2019 Vol. 32, No. 4
Changes of Spring Phenology and Sensitivity Analysis in Temperate Grassland and Desert Zones of China
2019, 32(4): 1-10. doi: 10.13275/j.cnki.lykxyj.2019.04.001
[Abstract](3864) [FullText HTML] (2052) [PDF 4002KB](101) [Cited by] ()
Objective To analyze the trends of spring phenology in temperate grassland and desert zones of China under the context of global climate change, and to explore the relationship between spring phenology and climate factors. Method Using the Normalized Difference Vegetation Index (NDVI) dataset from 1982 to 2015, the start date of the vegetation growing season (SOS) in temperate grassland and desert zones of China was extracted, and the linear trends of SOS for the entire study area, meadow, steppe and desert were evaluated. The relationship between SOS and preseason (May through October of last year) temperature and preseason precipitation was analyzed with partial correlation and multiple linear regressions, along with the spatial pattern of SOS response to climate change. Result Over the temperate grassland and desert zones of China, the SOS was significantly advanced by 0.14 d·a-1 from 1982 to 2015. Spatially, 68% of natural vegetation pixels showed an advancing trend in SOS, whereas 32% of pixels displayed a delay trend. It showed the SOS was negatively correlated with preseason mean temperature and preseason precipitation for different preseason periods, and was more significantly correlated with preseason mean temperature. SOS was most correlated with mean temperature during 40 days of preseason period and precipitation during 200 days of preseason period, respectively. From 1982 to 2015, a warming of 1℃ in preseason (40 days) mean temperature would significantly advance SOS by 1.31 days over the temperate grassland and desert zones of China, whereas an increase of 10 mm in preseason precipitation would advance SOS by 0.44 days. Spatially, an increase of 10 mm in the long-term average preseason (200 days) precipitation would increase temperature sensitivity of SOS by 0.093 d·℃-1, and would decrease the precipitation sensitivity of SOS by 0.019 d·(10 mm)-1. Conclusion SOS showed an advancing trend in temperate grassland and desert zones of China in the past 34 years. Preseason mean temperature is the dominant factor driving variations of SOS. Increase in preseason mean temperature and preseason precipitation will lead to SOS advance. Preseason precipitation determines the spatial pattern of temperature sensitivity of SOS and precipitation sensitivity of SOS. SOS is more sensitive to preseason mean temperature in the areas with more preseason precipitation; and is more sensitive to preseason precipitation in the areas with less preseason precipitation.
2019, 32(4): 11-18. doi: 10.13275/j.cnki.lykxyj.2019.04.002
[Abstract](2737) [FullText HTML] (1463) [PDF 777KB](29) [Cited by] ()
Objective The analysis of combining ability was conducted through full-diallel mating design to study the relative contribution of special combining ability (SCA) to economically important traits, aiming to provide important genetic parameter information for the development of Japanese larch (Larix kaempferi) breeding strategies and the management of breeding populations. Method The progeny trail mainly consists of two full-diallels (6×6 and 4×4, respectively) derived from 13 parent trees used as female and 23 used as male. The phenotypic data for growth traits measured at age 16 and age 26 were adjusted using first order autoregression model, and then were used in individual mixed models to conduct combining ability and reciprocal effect analysis. The importance of dominance related to additive effect was investigated and its application in Japanese larch breeding was discussed. Result The self-crossed offspring showed no significant self-depression in the survival, and even outperformed the corresponding non-selfed individuals in some parents in terms of growth. The reciprocal effects of the growth traits were not notable, indicating that the mating direction needs not to be considered in future's breeding. At age 16, the additive and dominance effect of DBH and volume were significant, and the dominant effect was greater than the additive effect. At this age, the genetic gains were 3.21% and 8.04% when selected for the top 10 families based on combining breeding value and SCA, which increased by 16.30% and 12.92% compared with selection on breeding value solely (2.76% and 7.12%, respectively). The additive effects of DBH and volume were significant at age 26 while the dominant effects were disappeared. The narrow-sense heritability, broad sense heredity and broad family heritability of the average family were 0.070-0.074, 0.164-0.173, and 0.546-0.572 for DBH and volume at age 16, and the narrow-sense heredity increased to 0.13 and 0.10 for this two traits, respectively. Conclusion The SCA effects are significant for DBH and volume at age 16. More genetic gain can be captured by the utilization of SCA through producing improved seeds from mating those parent pairs with high GCA and high SCA effects. Further, genetic gain can be maximized through vegetative propagation of the trees developed from those seeds.
The Site and Planting Density Effects on the Wood Volume Growth of Chinese Fir Plantations in South Subtropical Area
2019, 32(4): 19-25. doi: 10.13275/j.cnki.lykxyj.2019.04.003
[Abstract](3316) [FullText HTML] (1500) [PDF 2812KB](56) [Cited by] ()
Objective To provide theoretical and practical basis for the efficient cultivation of Chinese fir, the effects of site and planting density on stand wood volume growth rules of Chinese fir (Cunninghamia lanceolata) plantations in south subtropical area of China were studied. Method Based on 36-year positioning observation data of Chinese fir plantations in Daqingshan, Guangxi, including five planting densities, i.e. 1 667 trees·hm-2 (A), 3 333 trees·hm-2 (B), 5 000 trees·hm-2 (C), 6 667 trees·hm-2 (D) and 10 000 trees·hm-2 (E), the dynamics of total wood volume and living trees wood volume were analyzed. Result The effects of planting density and site on the growth of total wood volume and living trees wood volume were consistent. The total wood volume was obviously positively related to stand planting density and site index during middle and young ages. The higher the planting density and the site index were, the bigger the total wood volume became, and the total wood volume of stand with medium density became much bigger than the other stands after 15 years. The mean annual increment (MAI) of total wood volume increased rapidly at first and then declined after reaching to the peak, and the higher the density was, the earlier the decline started and more obvious it became. The stand ages at which the current annual increment, and the MAI of total wood volume reached to its peaks were at the 10th and 14th years, respectively, and the growth rate of total wood volume decreased to 3% at the age of 1925. Conclusion The influence of site index on total wood volume of stands with relatively low planting density is greater, but with the increasing of planting density, the influence becomes weak. If the maximum wood volume is taken as the cultivation target, density C is the most suitable planting density at the site index of 16. The first thinning, last thinning and final cutting in south subtropical area of China should be at about 10, 14, 25 years old, respectively. The final cutting should not be earlier than 19 years old, the lower the planting density is, the later the final cutting will be, and the final cutting of the stands with density A and B can be postponed to 25 years old.
Hydrological Effects of Forest Litters of Larix principis-rupprechtii Plantations with Varying Ages in Liupanshan of Ningxia, China
2019, 32(4): 26-32. doi: 10.13275/j.cnki.lykxyj.2019.04.004
[Abstract](3046) [FullText HTML] (1313) [PDF 1221KB](33) [Cited by] ()
Objective To study the impacts of forest age on hydrological functions of humus. Method Four Larix principis-rupprechtii plantations (mature, near mature, middle age and young) at Xiangshuihe Watershed in Liupanshan were selected in June 2017. The hydrological functions of litter of these L. principis-rupprechtii plantations were surveyed by investigating the stand structure and measuring the amount, thickness and water holding capacity of litter accumulation. Result (1) The thickness of litter ranged from 4.5 to 6.0 cm, the total accumulation was 29.0833.21 t·hm-2, and the storage of semi-decomposed layer were higher than that of the undecomposed layer. The thickness and accumulation of litter in these plantations were found in the order of mature forest > near mature forest > middle age forest > young forest. (2) The litter of mature forest had the maximum water holding capacity which was between 79.47 and 110.05 t·hm-2. The middle aged forest had the highest change rate of water holding capacity, which varied from 273.32% to 341.27%. (3) Dynamic relationship between water holding capacity and soaking time of litter of all these plantations was similar. The water absorption rate of the litter was the highest within 0.5 hour, and the variation of water absorption rate tended to be gentle after 4 hours. The water content of the litter was basically saturated after 10 hours, the relationship between water holding capacity and soaking time followed a significant logarithmic relationship (R2>0.92). (4) The valid water-interception capacity of litter was between 43.64 and 70.52 t·hm-2, the mature forest had the strongest intercepting capacity. Conclusion The hydrological function of litter reaches their maximums in mature forest. The results of this study can be used as a reference for the research on hydrological process of the litter layer of L. principis-rupprechtii plantation.
2019, 32(4): 33-40. doi: 10.13275/j.cnki.lykxyj.2019.04.005
[Abstract](2657) [FullText HTML] (1360) [PDF 1400KB](42) [Cited by] ()
Objective Compatible models for the single tree biomass and stand biomass of Larix olgensis were established to represent different levels of variations and to improve generalization capability of models. Method Based on the biomass data of 64 trees in 40 sample plots of L. olgensis plantation, the compatible models were established by combining dummy variable and nonlinear seemingly unrelated regression under the conditions of considering or not considering stand age. Result (1) The models have good estimation precision with Radj2>0.95 and Radj2>0.78 for single tree biomass and stand biomass, respectively. (2) Under the consideration of stand age with dummy variable, the fitting goodness of model is improved with smaller TRE, MPE and MSE, the evaluation statistics are stable overall and the range of parameter b reduces form 0.905 52.512 5 to 1.047 02.202 8 for single level and Radj2 increases by 0.201 9 and the range of parameter b reduces form 0.071 11.560 7 to 0.781 11.055 1 for stand level. (3) Using the linear regression model of logarithmic transformation, the distribution trends of model residual error of the whole plant and its components are parallel to the transverse axis. Conclusion The method of combing dummy variable and nonlinear seemingly unrelated regression is flexible, simple and applicable to the establishment of single tree biomass and stand biomass models. The fitting goodness of biomass model is improved with the consideration of stand age, especially in stand biomass model. Thus, the influence of stand age should be considered in the process of stand biomass modeling.
2019, 32(4): 41-46. doi: 10.13275/j.cnki.lykxyj.2019.04.006
[Abstract](3455) [FullText HTML] (1664) [PDF 813KB](41) [Cited by] ()
Objective To study the genetic diversity of Eucalyptus cloeziana for the purposes of germplasm conservation and breeding potential evaluation. Method Fourteen simple sequence repeats (SSR) markers were used to detect the variation in four main distribution areas of E. cloeziana. The locus polymorphism and population diversity were analyzed, the differentiation coefficient and genetic similarity among regions and the molecular variance components inter-and intra-regions were calculated. Cluster analysis was conducted based on genetic similarity. Result A total of 249 alleles were detected in 14 SSR markers, with an average of 18 alleles per marker. Based on all the markers, the Shannon's information index was 1.785 4, the observed heterozygosity was 0.510 0, and the expected heterozygosity was 0.788 2, indicating a high genetic diversity. The average coefficient of genetic differentiation among regions was 0.071 6, and the component of variance among populations in analysis of molecular variance (AMOVA) was only 6.8%. This indicated that the level of genetic differentiation was moderate and genetic variation mainly exists in populations. Unweighted pair group method with arithmetic (UPGMA) clustering analysis divided the four main distribution areas of E. cloeziana into two major categories:north and south. Conclusion The germplasm resource conservation should give priority to the areas with high diversity. The genetic diversity of E. cloeziana is high, and it has great potential for breeding.
C, N and P Distribution and Stoichiometry Characteristics of Caragana microphylla Seedlings to Drought Stress
2019, 32(4): 47-56. doi: 10.13275/j.cnki.lykxyj.2019.04.007
[Abstract](2963) [FullText HTML] (1671) [PDF 2494KB](54) [Cited by] ()
Objective To study the effects of drought stress on C, N and P distribution and stoichiometry of C. microphylla seedlings in order to provide theoretical basis for water management of Caragana microphylla seedlings. Method The two-year-old C. microphylla seedlings were grown under suitable water level, mild, moderate and serious water stress treatment by using water controllable pot planting method. The C, N, and P concentrations and their ratios in leaves, stems, coarse and fine roots of C. microphylla seedlings were measured to analyze the C, N, and P stoichiometric distribution patterns and variation characteristics. Result Compared with the suitable water level treatment, the C concentration decreased in leaves but increased in coarse roots and fine roots, meanwhile, the N concentration declined in coarse roots whereas increased in fine roots. However, the P concentration declined at first and then promoted in leaves, and it increased initially and then decreased in fine roots. At last, they both maintained constant in the drought stress treatments. In addition, C:N and C:P increased in coarse roots and fine roots in the drought stress treatments, whereas C:P declined in stems, and N:P declined at first and then maintained unchanged in leaves and declined in stems, coarse roots and fine roots. The variation coefficients of nutrient concentration followed the order:P > N > C. The variation coefficient of C concentration was the highest in fine roots and the lowest in stems. Meanwhile, the variations coefficients of N concentration, P concentration, C:N, C:P, and N:P were the greatest in coarse roots and the lowest in leaves. Conclusion P is the main element limiting the growth of C. microphylla seedlings, but N limitation is enhanced by drought stress. Drought stress increases the C and N allocation in fine roots, and improves the utilization efficiency of N and P. Meanwhile, the stability of N and P is stronger in leaves than in stems and roots under drought stress.
2019, 32(4): 57-63. doi: 10.13275/j.cnki.lykxyj.2019.04.008
[Abstract](3226) [FullText HTML] (1814) [PDF 813KB](28) [Cited by] ()
Objective A total of 50 healthy clusters about 150 needles were sampled from 40 Larix olgensis trees at the age of 10 to 40 years in Jingouling Forest Farm of Wangqing Forestry Bureau, Jilin Province, for the establishment of leaf area regression models and estimation of specific leaf area. Method The needle area, needle length, needle width and needle perimeter were obtained using WinSEEDLE software, and the needles were dried to a constant weight to obtain the needle dry mass. The unitary, binary and ternary regression models were established with needle length (L), needle width (W), needle perimeter (P) and needle dry mass (M) as independent variables and needle area (LA) as a dependent variable. Linear, exponential and power function models were used for fitting. The mean error, total relative error, mean system error, mean prediction error and root mean square error were used to verify the errors and evaluate the goodness of model fitting. The variance of arithmetic average method, ratio estimation method and the least square method was compared to obtain the specific leaf area of Larix olgensis. Result LA=5.929e1.313W (R2=0.858), LA=6.194e(0.023L+0.637W (R2=0.936) and LA=6.445e(0.021L+0.598W+18.067X)(R2=0.941) are proved to be the best unitary, binary and ternary regression models. Conclusion The arithmetic average method is the best for specific leaf area estimation of L. olgensis which is 8.026 m2·kg-1.
Effects of Thinning on Contents and Stoichiometry of C, N, and P in Different Components of Chinese Fir Plantation
2019, 32(4): 64-69. doi: 10.13275/j.cnki.lykxyj.2019.04.009
[Abstract](3103) [FullText HTML] (1543) [PDF 788KB](80) [Cited by] ()
Objective To study the changes of carbon (C), nitrogen (N) and phosphorus (P) stoichiometry in Chinese fir (Cunninghamia lanceolata) plantations after thinning. Method Nine 20 m×20 m plots were established in 17-years-old Chinese fir plantation in Kaihua Forest Farm of Zhejiang. The contents and stoichiometry of C, N, and P in litter, understory, fine roots and soil were studied under three thinning intensities, i.e. unthinning, moderate thinning (20%), and heavy thinning (37%). Result After 2 years of thinning, the litter biomass and fine root biomass of Chinese fir decreased significantly (P < 0.05) in the heavy thinning treatment, while the understory vegetation biomass increased significantly. Compared with the unthinned stands, the total N content decreased significantly in the litter and increased in the understory vegetation in the heavy thinning treatment (P < 0.05), and the contents of soil organic carbon and total nitrogen also increased significantly in the heavy thinning treatment (P < 0.05). The contents of C, N, and P in the fine roots of Chinese fir showed no significant difference among the unthinned, 20% thinned and 37% thinned stands. The ratios of C/N and C/P in the litter increased with increasing thinning intensity. The C/N ratio of the understory vegetation decreased with increasing thinning intensity, and N/P ratio increased with increasing thinning intensity. The ratios of C/N, C/P and N/P in the fine root and soil showed no significant difference among the three thinning treatments. There was positive correlation in the contents of C, N and P and their ratios between soil and understory vegetation. Conclusion The contents of C and N in the litter, understory vegetation and soil are strongly affected by thinning intensity during a short time after thinning. Thinning alters C, N and P stoichiometry in litter and understory vegetation, but has no effect on fine roots of Chinese fir and soil.
Optimization of SSR-PCR Reaction System and Study on Genetic Diversity of Natural Populations of Machilus pauhoi
2019, 32(4): 70-78. doi: 10.13275/j.cnki.lykxyj.2019.04.010
[Abstract](3501) [FullText HTML] (1659) [PDF 2411KB](30) [Cited by] ()
Object To establish SSR-PCR reaction system of Machilus pauhoi, screen the high polymorphic primers from the SSR primers of Lauraceae, and to investigate the genetic diversity of M. pauhoi. Method In order to establish the optimum SSR-PCR reaction system of M. pauhoi, seven concentration levels were set for each of five factors to determine the suitable concentration range by using L16(45) orthogonal design. The system was used to filter primers from 187 candidate primers. The software of POPGENE1.32, PowerMarkerv3.25, FSTAT, GenAlex6.5, Structure2.3 and POPTREE were used to calculate the observed allelic number (Na), observed heterozygosity (Ho), expected heterozygosity (He), Polymorphism Information Content (PIC), gene flow (Nm), the genetic structure and cluster analysis based on the unweighted pair group method of arithmetic averages (UPGMA). Result The optimal reaction system was established, the optimum concentration of five factors are as follows:Taq polymerase, dNTPs, Mg2+, primers and template DNA were 1.0 U·μL-1, 0.25 mmol·L-1, 1.25 mmol·L-1, 0.5 μmol·L-1and 50 ng in a total volume of 20 μL, respectively. Twelve pairs of SSR primers with high polymorphism were screened. The average Na, Ho, He and PIC were 15.083, 0.576, 0.751, and 0.722, respectively, which means higher genetic diversity in M. pauhoi. The average Nm was 1.500, which means high gene flow existed among the provenances. The analysis with UPGMA was consistent with Structure software which indicated that the twenty-four provenances could be divided into three groups. Conclusion The study optimizes the SSR-PCR reaction system successfully, twelve primers are screened out from 187 candidate primers using the optimal reaction system.There is higher genetic diversity in M. pauhoi population. The limited gene flow exists in these provenances, and the twenty-four provenances can be divided into three groups.
2019, 32(4): 79-87. doi: 10.13275/j.cnki.lykxyj.2019.04.011
[Abstract](3251) [FullText HTML] (1708) [PDF 1474KB](31) [Cited by] ()
Objective To analyze the genetic variation of wood properties of Catalpa fargesii f. duclouxii clones and to improve their efficiency of genetic improvement of wood properties. Method Twenty clones from Guizhou Province were chosen as sampling materials, the height, diameter at breast height (DBH), wood basic density, double wall thickness, cell lumen diameter and fiber length were measured. The genetic parameters were estimated by maximum likelihood method, the phenotype and genetic correlation were analyzed. The wood properties of clones were evaluated by clustering and membership function methods. Result The results showed that the growth and wood property traits were significant different among clones; the range of traits phenotype variable coefficient were 6.21% to 21.29%; the basic density, cell wall rate and double wall thickness were strongly controlled by heritability, the repeatability were 0.88, 0.87 and 0.73, respectively; the basic density had significantly positive correlation with vessel percentage ratio (0.542), cell wall ratio (0.908) and double wall thickness (0.747). However it was negatively correlated with cell lumen diameter. The correlation between wood property traits was strongly influenced by the heritability. Regression analysis showed that the basic wood density had significantly positive linear relationship with cell wall ratio and double wall thickness. On the contrary, it had negative linear relationship with tangential cell lumen diameter. Conclusion The wood properties are significantly different among clones, and have greater variation. The evaluation results of combining clustering and membership function show that the wood properties of all the 20 clones can be divided into four groups, group A has higher wood density, group B has shorter fiber length, group C has lower wood density and group D has longer fiber length.
Tolerance of Liquidambar formosana Seedlings to Pb: Physiological and Biochemical Response and Elements Distribution
2019, 32(4): 88-95. doi: 10.13275/j.cnki.lykxyj.2019.04.012
[Abstract](3168) [FullText HTML] (1563) [PDF 3644KB](28) [Cited by] ()
Objective A greenhouse pot experiment was conducted to determine the characteristics of Pb micro-distribution and chemical forms in Liquidambar formosana seedlings and evaluate the implication on Pb toxicity and the plant tolerance. Method The response of seedlings to Pb concentrations (0, 50, 100, 200 and 400 mg·L-1) in the solution was studied. the seedling growth, chlorophyll, carotenoid, Pb accumulation and translocation were assessed. Different chemical reagent extraction techniques were carried out to analyze the chemical forms of Pb. The characteristics of Pb distribution in root of L. formosana were investigated by synchrotron radiation X-ray fluorescence analysis. Result The results showed that Pb concentration treatments induced toxicity symptoms in seedlings' leaves. Compared to the control, the biomass increased slightly at low concentration (50 mg·L-1), and the tolerance index values of all Pb treatments were great than 0.9. Under Pb stress conditions, the photosynthetic pigments significantly declined. During the experiment, a greater quantity of Pb was uptake and mostly retained in L. formosana roots, and the translocation factor values of all Pb treatments were lower than 0.1. Most of Pb in L. formosana tissues was stored in the cell wall with HAc-, HCl-, and NaCl-extractable form. The synchrotron radiation X-ray fluorescence analysis indicated that most of Pb was detected in the epidermal cells of roots. Conclusion Our results suggested that Pb deposited in the epidermal cells of roots and integration with phosphate or oxalate might be responsible for the tolerance of L. formosana under Pb stress in short period.
2019, 32(4): 96-104. doi: 10.13275/j.cnki.lykxyj.2019.04.013
[Abstract](3044) [FullText HTML] (1508) [PDF 2369KB](51) [Cited by] ()
Objective To evaluate and select Catalpa bungei superior clones. Method The field test data of seven years'growth were collected to analyze the early growth processes and tendencies of different C. bungei clones. Logistic fitting regression analysis method was used on individual volume growth of each clone. In addition, the correlation among different indexes were analyzed and a cluster analysis of 32 clones was carried out. Result The differences in DBH, tree height and individual volume among C. bungei clones in different ages (except 1 year old) were extremely significant, indicating that there was a high variation among the clones. The coefficient of variation of individual volume showed the highest (7.84-35.56), followed by DBH (11.89-17.29) and tree height (6.91-10.87), suggesting a greater potential for improvement in the individual volume of clones. At the same time, in the later growth period, the individual volume (0.75) and DBH (0.82) maintained high repeatability, implying that individual volume was strongly controlled by heritability. Using the mean annual increment of individual volume growth in clones, a logistic model of the individual volume growth curve of the C. bungei clones was fitted. The estimated growth parameters were quite different among clones. The mean annual individual volume growth of 7-year-old C. bungei presented a S-shaped growth curve; the annual individual volume growth increased at first and then decreased, and reaching a peak at the 5th year, however, the clones observed did not reach quantitative maturity according to the curves. The correlation analysis showed that the individual volume increment was significantly positively correlated with the maximum growth rate, linear growth rate, and linear growth increment of C. bungei clones. The results of cluster analysis showed that the 32 C. bungei clones could be divided into 4 categories, the total individual volume of category I was larger and with stronger potential for growth in the later period than the others. Conclusion The genetic variation of C. bungei clones is rich. The growth potential of 6 clones among the 32 clones is higher, so they can be used as superior clones for expanding.
Response of Photosynthesis Characteristics and Leaf Anatomical Structure of Vietnam Camellia hirsuta under Different Light Environment
2019, 32(4): 105-113. doi: 10.13275/j.cnki.lykxyj.2019.04.014
[Abstract](3433) [FullText HTML] (1576) [PDF 1911KB](41) [Cited by] ()
Objective Vietnam Camellia hirsuta were used as experimental materials to study the effect of different light treatments on the photosynthetic characteristics and anatomical structure of C. hirsuta in order to provide references for introduction, cultivation and management of the species. Method In early May of 2017, the Vietnam C. hirsuta plants were grown in the shade sheds with different light intensity and the trials lasted for two months. The light intensities of 10%, 20%, 30%, 40%, and 50% were obtained by covering the shading net of different layers. Result The variation trend of the net photosynthetic rate of different light treatments was different. 20% and 30% light intensities significantly improved the net photosynthetic rate and transpiration rate of C. hirsuta, while the vapor pressure deficit decreased (P < 0.05). These results showed the photosynthetic function was promoted. The content of photosynthetic pigments of C. hirsuta leaves were the highest in the 30% light treatment. Furthermore, the total chlorophyll content was the highest, but the chlorophyll a/b was the lowest, which was beneficial to the synthesis of chlorophyll b of C. hirsuta leaves under the 30% light treatment. There were more developed palisade tissue, spongy tissue and thicker blade thickness in C. hirsuta leaves under 20% and 30% light treatments, which promoted its adaptation to the environment and enhanced the photosynthesis. Under the appropriate shade conditions (20%-40% light treatments), the maximum net photosynthetic rate of C. hirsuta increased. Conclusion Under 20% and 30% light treatments, the blade has more developed palisade tissue and thicker leaf thickness, and the stoma density is relatively low. The net photosynthetic and transpiration rate of C. hirsuta leaves are improved. On the contrary, the internal carbon dioxide concentration and vapor pressure deficit of C. hirsute are decreased, which leads to the smaller resistance of CO2 and water vapor in and out of the stomata. At the same time, under 30% light treatment, the total chlorophyll content is the highest. It shows that the photosynthetic rate is improved effectively. It is concluded that C. hirsuta is suitable for growing in the environment with 20%-30% light intensity.
2019, 32(4): 114-119. doi: 10.13275/j.cnki.lykxyj.2019.04.015
[Abstract](2940) [FullText HTML] (1548) [PDF 973KB](35) [Cited by] ()
Objective To clarify the effect of temperature on the reproduction and development of Sclerodermus alternatusi, the ectoparasitoid of Monochamus alternatus, and provide scientific supports for artificial rearing of parasitoid and biological control utilization in practice. Method The parasitoids were reared artificially at different constant temperatures (21, 24, 27, 30, and 33℃) under laboratory conditions. The development duration of each stage and the progeny number were recorded. The development threshold temperature and effective accumulated temperature were also calculated by using the least squares method. Result It showed that the development durations of S. alternatusi declined with the increase of temperature. For example, the durations of egg stage at the different temperature were 3.29±0.14, 2.89±0.17, 2.61±0.14, 2.16±0.11 and 1.86±0.93 days, respectively. The development threshold temperatures for egg, larva, pupa were 6.99±2.12, 10.67±3.43 and 13.5±2.71℃, while the effective accumulated temperatures were 49.28±5.08, 166.67±34.02 and 225±43.30 degree-day respectively. The temperature also showed significant effects on the amount and sex ratio of the progenies. As the rearing temperature exceeded 30℃, the amount and male proportion of the progenies decreased significantly. Conclusion These findings reveal that the proper rearing temperature can improve the reproduction and development of S. alternatusi. However, once the temperature is over the optimum threshold, the parasitism of maternal parasitoids and development of progenies will be adversely affected. The optimum temperature range for artificial mass rearing is 2430℃.
2019, 32(4): 120-128. doi: 10.13275/j.cnki.lykxyj.2019.04.016
[Abstract](3494) [FullText HTML] (2022) [PDF 1271KB](31) [Cited by] ()
Objective To compare and analyze the differences of physiological characteristics of different tree species and their effects on negative air ion (NAI) concentration in order to provide references for studying the mechanism of forest vegetation acting on NAI. Method The NAI effect of six typical subtropical tree species was monitored continuously in artificial climate room located in Research Institute of Subtropical Forestry, Chinese Academy of Forestry, from June to September, 2018. The soil basin without plant was selected as blank control, and the characteristics of leaf morphology, chlorophyll fluorescence parameters and chlorophyll content of each tree species were also measured. Result The concentration of NAI in the artificial climate chamber was significantly different from that in the control group (P < 0.01). The results of daily mean value showed that the order of NAI concentration from high to low was:Taxus chinensis var. mairei (876 ion·cm-3) > Liquidambar formosana (828 ion·cm-3) > Cunninghamia lanceolata (733 ion·cm-3) > Zelkova serrata (685 ion·cm-3) > Quercus aliena (677 ion·cm-3) > Phoebe bournei (665 ion·cm-3) > control (345 ion·cm-3). On the whole, the NAI effect of coniferous tree species was significantly higher than that of broadleaved tree species (P < 0.05) and the deciduous broadleaved tree species was significantly higher than that of evergreen broadleaved tree species (P < 0.05). A comprehensive comparison of six tree species showed that NAI concentration was positively correlated with the number of leaf tips, leaf water content and leaf area (P < 0.01), the effect of leaf biomass had a significant positive correlation (P < 0.05). There was a significantly negative correlation between chlorophyll a/chlorophyll b (P < 0.05). Comparing broadleaved tree species, it was found that NAI concentration had a significantly negative correlation with leaf thickness and leaf length and width ratio (P < 0.05) while had a very significantly positive correlation with most chlorophyll fluorescence parameters (P < 0.01). Conclusion The concentration of negative ions in the air was significantly increased by plants, and the NAI effect was different among tree species. The NAI effect of coniferous tree species is higher than that of broadleaved tree species, and the NAI effect of deciduous broadleaved tree species is higher than that of evergreen broadleaved tree species. Leaf morphology, leaf tip number and photosynthetic fluorescence physiological characteristics are important reasons for the difference of NAI effect among tree species.
Preliminary Evaluation of Fruit Characteristics and Nut Quality of Juglans cathayensis Dode var. formosana (Hayata) from Anhui Province
2019, 32(4): 129-136. doi: 10.13275/j.cnki.lykxyj.2019.04.017
[Abstract](3242) [FullText HTML] (1914) [PDF 817KB](26) [Cited by] ()
Objective To investigate the fruit traits, the seed kernel components and their correlations of Juglans cathayensis Dode var. formosana. Method The fruits of J. cathayensis Dode var. formosana from southern Anhui Province were used to measure the fruit characters and nut contents such as fresh fruit weight, peel thickness, nut weight, shell thickness, and kernel, and their correlations were analyze. Result The results showed that the phenotypic traits of fresh fruit of J. cathayensis Dode var. formosana had abundant variation (most variation coefficients were more than 10%), among which the maximum variation coefficient of nuts thickness was 43.92%. Furthermore, the determination of nut kernel contents showed that the kernel had the highest fat content, the protein followed, and the total sugar was lower. Further analysis of the fatty components showed that the unsaturated fatty acids (especially linoleic acid and oleic acid) contents were up to 92.68%. These results also revealed that there was a significant positive correlation between nut weight and kernel fat content. Principal component analysis showed that the fruit size and the fatty acid content of the nutmeat were very important in the fruit evaluation. The comprehensive evaluation showed that the fresh fruit size and unsaturated fatty acid content of two plant samples were the best among the plants tested, so they could be used as the candidate individual for cultivating excellent cultivar. Conclusion The fatty acid content of J. cathayensis Dode var. formosana is higher than that of Carya illinoinensis and C. cathayensis, and the content of unsaturated fatty acids is also higher. The results show that the nutmeat is a new food resource worth developing.
2019, 32(4): 137-143. doi: 10.13275/j.cnki.lykxyj.2019.04.018
[Abstract](2850) [FullText HTML] (1621) [PDF 2505KB](23) [Cited by] ()
Objective To determine the degree and mechanism of frost damage on water use in growing season of apple trees. Method Thermal dissipation probe (TDP) was used to monitor continuously the sap flux density (Js) of apple trees before and after the frost during the main growing seasons for two years. The micro-meteorological factors such as net radiation (Rn), air temperature (Ta) were measured synchronously and the derived variables such as vapour pressure deficit (VPD) was calculated. The effects of late frost on water use of apple trees were analyzed. Result The maximum sap flux density (Js-max) around noon on the frost-occurred day decreased by 9%-27% compared with the days before the frost occurring, and Js-max/VPD decreased continuously in the days after the frost occurring. By comparison, the average daily sap flux density (Js-mean) in growing season of the frost year (2018) was 35% lower than that in the non-frost year (2017). In the whole main growth season, Js-mean showed a significant exponential relationship with Rn or VPD, but the Js-mean of frost-year was significantly lower than that of non-frost-year at the same level of Rn (or VPD). Conclusion The severe low temperature frost with rapid rise of air temperature after frost together, will cause a significant decline in water use potential of apple trees during the growing season. The results provide support for understanding the mechanism of frost's influence on water physiology of apple trees.
Phosphate Solubilizing Characteristics and Growth Promoting Effect of Aspergillus neoniger on Phyllostachys edulis Seedling
2019, 32(4): 144-151. doi: 10.13275/j.cnki.lykxyj.2019.04.019
[Abstract](3410) [FullText HTML] (1584) [PDF 1827KB](23) [Cited by] ()
Objective The aim of this study is to investigate the phosphate-solubilizing characteristics and growth promoting effect of Aspergillus neoniger (JXBR16) from rhizosphere soil of Phyllostachys edulis. Method The phosphate-solubilizing ability of strain JXBR16 on five different types of mineral phosphate, including Ca3(PO4)2, CaHPO4, FePO4, AlPO4 and calcium phytate, were compared and the effects of carbon sources, nitrogen sources, initial pH, liquid filling volume, temperature and salt ions on phosphate solubilizing ability of strain JXBR16 were studied using the liquid fermentation experiment. Also, the effects of strain JXBR16 on nutrient acquirement and growth of Ph. edulis were evaluated using pot experiment. Result The strain JXBR16 showed the greatest ability to solubilize FePO4 and CaHPO4 with 3 208.31 and 3 027.09 mg·L-1, respectively. The strain JXBR16 displayed the highest phosphate-dissolving capacity when the initial pH reached 3.5, the volume of liquid was 2/5, the temperature was 25℃, the NaCl concentration was 0.01.0 g·L-1, sugar and yeast powder were used as carbon and nitrogen sources, respectively. Meanwhile, compared with control, the rhizosphere soil available phosphorus, mineral nitrogen, root, stem, and leaf phosphorus contents increased by 37%, 41%, 95%, 102% and 43%, respectively in Ph. edulis seedling inoculated with strain JXBR16 for 180-days. In addition, the ground diameter, seedling height and biomass accumulation were higher by 44.44%, 47.27% and 50.40%, respectively in strain JXBR16 treatment than control. Conclusion A. neoniger can effectively enhance soil phosphorus supply, promote nutrient uptake and utilization, and improve the growth of Ph. edulis in red soil region. It has great potential to be used in development of biological fertilizer for bamboo forests in southern China.
2019, 32(4): 152-157. doi: 10.13275/j.cnki.lykxyj.2019.04.020
[Abstract](2475) [FullText HTML] (1156) [PDF 854KB](20) [Cited by] ()
Objective To clear the use of phosphorus and potassium, improve the production and reduce the cost for the purpose of the cultivation of camphor. Method Three-years-old camphor trees were selected as the test materials, no phosphorus and potassium fertilizer treatment (CK), P treatment, K treatment and P+K treatment were set up to analyze the influence of phosphorus and potassium on the growth traits, leaf physiology, yield and oil yield of camphor. Result Compared with the CK, K treatment increased the content of chlorophyll a and chlorophyll (a+b) significantly, and promoted the growth of the thick tip and branch, but inhibited the tip length, height and crown, significantly increased the leaf width, decreased the ratio of leaf length to width, enhanced the activity of POD and decreased the contents of malondialdehyde (MDA) and soluble sugar (SS). P treatment contributed to the composition of chlorophyll b the best, increased the contents of chlorophyll a and chlorophyll (a+b) significantly, but not as good as P. K treatment could promote tip growth and increase the branch number, but inhibit the growth of thick twigs and leaves, increase the height, crown and SS, enhance the activity of POD the best and decrease the content of MDA. P+K treatment increased chlorophyll a significantly, good to tip growth, increased leaves width and height, but it is not conducive to leaf growth and has the best effect on reducing MDA, significantly increasing peroxidase activity and reducing SS content. The biomass and oil of P+K treatment were increased by about 23.9% and 24.5%;P treatment increased by 8.4% and 5.9% of the biomass and oil compared with CK. Conclusion Phosphorus can promote the synthesis of chlorophyll in camphor and enhance the ability to resist external interference as well as potassium in camphor, but the effect on the growth is completely different. K is not good for the growth and oil yield of camphor, so it is not recommended to apply potash fertilizer alone in the field management. P and K fertilization can increase production and oil production. The best formula is P150 g+K100 g for each plant.
2019, 32(4): 158-164. doi: 10.13275/j.cnki.lykxyj.2019.04.021
[Abstract](2871) [FullText HTML] (1515) [PDF 2624KB](28) [Cited by] ()
Objective To investigate the physiological and biochemical mechanisms of leaf colorization of two Liquidambar formosana families under different light quality to provide reference for exploring the response of leaf color to light quality. Method The change of the chlorophyll, carotenoid, anthocyanin, soluble sugar, flavonoid and phenylalanine ammonia-lyase (PAL) contents in L. formosana leaves were assessed. The relationship among all indexes was also discussed. Result The leaf color of L. formosana was slightly changed from green to red or dark red during the experiment. In addition, the change of leaf color of the 2 L. formosana families showed difference. The content of chlorophyll of L. formosana in the red light treatment group was significantly higher than that in other treatment groups, while the chlorophyll content in the blue light treatment group was significantly lower compared with that in other treatment groups. The contents of anthocyanin of the 2 L. formosana families were significantly improved under blue light treatment, while the contrary trend was observed in red treatment. At the same time, blue light treatment significantly increased the contents of carotenoid, soluble sugar and flavonoids and phenylalanine ammonia enzyme activity. Variance analysis indicated that different light treatments had significant effects on the content of chlorophyll within the L. formosana leaves, while the effects on the concentration of anthocyanin and carotenoid were indistinctive. Conclusion The change of leaf color of the 2 L. formosana families shows the same trend under the different spectrum light treatments, the red light treatment can promote the synthesis of chlorophyll; however, the concentration of anthocyanin in blue light treatment is higher than that in other spectrum light treatments.
2019, 32(4): 165-170. doi: 10.13275/j.cnki.lykxyj.2019.04.022
[Abstract](2936) [FullText HTML] (1612) [PDF 1241KB](58) [Cited by] ()
Objective In order to screening for superior clones and laying the foundation for the genetic improvement of Toona sinensis, the grafting seedling growth of 49 T. sinensis were evaluated. Method The plant height and DBH of 49 T. sinensis clones with the age of 1, 2, and 3 years were measured in 2015, 2016, 2017, respectively. The volume was calculated. Variance analysis and genetic parameter estimation were used to estimate the phenotypic characters and their growth. The top 20% of the clones were selected by independent elimination method. The genetic gains of the selected clones were estimated, and the correlation between characteristic meteorological factors and the phenotypic traits of the tested clones were analyzed. Result There were significant differences in the height, DBH and volume of T. sinensis clones in the continuous 3 years. The genetic variation coefficient and phenotypic variation coefficient of the 3 growth traits showed a decreasing trend, while the variation range and the repeatability (R) increased year by year. The repeatabilities of height, DBH and volume of T. sinensis clones reached the highest point at the third year, which were 0.55, 0.50, and 0.67, respectively. The DBH and volume growth showed significant and highly significant differences among clones from 2015 to 2017. There was a highly positive correlation between volume with the growth of volume and DBH. According to the volume of 3-year-old clones and their growth, 10 superior clones were screened out. The average volume of the selected clones was greater than 0.010 4 m3, and the growth was greater than 0.009 7 m3. The genetic gain of the 3-year-old biomass was 17.38%. And the coefficient of stability (b) value of the selected clones was greater than 1, showing that the selected clones were sensitive to the environmental change. The correlation analysis of meteorological factors-phenotypic traits showed that the volume had a significant positive correlation with total annual precipitation and average daily precipitation. Conclusion The difference in volume between the tested clones is extremely significant, which demonstrates a large selection potential. The genetic gain of the selected clones is high, but it is different among years and the stability is poor, which might be related to the annual precipitation.