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Ultrastructure of the Antennal Sensilla of Parasitic Wasp, Sclerodermus pupariae (Hymenoptera: Bethylidae)
WEI Ke, WANG Xiao-yi
, Available online  , doi: 10.12403/j.1001-1498.20220548
Objective Antennae are the most important olfactory organs of insects, and the antennal sensilla are the fundamental morphological units in their olfactory recognitions. To understand the variety and morphology of the antennal sensilla of Sclerodermus pupariae (Hymenoptera: Bethylidae), an important natural enemy of many buprestids and longhorned beetles. Method The ultrastructures of antennae and sensilla of male and female parasitoid adults were investigated by scanning electron microscope, and the distribution and quantity of sensilla on female and male antennae were analyzed. Result The antennae of both male and female parasitoids were knee shaped, and they were consistently constituted with scape, pedicel, and 11 flagellomeres. The antennae of male parasitoids were much longer than those of female bees. There were seven categories with 11 types of sensilla on the antennae of S. pupariae, including two types of sensilla chaetica (Ch1 and Ch2), three types of sensilla trichodea (Tr1, Tr2, and Tr3), one type of sensilla basiconica (Ba), one type of sensilla placodea (Pl), two types of sensilla styloconica (St1 and St2), one type of sensilla coeloconica (Co), and one type of sensilla squamiforma (Sq). Ten types of sensilla were observed on the antennae of female, and the sensilla Tr1, Tr2, and Ba were restrictedly distributed on female′s antennae. There were eight types of sensilla on the antennae of male, and the sensilla Tr3 were only observed in males. There were six types of sensilla showed consistent quantities across individuals of the same sex, including sensilla Tr1, Ba, Pl, St1, St2, and Co. For other five types of sensilla, their numbers varied among individuals in both females and males. The number of sensilla Ch1 and St1 on the antennae of female adults was significantly higher than that on male adults. Nevertheless, the number of sensilla Pl and St2 on the antennae of male adults was significantly higher than that on female adults. The number of sensilla Co was the same between female and male parasitoids. The sensilla Tr1, Tr2, Tr3, Ba, Pl, and Co were six typical chemosensilla because multiple wall pores could be found on their surfaces. Conclusion We analyzed the ultrastructure of antennal sensilla of S. pupariae, and found that the types, quantities, and distributions of antennal sensilla between female and male parasitoids have typical sexual dimorphism, which will provide fundamental data for the future investigations on the chemoreception mechanism and olfactory behavior differences between the male and female parasitoids.
Effects of Topography and Forest Vegetation Factors on Occurrence and Population Size of Overwintering Dendrolimus superans
HAN Da-xiao, WANG Qian-xue, WANG Shuo, JI Hao-nan, CHAI Lin-qi, ZHANG Ji-li
, Available online  , doi: 10.12403/j.1001-1498.20220187
Objective The objective is to explore the influences of topography and forest vegetation on the occurrence probability of overwintering Dendrolimus superans and clarify the relationship between these factors and the occurrence quantity of Dendrolimus superans, which will provide scientific reference for the prevention and control of the infestations of this pest. Method Factors such as topography, forest vegetation, and the number of larvae of Dendrolimus superans were investigated in 142 plots (20 m × 20 m) of different forest types established in the main distribution area of Dendrolimus superans in the Great Xing’an Mountains. The binary logistic regression and the theory of quantificationⅠ were used to establish the models of the occurrence probability and quantity of Dendrolimus superans, respectively, and the performance of these models was evaluated. Result The discriminant accuracy of the probability model was relatively high (AUC=0.826), the slope aspect and herb cover were the key factors affecting the occurrence probability of Dendrolimus superans, the occurrence probability of which was the lowest on shady slopes and was the highest on sunny slopes. The occurrence probability increased with the increase of herb cover. There were significant differences in the number of Dendrolimus superans in the stands with different slope aspects, levels of slope gradients, slope positions, altitudes, herb coverage, and stand density (P<0.05). The model of quantification established by the five factors of slope aspect, levels of slope gradient, slope position, canopy cover, and stand density had little difference in fitting degree from the model established by the full factors. The coefficient of determination (R2) of them was 0.635 and 0.685, respectively, and their root mean square error (RMSE) was 0.964 and 0.936, respectively. The model of quantification showed that the occurrence quantity of Dendrolimus superans was the least on the shady slope and the most on the sunny slope. As the levels of slope gradient increased, its occurrence quantity would decrease. The occurrence quantity of Dendrolimus superans was the most on the ridges. Similarly, with the increase of canopy cover, or the decrease of stand density, the occurrence quantity of Dendrolimus superans would increase accordingly. Conclusion The study revealed that Dendrolimus superans were prone to occur on sunny slopes, flat slopes, and ridges, which should be the focus of prevention and control, which forest management practices such as replanting, thinning and regular weeding could help restrain the population growth.
Ovarian Development of Monochamus saltuarius Female Adults
WANG Jue, FAN Li-chun, WANG Wei-tao, ZHENG Ya-nan
, Available online  , doi: 10.12403/j.1001-1498.20220253
Objective Clarify the developmental period from emergence to sexual maturity, and the effects of feeding and mating on the ovary development of female adults. Method In this study, the mature larvae of M. saltuarius were collected and reared in the laboratory till adult emerged. The one-day-old female adults were treated by four ways: 1) reared alone without being fed, 2) fed alone, 3) fed together with male adults, 4) reared together with male adults without being fed. The ovaries of female adults were continuously dissected every day until wilting or death of female adult ovaries was observed. Result The results showed that: 1) The ovarian development process of M. saltuarius was divided into five stages. 2) The ovaries of female adults of the unfed M. saltuarius stopped developing after reaching the second stage. 3) The ovaries of fed and mated female adults matured on the 14th day, and the ovaries of fed but unmated female adults matured on the 17th day. Conclusion It can be seen that the ovaries of the adult females of M. saltuarius need to be fed before their ovaries develop to maturity normally. In addition, the mating promote the development of ovariy, shorten the developmental process by three days.
Analysis on the Effect of Close-to-nature Transformation of Pinus massoniana Pure Forest Plantation
XIE Yang-sheng, MENG Jing-hui, ZENG Ji, MING An-gang, LIU Xian-zhao, JIA Hong-yan, LEI Xiang-dong, LU Yuan-chang
, Available online  , doi: 10.12403/j.1001-1498.20220459
Objective To provide the reference basis for decision-making for the close-to-natural management of plantations, the changes of forest quality and the development of tree species were analyzed after the close-to-natural transformation of Pinus massoniana. Method In 2007, 20 experimental plots for close-to-natural transformation of Pinus massoniana single species plantation were set up in the Tropical Forestry Experimental Center of Chinese Academy of Forestry in Pingxiang County, Guangxi , including16 operational plots and 4 control plots. In 2007, the first comprehensive survey was done to obtain basic data, and the implementation of selective cutting for target tree management was carried out in the winter of the same year. In the spring of 2008, trees of six broad-leaved species were planted in the stand. In 2016, the second felling for target tree tending was implemented. After 2007, the re- survey of the sample plot was carried out every 2 years, and a total of 7-phase monitoring data were obtained. Statistical calculation was made for the important value index (IVI), average diameter at breast height and pure growth of standing volume based on the monitoring data, and the effect of close-to-natural transformation of Pinus massoniana single species plantation towards multi-species mixed forest was analyzed and evaluated based on tree species composition, stand structure, stand growth, soil and microorganisms development in forest. Result After 13 years of close-to-natural transformation of Pinus massoniana pure plantation, the stand gradually transited to the structure of uneven-aged multi-species mixed forest. The IVI of the 6 tree species enriching planted under the forest were in the top 10 of IVI series, and the natural regeneration of Styrax tonkinensis and Vernicia fordii species appeared in the stand. The distribution of diameter at breast height of Pinus massoniana transformed forest was enlarged from 5 cm to 55 cm, showing the rapid development trend of mixed uneven-aged forest under the promotion of management measures. However, the untreated control stands still showed diameter class distribution of single species even-aged stand. The growth of the transformed stand was significantly higher than that of the control stand, and the growth of the stand was mainly concentrated in the trees with larger diameter, which improved the economic value of forest woods. In addition, the soil microbial content and soil physical and chemical properties of the transformed stand were significantly improved than those of the control stand. Conclusion Adjusting tree species composition is the most important management measure in Close-to-natural transformation of forest. Enlarging the distribution range of diameter class structure is the basic target of close-to-natural transformation of conifer even-aged plantation. Close-to-natural transformation increases significantly the forest growth, promotes the development of soil micro-organisms and improves the quality of forest ecosystem.
Effects of Different Stand Types on Leaf Functional Traits, Understory Species Diversity and Soil Nutrients
REN Yi-wei, ZHONG Xiao-ying, YI Hua-peng, CHANG Yao
, Available online  , doi: 10.12403/j.1001-1498.20220492
Objective To explore the needle functional traits, understory species diversity and understory soil factors of different forest types (Pinus thunbergia pure forest, Pinus thunbergia -Robinia pseudoacacia mixed forest, Pinus thunbergia -Quercus acutissima mixed forest) for providing basis and reference for the construction and management of Pinus thunbergia in the coastal shelter forest. Methods Based on Pinus thunbergia in the coastal shelter forest of Muping, Yantai, the needles and understory 0~20cm soil samples of Pinus thunbergia were collected, and the understory species diversity was investigated. The related functional traits of needles and soil physical and chemical properties were measured, and the understory species diversity index was calculated. Also the effects of understory soil factors on needle functional traits and understory species diversity were analyzed by RDA. Results (1) Different stand types had significant effects on leaf structural traits such as leaf area (LA), leaf length (LL), specific leaf area (SLA), specific leaf weight (SLW), leaf dry matter mass (LDMC) and leaf water content (LWC), while only C and N contents were significantly affected by leaf chemical traits. (2) Different stand types had significant effects on understory vegetation diversity indexes. Simpson index was the highest in the Pinus thunbergia -Quercus acutissima mixed forest, Shannon-Wiener index, Margalef index and Pielou index were the highest in the Pinus thunbergia -Robinia pseudoacacia mixed forest, and all indexes were the lowest in the Pinus thunbergia pure forest. Digitaria sanguinalis and Pennisetum alopecuroides were dominant in each community. (3) Different stand types had significant effects on soil EC, SOC, TN, NO3-N, NH4+-N and AK. (4) SOC, AK and NH4+-N had significant effects on leaf functional traits and understory species diversity, while TP and NO3-N had significant effects on functional traits and species diversity, respectively. Conclusion Under the experimental conditions, the functional traits of Pinus thunbergii needles and the diversity of understory species under different stand types have certain responses to the understory soil factors. The construction and management of shelterbelt should comprehensively consider the role of stand type, understory vegetation and soil nutrients.
Age-independent Dominant Height Growth Model for Pinus massoniana Plantation
ZHANG Ke-xin, LIU Xian-zhao, GUO Hong, LIU Dan, LEI Yuan-cai
, Available online  , doi: 10.12403/j.1001-1498.20220349
Objective An age-independent theoretical growth equation was constructed to predict the dominant height of Pinus massoniana plantation when the age was unknown or not an effective influence factor. Methods Based on the four theoretical growth equations of Hossfeld IV, Lundqvist-Kolf, Richards and Schumacher, an age-independent dominant height model of Pinus massoniana was constructed by using the difference form of hidden age factors, and the free parameters were expressed as a function of site index. Results Among the four basic theoretical growth models, the age-related dominant growth model of Pinus massoniana plantation established by Richards model performed the best. The fitting accuracy of age-independent models was higher than that of age-related models, and the age-independent dominant growth model of Pinus massoniana plantation established by Richards model and Korf model performed the best. When the site index was introduced to the model, the fitting accuracy of Hossfeld model improved most obviously, and when k was set as a variable parameter, the age-independent dominant high growth model was the best. Conclusion When the forest of different age or age is difficult to obtain, the theoretical growth model independent of age can predict the growth of dominant height. After the functional relationship between site index and free parameters is replaced in the model, the accuracy of the model is improved and the model can be better applied to predict stand growth.
Comprehensive Evaluation of Forest Spatial Structure Based on the Mean Values of Structural Parameters
HUI Gang-ying, ZHAO Zhong-hua, HU Yan-bo, ZHANG Gong-qiao, CHENG Shi-ping, XU Xue-fei
, Available online  , doi: 10.12403/j.1001-1498.20220432
Objective A comprehensive index of stand spatial structure based on adjacent trees was constructed to evaluate the advantages and disadvantages of stand spatial structure and guide the optimization of stand structure. Method Based on the interpretation of the mean values of stand spatial structure parameters of uniform angle index, crowding, neighborhood comparison and mingling, they were assigned and standardized to make them positive indicators; the average value of mingling is a positive index, and the measured value is adopted; Then the stand spatial structure parameters were combined with the unit circle method to construct the stand spatial structure comprehensive evaluation index (FSS), and its effectiveness was verified by different stand types. Result The evaluation results of 47 sample plots in 4 regions of China using the constructed spatial structure comprehensive evaluation index showed that: 1) The spatial structure of natural pure forests under extreme site conditions was the worst among natural forests; 2) The spatial structure of natural mixed forest was better than that of artificial mixed forest; 3) The stand spatial structure of mixed plantation is obviously better than that of pure plantation; 4) The spatial structure of natural pure forest was better than that of artificial pure forest. Conclusion The comprehensive evaluation index of stand spatial structure can evaluate the advantages and disadvantages of stand spatial structure, and can scientifically express the general understanding that "the spatial structure of natural mixed forest is superior to that of artificial mixed forest, artificial mixed forest is superior to that of artificial pure forest, and natural pure forest is superior to that of artificial pure forest". It is a better comprehensive measure index of stand spatial structure, and has guiding significance for optimization of stand spatial structure and effect evaluation.
Effects of Cadmium Stress on Growth and Photosynthetic Physiological Characteristics of Robinia pseudoacacia Seedlings
LIU Jin-xiu, ZHANG Song-yan, ZHOU Jian
, Available online  , doi: 10.12403/j.1001-1498.20220447
Objective To explore the effects of cadmium (Cd) stress on the growth and photosynthetic physiological characteristics of Robinia pseudoacacia. Method The characteristics on the growth, chlorophyll content, chlorophyll fluorescence parameters, respiration rate and stomatal indices of Cd-stressed R. pseudoacacia seedlings were studied in this experiment. Result Under Cd stress, the stem diameter and plant height of these seedlings were obviously inhibited. The fresh weight and dry weight of treated plants with high concentration decreased, while those with low concentration increased slightly, but all the differences were insignificant between them and the control treatment. With an increase of cadmium concentration, the contents of chlorophyll a and total chlorophyll decreased, chlorophyll b and carotenoids changed irregularly, but there were insignificant differences between them and the control for R. pseudoacacia seedlings. However, the initial fluorescence (F0) and the maximum fluorescence yield (Fm) increased first and then decreased. The maximum photochemical efficiency (Fv/Fm) gradually decreased, the non-photochemical quenching coefficient (qN) gradually increased, and the actual photochemical quantum efficiencies (ΦPSII) were all lower than the control with insignificant-difference for those stressed plants during this experiment. Simultaneously, the stomatal width and stomatal area decreased, the stomata gradually closed in the treated-seedlings, and their respiratory efficiency was significantly inhibited. It was shown that the most of indicators were significantly correlated each other by correlation analysis. Through random forest regression analysis, the importance of initial fluorescence (F0), root cadmium content, stomatal width and chlorophyll a were the strongest among chlorophyll fluorescence parameters, plant cadmium enrichment content, stomatal characteristics and photosynthetic pigments, respectively, and became the most critical factors affecting the photosynthetic function of R. pseudoacacia seedlings. Conclusion Although the growth and photosynthetic physiology of R. pseudoacacia seedlings are affected by cadmium concentration to some extent, the seedlings still show strong tolerance to cadmium stress. It provides a reference for garden application in cadmium polluted areas.
Effects of Drought and Shading on Water Carbon Balance and Flavonoids Contents of Hippophae rhamnoides subsp. sinensis Rousi
LI Xiao-qing, LIU Yong-qiang, XUE Jing-ru, LI Jun-peng, HAN You-zhi, WANG Lin
, Available online  , doi: 10.12403/j.1001-1498.20220464
Objective To study the effects of drought and shade on growth, water and carbon metabolism, and the flavonoid content of Hippophae rhamnoides subsp. sinensis Rousi for comprehensively understanding the ecological adaptability of sea-buckthorn and the response of flavonoid content to drought and shade. Methods The changes of water potential, branch hydraulic conductivity loss (PLC), photosynthesis, biomass, non structural carbohydrate (NSC) content and flavonoid content of Hippophae rhamnoides in drought (40% saturated soil water content), shading (50% shading) and their interaction were compared. Results Drought treatment significantly reduced branch water potential, net photosynthetic rate, leaf biomass, and NSC content in root and stem of Hippophae rhamnoides, and significantly increased the branch PLC and root biomass. Shading treatment significantly decreased the net photosynthetic rate, leaf biomass, NSC content of each part, and flavonoid content. The interaction of drought and shading significantly increased branch PLC, but decreased the leaf net photosynthetic rate, the biomass and NSC content of roots, stems and leaves. Moreover, there was a significant negative correlation between leaf flavonoids content and branch water potential. Conclusion Drought will affect water status and carbon uptake, reduce NSC storage in stems and roots, and increase flavonoids content in Hippophae rhamnoides.. Shading will affect photosynthetic rate, and NSC storage of roots, stems and leaves, And the combination of drought and shade will further reduce the water transport capacity, photosynthesis, biomass accumulation and NSC storage of Hippophae rhamnoides. Shading will reduce the adaptability of Hippophae rhamnoides. to drought stress, and moderate drought is beneficial to the synthesis of flavonoids.
Analysis of Expression Pattern of MYC Family Members in Populus
HU Meng-xuan, SONG Xue-qin, LIU Ying-li, ZHAO Shu-tang
, Available online  , doi: 10.12403/j.1001-1498.20220503
Objective To explore the expression pattern of bHLH subfamily member MYC gene in poplar growth, development and response to environment for revealing the jasmonate signal pathway hub gene MYC in regulation of growth and development and response to different kinds of stress. Method Bioinformatic analysis was used to determine the family member of MYC and their gene structure and conserved motifs. Quantitative real-time PCR was carried out to analyze the expression of MYC family members in different tissues and under different kinds of phytohormone and stress treatment. Result Ten MYC members was found in the genome of Populus and the PtrMYC genes were conserved during evolution, and all of them contained bHLH domains, which were divided into three classes in phylogenetic tree. Analysis of the expression patterns showed that most members were mainly expressed in the roots, and two gene pairs in cladeⅡ had opposite expression pattern during stem development. The MYC genes exhibited distinct expression pattern under different hormone treatments and abiotic stress, but most gene pairs shared similar expression patterns. Conclusion Different MYC members may be involved in different biological processes. The results of this study provide a reference for further decipher the function of MYCs in poplar.
Variation Characteristics of Secondary Vascular Bundles in Pinus massoniana
YANG Chao, FAN Fu-hua, XU Gang
, Available online  , doi: 10.12403/j.1001-1498.20220483
Objective This study is to reveal the changes of cellular structure, composition and function of secondary vascular tissue in Pinus massoniana during development. Methods The change of morphology, structure, lignin and cellulose in the vascular tissue of P. massoniana were studied by histochemical analysis and cell segregation. Results The vascular cambium gradually enriched cellulose when it differentiated into new phloem and xylem. During the development of phloem, the sieve cells were deformed and lignified, and the proportion of cellulose in phloem decreased. During the development of xylem tracheids from early wood to late wood, the diameter of striated pores decreased, the number of striated pores decreased, the lignification degree of secondary wall increased, the cell lumen area decreased, the proportion of cellulose content decreased, and the choroidal and radial walls thickened. Conclusion The cellular composition and structure of secondary vascular tissues change regularly with development. The intracellular and intercellular transport capacity of xylem cells decrease, while the mechanical strength increases. The secondary phloem loses its ability to transport and its mechanical strength increases.
Cytomorphology of Laticifer Cells in Stems and Cotyledons of Eucommia ulmoides Oliv.
ZHANG Ming-jian, YUE Ya-dong, GAO Shun-kai, GAN Min, DONG Yi-yang, Zhang Ji-chuan
, Available online  , doi: 10.12403/j.1001-1498.20220477
Objective To further understand the cytomorphological of maturating laticifer cells and mature laticifer cells in Eucommia ulmoides stem and cotyledons and provide cytomorphological evidence for explaining the origin, development and maturation processes of laticifer cells in E. ulmoides. Method The stem, seed germination cotyledons, and seedling cotyledons of E. ulmoides were studied by whole observation and tissue section methods, and the morphology of laticifer cells in E. ulmoides was analyzed and compared. Result The images of 14 mature laticifer cells, 46 enlarged ends of laticifer cells, and 2 mature gelatinous cells in the stem cortex of E. ulmoides were obtained. The optical microscope images of primitive cell morphology and maturating laticifer cells in E. ulmoides seed germination cotyledons and the optical microscope images of mature maturating cells in seedling cotyledons and transmission electron microscope images of laticifer cells in E. ulmoides were obtained. The length of laticifer cell axes in E. ulmoides stems ranged from 981 to 3167 μm, and the volume ranged from 1 × 10−4 to 3 × 10−4 mm3. The length of the minor axis of the enlarged ends ellipsoid ranged from 8.6 μ m to 22.4 μ m, and the ratio of the major axis to the minor axis of the enlarged ends ranged from 1.08 to 1.77. Conclusion 1) The mature laticifer cells in the cortex of E. ulmoides are non-articulated and unbranched laticifer cells consisted of an elongated cylindrical cell body and two ellipsoidal dilated terminations. 2) Most of the xylene vitrification laticifer cells have no internal structure, and a small number of them have low refractive index internal structure. 3) The laticifer cells in the cotyledons of E. ulmoide originate from a series of dumbbell-shaped primitive cells, and tThere are a series of cytomorphological changes in the process of generation of laticifer cells.
The Allocation and Cycling Characteristics of Main Nutrients for Caragana Intermedia With Different Stand Age on Alpine Sandy Land
LI Qing-Xue, JIA Zhi-Qing, HE Ling-Xian-Zi, ZHAO Xue-Bin, Yang Xiu-Ben
, Available online  , doi: 10.12403/j.1001-1498.20220528
Objective Understanding the allocation and cycling characteristics of the main nutrients in the process of artificial vegetation restoration on sandy land will help us fully understand the strategies of plant adaptation to the desert ecosystems, and provide theory for the vegetation management. Method This study was conducted in the shrub plantations of Caragana intermedia with different stand age of 6-, 9-, 11-, 17- and 31-year-old on alpine sandy land. The whole plant of average shrubs was completely harvested for analysing the main nutrients N, P and K concentration, accumulation, allocation and cycling characteristics. Result (1) In components, leaves and stem bark with the highest nutrient content, and stem wood with the lowest nutrient content. As the plantation age increased, N content in three root-diameter (coarse root: diameter > 5 mm, medium root: 2 mm < diameter ≤ 5 mm, fine root: diameter ≤ 2 mm) and P content in leaves increased significantly, whereas P and K contents in fine root, K contents in branches and medium root decreased significantly. The N contents of three root-diameters had a significant negative correlation with the P and K contents of fine root, and the N contents of medium and fine root had a significant negative correlation with the K contents of branches and medium root. (2) The nutrient accumulation of root was higher than aboveground components. The percentage of the nutrient accumulation of the root to the aboveground components firstly increased and then decreased as the plantation age increased. It peaked in 17-year-old plantation, and the percentage of N, P and K were 70%, 66% and 63%, respectively. (3) As the plantation age increased, the utilization coefficient of the nutrients decreased, while the recycling period and cycling coefficient increased. Utilization coefficient and cycling coefficient of K were higher and recycling period was shorter than N and P in all plantations. Conclusion With the development of C. intermediate plantation on alpine sandy land, more nutrients were allocated to the root system to adapt to the harsh environment. The nitrogen fixation process of C. intermediate will consume its own K and P, of which K with fast circulation rate and high mobility. Therefore, we suggested that K and P fertilizer should be added in the management and protection of C. intermedia shrub plantation.
Family Variation and Evaluation of Growth Traits On 36-year-old Pinus Massoniana Lamb in Fujian Province
TANG Dao-ping
, Available online  , doi: 10.12403/j.1001-1498.20220499
Objective To study the genetic variation of growth traits of Pinus massoniana provenances and families from three regions in Fujian Province, and provide scientific basis for the selection of fine provenances and families of Pinus massoniana. Method A total of 94 families from three provenances in Longyan, Quanzhou and Nanping in Fujian Province were selected. The genetic differences of three growth traits, tree height, DBH and tree volume were analyzed and evaluated through a completely randomized block design experiment, and excellent provenances and families were selected. Result The results showed that the average tree height, DBH and volume of the provenances were 18.76 m, 22.23 cm and 0.36 m3 in Longyan, followed by 17.43 m, 20.77 cm and 0.31 m3 in Quanzhou, and 15.54 m, 19.25 cm and 0.25 m3 in Nanping, which was poorer than the control. The comprehensive evaluation showed that Quanzhou and Longyan materials can be used as the source of excellent provenance of Pinus massoniana. The heritability of the three growth traits at the family level ranged from 3.81% to 16.08%. At the same time, the 94 families were divided into excellent, superior, medium and average families by cluster analysis, with the corresponding number of 3, 24, 42 and 25 families, respectively. The average genetic gain of tree height, DBH and tree volume per tree with 77-561, 77-569 and 77-568 reached 15.63%, 26.54% and 11.27%, respectively. Conclusion The excellent individuals are selected from the excellent families and divided into three categories: 22 excellent individuals, 80 superior individuals and 52 general individuals.
Relationship between Ammonia-Oxidizing Archaea Community Structure and Nitrate Nitrogen Content in Chinese Fir Plantations at Different Generations
CHEN Wen-wen, WANG Shu-zhen, JIANG Yu-jie, ZHOU Chui-fan
, Available online  , doi: 10.12403/j.1001-1498.20220369
Objective This article aims to analyze the changes of soil available nitrogen content in Chinese fir plantations at different generations, and explore the internal relationship between nitrate nitrogen and the structure and diversity of ammonia-oxidizing archaea community, which provides reference for the effective use of soil nitrogen of plantations and soil quality assessment of Chinese fir forest. Method Four Chinese fir plantations with different generations were selected in Nanping, Fujian Province. High-throughput sequencing technology was used to determine the amoA gene amplified by PCR. Mantel_r correlation analysis, random forest model and partial least squares path model were used to study the relationship between soil available nitrogen content, ammonia-oxidizing archaea community abundance and diversity in different generations. Result With the increase of continuous cropping generations of Chinese fir, the content of nitrate nitrogen (NO3--N) decreased significantly, and the content of ammonium nitrogen (NH4+-N) and microbial biomass nitrogen (MBN) did not change significantly. Soil enzyme activity and the abundance and diversity of ammonia-oxidizing archaea (AOA) community showed a decreasing trend. Soil available nitrogen content was closely related to ammonia-oxidizing archaea community and enzyme activity, and the abundance and diversity of ammonia oxidizing archaea community was the most important factor affecting nitrate nitrogen content. Conclusion With the increase of planting generation, the abundance and diversity of ammonia oxidizing archaea community decrease to a certain extent. Except for the fourth generation of soil urease and ammonia nitrogen oxygenase enzyme activity increased slightly, soil nitrogen cycle related enzyme activity shows a decreasing trend, resulting in a significant reduction in soil nitrate nitrogen content, which limits the effectiveness of soil nitrogen in continuous cropping Chinese fir plantations.
Transcriptome Analysis and Gene Discovery of Abscisic Acid Signaling Pathway in Kandelia obovata under Low Temperature Stress
GUO Jin-min, YANG Sheng, LIU Xing, WANG Jin-wang, WANG Wen-qing, CHEN Qiu-xia
, Available online  , doi: 10.12403/j.1001-1498.20220417
Objective To understand the molecular mechanism of Kandelia obovata in response to low temperature stress and cultivate new varieties of cold resistance. Method Based on the annual container seedlings of 'Longgang' K. obovata, a cold-tolerant mangrove cultiva, the control group ( CK ) was treated at 15 oC for 12 h and the low temperature group ( LT ) was treated at −5 oC for 12 h. Illumina HiSeq sequencing platform was used for transcriptome sequencing, and the genes related to abscisic acid signaling pathway were discovered. Result The results showed that a total of 148 transcription factors were identified by transcriptome sequencing, which belonged to 25 transcription factor families. Among them, ERF, NAC, WRKY, bHLH, MYB, bZIP, HB-other and MYB-related families contained more genes, which were 17, 14, 12, 12, 10, 9, 6 and 6, respectively. A total of 1 330 differentially expressed genes ( DEGs ) were screened in the differential group, of which 698 ( 52.48% ) were up-regulated and 632 ( 47.52% ) were down-regulated. KEGG pathway enrichment analysis showed that DEGs were significantly enriched in plant hormone signal transduction, phenylpropanoid biosynthesis, galactose metabolism, photosynthesis-antenna protein, and alpha-Linolenic acid metabolism. Among the abscisic acid signaling pathways, KoPYL1, KoABF1, and KoABF2 were up-regulated and KoPP2C1 and KoABF3 were down-regulated, and the expression of these genes was consistent with the qRT-PCR validation results. Conclusion ERF, NAC, WRKY, bHLH, MYB, bZIP, HB-other and MYB-related play an important role in regulating the response of K. obovata to low temperature stress. Phytohormone signal transduction, phenylpropanoid biosynthesis, galactose metabolism, photosynthesis-antenna protein and alpha-Linolenic acid metabolism are important KEGG pathways in K. obovata in response to low temperature stress. KoPYL1, KoPP2C1, KoABF1, KoABF2 and KoABF3 genes in abscisic acid signaling pathway can be used as important candidate genes for future studies on the response of K. obovata to cold stress.
Genome-wide Identification and Expression Analysis of BpAMT Gene Family in Betula platyphylla
Yang Hai-xin, Liu Xiao-ying, Zhan Ya-guang, Fan Gui-zhi
, Available online  , doi: 10.12403/j.1001-1498.20220242
Objective To identify AMT gene family members in Betula platyphylla and analyze the expression pattern of AMT genes. Method Bioinformatics methods were used to identify the family genes and real-time fluorescence quantitative analysis of gene expression. Result 9 AMT genes were identified from the B.platyphylla genome and divided into two subfamilies, AMT1 and AMT2, named BpAMT1.1-1.4 and BpAMT2.1-2.5; These BpAMT proteins contained 384-522 amino acid residues with isoelectric points ranging from 4.61 to 8.16, and all of which were located on the plasma membrane and organelle membrane; The genes of BpAMT family were distributed on 5 chromosomes unevenly, and there were tandem duplication among the members. BpAMTs’ expression patterns had specificity in different tissues, showing a leaf>root>stem trend; At the same time, KNO3, NH4Cl, MeJA, GA3, ABA, CdCl2 and diurnal variation could affect the expression of BpAMT gene, and the response of members differed under different treatments. Conclusion 9 BpAMT genes are identified and divided into two subfamilies. BpAMT gene plays an important role in regulating nitrogen uptake, transport and in response to hormone signals or abiotic stress. These results lay a foundation for further analysis of the function of BpAMT gene in growth and resistance to stress in B.platyphylla.
Identification of MicroRNAs during Seed Germination and Its Response to PEG and NaCl Stresses
Wang Xiao-jing, Wang Tao, Yang Kai, Li Lu-bin
, Available online  , doi: 10.12403/j.1001-1498.20220211
Objective To identify microRNAs (miRNAs) and reveal its expressional pattern in seed coat rupture stage of Moso bamboo seeds (Phyllostachys edulis) under different drought and salt stresses. Methods Polyethylene glycol (PEG6000) and NaCl were used to simulate drought and salinity stress, respectively. Small RNA libraries were separately built for Moso bamboo seeds germinated under H2O, 10% PEG, 15% PEG, 50 mmol·L−1 NaCl and 100 mmol·L−1 NaCl, and the seeds were all sampled at seed coat rupture stage. High throughput sequencing and bioinformatics analysis were used to explore the expressional pattern of miRNA. Results A total of 246 known miRNAs and 262 novel mature miRNAs were identified in this study. The most abundant miRNAs in seed coat rupture stage of Moso bamboo was miR166, followed by miR159, miR6478, miR319, etc. According to miRNA target prediction, MIR396 family owned the largest number of target genes, and ph02gene13935 (GAMYB) could to be regulated by 28 miRNAs of MIR159, MIR319 or MIR396; A total of 181 differentially expressed miRNAs (DEmiRNA) were identified in six comparison groups; Compared with control group, in 10% PEG, 15% PEG, 50 mmol·L−1 NaCl and 100 mmol·L−1 NaCl treatments, phe-miR171e-5p, phe-miR3630-3p, phe-miR171e-5p and phe-miR159a were differentially expressed respectively with highest expressional level in known miRNAs; The target genes of DEmiRNA were significantly enriched in different GO and KEGG pathways; Ten DEmiRNAs were verified by qPCR, and the overall trend of qPCR results was consistent with the sequencing data. Conclusion In seed coat rupture stage of moso bamboo, there exhibit high accumulation of known miRNAs such as miR159, miR6478, miR319 in all control and four treatment groups, which may play a conservative regulatory role in Moso bamboo seed germination. Compared with the control group, phe-miR171e-5p, phe-miR3630-3p, phe-miR171e-5p and phe-miR159a 1 are differentially expressed in 10% PEG, 15% PEG, 50 mmol·L−1 NaCl and 100 mmol·L−1 NaCl, respectively, which can respond to PEG or NaCl stress during seed coat rupture stage of Moso bamboo.
Community composition and ecological functional analysis of the endophytic microorganisms in Eucommia ulmoides seeds
ZHANG Qing-Qing, DONG Chun-Bo, SHAO Qiu-Yu, LU Ying-Xia, DONG Xuan, LIANG Zong-Qi, HAN Yan-Feng
, Available online  , doi: 10.12403/j.1001-1498.20220239
Objective To reveal the microbial community composition and diversity in Eucommia ulmoides seeds and enrich the related microbial resources. Methods In this study, the diversity of endophytic microorganisms in E. ulmoides seeds was analyzed by traditional culture method and high-throughput sequencing technology, and functional annotated by FAPROTAX and FUNGuild database. Results A total of 40 fungi strains (3 phyla and 11 genera) were isolated from E. ulmoides seeds, and the dominant genus was Aspergillus (30%); 142 bacterial strains (1 phylum, 6 genera) were isolated, of which Solibacillus was the dominant genus (47.18%). Through high-throughput sequencing, 141 fungal OTUs were obtained belonging to 6 phylum and 101 genera; 442 bacterial OTUs were obtained belonging to 24 phylum and 313 genera. At the genus level, the dominant fungi were Apiotrichum (31.28%) and Debaryomyces (26.07%); The dominant bacterial genera were Pseudomonas (16.66%) and Lactobacillus (9.68%). The results of functional annotation showed that fungi mainly degraded organic matter, promoted the growth of host plants and the absorption of soil nutrients by host, improved soil microbial community structure and Pathogen community. The bacteria mainly consisted of chemoheterotrophic, heterotrophic, fermentation. and nitrogen fixation bacteria. Conclusion E. ulmoides seeds carry a variety of probiotics and potential phytopathogens, which have important effects on plant growth and development. In addition, a number of beneficial functional bacteria were isolated in this study, which will provide microbial resources for the subsequent artificial control of seed microbiome to enhance plant health.