Grandis Cv Research Articles

Spatial Heterogeneity and Key Influencing Factors of Soil Organic Carbon, Soil Total Nitrogen, and Carbon to Nitrogen Ratio in main plantations of Torreya grandis cv. Merrillii

Soil organic carbon （SOC） and soil total nitrogen （STN） serve as important indicators of the elemental balance within forest ecosystems reflecting soil fertility and quality. Accurate knowledge regarding the spatial variability of regional SOC, STN, and C∶N ratio and their influencing factors is of great significance for precise fertilization and soil health. In this study, a total of 117 topsoil samples （0-20 cm in depth） based on a 1 km×1 km grid were collected in the Torreya grandis cv. Merrillii plantation in Zhejiang Province. A combination of multi-dimensional statistical approaches （random forest model, structural equation model, redundancy analysis, and variation partitioning analysis） and diverse spatial analytical techniques （geostatistics, Moran's I index, etc.） were applied to reveal the spatial distributions and influencing factors of SOC, STN, and C∶N ratio in the Torreya. grandis cv. Merrillii region. The results showed that the average ω（SOC）, ω（STN）, and C∶N ratio were 17.63 g·kg-1, 1.48 g·kg-1, and 12.65, respectively, and their coefficients of variation were 68.08%, 67.41%, and 46.03%, respectively, indicating a moderate degree of variability. In general, the SOC, STN, and C∶N ratio of the Torreya grandis cv. Merrillii plantations were at an intermediate level in the national plantation. The semi-variance results showed that the nugget/sill values of SOC, STN, and C∶N ratio were 49.98%, 45.88%, and 49.93%, respectively, demonstrating a moderate level of spatial autocorrelation. The spatial distribution results showed that SOC, STN, and C∶N ratio decreased from northeast to southwest, with the majority of the region exhibiting above-medium fertility levels of SOC. The results of correlation analysis and redundancy analysis indicated that AN, AP, and AK were significantly correlated with both SOC, STN, and C∶N ratio （P<0.05）. The results of random forest, structural equation model, and variation partitioning analysis evidenced that the main influencing factors of SOC and STN were soil-available nutrients （AN, AP, and AK）. Therefore, our results could provide important insights for enhancing soil carbon and nitrogen pools in special plantations in Zhejiang Province, enhancing the capacity of plantations to adapt to regional climate change through ecological measures such as appropriate fertilization practices and strategic understory vegetation cultivation.

Shortage of storage carbohydrates mainly determines seed abscission in Torreya grandis ‘Merrillii’

Torreya grandis cv. Merrillii is a well-known nut in South China with high nutritional value. Severe premature seed abscission limits the industrial development of T. grandis by causing serious economic losses. However, the physiological mechanisms of seed abscission in T. grandis remain poorly understood. To gain insight into the relationships between carbohydrate status and seed abscission, three-year-old seed-bearing branches were taken as representative materials for the entire tree. Furthermore, the time course of changes in the photosynthetic rate and the non-structural carbohydrate (NSC) dynamics were monitored in the main sources (the one-year-old and two-year-old shoots), and the dry weight and NSC levels of sinks (the seeds, current female cone cluster, and current vegetative cluster) across all seed development stages were recorded. The cumulative seed abscission rate significantly increased, reaching 91.5% from 0 to 72 days after seed protrusion time (SPT). NSC levels in the main sources significantly decreased by 56%–79%, accompanied by a significantly increased photosynthesis rate of 17.1%–49.1% during that period and increased NSC levels in the three sinks. The gene expression level of cell wall invertase (TgCWIN) was significantly correlated with sucrose, fructose, and glucose levels. The carbon storage capacity of the main sources significantly decreased from 6.03 to 3.14 mmol C · d−1, with a stable photosynthetic capacity, from 0 to 72 days after SPT, whereas the carbon demand of the three sinks showed a continuously increasing trend from 3.14 to 7.71 mmol C · d−1. In addition, sucrose supplementation significantly decreased the cumulative seed abscission rate. These results suggest that storage carbohydrates play a major role in the regulatory mechanism of seed abscission in T. grandis. Our study provides a theoretical basis for improving T. grandis yield through establishing a better carbon balance between sources and sinks using timely fertilization or proper pruning procedures.

Alternaria tomentosae (Pleosporaceae, Dothideomycetes); novel endophytic species from Citrus grandis cv. ‘Tomentosa’ fruits in China

ABSTRACT Alternaria species show a wide range of life modes, viz. pathogens in plants, animals and human, saprobes and rarely endophytes. In the present study, three Alternaria isolates were obtained from healthy fruits of Citrus grandis cv. ‘Tomentosa’ in an industrial planting area in Guigang City, Guangxi Province, China. The nuclear internal transcribed spacer of the rDNA region (ITS), 28S large subunit rDNA (LSU), 18S small subunit rDNA (SSU), glyceraldehyde-3-phosphate dehydrogenase (gapdh), translation elongation factor 1 alpha (tef1-α), RNA polymerase second largest subunit (rpb2) and Alternaria major allergen (alt-a1) gene regions were sequenced and employed to construct phylogenetic trees. Based on the morphology and combined multi-genes phylogeny, our isolates were identified as a novel species, Alternaria tomentosae.

First report of Fusarium commune causing Torreya grandis crown and root rot in China

AbstractTorreya grandis cv. Merrillii is an important economic tree widely cultivated in hilly subtropical areas in China and some parts of Japan and Korea. Crown and root rot was found on T. grandis in Zhejiang Province of China. Three isolates with similar morphology were isolated from diseased samples, and used for identification and pathogenicity tests. The pathogenicity of the isolates was confirmed by fulfilling Koch's postulates. The pathogen was identified as Fusarium commune based on morphological characteristics and phylogenetic tree constructed by combining ITS and TEF‐1α gene sequences. This is the first report of F. commune causing crown and root rot on T. grandis in China.

Formulation of a Stable Oil-in-Water Microemulsion of Torreya grandis cv. Merrillii Aril Essential Oil and Its Application in Loquat Fruit Preservation.

Loquat is a nutrient-rich fruit with juicy and sweet pulp, but it is vulnerable to rot and deterioration without proper postharvest preservation measures. This study aimed to improve the postharvest quality of loquat by developing a microemulsion system based on an essential oil extracted from the Torreya grandis cv. Merrillii aril (TaEO), which has antimicrobial and antioxidant properties. An optimal TaEO microemulsion (TaEO-ME) was formulated, using a mixture of Tween-40 and Tween-80 as the surfactant, 1-butanol as the co-surfactant, and TaEO as the oil phase, with mass ratios of 9:1, 3:1, and 6:1, respectively. Two TaEO-ME formulations with 60% and 70% water contents were stable for 180 days at room temperature, with a mean droplet size below 12 nm and polydispersity index less than 0.24. They also exhibited higher stability and enhanced biological activities compared to free TaEO. Loquat fruit treated with TaEO-ME displayed a reduced decay index and lower membrane lipid peroxidation after 15 days of storage at 15 °C, as indicated by the lower malondialdehyde content and higher peroxidase activity. Moreover, the TaEO-ME treatment preserved the nutrient quality by maintaining the total phenolic compounds and ascorbic acid content. Our findings suggested that TaEO-ME can be used as a substitute for chemical preservatives to keep fruits fresh.

Effect of dietary administration of Chinese torreya nut on reproductive function in ICR female mice and its possible mechanism of action

AbstractChinese torreya nut (Torreya grandis cv. Merrillii) is a unique edible nut that grows in China, which is known for its ability to reduce blood lipids, prevent blood sclerosis, and coronary heart disease. However, its effect on reproduction is not well understood. In this study, the comprehensive effects of Chinese torreya nut on the sex hormones and endometrium in female mice and their uterine expression profiles were investigated. Here, feeding of mice with Chinese torreya nut resulted in a decrease in uterine coefficients and serum progesterone levels, thickening of the endometrium, and an increase in estrogen levels. The enrichment analyses indicated that the differentially expressed genes between the Chinese torreya nut addition and control mice were enriched in NOD‐like receptor signaling pathway, complement and coagulation cascades and p53 pathway. Quantitative real time PCR and western blot results showed that there were significant differences in the transcripts and protein expression of estrogen receptor alpha and progestogen receptor associated with G protein coupled estrogen receptor. These findings suggest that Chinese torreya nut may have a potentially beneficial effect on coordinating uterine contractions in mice, rendering it a promising functional food.

Endophytic Colletotrichum (Sordariomycetes, Glomerellaceae) species associated with Citrusgrandis cv. "Tomentosa" in China.

Colletotrichum species are well-known plant pathogens, saprobes, endophytes, human pathogens and entomopathogens. However, little is known about Colletotrichum as endophytes of plants and cultivars including Citrusgrandis cv. "Tomentosa". In the present study, 12 endophytic Colletotrichum isolates were obtained from this host in Huazhou, Guangdong Province (China) in 2019. Based on morphology and combined multigene phylogeny [nuclear ribosomal internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (gapdh), chitin synthase 1 (chs-1), histone H3 (his3) actin (act), beta-tubulin (β-tubulin) and glutamine synthetase (gs)], six Colletotrichum species were identified, including two new species, namely Colletotrichumguangdongense and C.tomentosae. Colletotrichumasianum, C.plurivorum, C.siamense and C.tainanense are identified as being the first reports on C.grandis cv. "Tomentosa" worldwide. This study is the first comprehensive study on endophytic Colletotrichum species on C.grandis cv. "Tomentosa" in China.

Qualitative and Quantitative Analyses of the Chemical Components of Peels from Different Pomelo Cultivars (Citrus grandis [L.] Osbeck) Based on Gas Chromatography-Mass Spectrometry, Ultraperformance Liquid Chromatography-Q-Exactive Orbitrap-MS, and High-Performance Liquid Chromatography-Photodiode Array Detection.

The volatile and nonvolatile phytochemicals in peels of 5 major pomelo cultivars (including Citrus grandis cv. Yuhuanyou, C. grandis cv. Liangpingyou, C. grandis cv. Guanximiyou, C. grandis cv. Duweiwendanyou, and C. grandis cv. Shatianyou) from 11 places in China were characterized. First, 194 volatile compounds in pomelo peels were identified by gas chromatography-mass spectrometry (GC-MS). Of these, 20 major volatile compounds were subjected to cluster analysis. The heatmap indicated that the volatile compounds in peels of C. grandis cv. Shatianyou and C. grandis cv. Liangpingyou were different from those in other varieties, while there was no difference among C. grandis cv. Guanximiyou, C. grandis cv. Yuhuanyou, and C. grandis cv. Duweiwendanyou from different origins. Second, 53 nonvolatile compounds were identified in pomelo peels by ultraperformance liquid chromatography-Q-exactive orbitrap tandem MS (UPLC-Q-exactive orbitrap-MS), of which 11 components were detected for the first time. Third, six major nonvolatile compounds were quantitatively analyzed with high-performance LC-photodiode array detection (HPLC-PDA). Combining the results of HPLC-PDA and the heatmap, 6 nonvolatile compounds in 12 batches of pomelo peel were well separated among varieties. Comprehensive analysis and identification of chemical components in pomelo peels are of great significance for their further development and utilization.

How Do Morphological Factors Influence the Green Nut Yield of Chinese Torreya?

As an important economic tree species, Chinese Torreya (Torreya grandis cv Merrillii) has been widely planted in the subtropical regions of China. However, it remains to be studied whether morphological traits are the key factors reflecting or affecting the green nut yield of Chinese Torreya, which is necessary for breeding research and plantation management. Therefore, in Zhuji in the Zhejiang Province, the central production area of Chinese Torreya, we investigated the morphological traits (height, ground diameter, under-crown height, crown width, and branching amount) and green nut yield of 120 randomly selected Chinese Torreya. Our results indicated that the differences in the morphological traits among Chinese Torreya individuals were relatively small, but those in the green nut yield traits were great. There was highly significant (p < 0.01) correlation between green nut yield and crown area and between green nut yield and root collar diameter (ground diameter). A moderate relationship (r = 0.38; p < 0.05) was observed between green nut yield and crown area, while a weak relationship (r = 0.294; p < 0.05) was detected between green nut yield and ground diameter. Tree height and branching amount had positive effects on green nut yield through other morphological traits, and under-crown height had indirect negative effects on green nut yield. Linear regression analysis showed a significant linear positive correlation between green nut yield and crown area, ground diameter, and crown width in the north–south and east–west directions (p < 0.01). These findings imply that if the tree height is fixed, increasing the ground diameter and crown area, appropriately increasing the branching amount, and reducing the under-crown height could be potential technical measures to improve the green nut yield of Chinese Torreya. Our study provides background information on green nut yield and its morphological traits in Chinese Torreya.

Thermal conditions and active substance stability affect the isomerization and degradation of lycopene

This study evaluated the effects of thermal treatment conditions (100–120 °C, 0–5 h) and active substance stability on the isomerization and degradation of lycopene in the “Sanhong” pummelo (C. grandis cv. Sanhongmiyou) matrix. The results revealed that the degradation of (all-E)-lycopene and total lycopene in pummelo could be well fit by the first-order kinetic model under thermal treatment. The total Z-lycopene ratio was maintained at nearly 40 % (120 °C, 4 h). The behavior of lycopene was related to the degradation of active substances, such as the degradation of ascorbic acid and polysaccharides. The stability of polysaccharides was temperature-dependent, and with the increasing temperature (100–120 °C), a significant negative correlation was observed between the content of Z-isomers and polysaccharides. The enhancement of lycopene isomerization was attributed to the degradation of polysaccharides under thermal treatment. These findings facilitate the functional development and efficient utilization of lycopene in fruit processing.

Spatial variation, sources identification and risk assessment of soil heavy metals in a typical Torreya grandis cv. Merrillii plantation region of southeastern China

Torreya grandis (Torreya grandis cv. Merrillii) is a unique nut tree species in China. Currently, researches on Torreya grandis focus on nuts quality and yield, while few works are related to the soil quality of Torreya grandis plantation. In this study, the typical Torreya grandis production areas of Zhuji, Shengzhou, Keqiao and Dongyang cities along the Kuaiji Mountain were selected. A total of 121 topsoil samples (0–20 cm) were collected based on a grid of 1 km × 1 km. The results indicated that the average concentrations of Cd, Cr, Cu, As, Ni and Pb in soils were 0.12, 49.01, 27.95, 14.28, 26.97 and 40.28 mg kg−1, respectively. The concentrations of six heavy metals all exceeded the background values, and there were different degrees of pollution levels. The results of Moran's I indicated that the spatial high-high clusters of soil heavy metals were mainly distributed in Zhuji and the junction of Shengzhou and Keqiao. The partial least squares path analysis of structural equation modeling (PLS-SEM) showed that OM and soil nutrients had extremely significant effects on soil heavy metals. Sources identification of principle component analysis (PCA) and positive matrix factorization model (PMF) revealed that agricultural activities, natural factors and mining were the main sources of soil heavy metals. The human health risks caused by soil heavy metals pollution were generally acceptable based on Monte Carlo simulation method. For the heavy-metal polluted area, management measures should be considered in order to protect human health.

Diversity of Endophytic Bacterial Populations in Citrus grandis cv. Tomentosa

It is necessary to understand the microbial interactions with this plant to study the effect of its medicinal quality. In the present study, high-throughput sequencing was used to analyze the diversity of endophytic bacteria on leaves, branches and fruits of C. grandis cv. Tomentosa. This study obtained a total of 607,952 high-quality sequence fragments of the V3-V4 region from nine samples that belonged to three groups, and 382 operational taxonomic units. The diversity of endophytic bacteria is high while occurrence was different in fruits, branches and leaves. There were 191 OTUs in the three groups. Candidatus Liberibacter was the most abundant class in branches and fruits, while the dominant population of leaves was Massilia. The 16S rRNA function prediction was taken to understand the function of C. grandis cv. Tomentosa. All results not only have reference signifi cance for the functional study of endophytic fungi and the utilization of endophytic fungi, but also have reference signifi cance for the biological control of plant diseases on C. grandis cv. Tomentosa.

Apple stem grooving virus is associated with leaf yellow mottle mosaic disease on Citrus grandis cv. Huangjinmiyou in China

Although it is usually latent on citrus, apple, and pear, apple stem grooving virus (ASGV) poses a great risk to many sensitive cultivars. Since severe leaf yellow mottle mosaic (LYMM) symptoms have been observed on Huangjinmiyou (HJY) pummelos (Citrus grandis cv. Huangjinmiyou), a commercial variety that is widely cultivated in South China, high throughput sequencing (HTS) was used to find potential pathogens and only three divergent ASGV variants were identified. The three ASGV variants shared 81.03–82.34% genome-wide pairwise identities with each other, and were separately closest to other ASGV variants from different hosts and/or geographical regions, as indicated by viral phylogenies. However, these new variants may have developed from viral interstrain interactions, based on the results of recombination analysis. A large-scale survey using reverse transcription-PCR (RT-PCR) protocols designed for the three ASGV variants revealed a high incidence (92.7–100%) of ASGV in symptomatic HJY trees from 11 major citrus-producing regions in China. None of ASGV were detected in asymptomatic trees. Temperature treatments applied to the symptomatic HJY plants showed that ASGV is sensitive to high temperatures (30–35°C), at which not only the plants recovered, but also the viruses were not detected by RT-PCR, while at low temperatures (20–24°C), both the symptoms and viruses remained detectable. These data show that ASGV is associated with the LYMM disease prevalent on HJY in China, and this is the significant basis especially of taking appropriate measures timely to manage the disease.

Analysis of the chemical components of pomelo peels (Citrus grandis [L.] Osbeck) from different cultivars by using supercritical CO2 fluid extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry.

Five pomelo cultivars (i.e., Citrus grandis cv. Shatianyou, Citrus grandis cv. Guanximiyou, Citrus grandis cv. Yuhuanyou, Citrus grandis cv. Duweiwendanyou and Citrus grandis cv. Liangpingyou) from different origins in China were selected to analyze their components by using supercritical CO2 fluid extraction coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry. A total of 45 compounds were identified in the supercritical CO2 fluid extracts of the pomelo peels from the five cultivars. These compounds included eight flavonoids, 18 coumarins, four organic acids, three aldehydes, and 12 other compounds, which were identified using the obtained MS data and by comparison with commercial standards, orbitrap Chinese Traditional Medicine Library, and previous literature. Twenty-five of the identified compounds were detected for the first time in the pomelo peel extracts. Results suggested that the pomelo peels of C. grandis cv. Shatianyou contained the most natural chemical compositions. The pooled result may offer scientific evidence for further development and utilization of pomelo peels and a route for screening appropriate varieties for various demands.

Phytochemical characterisation of two news blood grapefruits by means of HPLC-MS

In this study, the main flavanones, polymethoxyflavones, anthocyanins and furanocoumarins were evaluated in two blood grapefruits (CQP 31 and CQP 32), in their juice, peel, and leaves, by means of HPLC-DAD analysis and identified by HPLC-MS-MS. They are compared with the contents of these secondary metabolites in three commercial grapefruits: Star Ruby, Marsh, and Duncan; a blood orange, cv. Sanguinelli and with the parents of both cultivars Citrus grandis cv Azimboa and cv. Violeta de los valles. The flavonic profile in cultivars CQP 31 and CQP 32 revealed the presence of the characteristic flavanones of grapefruit, naringin being the most abundant. The ripe fruits of cultivars CQP 31 and 32 showed a red coloring due to the presence of anthocyanins with a total juice content of 145 and 136 ppm. The levels of furanocoumarins in juices of cultivar CQP 31 were well below the values quantified in Star Ruby, Marsh and Duncan. These furanocoumarins were not detected in the juice of the cultivar CQP 32. These results indicate that CQP 31 and 32 can be classified as blood grapefruits with a high content of bioactive compounds and low content or absence of furanocoumarins.

Multi-omics analysis reveals the molecular responses of Torreya grandis shoots to nanoplastic pollutant

Micro/nanoplastic has become an emerging pollutant of global concern. At present, ecotoxic researches on micro/nanoplastics mostly focus on marine aquatic organisms and freshwater algae. Research on the ecological impacts of plastics on higher terrestrial plants, especially on forest plants, is relatively limited. Torreya grandis cv. Merrillii, a species of conifer in the family Taxaceae, is a unique and economically valuable tree species in China. The physiological and biochemical responses of T. grandis seedlings to polystyrene nanoplastics (PSNPs) with a diameter of 100 nm were systematically studied inthe present study. The results showed that nanoplastics enhanced the accumulation of the thiobarbituric acid reactive substance and the activities of catalase and peroxidase. The concentrations of iron, sulfur, and zinc were reduced after nanoplastic exposure. PSNP treatment had an important effect on a series of chemical and genetic indicators of T. grandis, includingantioxidants, small RNA, gene transcription, protein expressions, and metabolite accumulation. Multi-omic analysis revealed that PSNPs modulate terpenoid- and flavonoid-biosynthesis pathways by regulating small RNA transcription and protein expression. Our study provided novelty insights into the responses of forest plants to nanoplastic treatment.

Chinese Torreya agroforestry alters the rhizosphere soil bacterial communities and potential functions

The agroforestry practice has been regarded as a practical land-use selection to improve the Torreya grandis cv. Merrillii plantation management benefits. However, the relative report about the variation of rhizosphere soil bacterial communities and the potential functions under T. grandis-based agroforestry systems is currently limited. In the present study, we investigated the variation of soil bacterial communities and potential functions under the T. grandis-based agroforestry systems (T. grandis intercropping with Polygonatum sibiricum, PT; T. grandis silvopasture with goose, GT), using the Illumina MiSeq platform conjoined with Functional Annotation of Prokaryotic Taxa (FAPROTAX) annotation. The findings indicated that both silvopasture and intercropping significantly increased soil pH, total nitrogen (TN), available nitrogen (NH4+-N and NO3−-N), and total potassium (K) in comparison to the monoculture. According to the relative abundances of bacterial communities in T. grandis rhizosphere, Proteobacteria, Actinobacteria, Acidobacteria, and Planctomycetes were the dominant phyla. The intercropping and silvopasture showed a significant increase in phyla Chloroflexi and Verrucomicrobia and a decrease in phyla Proteobacteria and Rokubacteria. Besides, the intercropping significantly increased Actinobacteria compared to the monoculture. The result indicated that the different agroforestry systems formed distinct bacterial community structures. The bacterial functional structures shifted from nitrogen-utilizing bacteria to carbon-utilizing bacteria under silvopasture and intercropping. The soil available N (NH4+-N and NO3−-N), pH, and TN were the most critical variables that impact the bacterial community and functional structures. These findings demonstrate that the bacterial community and potential function structures shift significantly under the agroforestry systems, reflecting the shift in the soil ecosystems caused by the plant-soil-microorganism interaction. Our findings provide valuable information for understanding the response of bacteria to land-use changes and emphasize the influence of T. grandis-based agroforestry systems on soil bacteria.

Microbial Composition and Diversity in Soil of Torreya grandis cv. Merrillii Relative to Different Cultivation Years After Land Use Conversion

In order to explore the impacts of the land use conversion from a Phyllostachy pubescens (moso bamboo) forest to a Torreya grandis cv. Merrillii plantation, as well as the cultivating years of the T. grandis cv. Merrillii plantation, on the soil microbial community, this research studied the soil microbial structure and diversity of a moso bamboo forest, T. grandis cv. Merrillii plantations (5, 10, and 30 a), and a T. grandis cv. Merrillii-mountain rice interplanting plantation (5 a) using the high-throughput sequencing technique, and the relationship between the microbial community and environmental factors was further explored. The results showed that after the land use change, the Shannon index and Chao1 index of the soil bacterial community increased significantly; the Simpson index increased significantly in the 30 a T. grandis cv. Merrillii plantation, whereas the Shannon index decreased significantly. Both the Simpson index and Chao index of the soil fungal community had no significant difference under different land use types. whereas the Shannon index was significantly decreased in the 30 a T. grandis cv. Merrillii plantation. PCoA analysis of the soil microbial community at the genus level showed that land use type played a vital role in driving the changes in soil bacterial and fungal communities. The compositions of the soil microbial communities between the two 5 a stands were most similar. The dominant phyla of soil bacteria mainly included Acidobacteria, Proteobacteria, Actinobacteria, and Chloroflexi. The results of cluster analysis showed that the soil bacterial community changed significantly at the genus level after the conversion of land use; the abundance of most dominant bacterial communities decreased with increasing cultivation. The fungal community was mainly composed of Ascomycota, Basidiomycota, and Zygomycota, whose changes in community characteristics were similar to those of bacteria. The results of RDA analysis showed that pH, organic matter, available phosphorus, available potassium, and water-soluble organic carbon and nitrogen were significantly correlated with soil microbial community. Therefore, these soil fertility properties might be the driving factors affecting the structure of bacterial communities. This study provided a theoretical basis for solving the problem of soil quality deterioration in T. grandis cv. Merrillii stand land management.

Spatial Heterogeneity of Selected Soil Nutrients Related to Torreya grandis cv. Merrillii Plantation in Southeastern China

Chinese Torreya grandis (Torreya grandis cv. Merrillii) is a unique economic tree species in China. Intensive management related to application of chemical fertilizer and herbicides caused serious soil quality degradation of Chinese Torreya grandis plantations. Totally, 120 soil samples were collected from the main disbtributed areas of Chinese Torreya grandis in Southeastern China. In this area, soil pH values varied from 3.68 to 6.78, with a median value of 4.91, implying a trend of acidification. The average concentrations of organic matter, available nitrogen, available phosphorus and available potassium were 27.52 g kg−1, 135.77 mg kg−1, 15.12 mg kg−1, and 153.43 mg kg−1, respectively. The results of spatial analysis revealed that target variables had clear spatial patterns. The soil fertility was relevantly high in most of the study area, with soil nutrient imbalances existing. The stand age had a large effect on soil properties, which were also mainly influenced by human activities. Therefore, it is necessary to change the fertilization method for a sustainable management of Torreya grandis plantation.

Chinese Torreya grandis cv. Merrillii seed oil affects obesity through accumulation of sciadonic acid and altering the composition of gut microbiota

Torreya grandis cv. Merrillii (Taxace, Torreya) is mainly distributed across the hilly areas of subtropical China and is well known for its nutritional value. In this study, the ameliorative effects of T. grandis seed oil on lipid metabolism were investigated, and the underlying mechanism was explored from the perspective of gut microbiota. Mice experiments showed that the rate of body mass gain in the group where the mice were fed a high-fat diet (HFD) and supplemented with 550mg/(kg·day) T. grandis seed oil (HFD+TO550 group) was 42.27%, while it was 62.25% in the HFD group. Compared with the HFD group, the liver and fat indices, total cholesterol, triglycerides, and low-density lipoprotein cholesterol were reduced in the oil-supplement groups. Moreover, the oil supplement significantly changed the fatty acid composition and alleviated pathological damage to the liver caused by the high-fat diet. Additionally, the distinct clustering of bacteria in the composition of gut microbiota was observed in the oil treatment group compared with that in the HFD group. T. grandis seed oil significantly increased the abundance of the beneficial bacteria and short-chain fatty acid producers, including Lactobacillus, Bifidobacterium, Faecalibaculum and Allobaculum. Our results suggest that the supplements of T. grandis seed oil could alleviate hyperlipidemia caused by HFD. These positive effects are considered to be related with sciadonic acid (SCA) and are partially mediated by alterations in gut microbiota composition and functionality.