Subjects: Biology >> Zoology submitted time 2023-09-20 Cooperative journals: 《古脊椎动物学报》
Abstract： Trilophodon connexus Hopwood, 1935 has long been considered a typical species of Gomphotherium in China. However, due to the unknown state of the mandibular symphysis and tusks, there is no definite evidence to assign “T. connexus” to Gomphotherium. Here we describe and reevaluate a hemimandible from the Halamagai Formation, Ulungur region, northern Junggar Basin, which was previously identified as Gomphotherium cf. G. shensiensis. The mandibular symphysis is deeply troughed and lacks mandibular tusks; therefore, it undoubtedly belongs to the Choerolophodontidae. Further comparison revealed that the cheek tooth morphology is identical to that of the type specimen of Trilophodon connexus. The characteristic features include high bunodonty, elongation of the m3 with four lophids, an only weakly chevroned lophid 2, enlargement of the posterior pretrite central conule 2, unfused state of the pretrite mesoconelet 2 (if present) and anterior pretrite central conule 2, as well as the absence of ptychodonty, choerodonty, and cementodonty. Therefore, T. connexus Hopwood, 1935 is a choerolophodontid rather than a species of Gomphotherium. Based on the above features, we provisionally refer to it as “Choerolophodon” connexus. “Choerolophodon” connexus is characterized by the following features: weak or absent ptychodonty, choerodonty, and loph chevron (which were all strong in the typical species of Choerolophodon), as well as multiplication of the lophids in the m3, which were similar to that of the North American Gnathabelodon. Therefore, Gnathabelodon might represent a distinct lineage within the Choerolophodontidae, and may be derived from the East Asian “Choerolophodon” connexus.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： This research aimed to establish an accurate analytical methods for the quantification of 10-deacetylbaccatin III (10-DAB Ⅲ) and taxol in Taxus wallichiana var. chinensis. The method utilized matrix solid-phase dispersion coupled with high performance liquid chromatography for the respective quantification of 10-DAB Ⅲ and Taxol. The influence of various parameters was investigated, including the types of solid-phase dispersants (silica gel, florisil, acid alumina, neutral alumina, alkaline alumina, C18, C18-ME, C18-G1, C18-HC, Diol, Xamide, Xion), the mass of the dispersants, and the type, concentration, and volume of the eluent on the analysis of the two components. After optimization of these conditions, the methodology was validated. Additionally, a comparative analysis was conducted with the conventional ultrasonic extraction and hot reflux extraction pretreatment methods to ascertain their effectiveness of our novel method. (1) Results indicated that among the 12 solid-phase dispersants examined, alkaline alumina yielded a superior extraction detection rate for 10-DAB Ⅲ and Taxol when used in a 3∶ 1 ratio with the sample mass and 6 mL of methanol as the eluent. (2) The developed method demonstrated excellent linearity (r ≥ 0.999 9) with detection and quantification limits for 10-DAB III and Taxol ranging from 0.023 9 to 0.030 1 μg·mL-1 and 0.142 to 0.178 μg·mL-1, respectively. The average recoveries of the target analytes varied between 93.6% and 109.0%. (3) A comparative analysis revealed negligible differences in extraction detection of the two taxanes between the three methods. However, the MSPD method stood out due to its lower solvent consumption, simple operation, short analysis time and high purification efficiency, making it more suitable for the rapid analysis of Taxus yunnanensis raw materials. Therefore, this study presents a rapid and efficient analytical method for the extraction and analysis of 10-DAB Ⅲ and Taxol in Taxus yunnanensis, using alkaline alumina as a dispersant, providing a significant contribution to the quantitative analysis of taxanes in this species.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： Seventeen newly recorded species from Guangxi, China are reported, including Yinshania henryi (Oliv.) Y. H. Zhang, Lepidium didymum L., Rumex acetosella L., Impatiens chekiangensis Y. L. Chen, Pittosporum kweichowense Gowda, Reevesia orbicularis Tardieu, Itea ilicifolia Oliv., Eriobotrya henryi Nakai, Myrsine verruculosa (C. Chen) Pipoly & C. Chen, Mycetia hirta Hutch., Spermacoce exilis (L. O. Williams) C. D. Adams, Picris divaricata Vaniot, Mazus gracilis Hemsl. ex Forbes et Hemsl., Viburnum rhytidophyllum Hemsl., Caryopteris nepetifolia (Benth.) Maxim., Salvia nanchuanensis var. pteridifolia Sun, and Smilax elegantissima Gagnep. These newly recorded species are of great value to the study of floristic geography, the innovative utilization of plant resources and the protection of plant diversity in Guangxi. The invasiveness of Lepidium didymum L. and Spermacoce exilis (L. O. Williams) C. D. Adams, which are alien species, was evaluated. The medicinal efficacy of Yinshania henryi (Oliver) Y. H. Zhang, Lepidium didymum L., Rumex acetosella L., Picris divaricata Vaniot, Mazus gracilis Hemsl. ex Forbes et Hemsl., Schnabelia nepetifolia (Benth.) P. D. Cantino, Salvia nanchuanensis var. pteridifolia Sun, Viburnum rhytidophyllum Hemsl., Itea ilicifolia Oliv., which are new records of medicinal plants in Guangxi, was briefly summarized. The voucher specimens, geographical distribution and plant photographs are also provided for each species.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： In order to identify the pathogens that caused tuber rot in Bletilla striata and study the inhibiting effects of herbal extracts on pathogens, the pathogens that caused tuber rot of Bletilla striata were isolated using usual tissue isolation. Morphological and molecular biological techniques were used to identify the strains. And seven herbal extracts were used to study the inhibiting effects on the pathogen. The results were as follows:（1） A total of 14 fungi and 4 bacteria were isolated from diseased leaves, leaf sheaths and tubers. But only strain GF-1 caused disease, whose symptoms consistent with those in the field. The incidences of GF-1 disease reinoculated in the field and laboratory were 100％, respectively. （2）GF-1 was identified as a memmber of Epicoccum, and its colonial morphology is a circular form, with white mycelium, prostrate on the medium, aerial, diaphragms and branches. There are conidia and chlamydospores. （3）At last, the sequence of internal transcribed spacer (ITS) region of GF-1 were analyzed, the length was 522 bp. The sequence was compared with other species in the GenBank and reached 99.62% similarity to E. sorghinum (MN493119.1) isolated form Sorghum, which was closer than others, including E. sorghinum (MF948994.1) isolated form leaves of B. striata. （4）GF-1 could be fully inhibited when the medium contained 0.1- 0.2 g·mL-1 extracts that extracted from 7 Chinese herbal, respectively. And it also could be fully inhibited by 0.05 g·mL-1 of C. cassia or Syringa oblate. In summary, the pathogen that caused tuber rot in Bletilla striata was identified as E. sorghinum. And GF-1 could be fully inhibited cultivated on the medium which contained 0.1- 0.2 g·mL-1 herbal extracts, e.g.: C. cassia, S. oblate, Cyclocarya paliurus, B. striata, Houpoea officinalis, Illicium verum or Cnidium monnieri.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： Saxifraga L. is rich in species diversity with about 440–500 species and broad distribution. The taxonomical issues of this genus have been continuously concerned by the botanists. Saxifraga has important ornamental and medicinal values. Some of European countries have made great efforts on the exploitation and utilization of its ornamental resources. China is one of the diversity centers of Saxifraga, but it has been lagged far behind Europe, USA and even Japan in exploitation and utilization on ornamental value of this genus. The world breeding work in Saxifraga started 150 years ago. By the end of 2022, the 1 692 names of cultivars had been on-line listed by The Saxifrage Society, but only one came from China. In this paper, the germplasm resources of Saxifraga, and progress on its classification and breeding were reviewed, and also the utilization of its ornamental resources was briefly introduced, which will provide an important reference for taxonomical research, breeding and horticultural application of this genus in China. The results were as follows: (1) Saxifraga is rich in germplasms, but many scientific issues remain in the evolutionary relationships of its subordinate systems, which require a systematic and in-depth investigation by integrating morphological and molecular biology methods. (2) The cultivars of this genus are mainly raised through cross-breeding and mutant selection, and the majority of cultivars produced from the UK, Czech Republic, Germany, and the Netherlands. (3) The breeding of Saxifraga started very late in China, with only few cultivars from one breeding method.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： The spatial structure evolution of forests in karst areas is a key scientific issue in global forest research. In order to explore the dynamics of spatial structure in karst evergreen and deciduous broad-leaved forests, a study was conducted in the Guolin National Nature Reserve, focusing on a fixed monitoring plot of 2 hm2. Based on data from three surveys conducted in 2007, 2012, and 2017, the dynamics of community spatial structure were analyzed using the spatial structure parameters: individual distribution index (Wi), mixing degree (Mi), and size-number ratio (Ui). The results were as foloows: (1) The univariate distribution of spatial structure parameters revealed that the forest structure gradually shifted towards a slightly clumped distribution state as the stand age increased between 2007 and 2017. The mixing degree was at a level of strong mixing and showed a tendency towards extreme mixing. In terms of the size-number ratio, the stand exhibited a moderate state, shifting towards subdominance as the stand grew. (2) The study of spatial structure for different diameter classes of trees showed that the angle scale, size-number ratio, and mixing degree of trees in diameter classes 1~15 cm gradually increased with stand growth. As the diameter class increased, the values of the size-number ratio showed a decreasing trend while the mixing degree showed an increasing trend. (3) The study of spatial structure for dominant tree species revealed that, during the ten-year period from 2007 to 2017, all five dominant tree species groups exhibited a slightly clumped distribution. The size-number ratio showed a tendency towards subdominance and a moderate distribution state, while the mixing level was at a high degree and gradually shifted towards extreme mixing. The study concludes that the karst evergreen and deciduous broad-leaved forest in Guolin currently exhibits a slightly clumped distribution, a strong degree of mixing, and a tendency towards subdominance. The community is relatively stable, the stand regeneration is in good condition, and the forest is gradually transitioning towards a climax community. The analysis of the dynamic changes in vegetation structure in karst evergreen and deciduous broad-leaved forests is of great significance for predicting the future development and changes of forests.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： Flowers of Rhododendron have unique poricidal dehiscence anther, but the formation of the dehiscence pore and the mechanism of pollen releasing are not known. The purpose of this research was to study the anther development of Rh. × pulchrum Sweet through microdissection and paraffin section to find out how the dehiscence pore develops and what tissues are involved in its development. The results were as follows: (1) The tissue forming the apical pore and the main body of the anther diverged from the very beginning of the stamen development. The dehiscence pore is formed by breaking down of parenchyma tissue, which is derived from the apical meristem of stamen primordium. The body part of the anther comes from the archesporial cells and they develop into regular pollen sacs with multi-layered anther walls. (2) The anther wall is fully differentiated at the stages from microspore mother cell to microspore tetrad and it consists of 6-7 layers: 1 layer of epidermis, 2-3 layers of endothecia, 1-2 layers of middle layers and 1 layer of tapetum. The middle layers soon break down after completion of microspore tetrads and the tapetum disappears before the pollen tetrads are fully mature. The epidermis and 2~3 layers of endothecia remain to the end; (3) Unlike those of longitudinal dehiscent anthers, the endothecia of Rh. × pulchrum are not fibrous at maturation. Instead, they are persistent and somewhat elastic through accumulation of polysaccharide granules in cells; (4) The four microspores produced by one microspore mother cell do not separate from each other and the pollens are released as tetrads, with viscous threads between pollens and among tetrads. The authors assume that the thickened multi-layer endothecia reduced the inner volume of the pollen sacs, therefore the pollen tetrads at the top are “squeezed out” from the dehiscence pore, and the viscous threads allow the pollen tetrads to be pulled out in clumps by pollinators.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： Semiliquidambar cathayensis is treated as a grade-two protected plant in China. However, its phylogenetic relationships with species from Hamamelidaceae and Altingiaceae remain unclear. In order to analyze the phylogenetic relationships and adaptive evolution of chloroplast genomes between S. cathayensis and its closely related taxa including species from Hamamelidaceae and Altingiaceae, we reconstructed the Maximum Likelihood tree and the Bayesian tree to discover the phylogenetic relationships between S. cathayensis and its closely related taxa from 24 sequences that representing 22 species, and further detected the correlation between adaptive sites and selective pressure of protein coding genes under varying models including site model, clade model and branch model. Altingiaceae clade was chosen as the foreground clade. The results were as follows: (1) A total of 133 genes were annotated, including 88 protein-coding genes (11 genes with intron), 37 tRNA genes and eight rRNA genes. (2) Eight chloroplast genomes representing eight species from S. cathayensis and Altingia, Liquidambar were relatively conservative in sequence length, gene number and composition, GC content, and there was not obvious diversity in the four boundaries. Relatively high variation interspecific were also detected in LSC and SSC regions among these eight chloroplast genomes, while the IR regions were high conservatism. (3) Phylogenetic trees showed that S. cathayensis and sampled species of Altingiaceae clustered a group, which further divided into three clades, namely clade I, clade II and clade III. The phylogenetic relationships among these clades remain unclear due to hybridization or incomplete lineage sorting (ILS) according to the results of test of ILS. (4) The chloroplast genes such as ndhA, ndhG and rps12 were subjected to selection pressure under the clade model and branch model. Furthermore, 28 sites of ten genes were detected under positive selection with p-value greater than 0.99 based on the site model, which may be related to the adaptive evolution of Altingiaceae. In this study, the results of plastid phylogenomics supports that S. cathayensis belongs to Altingiaceae. Several coding genes among these species of Altingiaceae may have adaptive evolution. These results will provide data for the further resource protection of homonym drugs and pharmacognostic researches of ethnodrug.
Subjects: Biology >> Other Disciplines of Biology submitted time 2023-09-05 Cooperative journals: 《古脊椎动物学报》
Abstract： Bothriolepis sinensis Chi 1940, mainly based on anterior median dorsal plates from the Middle Devonian Tiaomachien Formation of Hunan, is the first Paleozoic vertebrate taxon erected in China. Although additional materials of B. sinensis from the type locality were described by Lu in 1988, its morphology and phylogeny remain poorly understood. In this study, we complemented the morphology of the skull and trunk armor of B. sinensis based on Chi’s specimens housed in the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, and several previously undescribed specimens in the Geological Museum of China. Bothriolepis sinensis differs from other Bothriolepis in the following combination of characteristics: enlarged supraotic thickening, length/width ratio of head shield 1.4–1.6, broad orbital fenestra (greater than 1/3 of the head shield width), and fan-shaped preorbital recess. The phylogenetic analysis did not place B. askinae in the most basal position of the genus and revealed that B. sinensis and B. kwangtungensis consistently from a monophyletic group characterized by their slender proximal segment of the pectoral fin (length/width ratio greater than 7). A majority of Chinese Bothriolepis species (B. niushoushanensis, B. lochangensis, B. tungseni, B. kwangtungensis and B. sinensis) were clustered in a clade characterized by the pectoral pit-line on the ventral central plate 1 extending to the ventral central plate 2. The paleogeographic reconstruction using the data from the DeepBone platform showed that Bothriolepis had its oldest occurrences in South China and East Gondwana in Eifelian, dispersed rapidly worldwide, and then diversified across the coasts of the Rheic Ocean.
Hits
Hits
Downloads
Comment