triggers the secretion of soil extracellular enzymes and facilitates the release of carbon (C), nitrogen (N), and phosphorus (P) from decomposing litter. However, how soil extracellular enzyme activities were controlled by litter input with various substrates is not fully understood. We examined the activities and stoichiometry of five enzymes including ß-1,4-glucosidase, ß-D-cellobiosidase, ß-1,4-N-acetyl-glucosaminidase, leucine aminopeptidase and acidic phosphatase (AP) with and without litter input in 10-year-old Castanopsis carlesii and Cunninghamia lanceolata plantations monthly during April to August, in October, and in December 2021 by using an in situ microcosm experiment. The results showed that: 1) There was no significant effect of short-term litter input on soil enzyme activity, stoichiometry, and vector properties in C. carlesii plantation. In contrast, short-term litter input significantly increased the AP activity by 1.7% in May and decreased the enzymatic C/N ratio by 3.8% in August, and decreased enzymatic C/P and N/P ratios by 11.7% and 10.3%, respectively, in October in C. lanceolata plantation. Meanwhile, litter input increased the soil enzymatic vector angle to 53.8° in October in C. lanceolata plantations, suggesting a significant P limitation for soil microorganisms. 2) Results from partial least squares regression analyses showed that soil dissolved organic matter and microbial biomass C and N were the primary factors in explaining the responses of soil enzymatic activity to short-term litter input in both plantations. Overall, input of low-quality (high C/N) litter stimulates the secretion of soil extracellular enzymes and accelerates litter decomposition. There is a P limitation for soil microorganisms in the study area.

The influence of stand composition and season on canopy structure and understory light environment in different subtropical montane Pinus massoniana forests.

Canopy structure and understory light have important effects on forest productivity and the growth and distribution of the understory. However, the effects of stand composition and season on canopy structure and understory light environment (ULE) in the subtropical mountain Pinus massoniana forest system are poorly understood. In this study, the natural secondary P. massoniana-Castanopsis eyrei mixed forest (MF) and P. massoniana plantation forest (PF) were investigated. The study utilized Gap Light Analyzer 2.0 software to process photographs, extracting two key canopy parameters, canopy openness (CO) and leaf area index (LAI). Additionally, data on the transmitted direct (Tdir), diffuse (Tdif), and total (Ttot) radiation in the light environment were obtained. Seasonal variations in canopy structure, the ULE, and spatial heterogeneity were analyzed in the two P. massoniana forest stands. The results showed highly significant (P < 0.01) differences in canopy structure and ULE indices among different P. massoniana forest types and seasons. CO and ULE indices (Tdir, Tdif, and Ttot) were significantly lower in the MF than in the PF, while LAI was notably higher in the MF than in the PF. CO was lower in summer than in winter, and both LAI and ULE indices were markedly higher in summer than in winter. In addition, canopy structure and ULE indices varied significantly among different types of P. massoniana stands. The LAI heterogeneity was lower in the MF than in the PF, and Tdir heterogeneity was higher in summer than in winter. Meanwhile, canopy structure and ULE indices were predominantly influenced by structural factors, with spatial correlations at the 10 m scale. Our results revealed that forest type and season were important factors affecting canopy structure, ULE characteristics, and heterogeneity of P. massoniana forests in subtropical mountains.

[Response of soil microbial necromass carbon to litter and root carbon inputs in a mid-subtropical Castanopsis carlesii plantation]. / ä¸­äºšçƒ­å¸¦ç±³æ§ äººå·¥æž—åœŸå£¤å¾®ç”Ÿç‰©æ®‹ä½“ç¢³å¯¹å‡‹è½ç‰©å’Œæ ¹ç³»ç¢³è¾“å ¥çš„å“åº”.

Microbial necromass carbon (MNC) is a crucial source for stable soil carbon pool, and understanding its response to carbon inputs from both aboveground (litter) and belowground (roots) in subtropical forest soils is essential for assessing soil carbon stocks in global ecosystems. In a Castanopsis carlesii plantation at the Sanming Forest Ecosystem National Observation and Research Station in Fujian Province, we conducted an experiment with five treatments, including root removal (NR), aboveground litter removal (NL), no litter input (removals of both aboveground litter and roots, NI), double aboveground litter addition (DL), and control (CK). After seven years, we collected soil samples in the 0-10 cm soil layer to examine changes in MNC content and its contribution to soil organic carbon (SOC). Results showed that NR treatment reduced MNC, bacterial necromass carbon (BNC), and fungal necromass carbon (FNC) by 15.9%, 20.2%, and 14.5%, respectively, while other treatments did not induce significant changes. The NR, NL, NI, and DL treatments did not affect the contributions of BNC, FNC, and MNC to SOC. Correlation and path analyses revealed that litter and root carbon input treatments could alter the MNC content directly or indirectly through changing soil available substrates and microbial community structure. Our results suggested that roots exert a stronger influence on the maintenance of MNC than aboveground carbon source in the mid-subtropical plantations.

Effects of forest regeneration types on phosphorus fractions of soil aggregates in subtropical forest.

Soil aggregates are important for the storage and availability of phosphorus in the soil. However, how forest regeneration types affect phosphorus fractions of soil aggregates remains unclear. In this study, we examined the composition of aggregate particle size, phosphorus fractions, phosphorus sorption capacity index (PSOR), legacy phosphorus index (PLGC) and degree of phosphorus saturation by Mehlich 3 (DPSM3) in bulk soils and soil aggregates of Castanopsis carlesii secondary forest (slight disturbance), C. carlesii human-assisted regeneration forest (moderate disturbance), and Cunninghamia lanceolata plantation (severe disturbance), aiming to explore the impact of forest regeneration types on phosphorus availability and supply potential of bulk soils and soil aggregates. The results showed that forest regeneration types significantly influenced the composition of soil aggregates. The proportion of coarse macroaggregates (>2 mm) in the soil of C. carlesii secondary forest and human-assisted regeneration forest was significantly higher than that in the C. lanceolata plantation, while the proportion of silt and clay fraction (<0.053 mm) showed an opposite trend. The composition of soil aggregates significantly affected the contents of different phosphorus fractions. The contents of soil labile phosphorus fractions (PSOL and PM3) decreased as aggregate particle size decreased. The contents of soil total phosphorus (TP), total organic phosphorus (Po), mode-rately labile phosphorus fractions (PiOH and PoOH), and occluded phosphorus (POCL), as well as PSOR and PLGC, exhibited a trend of decreasing at the beginning and then increasing as particle size decreased. The contents of TP, Po, and PiOH in coarse and silt macroaggregates was significantly higher than that in fine macroaggregates (0.25-2 mm) and microaggregates (0.053-0.25 mm). Forest regeneration types significantly influenced the contents of phosphorus fractions of bulk soils and soil aggregates. The contents of TP, Po, PSOL, and PM3 in the soil of C. carlesii secondary forests was significantly higher than that in C. carlesii human-assisted regeneration forest and C. lanceolata plantation. The contents of PSOL and PM3 in different-sized aggregates of C. carlesii secondary forests were significantly higher than that in the C. lanceolata plantation. Forest regeneration types significantly influenced the composition and supply potential of phosphorus fractions in soil aggregates. The proportions of PSOL, and PM3 to TP in different-sized soil aggregates were significantly lower in C. carlesii human-assisted regeneration forest compared with C. carlesii secondary forest. PSOR and DPSM3 in different-sized soil aggregates were significantly lower in C. lanceolata plantation than that in C. carlesii secondary forest. Overall, our results indicated that natural regeneration is more favorable for maintaining soil phosphorus availability, and that forest regeneration affects soil phosphorus availa-bility and its supply potential by altering the composition of soil aggregates.

A new species of Paraputo Laing (Hemiptera: Coccomorpha: Pseudococcidae) on Fagaceae from southern China.

A new species of mealybug (Hemiptera: Coccomorpha: Pseudococcidae), Paraputo nanlingensis Li & Wu, sp. n., is recorded on Fagaceae from Guangdong Province, China. The adult female is described and illustrated, and an identification key is provided to separate the adult females of Paraputo species known from China.

Comprehensive evaluation of fruit quality for premium Wangmo Castanea mollissima plants.

In this study, the fruit phenotype and quality of 32 superior Wangmo Castanea mollissima plants (designated GM1 to GM32) were examined to identify the trait characteristics of different cluster groups and germplasms with excellent comprehensive performance. The goal was to provide a theoretical basis and research foundation for collecting high-quality germplasm resources and breeding superior cultivars of Wangmo C. mollissima. Ten fruit phenotypic traits and 13 quality traits were measured and analyzed in these 32 superior Wangmo C. mollissima plants. Cluster analysis and principal component analysis (PCA) were used to perform a comprehensive evaluation. Extremely significant positive correlations (P<0.01) were observed for 15 pairs of fruit phenotypic and quality traits, and significant positive correlations (P<0.05) were observed for 16 pairs of traits. Highly significant negative correlations (P<0.01) were observed for 4 pairs of fruit phenotypic and quality traits, and significant negative correlations (P<0.05) were observed for 15 pairs. The plants were divided into three groups by cluster analysis: the first group had large fruits and good fruit quality, the second group had small fruits and poor fruit quality, and the third group had medium-sized fruits with a high starch content. Four principal components were extracted from the 23 traits by PCA, contributing 76.23% of the variance. The ten plants with the highest comprehensive quality were GM32, GM31, GM29, GM1, GM8, GM17, GM10, GM30, GM3 and GM28. The results of this study provide a reference for the development and utilization of Wangmo C. mollissima germplasm resources.

Draft genome of Castanopsis chinensis, a dominant species safeguarding biodiversity in subtropical broadleaved evergreen forests.

OBJECTIVES: Castanopsis is the third largest genus in the Fagaceae family and is essentially tropical or subtropical in origin. The species in this genus are mainly canopy-dominant trees, and the key components of evergreen broadleaved forests play a crucial role in the maintenance of local biodiversity. Castanopsis chinensis, distributed from South China to Vietnam, is a representative species. It currently suffers from a high disturbance of human activity and climate change. Here, we present its assembled genome to facilitate its preliminary conservation and breeding on the genome level. DATA DESCRIPTION: The C. chinensis genome was assembled and annotated by Nanopore and MGI whole-genome sequencing and RNA-seq reads using leaf tissues. The assembly was 888,699,661 bp in length, consisting of 133 contigs and a contig N50 of 23,395,510 bp. A completeness assessment of the assembly with Benchmarking Universal Single-Copy Orthologs (BUSCO) indicated a score of 98.3%. Repetitive elements comprised 471,006,885 bp, accounting for 55.9% of the assembled sequences. A total of 51,406 genes that coded for 54,310 proteins were predicted. Multiple databases were used to functionally annotate the protein sequences.

Development of polymorphic microsatellite markers for Fagus pashanica (Fagaceae) using next-generation sequencing.

Fagus pashanica is an endangered and endemic tree species in China. To understand its genetic diversity and structure for effective conservation, we used next-generation sequencing data to develop a set of microsatellite markers. Twenty-three of the 68 designed loci were successfully amplified. Fifteen polymorphic loci with clear peaks were selected for further analyses in three F. pashanica populations sampled from Nanjiang, Wangcang and Pingwu counties in Sichuan Province, China. The number of alleles per locus ranged from two to 11. The levels of observed and expected heterozygosity ranged from 0.033-0.852 and 0.033-0.787, respectively. All 23 loci were also successfully amplified in F. longipetiolata and F. lucida, and 19 were successfully amplified in F. engleriana. These microsatellite markers will be useful for population genetic studies of F. pashanica and other Fagus species.

Identification and Quantification of the Major Phenolic Constituents in Castanea sativa and Commercial Interspecific Hybrids (C. sativa x C. crenata) Chestnuts Using HPLC-MS/MS.

Due to the lack of studies on chestnut metabolites, this study was conducted to identify and quantify the major phenolic constituents in chestnuts. Data were compared with the three most commonly grown interspecific hybrids of C. sativa and C. crenata ('Bouche de Betizac', 'Marsol', and 'Maraval') and three "native" accessions of C. sativa. High-performance liquid chromatography coupled with mass spectrometry was used to identify and quantify these compounds. Four dicarboxylic acid derivatives, five hydroxybenzoic acids, nine hydroxycinnamic acids, and three flavanols were identified and quantified, most of them for the first time. Hydroxybenzoic acids were the major phenolic compounds in all chestnut cultivars/accessions, followed by flavanols, dicarboxylic acid derivatives, and hydroxycinnamic acids. Of all the compounds studied, the (epi)catechin dimer was the most abundant in chestnut. The assumption that cultivars from commercial hybrids have a better and different metabolic profile than "native" accessions was refuted.

Use of retrotransposon based iPBS markers for determination of genetic relationship among some Chestnut Cultivars (Castanea sativa Mill.) in Türkiye.

BACKGROUND: The aim of this study was to reveal the genetic relationships among some economically important chestnut cultivars for Türkiye by using retrotransposon-based inter primer binding site (iPBS) markers. METHODS AND RESULTS: In this study, a total of 19 iPBS markers were used to determine the genetic relationships among 11 chestnut cultivars (Castanea sativa Mill.). In the study, chestnut cultivars named Haciömer, Osmanoglu, Sariaslama, Erfelek, Kemer, Isiklar, Sekerci, Siyah Bursa, Tülü, Bouche De Betizac and Marigoule were the preferred cultivars utilised. Using the online marker efficiency calculator (iMEC), some indices of polymorphism, such as the mean heterozygosity, polymorphism information content, marker index and discriminating power, were determined. In addition, the size ranges of alleles, number of average alleles, number of total alleles, number of polymorphic alleles, and polymorphism rate were determined at a successful level. The chestnut cultivars of Haciömer and Sekerci were determined to be the most similar cultivars with a similarity coefficient value of 0.924, and they formed a subgroup together with the chestnut cultivars Osmanoglu and Erfelek, showing close similarity with these two cultivars. CONCLUSIONS: The use of iPBS markers in chestnuts in Türkiye was carried out for the first time in this study. The power of iPBS markers to evaluate the genetic relationship for our preferred chestnut cultivars was revealed. For this reason, it has emerged that it will be useful in the molecular characterization of both genotypes in natural chestnut populations and chestnut breeding materials such as varieties and cultivars in chestnut breeding programs.

Rapid and easy construction of a simplified amplicon sequencing (simplified AmpSeq) library for marker-assisted selection.

Marker-assisted selection (MAS) is fundamental for plant breeding programs, as it can identify desirable seedlings at a young stage and reduce the cost, time and space needed for plant maintenance, especially for perennial crops. To facilitate the process of genotyping, which is time consuming and laborious, we developed a simplified amplicon sequencing (simplified AmpSeq) library construction method for next-generation sequencing that can be applied to MAS in breeding programs. The method is based on one-step PCR with a mixture of two primer sets: the first consisting of tailed target primers, the second of primers that contain flow-cell binding sites, indexes and tail sequences complementary to those in the first set. To demonstrate the process of MAS using s implified AmpSeq, we created databases of genotypes for important traits by using cultivar collections including triploid cultivars and segregating seedlings of Japanese pear (Pyrus pyrifolia Nakai), Japanese chestnut (Castanea crenata Sieb. et Zucc.) and apple (Malus domestica Borkh.). Simplified AmpSeq has the advantages of high repeatability, ability to estimate allele number in polyploid species and semi-automatic evaluation using target allele frequencies. Because this method provides high flexibility for designing primer sets and targeting any variant, it will be useful for plant breeding programs.

The fertilization process in Lithocarpus dealbatus (Fagaceae) and its implication on the sexual reproduction evolution of Fagales.

MAIN CONCLUSION: The pistillate flowers of Lithocarpus dealbatus show two pollen tube (PT) arresting sites (the style-joining and micropyle) within the pistil during the postpollination-prezygotic stage. The PT, arrested at the pre-ovule stage, enhanced PT competition allowing the most compatible PTs to enter the ovary to ensure the highest fertilization success. During the shift from animal pollination to wind pollination, plants require a series of changes in reproductive traits. The mode of pollination is striking labile in Fagaceae. Lithocarpus is insect pollinated and is closely related to wind-pollinated Quercus. Little is known about the sexual reproduction of Lithocarpus. This study aimed to reveal the sexual reproduction of Lithocarpus dealbatus and to explore the evolutionary pattern of the key sexual reproduction traits to better understand their possible role in labile pollination. We found that after pollination, L. dealbatus PTs grew slowly in the style reaching style-joining in mid-January of the second year; then PT growth was arrested at style-joining for four months. Only two to three PTs resumed growth in mid-May to reach the micropyle, where PT growth ceased for one month before one PT resumed growth and passed through the micropyle to the embryo sac. Fagaceae showed a generalized mating system. Vast pollen production, small-sized pollen grains, long stigmatic receptive time, and reduced perianth were compatible with beetle pollination syndrome, representing the plesiomorphic status in Fagaceae. A large stigmatic surface and dry pollen grains linked to wind pollination might be independently derived several times in fagaceous lineages. Beetle pollination syndrome can cope with the uncertainty of pollinators to ensure conspecific pollen capture, which represents pre-adaptation status and has a selective advantage when conditions change, favouring wind pollination. The arrest of the PT at style-joining is a unique mechanism in later derived fagaceous lineages to enhance PT competition and promote outcrossing.

Distribution, causal agents, and infection dynamic of emerging ink disease of sweet chestnut in Southern Switzerland.

Emerging diseases caused by both native and exotic pathogens represent a main threat to forest ecosystems worldwide. The two invasive soilborne pathogens Phytophthora cinnamomi and Phytophthora × cambivora are the causal agents of ink disease, which has been threatening Castanea sativa in Europe for several centuries and seems to be re-emerging in recent years. Here, we investigated the distribution, causal agents, and infection dynamics of ink disease in southern Switzerland. A total of 25 outbreaks were identified, 19 with only P. cinnamomi, 5 with only P. × cambivora, and 1 with both species. Dendrochronological analyses showed that the disease emerged in the last 20-30 years. Infected trees either died rapidly within 5-15 years post-infection or showed a prolonged state of general decline until death. Based on a generalized linear model, the local risk of occurrence of ink disease was increased by an S-SE aspect of the chestnut stand, the presence of a pure chestnut stand, management activities, the proximity of roads and buildings, and increasing annual mean temperature and precipitation. The genetic structure of the local P. cinnamomi population suggests independent introductions and local spread of the pathogen.

Chinese chestnut shell polyphenol extract regulates the JAK2/STAT3 pathway to alleviate high-fat diet-induced, leptin-resistant obesity in mice.

Chinese chestnut shell is a by-product of chestnut food processing and is rich in polyphenols. This study sought to investigate the effect of chestnut shell polyphenol extract (CSP) on weight loss and lipid reduction in a 12-week high-fat diet (HFD)-induced murine obesity model. CSP (300 mg per kg body weight) was administered intragastrically daily. AG490, a JAK2 protein tyrosine kinase inhibitor, was also intraperitoneally injected. The results showed that an HFD induced leptin resistance (LR). Compared to corresponding values in the HFD group, CSP treatment improved blood lipid levels, weight, and leptin levels in obese mice (p < 0.01). Additionally, CSP treatment enhanced enzyme activity by improving total antioxidant capacity, attenuating oxidative stress, and reducing fat droplet accumulation and inflammation in the liver, epididymal, and retroperitoneal adipose tissue. CSP also activated the LEPR-JAK2/STAT3-PTP1B-SOCS-3 signal transduction pathway in hypothalamus tissue and improved LR while regulating the expression of proteins related to lipid metabolism (PPARγ, FAS, and LPL) in white adipose tissue in the retroperitoneal cavity. However, the amelioration of lipid metabolism by CSP was dependent on JAK2. Molecular docking simulation further demonstrated the strong binding affinity of procyanidin C1 (-10.3983297 kcal mol-1) and procyanidin B1 (-9.12686729 kcal mol-1) to the crystal structure of JAK2. These results suggest that CSP may be used to reduce HFD-induced obesity with potential application as a functional food additive.

The Fungal Pathogen Gnomoniopsis castaneae Induces Damaging Cankers in Multiple Domestic Fagaceae Species.

Gnomoniopsis castaneae is internationally recognized as a destructive pathogen of chestnut species. Primarily associated with nut rot, it has also been associated with branch and stem cankers of chestnut and as an endophyte of multiple additional hardwood species. The present study evaluated implications of the recently reported United States presence of the pathogen for domestic Fagaceae species. Stem inoculation assays of Castanea dentata, C. mollissima, C. dentata × C. mollissima, and Quercus rubra (red oak) seedlings were utilized to examine the cankering ability of a regional isolate of the pathogen. The pathogen induced damaging cankers in all assessed species and significant stem girdling in all chestnut species. No previous study has associated the pathogen with damaging infection in Quercus species, and its presence in the United States has the potential to compound ongoing chestnut recovery programs and oak regeneration problems within forest systems.

Advances in the development of tailor-made color alcoholic beverages based on an accelerated maturation process.

The study of the evolution of color of alcoholic beverages subjected to accelerate maturation process using heat-treated French oak wood fragments is presented. The results show that it is possible to obtain tonalities like aged beverages in 4 weeks. In this sense, the fragments conditioned at 150 °C (light toasted) proportionated colors like white wine, pale straw, and pale gold. On the other hand, the fragments that received a heat treatment at 200 °C (medium toasted) present yellow tones such as old gold, amber, and deep gold. Finally, the fragments treated at 250 °C (heavily toasted) are those with the most intense yellow tones, classified as sweet chestnut, sherry, russet, muscat, and tawny. The studies of kinetic maturation concluded that the mathematical model of parabolic diffusion could correctly describe the process. Based on this, it is concluded that the heat treatment increases the cavities of the most exposed surface of the wood, increasing the maximum humidity of the materials by 20 %; in such a way that during the first two weeks, there is a diffusion of the solution to the active sites. Wood bioactive compounds on the outer surface achieve a rapid extraction, such as flavonoids, which oxidize rapidly within the solution, generating an increase in yellow color. The previous results were corroborated in a real case analysis using Tequila which can be concluded that the proposed process can give the beverage similar colors to an aged, extra-aged, and ultra-aged class in less than 4 weeks.

C, N, and P stoichiometry for leaf litter of 62 woody species in a subtropical evergreen broadleaved forest.

To understand leaf litter stoichiometry in a subtropical evergreen broadleaved forest, we measured the contents of carbon (C), nitrogen (N) and phosphorus (P) in leaf litters of 62 main woody species in a natural forest of C. kawakamii Nature Reserve in Sanming, Fujian Province. Differences in leaf litter stoichiometry were analyzed across leaf forms (evergreen, deciduous), life forms (tree, semi-tree or shrub), and main families. Additionally, the phylogenetic signal was measured by Blomberg's K to explore the correlation between family level differentiation time and litter stoichiometry. Our results showed that the contents of C, N and P in the litter of 62 woody species were 405.97-512.16, 4.45-27.11, and 0.21-2.53 g·kg-1, respectively. C/N, C/P and N/P were 18.6-106.2, 195.9-2146.8, and 3.5-68.9, respectively. Leaf litter P content of evergreen tree species was significantly lower than that of deciduous tree species, and C/P and N/P of evergreen tree species were significantly higher than those of deciduous tree species. There was no significant difference in C, N content and C/N between the two leaf forms. There was no significant difference in litter stoichiometry among trees, semi-trees and shrubs. Effects of phylogeny on C, N content and C/N in leaf litter was significant, but not on P content, C/P and N/P. Family differentiation time was negatively correlated with leaf litter N content, and positively correlated with C/N. Leaf litter of Fagaceae had high C and N contents, C/P and N/P, and low P content and C/N, with an opposite trend for Sapidaceae. Our findings indicated that litter in subtropical forest had high C, N content and N/P, but low P content, C/N, and C/P, compared with the global scale average value. Litter of tree species in older sequence of evolutionary development had lower N content but higher C/N. There was no difference of leaf litter stoichiometry among life forms. There were significant differences in P content, C/P, and N/P between different leaf forms, with a characteristic of convergence.

Diversity of Monochaetia Species from Fagaceous Leaf Spots in China and Pathogenicity for Chinese Chestnut.

Pestalotioid fungi have been frequently studied with respect to their morphology, molecular phylogeny, and pathogenicity. Monochaetia is a pestalotioid genus that is morphologically characterized by 5-celled conidia with single apical and basal appendages. In the present study, fungal isolates were obtained from diseased leaves of Fagaceae hosts in China in 2016 to 2021 and identified based on morphology and phylogenetic analyses of the 5.8S nuclear ribosomal DNA gene with the two flanking internal transcribed spacer (ITS) regions, the nuclear ribosomal large subunit (LSU) region, the translation elongation factor 1-α (tef1) gene, and the ß-tubulin (tub2) gene. As a result, five new species are proposed here, namely, Monochaetia hanzhongensis, Monochaetia lithocarpi, Monochaetia lithocarpicola, Monochaetia quercicola, and Monochaetia shaanxiensis. In addition, pathogenicity tests for these five species and Monochaetia castaneae from Castanea mollissima were conducted with detached leaves of Chinese chestnut. Results demonstrated that only M. castaneae successfully infected the host C. mollissima and caused brown lesions. IMPORTANCE Monochaetia is a pestalotioid genus, with members that are commonly known as leaf pathogens or saprobes; some strains were isolated from air, in which case their natural substrate is so far unknown. Fagaceae represents an ecologically and economically important plant family that is widely distributed in the Northern Hemisphere, including an important tree crop species, Castanea mollissima, which is widely cultivated in China. In the present study, diseased leaves of Fagaceae in China were investigated, and five new Monochaetia species were introduced based on morphology and phylogeny of combined ITS, LSU, tef1, and tub2 loci. Additionally, six species of Monochaetia were inoculated onto healthy leaves of the crop host Castanea mollissima to test their pathogenicity. The present study provides significant data on the species diversity, taxonomy, and host range of Monochaetia and enhances our understanding of leaf diseases of Fagaceae hosts.

Effects of warming on quantity and structure of litter-derived dissolved organic matter in subtropical natural Castanopsis kawakamii forests.

Litter-derived dissolved organic matter (DOM) is an important source of soil DOM, and the response of which to climate warming may change forest soil carbon and nitrogen dynamics, such as soil carbon and nitrogen mineralization. In this study, we conducted a field manipulative warming experiment in natural Castanopsis kawakamii forests. Combined with litter leaching solution collected in the field and ultraviolet-visible and three-dimensional fluorescence spectroscopy analyses, we explored the effects of warming on the content and structure of litter-derived DOM in subtropical evergreen broad-leaved forests. The results showed that litter-derived dissolved organic carbon and nitrogen content exhibited monthly dynamics, with the peak (in April) and the mean monthly content being 1.02 and 0.15 g·m-2, respectively. Litter-derived DOM had higher fluorescence index and lower biological index, indicating the microbial-origin of DOM from litter. The litter DOM mainly included humic-like fractions and tryptophan-like substances. Warming did not affect the content, aromaticity, hydrophobicity, molecular weight, fluorescence index, biological index and humification index of DOM, suggesting neutral effect of warming on the quantity and structure of litter DOM. Warming also did not affect the relative contribution of main components in DOM, indicating that the temperature variation exerted no effects on microbial degradation. In summary, warming did not change the quantity and quality of litter-derived DOM in subtropical evergreen broadleaved forests, indicating warming had little effect on litter-derived DOM input to soil.

A new genus and species of giant mealybugs (Hemiptera: Coccomorpha: Monophlebidae) from eastern China.

A new genus of giant mealybugs (Hemiptera: Coccomorpha; Monophlebidae), Coronaproctus Li, Xu & Wu gen. nov., is established for the species Coronaproctus castanopsis Li, Xu & Wu sp. nov., collected from Zhejiang province, China on the twigs of Castanopsis eyrei (Fagaceae). The adult female and male are described and illustrated. The new genus is characterized by the adult female possessing quadrilocular disc pores, 13 cicatrices on the venter, and a U-shaped opening of the marsupium, but lacking large bilocular pores.