Gansu Research Academy of Forestry Science and Technology

To efficiently utilize the olive germplasm resources in the Bailong River Valley region of Longnan, China, the oil content of fresh fruits from 98 olive germplasm samples and three maturity stages (Ⅰ, Ⅱ, Ⅲ) was determined and analyzed. Additionally, 13 oil-related traits were studied using variation, correlation, cluster, and principal component analyses (PCA), aiming to screen excellent germplasm resources through comprehensive evaluation. The results showed that the oil content of fresh fruits exhibits a wide range and increases with maturity: I: 28.00% ~ 60.20%; II: 32.50% ~ 64.60%; III: 34.10% ~ 64.80%. Oleic acid (C18:1) was the predominant fatty acid, and 'Grisha' exhibited the highest content across all three maturity stages. In terms of genetic variation, the coefficients of variation for 13 traits across 98 olive germplasm resources exhibited significant variability. PCA reduced the 13 traits to five principal components, which collectively accounted for a cumulative contribution rate of 77.87%. The comprehensive evaluation has identified the top five olive germplasm resources across three maturity stages, including 'K2', 'Agiou orous', 'FS17', among others. Cluster analysis classified germplasms into three distinct categories (Group I, II, III). Group I is recommended as core germplasm resources suitable for bulk commodity oil production. Group II represents ideal material for cultivating highly stable specialty oils and fats. Meanwhile, Group III offers valuable resources for developing hypoglycemic and lipid-lowering functional oils. This study establishes a foundation for olive breeding, cultivation promotion, and processing in Longnan, China.

Bumblebees are the most important pollinators in alpine areas. Their survival is vulnerable to anthropogenic disturbance. To comprehend the variation in bumblebee diversity in different habitat types and altitudinal gradient, this study carried out transect counting in three distinct habitat types and altitudinal gradient in the source area of the Bailong River between June and September from 2021 to 2022. The result indicates (1) high species richness in bumblebees, as 27 species and 1106 individuals from 9 subgenera were collected. It indicates that the Forest-Grassland ecotone has rich bumblebee diversity. Edge effective and suitable habitats bred rich bumblebees. (2) Species richness and abundance differed between three habitat types: alpine meadows had the highest; shrubs on the forest edge had the second highest; and grasslands had the lowest. (3) The distribution pattern in the altitude of bumblebees shows two peaks. The species richness and abundance of bumblebee are highest in the ranges of 3500-3700 m and 2900-3100 m, while 3100-3500 m is lower than the other altitude ranges, presumably because this range is just a large grassland with overgrazing. (4) The results of redundancy analysis indicate that environmental factors significantly affect the diversity of bumblebees. (5) The conservation measures should mainly focus on alpine meadows, as they are the most important habitat of the bumblebee. Reducing overgrazing in large-scale grasslands is beneficial to bumblebees as well as wildflower plants.

Xanthoceras sorbifolium Bunge ( X . sorbifolium ) is an economically significant woody oil plant. With abundant resource diversity, X . sorbifolium has remarkable value in edible, medicinal, ornamental and scientific aspects. Nevertheless, current research on the habitat distribution of X . sorbifolium and the eco-environmental factors that affect its suitability remains insufficient. This study initially identified 38 variables that potentially influence the spatial distribution of X . sorbifolium , including bioclimate, soil, topography, land use and land cover change, and human footprint (HF) variables. After screening via Spearman's correlation coefficient and the jackknife method, 19 variables were ultimately identified. Based on the maximum entropy (MaxEnt) model, this study developed three separate models to analyze how climate change and human activities affect the potential geographic distribution of X . sorbifolium. The analysis focused on three shared socioeconomic pathways (SSP126, SSP370, and SSP585) across both the 2050 s and 2090 s. The results indicated that soil type, precipitation of the wettest month, topsoil pH, altitude, and HF are the main factors influencing the distribution of X . sorbifolium . Human activities are projected to diminish the suitable habitats for X . sorbifolium under current climate conditions. Climate change is anticipated to curtail suitable areas across under most scenarios, except SSP585 in the 2050 s and SSP126 in the 2090 s. Under climate change, the future distribution center of X . sorbifolium is expected to shift northeastard under the SSP126 and SSP370 scenarios, southwestard along the horizontal gradient under the SSP585 scenario, and to lower altitudes along the vertical gradient. The findings of this study should provide a positive reference value for the long-term conservation and large-scale cultivation of X . sorbifolium. • We predicted the suitable habitat of Xanthoceras sorbifolium Bunge. • in China by MaxEnt. • Xanthoceras sorbifolium Bunge distributions were compared under human interference and climate change conditions. • The soil type, precipitation, soil acidity, altitude and human footprint dominantly affected distribution. • Xanthoceras sorbifolium Bunge will likely migrate northeast and southwest and to lower elevations in the future.

BackgroundIn China, a majority of apple orchards were initially planted under arboriculture. The branch number increases, causing a deterioration of the canopy light conditions as the trees age. This phenomenon blocks bud differentiation, resulting in yield decrease and deterioration of fruit quality. Thinning and reshaping are effective strategies for addressing these issues. However, the impact of thinning and reshaping remains unclear. This study analyzed the physiological and metabolic aspects of flower bud differentiation following thinning and reshaping of an overcrowded orchard.MethodsPhysiological and metabolomic analyses were conducted on terminal flower bud samples collected during early (T1) and late (T2) bud differentiation following thinning and reshaping alongside controls CK1 and CK2.ResultsSucrose, glucose, fructose, and sorbitol contents in T1 and T2 groups were significantly higher than in CK1 and CK2. Metabolomic analysis revealed significant differences: 60 metabolites (32 up-regulated, 28 down-regulated) in T1 vs CK1 and 51 metabolites (26 up-regulated, 25 down-regulated) in T2 vs CK2. KEGG enrichment analysis revealed that the biosynthesis of secondary metabolites was the most enriched pathway, with the crucial compounds associated with flower bud differentiation. There was an accumulation of coumarin (C05851), eriodictyol (C05631), and histidine (C00135) during both the early and late stages of flower bud differentiation, underscoring their promoting role. In T1 vs CK1, 2-isopropylmalic acid (C02504), (+)-catechin (C09727), and trans-ferulic acid (C01494) were significantly up-regulated, highlighting their potential as metabolic activators. Conversely, 3’,5’-dimethoxy-3,5,7,4’-tetrahydroxyflavone (C11620) and 4-hydroxyphenylpyruvic acid (C01179) decreased, implying divergent regulatory mechanisms. Temporal specificity emerged in T2 vs CK2, with significant upregulation of myricetin (C10107) and isopimpinellin (C02162). In contrast, umbelliferone (C09315) and trans-caffeic acid (C01197) exhibited opposing trends. Moreover, jasmonic acid (C08491) and 6-phosphogluconic acid (C00345) increased sharply in T2, while trans-traumatic acid (C16308) declined.ConclusionsThinning and reshaping improved light penetration and increased the accumulation of nutrients and secondary metabolites. Sucrose, glucose, fructose, and sorbitol contents and the relative levels of coumarin, eriodictyol, and histidine increased during early and late flower bud differentiation stages, which suggested their positive roles during these stages. 2-isopropylmalic acid, (+)-catechin, and trans-ferulic acid exhibited metabolic activation potential, while 3’,5’-dimethoxyflavone and 4-hydroxyphenylpyruvic acid were distinctly regulated in T1 vs CK1. Myricetin, isopimpinellin, jasmonic acid, and 6-phosphogluconic acid exhibited activation potential, while trans-traumatic acid was distinctly regulated in T2 vs CK2. Metabolic changes and pathway-specific activation/inhibition patterns underlying flower bud differentiation exhibited a direct-indirect regulatory network in secondary metabolism.

The propagation of peach rootstocks, particularly adventitious root (AR) formation, is influenced by multiple factors, with substrate temperature being crucial. This experiment studied the differential gene expression patterns of GF677 rootstock cuttings treated with 200 mg/L IBA under various substrate temperatures (unheated, 19℃, 22℃, 25℃, and 28℃) and cutting periods (7, 14, and 21 days). The results showed a maximum rooting rate of 91% at 25℃ for 40 days, with the highest number of differentially expressed genes (DEGs) observed between 22-25℃. Therefore, the optimal temperature for propagation was determined to be 25℃. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses highlighted “starch and sucrose metabolism” and “plant hormone signal transduction” as enriched pathways. Specifically, 26 plant hormone signaling pathways (ARFs, LBDs, SAURs, and GH3) and 22 AR formation-related pathways (AUR3, LRP1, RGF1, AIR9, AP2, and NAC) were identified from these DEGs. Weighted gene co-expression network analysis (WGCNA) clarified the involvement of various transcription factors (WRKYs, ERFs, NACs, bHLHs, bZIPs, and MYBs) in AR formation. These findings indicate significant differences in gene expression under different combinations of substrate temperatures and cutting periods. Overall, this study enhances our understanding of the molecular mechanisms underlying peach tree asexual reproduction.

The impact of various crop rotation systems on the potential for soil carbon sequestration and stoichiometric characteristics is not yet fully understood, which poses challenges for effective land management and utilization. This study selected three typical crop rotation methods in the Longzhong Loess Plateau: maize–alfalfa rotation (MA), maize–sainfoin rotation (MS), and maize–wheat rotation (MW). Soil physical and chemical indices were measured, and the soil carbon density and soil stoichiometry were calculated and analyzed. The results show that the soil C/N of the surface soils was low across the rotation methods, indicating a rapid rate of organic matter decomposition and mineralization, which may hinder soil nutrient accumulation. The soil N/P was found to be lower than the national average of 8.0, indicating that nitrogen is a limited nutrient in the soil under the three crop rotation systems in this region. The soil total nitrogen content can be increased by rotation with leguminous forage. Sainfoin rotation can enhance the soil total carbon and organic carbon content, thereby improving the soil’s carbon sequestration potential. The research findings provide a theoretical foundation for the selection of appropriate rotation methods and the maintenance of the stability of agricultural ecosystems in semi-arid regions.

Abstract Land use change is a key factor affecting habitat quality. In order to reveal the impacts of urban land use changes on habitat quality, this paper uses the city of Zhongwei, China, as a case study. Based on the land use data from 1980, 2000 and 2020, the PLUS-InVEST coupled model was used to predict and assess the land use and habitat quality of Zhongwei. The results showed that from 1980 to 2020, the areas of construction land and woodland increased significantly, while the areas of water and unused land decreased slightly, and the other lands remained essentially unchanged. The main factors such as precipitation, temperature, population and distance from government distance influenced the land expansion. Moreover, the habitat quality in Zhongwei showed a decreasing trend. The overall area of low habitat quality increased, while the overall area of relatively low and medium habitat quality decreased, and the other remained essentially unchanged between 2000 and 2020. The predicted habitat quality of the study area in 2040 was compared under different development scenarios. The comparison of results showed that highest habitat quality and the lowest habitat degradation under the Ecological protection scenario. Although the afforestation and desertification control projects in Zhongwei have proved successful in increasing woodland and improving habitat quality, its ecological restoration measures have not yet completely counteracted the adverse effects of ongoing urbanization and industrialization on habitat quality, resulting in a persistent decline in overall habitat quality.

BACKGROUND: Winter injury often threatens phenology and walnut survival in late spring and winter in northern areas of China. OBJECTIVE: This study aimed at evaluating seven walnut varieties which have superior economic traits. MATERIALS AND METHODS: Mature functional leaves were observed by paraffin section and the related anatomical structure indices were measured. The stem segments were placed at six temperatures [4 (control), -10, -15, -20, -25, -30°C] for low temperature stress treatment, and the relevant indices were measured. RESULTS: The thickness of palisade tissue (PT), sponge tissue (ST) and the PT/ST of ' Wen185 ' was significantly higher than in ' Longboxiang 2 ' , ' Longboxiang 3 ' and ' Suizhuang ' . However, the leaf thickness (LT) of ' Longboxiang 3 ' was markedly lower than that of other varieties. With the decrease in temperature, relative electrolyte leakage (REL), proline (Pro) and soluble sugar content (SS) of all varieties increased, while superoxide dismutase (SOD) and peroxidase (POD) activities showed a rise and fall trend. According to the LT50, the cold tolerance of seven walnut varieties was ranked from high to low, viz. ' Yuanlin ' > ' Wen185 ' > ' Xiangling ' > ' Suizhuang ' > ' Qingxiang ' > ' Longboxiang 2 ' > ' Longboxiang 3 '. CONCLUSION: The variety ' Yuanlin ' can adapt to low temperature and should be widely promoted.

Picea asperata and P. crassifolia have sympatric ranges and are closely related, but the differences between these species at the plastome level are unknown. To better understand the patterns of variation among Picea plastomes, the complete plastomes of P. asperata and P. crassifolia were sequenced. Then, the plastomes were compared with the complete plastomes of P. abies and P. morrisonicola, which are closely and distantly related to the focal species, respectively. We also used these sequences to construct phylogenetic trees to determine the relationships among and between the four species as well as additional taxa from Pinaceae and other gymnosperms. Analysis of our sequencing data allowed us to identify 438 single nucleotide polymorphism (SNPs) point mutation events, 95 indel events, four inversion events, and seven highly variable regions, including six gene spacer regions (psbJ-petA, trnT-psaM, trnS-trnD, trnL-rps4, psaC-ccsA, and rps7-trnL) and one gene (ycf1). The highly variable regions are appropriate targets for future use in the phylogenetic reconstructions of closely related, sympatric species of Picea as well as Pinaceae in general.