2012 Vol. 25, No. 6
In this study, a small RNA library mixed equally sRNA of needle leaves, stem and root tissues was constructed for 2-year-old seedling of Japanese larch (Larix kaempferi). Two hundred and eighty three recombinants from library were partially selected randomly and sequenced. These sequenced sequences were searched and compared in Rfam, Repbase, miRBase and PMRD databases by BLASTN to remove rRNA, tRNA, snRNA snoRNa and other non-candidate small RNA. The results indicated that 28 miRNAs were acquired and these sequences were same (miR159c, miR160a, miR162a, miR164b, miR165a, miR166a, miR166a*, miR166b*, miR169a, miR169b, miR171a, miR171b, miR172a, miR319b, and miR396a) as or highly homologous (miR156a, miR159a, miR159b, miR164a, miR166b, miR168a, miR169b*, miR319a, miR396b, miR408, miR482a, miR2111, and miR3701) to other known plant miRNAs, which belonging to 17 miRNA families. Additional 4 sequences could be matched to stem-arm sequences of stem-loop structure M-folded with our lab's transcriptome data (contigs/singlets). The 4 sequences could be characterized novel miRNAs of Japanese larch. Quantitative real-time polymerase chain reaction (qPT-PCR) analysis demonstrated that 20 miRNAs were expressed in larch. The putative target genes of these miRNAs were predicted using psRNATarget online service. There were 69 targets obtained by the prediction for 24 miRNAs among 28 conserved and 4 novel larch miRNAs, which are highly enriched in transcription factor (TF), signal transduction protein, stress-induced-associate protein and other uncharacterized protein.
The research aims to using dendrocola fungi of larch shoot to find the fungi which can inhibit Botryosphaeria laricina. During antagonistic activity test of B.laricina against 11 species of dendrocola fungi, the Trichoderma atroviride, Chaetomium globosum and Sordaria fimicola were identified as the biocontrol fungi, based on the overall evaluation of extent of coverage, inhibitory rate, antagonistic coefficient, and indoor infection experiment. Through field biocontrol test in Guofugou (Tongtianyi Forest Farm, Boli County, Heilongjiang Province), it was found that the comprehensive control effect was in the order of S.fimicola>Mancozeb 400 times>T.atroviride>C.globosum. When T.atroviride and S.fimicola were sprayed with a concentration of 50%, and C.globosum was sprayed with a concentration of 75%, there were the greatest diversity of fungi and the system of dendrocola fungi of larch shoot were more stable than other concertration. Compared with chemical control, it could be reaching prevention purpose without polluting the environment.
Casuarinas are important for coastal protection purpose in China. In recent years, many Casuarinas clones have been developed. The knowledge on genetic diversity and relationship of these clones is critical to guide Casuarinas breeding, but still limited. In this study, twenty-two selected ISSR primers were used to amplify the tested clones. A total of 199 bands were obtained in which 154 bands (77.4%) were polymorphic. The average effective number of alleles was 1.5. The Nei's gene diversity indices (H) ranged from 0.174 1 to 0.389 1 and the Shannon's information index (I) ranged from 0.273 2 to 0.556 0. The genetic similarity coefficients among the tested clones ranged from 0.467 3 to 0.995 0, with an average of 0.743 0. The results showed that the genetic differences among the 51 clones were relatively little. The cluster analysis based on ISSR markers revealed that the 51 clones could not be cluster according to their origin and there were no correlation between genetic relationship and geographical origin. The 51 clones of Casuarinas could be divided into 2 groups when the similarity coefficient was 0.678. The genetic relationship of all the 51 clones revealed by the ISSR dendrogram would be of great help for genotype screening in afforestation project and parental selection in Casuarinas breeding.
One-year-old larch seedlings cultivated in net container were treated with different formulations of controlled release fertilizers aiming at selecting suitable formulation among those controlled release fertilizers by Fuzzy Mathematic method based on the growth, biomass and chlorophyll content of the treated seedlings. The results indicated that the growth of Larix spp. seedlings treated with different formulations fertilizer after the seeds sowed could be divided into four stages which were the germination stage(7-39 d), initial growing stage (40-54 d), fast-growing stage(55-114 d) and the late growing stage(115-135 d). It was found that different controlled release fertilizer formulations had extremely significant effects on the height, basal diameter, individual biomass, aboveground biomass, underground biomass and chlorophyll content of the seedlings, while there were no significant differences on the ratio of root to shoot of the seedlings treated with those fertilizers. The formulations 2 displayed much better effects on larch seedlings than that of the other formulations and the Apex imported from America and it could be used for larch seedlings nurturing.
The special topographic and climate conditions of Himalaya-Hengduan Mountains gestate a rich forest resource, and plant and animal diversity in southeast Tibet. Through plot investigation, the species diversity and spatial distribution of Quercus aquifolioides community in southeast Tibet were studied using diversity index and detrended canonical correspondence analysis (DCCA) combining with specific association, interspecific covariation and systematic cluster analysis. The results indicated that: (1)The species richness decreased with the raise of altitude, but a certain degree of human disturbance (i. e. moderate disturbance), higher canopy density and lower canopy layer usually increased the species diversity. In addition, the pattern of species diversity was influenced by the microclimate of dry valley. (2)The species diversities of different layers in the community appeared as herb layer > shrub layer > tree layer. (3)Theoretically, the higher ratios of positive and negative association implied the more stable community structure, and the ecological habits and distributional differences among species of Q. aquifolioides community formed different interspecific relationship. Moreover, the distribution of species was mainly affected by altitudinal gradient and annual precipitation. (4)According to the outcomes of DCCA, specific association, interspecific covariation and systematic cluster analysis, the main populations of Q. aquifolioides community could be divided into four ecological species groups, it helps to understanding the local community structure and plant ecological habits, and further studying on the community succession, conservation and utilization.
By DBH wood core sampling method and the felled-wood sampling method, 14 open-pollinated families of the 24-year-old Larix olgensis progeny testing forest were sampled as the research object, whose growth traits, material quality traits of increment core, material quality traits of analytic wood and pulping and paper-making traits were the significant criteria. The results proved that there were abundant variations in growth traits, wood basic density and wood core fiber traits; the differences in growth trait among families were very significant; the differences in wood basic density and wood core fiber trait were both significant, and the heritability among families was between 0.56 to 0.80; there were very significant differences among families in basic density of analytic trees, the microfibril angle of early wood, tracheid length, wall cavity ratio of early wood, lignin, arabinose content, tensile strength, tearing strength, and the heritability among families was between 0.64 to 0.86; there were significant differences in latewood percentage, ratio of tracheid length to width, holocellulose content, the heritability among families was between 0.51 to 0.61, and there was great potential for improving the family trait levels. The growth traits were positively and very significantly correlated with wood fiber length and insignificantly correlated with wood basic density and the ratio of fiber length to width; the wood basic density, wood fiber length, width and the ratio of fiber length to width were positively and very significantly correlated with the correspondent traits of the analytic wood. In addition, the regression model based on this correlation was more ideal, and it could enable to predict the value of a single plant by use of each trait value of DBH increment core and directly select and evaluate the superior families of pulpwood. As a result of the research, the Family 166 and Family 169 were selected as the superior families according to the criteria of growth traits, wood basic density and the ratio of the fiber length to width of increment core. This result is in line with the ones selected out according to analytic wood growth traits, timber quality traits and paper sheet physical traits. The genetic gains of the timber volume, the wood basic density and the ratio of fiber length to width of increment core were 48.34%, 14.01% and 19.89% respectively and the three trait values above were larger than the correspondent contrasts by 38.80%, 3.63% and 6.42%.
Based on the TM/ETM + remote sensing data of Wuliangsuhai wetland in 2003-2011, the methods of ratio vegetation index and bond combination was used to obtain the information about the areas of open water, water plants, reed and farmland in Wuliangsuhai wetland and the change of area and their patterns were analyzed. By using the method of data point’s average absolute deviations, the change rates of above-mentioned areas were calculated and the changing trend was estimated. Based on these comparison and analysis, the dynamics change of Wuliangsuhai wetland was predicated and the results are as follows: the change rate of open water is 26.56%, and that of water plants and reed are -20.66% and -1.49% respectively, i.e. the area of open water will increase by 33.57 km2,while the areas of water plants and reed will decrease by 21.02 km2 and 4.92 km2 respectively in 2012.
The seedling layers(DBH<1 cm)under different recovery stages in the tropical lowland rain forest on Hainan Island were selected as study object. The species composition and variation of functional group of seedling community in different recovery phases were surveyed. The results showed that there were different species compositions of seedling community in different recovery stages. The seedling abundance decreased with the increase of height classes. The seedlings in the lowest height class had higher abundance than those in the other height classes These indicated that the survival curve of seedlings was close to the concave curve. The seedling abundance peaked in the 60-years-old secondary forest, which compiled with the intermediate disturbance hypothesis. Importance values of different functional groups varied significantly with recovery. The pioneer species decreased while the climax species increased with the increase of recovery time.
A randomized block field experiment was carried out from 2005-2008 (a rotation period) to study the changes of soil nutrient contents in three soil layers (0~20 cm, 20~40 cm and 40~60 cm) of the triploid Populus tomentosa(cv. B304) plantations with five stand spacings (2 m×2 m, 2 m×3 m, 2 m×4 m, 2 m×5 m and 3 m×4 m). The results showed that: (1)Soil pH value increased under different stand spacing after the 4-year growing, especially in low-density plantations (3 m×4 m) and deeper soil layers. (2)The contents of soil organic matter decreased at first and then increased. In the high-density plantations (2 m×2 m and 2 m×3 m), the contents of soil organic matter were significantly lower than that of the others. (3)The contents of soil total P and available P increased at first and then decreased. The available P in the plantation with stand density of 2 m×2 m was significantly lower than that of the others. (4)Significantly higher soil available N content was found in the plantation with stand density of 2 m×2 m while significantly lower available K in the middle-(2 m×4 m) and low-density (3 m×4 m) plantations. No regular variation was found in the contents of the other soil nutrients.
The change of sap flow rate along axial direction of trunk is considered to be the important evidence that water storage is involved in internal sap flow circulation. Based on monitoring sap flow rate at both crown base and stem base of half-mature Populus bolleana Lauche during the main growth season with thermal dissipation probe technique (TDP), the relationship between sap flow rate (Js) at two typical position and atmospheric evaporation potential (ET0) obtained with synchronous meteorological elements was analyzed. It was found that the diurnal variation pattern of sap flow rate at both crown (Js,u) and stem bases (Js,d) were consistent with ET0 in typical sunny days, but the former had more close correlation with ET0, which fitted well with the Hill function formula, while that between the latter and ET0 presented linear relation with different slopes. At noon, Js,u could be three times of Js,d, and started about 1 hour earlier than the latter in the early morning. The "net" sap flux between Js,u and Js,d changed with season, and was in a slight water-lose status in July and August but a slight water-surplus in June and September instead. Daily total amount of absorbed water was not completely consistent with water loss of crown. The average daily sap flux computed by Js,u from June to September was in the sequence of sunny > cloudy > overcast, which was consistent with solar radiation and ET0, while sap flux computed by Js,d sometimes was cloudy > sunny, showing the traits of leveling water stress by accelerated water-absorption in cloudy days for mid-serious atmospheric stress.
In order to construct a basis for the tung trees protein research, some key factors which could impact on the results of the protein separation were studied and an improved system of two-dimensional electrophoresis were built successfully including the suitable protein extraction method (TCA-acetone combined with phenol), the solution buffer (7 mol·L-1 urea, 2 mol·L-1 thiourea, 4% CHAPS, 65 mmol·L-1 DTT and 2% IPG buffer), the volumes of loading protein (700 μg) in IEF and the better conditions for the SDS-PAGE (15% separation gels and constant 5W for 8 h).
Microtubule protein, one key component of cytoskeleton, plays an important regulation role in the development process of cells. An homologue gene of Tua3 was isolated from the leaves of Phyllostachys edulis through RT-PCR method and designed as PeTua3. The open reading frame of PeTua3 was 1 356 bp encoding 451 aa. A prokaryotic expression vector pET-32b-PeTua3 was constructed and transformed into Escherichia coli for expression induced by IPTG. There was significant discrepancy in protein expression efficiency under different temperature and induced time. The best condition for PeTua3 expression was at 37 ℃ for 2 h induced by 0.4 mmol·L-1 IPTG. The seeds of Arabidopsis thaliana were treated with the recombination protein of PeTua3, the phenotype showed that the epicotyl of seedlings thickened obviously and the quantity of lateral roots increased significantly. The ultra-thin sectioning microscopy showed that the parenchyma cells were more and bigger, and the vascular bundles were thicker in epicotyl and main root of the treated seedlings than those of controls.
In order to explore the effects of Monochamus alternatus’ feeding on tree decomposition, the feeding amounts of larvae and adults M.alternatus were measured, the composition of phloem tissue of Pinus yunnanensis and the excrement of larvae M.alternatus were analyzed, and of the difference of decomposition abilities between M. alternatus and wood microorganisms were compared. The results indicated that the average tree biomass decomposed during larval phase of M. alternatus was 12.42 g (24.40 cm3), and 12.87 g (25.28 cm3) was decomposed in adulthood. The carbohydrate consuming was highly large for larva M.alternatus, so was the decomposition of fibre. The total sugar reduced by 83.58% and crude fibre decreased by 23.87% after feeding and digesting. One beetle could decompose 1.93g of crude fibre during larval phase, and the decomposition rate was 0.008 g·d-1. The results prove that M. alternatus, as an important pioneer of tree decomposing, can decompose trees. What's more, the progress that M. alternatus attacks sub-healthy trees will pave the way for microorganisms' infestation and decomposition; the beetle will quickens the decomposition and circulation of sub-healthy trees and plays an important role in material decomposition and circulation as decomposer in forest ecosystem.
Using the plots of Cathaya argyrophylla community with different habitats in Guangxi as resource complexes (resource position), and the species of important value as the state index on resource position the niche breadth (Levins index and Shannon Wiener diversity index), the proportion of niche similarity and niche overlap of the dominant species populations in C. argyrophylla community were quantitatively analyzed. The results show that: 1) The C. argyrophylla, Rhododendron simiarum, Pinus kwangtungensis, Dendropanax hainanensis, Pentaphylax euryoides and Dunnia sinensis have greater important value and wider niche breadth, and they are the dominant species resources in the community, with higher ability in the surveyed habitat and occupy an important position in C. argyrophylla forest. But Michelia figo, Gordonia axillaris and Clethra bodinieri var. parviflora are on the contrary. 2)There is a larger niche similarity among most of the species in C. argyrophylla forest, the ecological characteristics of them are similar in resource utilization. The species with wider niche breadth will have a bigger niche similarity value, while the species with smaller niche width have lower similarity value with other species. 3) The niche overlap value is low among the major tree species in C. argyrophylla forest and the competition among main tree species is weak. The species with larger niche breadth have larger niche overlap value and higher probability in occupy or use the same resources with other species, while the species with smaller niche breadth have smaller niche overlap value and lower probability in occupy or use the same resources with other species. 4) C. argyrophylla has a large important value in all the quadrats, so it has great niche breadth value. C. argyrophylla is the dominant species and the constructive species in C. argyrophylla forest community.
In order to investigate the effects of simulated nitrogen deposition on soil respiration in spruce-fir-Korean pine forests, a simulated nitrogen deposition experiment was conducted in Xiaoxing’anling Mountains area in Heilongjiang Province from May to October, 2011. The experiment included the Control (0, CK ), low-N (50 kg·hm-2·a-1, TL), medial-N (100 kg·hm-2·a-1, TM) and high-N (150 kg·hm-2·a-1, TH) treatment level. The results showed that the nitrogen deposition did not change the daily and seasonal variation patterns of soil respiration. Compared to Control,the TL, TM, and TH treatments increased the soil daily average respiration rates by 13.72%, 23.22% and 5.12%, and 13.98%, 18.26% and 1.12% for soil annul average respiration rates. Significant exponential relationship was found between soil respiration rate and soil temperature, but no significant relationship was found between the soil moisture and soil respiration rates. The Q10(the respiratory flux at one temperature over the flux at a temperature 10℃ lower) were 4.77, 5.71, 6.62 and 5.49 for soil respiration of the CK, TL, TM, and TH treatments respectively. The findings suggested that nitrogen deposition could promote soil respiration, and increase soil respiration temperature sensitivity in spruce-fir-Korean pine forests.
To study the genetic variation of slash pine (Pinus elliottii) resin components, 98 individual trees from 38 open pollinated families in Changle Forest Farm, Zhejiang Province, were selected for the determination of resin components and the hereditary correlation analysis, the result shows that slash pine resin contains ten kinds of monoterpene, namely α-pinene, β-pinene, camphene, α-phellandrene, β-phellandrene, β-myrcene, sabinene, tricyclene,estragole and trans-anethole, which altogether account for more than 9.86%. Analysis of variance indicates highly significant differences in all components except for estragole and tricyclene among the families (Pr=-0.46, P<0.01) between α-pinene and β-pinene. The resin acids mainly include twenty components in pimaric type acid and abietic type acid, namely: pimaric acid, palustric acid, sandaracopimaric acid, isopimaric acid, abieticacid, neoabietic acid, dehydroabietate, communic acid, levopimarate, pimaral, isopimaral, 8,12-abietadienoate, 8,15-abietadienoate, 8,13-abietadienoate, 7,13,15-abietatrienoate, 15-hydroxydehydroabietic acid, 8,15-pimarene, rimuen, isosteviol and kaurene, among which the abietic type acids is greater than the pimaric type acid, analysis of variance indicates highly significant differences in pimaric acid, isopimaric acid, abietic acid, neoabietic acid, pimaral, isopimaral, 8,12-abietadienoate, 8,15-abietadienoate, 7,13,15-abietatrienoate, 15-hydroxydehydroabieticacid, 8,15-pimarene, and rimuen, the estimated family heritability for these twelve resin acid components is between 0.50-0.81, the heritability is relatively stable.
To understand the diversity of the gut microbes of Chinese white wax scale Ericerus pela, 16S rDNA clone library was constructed to analyze the gut microbes of the female E. pela adults. The results showed that, the gut of E. pela contained abundant of Rickettsia. Gut microbes Arsenophonus and Variovorax were also been identified. And Rickettsia was the main bacteria in gut of E. pela. The phylogenetic analysis of the 16S rDNA showed that, the Rickettsia from E.pela has close relationship with that of pea aphid Acyrthosiphon pisum. PCR amplification was performed using the specific primers for Rickettsia to detect infection in 30 male and 30 female individuals. The result showed that, the infected male and female were 24 and 12 respectively.
To clarify the effect of coastal environment on quality of Phyllostachys edulis timber, comparison and analysis on physical and mechanical properties of bamboo timber from coastal windward side stand and inland stand was carried out. The results showed that the basic density, air-dry density, oven-dry density, compressive strength parallel to grain, bending strength, elastic modulus in bending of bamboo timber increased with bamboo age increasing on the whole. Effect of coastal windward environments on basic density, air-dry density, oven-dry density, compressive strength parallel to grain, bending strength and elastic modulus in bending of bamboo timber was not obvious, that on timber shrinkage was significant and bending strength of young bamboo (1 a and 3 a) increased remarkably. All results indicated that coastal windward environments was in favor of enhancement in mechanical properties and resistance to wind stress of Ph. edulis forest, and Ph. edulis can be used to construct eco-economic protective forests system at coastal region.
The survey was conducted on the growth of 10-year-old Manglietia glauc and their soil condition in different slope position from three sites: the original place Bào Yên of Lào Cai, Vietnam and the introduction places Baiyun and Shaoping in Pingxiang, Guangxi, China. It was found that the growth of M.glauc on different sites showed down slope>middle slope>upper slope. Comparing the down/upper slope with upper slope in different sites, the DBH, tree height and volume growth rose by 30.35%, 49.00%; 34.78%, 56.03%; 122.97%, 236.15% in Baiyun, 30.07%, 53.44%; 39.00%, 54.54%; 125.09%, 245.76% in Shaoping, and 19.75%, 35.08%; 11.08%, 27.49%; 56.58%, 119.21% in Bào Yên, respectively. Baiyun and Shaoping located in south subtropical zone, had higher effect on the growth of M. glauc than that in its original place Bào Yên located in north tropical zone. The effect of soil condition on M. glauc stands showed the same regularity. This implied that M. glauc is a soil sensitive species. Result of variance analysis showed that slope position on the growth of M. glauc reached a highly significant difference(PM. glauc was alike in the same climatic zones, but differed in the different climatic zones, the growth in the south subtropical zone was higher than that in the north tropical zone, the order of the growth linear gradient was the same as the trend of the effect on slope in different climatic zones. It is showed that the degree of effect on slope in M. glauc growth varied under different habitat condition.
Rhododendron changii is a monotypic species in China. This study isolated and obtained 10 same mycorrhizal fungi strains from Rhododendron changii and identified them by traditional classification method of morphology in conjunction with 18S rDNA sequence analysis. The results of identification suggest that this mycorrhizal fungi is Meliniomyces variabilis' sibling species.