Search Results (5)

Quercus gilva is a dominant species in the subtropical evergreen broad-leaved forests of East Asia with substantial economic and ecological value. However, efficient clonal propagation methods for this species remain limited. This study aimed to establish a micropropagation protocol for Q. gilva using nodal stem segments from two-year-old seedlings as explants, focusing on culture establishment, shoot induction, shoot proliferation, and ex vitro rooting. Aseptic culture was effectively established by rinsing explants under running water for 15 min, followed by immersion in 0.1% HgCl₂ for 8 min, which balanced contamination control and explant viability. Explant browning was reduced by pre-soaking in 1.0 g·L⁻¹ ascorbic acid (VC) and by supplementing the Murashige and Skoog (MS) medium with 3.0 g·L⁻¹ activated charcoal. The highest shoot induction percentage (80.0%) was obtained on MS medium containing 1.0 mg·L⁻¹ 2,4-D and 0.5 mg·L⁻¹ TDZ. Shoot proliferation was achieved by subculturing induced shoots on MS medium supplemented with 1.0 mg·L⁻¹ NAA and 1.0 mg·L⁻¹ 2iP. For ex vitro rooting, regenerated shoots were dipped in a solution containing 600.0 mg·L⁻¹ IBA plus 700.0 mg·L⁻¹ NAA and then transplanted into a substrate of peat and perlite (1:1, v/v), resulting in a rooting percentage of 70.0% and well-developed root systems. This study establishes a preliminary in vitro propagation framework for Q. gilva, providing a methodological reference for future studies aimed at improving clonal propagation efficiency. Full article

Since the Anthropocene, biodiversity loss owing to human activity and climate change has worsened. Quercus gilva is an evergreen oak species native to China, Japan, and South Korea and is threatened by a long history of human impact. The purpose of this study was to (1) reassess the threatened category of Q. gilva based on a detailed survey, and (2) identify the genetic structure and diversity of Q. gilva based on genomic data. First, we conducted a detailed survey of the populations in China. Second, we collated all the literature and information. Finally, genome-wide genetic variation was analyzed based on 65 individuals from 22 populations. We found that Q. gilva has suffered rapid population decline, and at present, most populations are very small. The evolutionary path of Q. gilva was from the southwest to east of China and then to Japan and South Korea. Quercus gilva showed no distinct genetic structure and had a relatively low genetic diversity. Among the 22 populations, most populations in southwestern China, South Korea, and Japan had high genetic diversity. The populations in Jingning (Zhejiang province; ZJN), Wuyuan (Jinaxi province; JWY), and Zherong (Fujian province; FZR) suffered a strong bottleneck. In conclusion, Q. gilva is an endangered species native to East Asia. Because of the very low genetic diversity of Q. gilva and most populations are small, we need to (1) strengthen the protection of this species, (2) conduct conservation actions with in-situ reinforcement populations, and (3) select populations with high genetic diversity as provenances for afforestation efforts. Finally, we suggest that in the future, genetic diversity should be considered as the sixth criterion for IUCN to evaluate the threatened category. Full article

The increasing demand for precious timber resources promotes immediate efforts to develop high-valuable hardwood resources in afforestation. However, the lack of valuable tree species seedlings for afforestation and their ecological adaptability must primarily be addressed. To explore a valuable tree species for precious timber resourcing in afforestation, a comparative analysis of the characteristics of photosynthetic physiology and leaf anatomy in three different Quercus L. Section Cyclobalanopsis seedlings of Quercus chungii, Quercus gilva, and Quercus glauca was performed during three growth stages (July, September, and November) in South China. The results showed that there are significant differences in photosynthetic physiological characteristic parameters, chlorophyll content, and leaf anatomical structure among the three seedlings in each growth stage (p < 0.05). The photosynthetic parameters, i.e., Pn, Gs, Tr, WUE and Ci in each tree species all had the same trend of increase from July to September and decrease from September to November, and with a pick point in September during the three stages. The Pn in Q. chungii was higher than that in the other two species in each stage, and the highest Pn with an average value of 8.26 μmol·m⁻²·s⁻¹ was obtained in September in Q. chungii, which was 13.77% and 20.06% higher than that of in Q. gilva and Q. glauca at the same time, respectively. Significant differences were also detected in the chlorophyll fluorescence of Fo, Fm, Fv/Fm, Y, ETR, qP, and NPQ among three seedlings within each growth stage from July to November (p < 0.05). The thickness of the mature leaf was decreased in order as Q. chungii, Q. glauca, and Q. gilva. From July to September, more notable changes were observed in Q. chungii in September, with a drop of 3.49% in leaf thickness, and a drop of 3.34% and 10.06% in the volume of palisade tissue and sponge tissue, respectively. Consequently, increasing tightness and deducing looseness were observed in Q. chungii. The principal component analysis (PCA) on photosynthesis and leaf anatomy showed that Q. chungii displayed a stronger photosynthetic physiology with a positive coordination on water, air, light, and heat. These findings facilitate the evaluation of ecological adaptability among the three Quercus seedlings and provide compelling evidence for the application of Q. chungii for precious timber resources in afforestation. Full article

Jeju Island is located at a marginal edge of the distributional range of East Asian evergreen broad-leaved forests. The low genetic diversity of such edge populations is predicted to have resulted from genetic drift and reduced gene flow when compared to core populations. To test this hypothesis, we examined the levels of genetic diversity of marginal-edge populations of Quercus gilva, restricted to a few habitats on Jeju Island, and compared them with the southern Kyushu populations. We also evaluated their evolutionary potential and conservation value. The genetic diversity and structure were analyzed using 40 polymorphic microsatellite markers developed in this study. Ecological Niche Modeling (ENM) has been employed to develop our insights, which can be inferred from historical distribution changes. Contrary to our expectations, we detected a similar level of genetic diversity in the Jeju populations, comparable to that of the southern Kyushu populations, which have been regarded as long-term glacial refugia with a high genetic variability of East Asian evergreen trees. We found no signatures of recent bottlenecks in the Jeju populations. The results of STRUCTURE, neighbor-joining phylogeny, and Principal Coordinate Analysis (PCoA) with a significant barrier clearly demonstrated that the Jeju and Kyushu regions are genetically distinct. However, ENM showed that the probability value for the distribution of the trees on Jeju Island during the Last Glacial Maximum (LGM) converge was zero. In consideration of these results, we hypothesize that independent massive postglacial colonization from a separate large genetic source, other than Kyushu, could have led to the current genetic diversity of Jeju Island. Therefore, we suggest that the Jeju populations deserve to be separately managed and designated as a level of management unit (MU). These findings improve our understanding of the paleovegetation of East Asian evergreen forests, and the microevolution of oaks. Full article

Quercus gilva Bume (QGB, family Fagaceae) is a tall evergreen oak species tree that grows in warm temperate regions in Korea, Japan, China and Taiwan. Quercus plants have long been the basis of traditional medicines. Their clinical benefits according to traditional medicine include relief of urolithiasis, tremors and inflammation. In the present study, the anti-urolithiasis activity including anti-inflammatory and anti-oxidative activities, of some phenolic compounds isolated from QGB were described. Seven compounds were isolated and identified as picraquassioside D (1), quercussioside (2), (+)-lyoniresinol-9′α-O-β-d-xylopyranoside (3), (+)-catechin (4), (−)-epicatechin (5), procyanidin B-3 (6), and procyanidin B-4 (7). Compounds 5–7 showed potent anti-oxidative and anti-inflammatory activities. These compounds were further tested for their inhibition of the gene expression of the inflammatory cytokines. The three compounds 5–7 showed dose-dependent inhibitory activities on gene expression of COX-2 and IL-1β. In vivo, urolithiasis was induced more effectively in an animal model of acute urolithiasis by the administration of QGB extract. These results indicate the potential of compounds from QGB in the treatment of urolithiasis. Full article