Abstract:In order to understand the indicative function of ground vegetation to soil nutrient, the relation between ground vegetation and soil nutrient was studied in evergreen broad-leaved forest of Guangdong by using indicator species analysis (ISA). The results showed that the concentrations of available nitrogen (AN), available phosphorus (AP), available potassium (AK) and organic matter (OM) had significantly integrative effects on the distribution patterns of ground vegetation (P<0.05), with in the order of AP > OM > AK > AN. Indicator species were Ampelopsis cantoniensis and Tricyrtis macropoda for soil AN ≤ 270 mg/kg, Tricalysia dubia for 270-360 mg/kg of AN, and which was Alpinia chinensis for soil AP ≤ 2 mg/kg. The indicator species was Syzygium buxifolium for soil AK ≤ 100 mg/kg, Carex cruciata for 100~150 mg/kg of AK, and Pteris fauriei for AK> 150 mg/kg. Indocalamus tessellatus was the indicator species for soil OM>0.8%, Alpinia chinensis and Elaeagnus glabra for OM ≤ 0.6%, and Premna microphlla for OM at 0.6%-0.8%. Therefore, it was convenient for forest management and soil health evaluation to monitor soil condition of forest by using effective ground vegetation survey. The response of indicator species of ground vegetation to soil nutrients could not only provide theoretical support for the site conditions of the study area, but also provide theoretical basis for the artificial cultivation of the species, which was of great significance for the introduction and cultivation of the habitat reconstruction and biodiversity conservation.

Abstract:In order to understand the symbiotic relationship between Epulorhiza sp. and the roots of Dendrobium officinale, and also to make certain the influence of Epulorhiza sp. on root morphology, the roots of D. officinale were irrigated with liquid cultured Epulorhiza sp., the changes in phenotype and ultrastructure of roots were observed after three months. The results showed that the cortical cells of root were invaded by mycelia, which induced the formation of mycelium group to form a symbiotic relationship between Epulorhiza sp. and the roots. The content of IAA in root increased after co-cultured with Epulorhiza sp., and the lateral roots were induced for increasing root volume, as well as the root vitality was significantly improved. Therefore, Epulorhiza sp. co-cultured with the roots of D. officinale not only could generate mycorrhizal to establish a symbiotic relationship, but also the symbiotic mycelium could colonize in roots, induced the changes in root structure, and the formation of lateral root played an important role in growth of D. officinale.

Abstract:In order to understand the resource-use strategies of nutrient elements of plants in tropical region, the C, N, and P concentrations and their stoichiometry of 9 species with three life forms in Hainan were studied. The results showed that there were not significant differences in C, N, and P concentrations and stoichiometric ratios among different life forms. The C, N, and P concentrations of leaves were higher than those of roots. The C and N concentration of leaves was positively related with that of roots, but the P concentration of leaves was negatively related with that of roots. The ratios of C:P and N:P were relatively smaller than that at national and global scale, indicating that plants had high growth rate in this region. N:P ratio less than 14 showed that plant growth were limited by N in Hainan. Therefore, it was suggested that the plants with different life forms in Hainan showed similar resource-use strategies, although N limitation occurred, the plants had high growth rate and retaining ability of N and P.

Abstract:To clarify the potential distribution and habitat ecological characteristics of Chinese endemic species Cerasus xueluoensis, the simulated diagram of suitable distribution of C. xueluoensis was drawn for the first time by using DIVA-GIS software coupled with the ecological niche model (BIOCLIM). Meanwhile, the qualitative and quantitative analysis of main climate factors influencing their distribution was also carried out. The results showed that the current suitable region of C. xueluoensis was mainly distributed in subtropical Yangtze River basin of China at high altitude mountainous above 1 200 m. Among them, the junctions of Chongqing-Hubei-Hunan belonging to the Daba-Wushan Mountain ranges were considered as the modern core distribution area, and boundary areas between Hunan and Guizhou Provinces belonging to the Nanling Mountains should be regarded as the southern distributional border. What's more, the southern foothill of the Qinling Mountain from the junction of Shanxi-Henan-Hubei provinces should be the northern border of suitable distribution. Principal component analysis (PCA) showed that the dominant climate factor and its contribution rates was in the order of annual precipitation (bio12) > precipitation of the coldest quarter (bio19) > precipitation of the warmest quarter (bio18) > precipitation of the wettest quarter (bio16). The cumulative frequency curve further confirmed their optimal ranges were 993.00-1 870.22, 500.00-680.00, 430.00-669.16 and 500.00-680.00 mm, respectively, indicating the precipitation is the dominant climate limiting factor affecting the current distribution pattern of C. xueluoensis. Pearson correlation analysis indicated that the distribution pattern of C. xueluoensis was affected by altitude, longitude and latitude at a regional scale. The seven wild populations of C. xueluoensis could be divided into two major branches, such as central & western China and eastern China, according to minimum tree analysis and cluster analysis. The receiver operating characteristic curve (ROC) was reached to 0.751, which met the basic requirements of model prediction accuracy. So, these would be help to formulate scientific plans for resource protection and reasonable introduction of C. xueluoensis.

Abstract:In order to understand the potential distribution characters of Cyclobalanopsis forest in Guizhou Province, based on the current distribution data, and combined with current climate data and future climate change scenario (RCP8.5 scenario, 2070-2099), the Maxent potential distribution modeling was established to predict the changes of potential distribution of Cyclobalanopsis forest in Guizhou Province. The results showed that the dominant climatic factors affecting its potential distribution were mean temperature of the coldest quarter (bio11), min. temperature of the coldest month (bio6) and annual precipitation (bio12). Under the RCP8.5 scenario, potential habitat area of Cyclobalanopsis forest in Guizhou would increase than that under current climatic conditions, there were 19 419 km² for moderate suitable habitat and 9 944 km² for high suitable habitat, respectively. The mean altitude of moderate suitable habitat would increase 126 m, and 85 m for high suitable habitat. In general, Cyclobalanopsis forest in Guizhou Province wouldn't be sensitive to the global climate change.

Abstract:In order to understand the loquat (Eriobotrya japonica) hybrid authenticity and DNA fingerprint, 19 new loquat varieties or lines were analyzed by using SSR marker. Nineteen pairs SSR primers with clear and stable fragments were selected from eighty-nine previously published SSR. Totally, 83 amplified bands were detected from 24 materials of loquat, with an average of 4.37 for each primer pair. Polymorphism information content values ranged from 0.234 to 0.983, with an average of 0.764. The authenticity of all 19 new loquat varieties or lines were confirmed by 12 SSR markers with special bands of male parent, and the true hybrid rate was 100%. The genetic similarities among hybrids ranged from 0.728 to 0.969. The UPGMA dendrograms indicated that 19 hybrids could be get together into one big group (with the crossing parents ‘Xinbai No. 2’ and ‘Guifei’) and divided into 4 subgroups, and do not cluster by color of flesh. Furthermore, the DNA fingerprints for the 19 cultivars were established by 8 polymorphic SSR primers. So, these would provide references for cultivar identification, protection of new variety right and crossbreeding of loquat.

Abstract:In order to understand the planting patterns on the growth of Morinda officinalis, its growth status was studied under two planting patterns in Gaoliang Town, Zhaoqing City, Guangdong. The results showed that the contents of available mineral nutrients and organic matter in soil of sloping land continguous planting base (PLZ) were lower than those of slope surrounded by forest planting base (PWZ) by 24%-28% and 38%-43% (P<0.01), respectively. The morphological indexes of stem, leaf and fleshy root of M. officinalis in PWZ were significantly better than those in PLZ (P<0.01) after planting for 3 years. However, with the extension of cultivation time, the growth of fleshy roots in PLZ was better than that in PWZ. The yield of 6-year-old M. officinalis in PLZ was 1.16-1.17 times higher than that in PWZ. The contents of polysaccharides, total flavonoids and proantho-cyanidins of M. officinalis in PLZ were significantly higher than those in PWZ (P<0.01), and the contents of effective components increased along the cultivation years. Therefore, it was suggested that the fleshy root quality of M. officinalis was good under PLZ pattern, which as medicine was more in line with the requirements of national pharmacopoeia. At the same time, the planting base surrounded by cinnamon forest should reasonably increase the illumination and inhibit rattan growth of M. officinalis, so as to increase the yield of fleshy roots and accumulation of effective ingredients.

Abstract:In order to understand the physiological mechanism of UV-B to improve drought resistance of Arabidopsis thaliana, the wild type (Columbia-0, WT) and sto mutant seedlings at 2-week-old were treated with UV-B for one week, and then the seedlings were treated with 30%PEG for 24 hours, the phenotypes of the plants were counted, and the contents of flavonoids, proline and MDA were determined. The results showed that low doses of UV-B pretreatment could enhance drought resistance of A. thaliana, the contents of proline and flavonoids increased for 20%-40% and 50%-65%, respectively, and the cell membrane damage reduced, the water retention was improved. The effect of low dose UV-B in enhancing A. thaliana drought tolerance disappeared in sto mutants, indicating the effect might be related to STO protein in the molecular mechanism.

Abstract:In order to understand the photosynthetic characteristics of Podocarpus nagi, the photosynthetic pigment content and gas exchange parameters of green and striped leaves of 3-year-old P. nagi seedlings were measured. The results showed that the chlorophyll (Chl) a, Chl b, carotenoid (Car), Chl a+b, Chl a/b and Chl a+b/Car in green leaves were significantly higher than those in striped leaves. The initial quantum efficiency, maximum photosynthetic rate and dark respiration rate in green leaves were significantly higher than those in striped leaves, and the light saturation point and light compensation point were significantly lower than those in striped leaves (P<0.05). The initial carboxylation efficiency, photosynthetic capacity, CO₂ saturation point and photorespiration rate of green leaves were higher than those of striped leaf, and CO₂ compensation point of green leaves was lower than that of striped leaves. The stomatal conductance, transpiration rate and water use efficiency increased with the increment of photosynthetic active radiation with the order of green leaf>striped leaf, while the intercellular CO₂ concentration had opposite trend with striped leaf>green leaf. So, it could be rationally planted according to the photosynthetic characteristics of two different color leaves according to the different phytosynthetic characteristics of two color leaves of P. nagi, which green leaf had strong ability to use weak light and striped leaf had strong ability to use stronger light.

Abstract:In order to explore excellent germplasm resources of Moringa trees, leaf phenotypic characters of 30 excellent single plant families were studied. The results showed that except of leaf shape, there were significant differences among families in petiole color, leaf color, compound leaf number, length and diameter of compound leaf petiole, compound leaf spacing, length and width of leaf. The compound leaf number was significant positive correlation with length and diameter of compound leaf petiole, compound leaf spacing, length and width of leaf. Principal component analysis showed that length and width of leaf, length and diameter of compound leaf petiole, compound leaf spacing, petiole and leaf color were important indicators for identifying these families. Based on the 8 leaf phenotypic traits, 30 families of Moringa could be divided into 3 categories by cluster analysis, there was far genetic distance among families which had significant differences in leaf phenotypic traits. Therefore, petiole and leaf color, compound leaf number, compound leaf petiole length and diameter, compound leaf spacing, leaf length and width would provide a reference for identifying Moringa families.

Abstract:From April to June in 2019, a naturalized population of Opuntia cespitosa was first found at Qiushan Hill, Guozhuang Town, Jurong City, southwestern Jiangsu. The population mainly occurs on an abandoned quarry at elevations of 46-90 m, covering an area of ca. 13.26 hm², 510 m long from east to west, and 260 m wide from north to south. A total of 910 mature shrubs bearing flowers and fruits have been recorded there, among which the longest axis of the largest shrub consists of 10 continuous cladodes, indicating an age of 10 years, which probably appeared at Qiushan Hill in 2010. This naturalized population may be derived from the pot plants of O. cespitosa, which were possibly discarded in situ by the staff of Qiushan quarry, when the quarry became abandoned. The morphological features are compared between O. cespitosa and known other four naturalized species of Opuntia in China, and a key to these species is prepared. Furthermore, the dispersal mechanisms and its invasion risk of O. cespitosa are also discussed.

Abstract:Three species, viz. Hedyotis herbacea, H. pumila and Scleromitrion koanum, of the family Rubiaceae are newly recorded for the flora of Hong Kong, on basis of the herbarium specimen examination. These findings provide some new basic data for the biodiversity research of Hong Kong.

Abstract:Dendrobium naungmungense Q. Liu & X. H. Jin, a newly recorded species of Orchidaceae from China is reported. Characteristic description and color photos are provided. The voucher specimens are deposited in Herbarium of College of Forestry, Fujian Agriculture and Forestry University (FJFC).

Abstract:To investigate the chemical metabolites from Fusarium tricinctum, an endophytic fungus isolated from Ningguo Peucedanum praeruptorum, 14 compounds were isolated from solid fermentation and purified by silica gel column chromatography, MPLC, and preparative liquid chromatography. Based on data of MS and NMR, their structures were identified as fungerin (1), fusagerins F (2), 6-[(3R)-3-hydroxybutan-2-yl]-5-(hydroxymethyl)-4-methoxy-2H-pyran-2-one (3), 6-[(3S)-3-hydroxybutan-2-yl]-5-(hydroxymethyl)-4-methoxy-2H-pyran-2-one (4), 6α-chlamydosporol (5), 6β-chlamydosporol (6), (3R,4R)-(-)-4-hydroxymellein (7), (3R)-(-)-8-hydroxymellein (8), enniatin B (9), enniatin B1 (10), enniatin A1 (11), enniatin A (12), enniatin B3 (13), enniatin B2 (14). All these compounds are isolated from this endophytic fungus for the first time. The cytotoxicity assay of all compounds did not show anti-tumor activities.

Abstract:Vegetative vivipary in plants refers to some organs, such as gemmae, bulbils, adventitious buds and leaves, which don't fall off after maturation, they absorb the maternal nutrition directly and continue to grow and develop, then break off and form new plants in the natural state. There are many kinds of viviparous plants, most of which are the results of long-term adaptation to harsh environment, such as drought, cold and high temperature at long term, it is an important supplement of breeding pathway. Compared with the traditional asexual reproduction, vegetative vivipary has higher propagation coefficient and regeneration, lower rate of virus infection, so it has an important application value in production. The four aspects, including morphological anatomy, physiology and biochemistry, molecular biology and reproduction characteristics of viviparous organs, were reviewed. At present, the researches were still in the early stage and the nature of vivipary phenomenon has not been systematically explained, the shortcomings in current studies are pointed out and the future directions are prospected which conclude the regulation mechanism and important functional genes of vegetative vivipary, and how to adapt the new environmental change is also the future research direction of viviparous plants. So systematic studies of vivipary not only help to understand the nature and evolutionary process of adaptive phenomenon, but also provide a theoretical basis for population propogation, mass production and wide application, and biodiversity conservation of viviparous plants.