2019 Vol. 32, No. 5
Identification of Candidate Constitutive Expressed Resistant Genes of Pine Wilt Disease in Pinus massoniana Based on High-throughput Transcriptome Sequencing
2019, 32(5): 1-10. doi: 10.13275/j.cnki.lykxyj.2019.05.001
[Abstract](3360) [FullText HTML] (1804) [PDF 2020KB](104) [Cited by] ()
Objective To study the genes related to the resistance of Masson pine ( Pinus massoniana ) to pine wood nematode ( Bursaphelenchus xylophilus , PWN). Method Based on two genotypes of resistant and susceptible P. massoniana for inoculating pine wood nematode, and sampling at the 1 dpi, 15 dpi and 30 dpi after inoculation, the authors performed a transcriptome analysis to identify differentially expressed constitutive genes associated with resistance to PWN infected. Result Comparing resistant and susceptible transcriptomes of P. massoniana inoculated with B. xylophilus , 2 866, 679 and 1 657 differentially expressed genes were obtained at 1, 15, or 30 days post-inoculation (dpi), and there were relatively few common differentially expressed genes at different time points. The GO enrichment analysis was performed on the differentially expressed genes, which indicated that the most significant biological process at the 1 dpi, 15 dpi and 30 dpi was oxidation-reduction process, while the stimulus response, transcriptional regulation and the geranyl diphosphate metabolic process in GO items were also significantly enriched. A further analysis of these related genes in the stimulus response GO term, 26 R genes were found at three time points after inoculation. The expression of the other R genes was constitutive except for two R genes, and no significant difference was observed between PWN and water inoculation. In the transcriptional regulation GO term, only two differentially expressed genes of ERF transcription factors were annotated by nr database, and the rest differentially expressed genes were unknown. After inoculation with PWN, the expression level of ERF transcription factors in resistant P. massoniana was always higher than that in susceptible ones, and there was insignificantly difference between trees inoculating PWN and the control. The result means that expression of the two ERF transcription factors is constitutive. In geranyl diphosphate metabolic process GO term, three GGPPS genes having higher expression level in high resistant P. massoniana , are constitutive expression genes. Here, the authors also found that the TIR-NBS-LRR gene (c65785.graph_c0), ERF transcription factor (c78073.graph_c0), and the three GGPPS genes, having higher expression in resistant P. massoniana , the expression levels were extremely low or even zero in susceptible P. massoniana , which suggested that these genes can be chosen as candidate genes for the development of molecular markers to identify resistant P. massoniana . Conclusion Most genes changed the expression level at 1 dpi between resistant and susceptible P. massoniana . The R genes, ERF transcription factors and GGPPS are related to the resistance of P. massoniana , some of which are expected to be developed as molecular markers for identifying PWN-resistance P. massoniana .
Sequencing and Analysis of Complete Mitochondrial Genome of Dendrolimus houi Lajonquiere (Lepidoptera: Lasiocampidae)
2019, 32(5): 11-20. doi: 10.13275/j.cnki.lykxyj.2019.05.002
[Abstract](3439) [FullText HTML] (2147) [PDF 5229KB](66) [Cited by] ()
Objective To identify and analyze the mitochondrial genome of Dendrolimus houi Lajonquiere, and to study the higher-level phylogenetic relationship of Lepidoptera moths based on the mitochondrial genome. Method The Illumina Hiseq technique was chosen to sequence the purified mitochondrial DNA of D. houi . The genes were located and annotated based on the known complete mitochondrial genomes of Lepidopteran species. The tRNA Scan-SE 2.0 was used to predict the secondary structure of the tRNA genes online. Based on the PCGs of the whole nucleotide sequences of mitochondrial genome, the phylogenetic trees of 32 species from 12 families of Lepidoptera moths and the phylogenetic trees of the relative species of the Dendrolimus were reconstructed. Result The results indicated that the complete mitochondrial genome of D. houi is 15 443 bp in length, including 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes and a 321 bp A+T-rich region, without gene rearrangement, and showed a higher A+T content (80.0%). All these PCGS except for ND2 and COX1, used ATN as the start codon. Nine PCGs shared the same stop codon TAA, and the stop codons of the other four genes were all defective. COX1, COX2, and ND4 used T as the stop codon and ND3 used TA as the stop codon. Among the 22 tRNA genes, tRNASer (AGN) lacked the DHU arm and could not form a clover structure, while the remaining tRNAs were typical clover structures. The mitochondrial structure was consistent with other insect's mitochondrial genome structures currently available in Lepidoptera. Conclusion The phylogenetic analysis indicates that D. houi and D. kikuchii are completely different relatives, and the relationship between D. houi and other Dendrolimus species is also far away. The phylogenetic relationship is:((((( D. tabulaeformis + D. punctatus wenshanensis ) + D. spectabilis + D. superans ) + ( D. houi + D. kikuchii )) + Bombyx mori ). The phylogenetic relationship between the families of Lepidoptera is:((((((((Lymantriidae + Arctiidae) + Noctuidae) + Notodontidae) + (Geometriidae + (Bombycidae + (Sphingidae + Satumiidae)))) + Lasiocampidae) + (Pyralidae + Cramnidae)) + Tortricidae) + Hepialidae).
Wing Dimorphism and Sex Ratio Changes in Progeny of Various Sister Broods in Parasitoid Sclerodermus pupariae (Hymenoptera: Bethylidae)
2019, 32(5): 21-26. doi: 10.13275/j.cnki.lykxyj.2019.05.003
[Abstract](3489) [FullText HTML] (1794) [PDF 987KB](31) [Cited by] ()
Objective This study aims to explore the changes of population parameters among different sister broods in parasitoids with multiple host attacking habit, so as to explain the mechanisms of expanding and sustaining population from the perspective of maternal effects. Method The parasitism on Thyestilla gebleri larva of Sclerodermus pupariae was studied during the production of successive sister broods in its lifetime. The number of female progeny, developmental duration, percentage of winged female, sex ratio and the other parameters of all the sister broods were recorded in the laboratory under the conditions of 30℃, photoperiod of 14L:0D, and RH 65% ±5%. Result The parasitism ability on host larvae and brood sizes reduced gradually. The percentage of winged females decreased with the number of produced sister broods till to zero, with the most dramatic decrease in the third sister brood. The sex ratio of progeny showed a parabolic trend at various successive sister broods and it was close to 1:1 for the third sister brood. Conclusion Wing polyphenism in various sister broods of S. pupariae may reflect adaptive evolution of this parasitoid coping with heterogeneous environment of forest. The production of the third sister brood might be a key point for regulating wing morph and sex ratio of progeny to maximize the fitness of the population in the lifetime in S. pupariae.
Correlation Analysis of Phenolic Compound Content and Hydroxyl Radical Scavenging Capacity in Seabuckthorn Berry
2019, 32(5): 27-33. doi: 10.13275/j.cnki.lykxyj.2019.05.004
[Abstract](3081) [FullText HTML] (1573) [PDF 2652KB](50) [Cited by] ()
Objective The relationship between hydroxyl radical scavenging capacity and seven phenolic substances in Seabuckthorn fruits was analyzed to provide reference for exploring the hydroxyl radical scavenging capacity of phenolic substances. Method The sea buckthorn fruits of Fengning cultivar and Xiangyang cultivar in three development stages (green fruit stage, discoloration stage and mature stage) were used as experimental materials. The contents of seven phenolic substances such as rutin, quercetin, isorhamnetin, kaempferol, myricetin, naringenin and vitamin E were determined by gas chromatography-mass spectrometry (GC-MS) technique. The hydroxyl radical scavenging ability of sea buckthorn fruit was determined by spectrophotometry. Then the correlation between the seven phenolic substances and hydroxyl radical scavenging capacity was analyzed. Result The results showed that the hydroxyl radical scavenging ability of Fengning cultivar was significantly higher than that of Xiangyang cultivar, the hydroxyl radical scavenging ability of Fengning cultivar decreased successively in the three development stages, while that of Fengning cultivar was the strongest in green fruit stage and the weakest in discoloration stage. The contents of rutin, quercetin, isorhamnetin, kaempferol, myricetin and naringenin in the sarcocarp of Fengning cultivar were higher than those in Xiangyang cultivar. The contents of rutin and myricetin in the sarcocarp of Fengning cultivar were significantly higher than those in Xiangyang cultivar during the three stages ( P < 0.05). In addition, the contents of quercetin, isorhamnetin, naringenin and myricetin increased at first and then decreased in the three developmental stages, while the changes of rutin, vitamin E and kaempferol were different between the two cultivars. The correlation analysis showed that the correlation coefficients between rutin, quercetin, isorhamnetin, kaempferol, myricetin and naringenin and hydroxyl radical scavenging ability were all greater than 0.6, while the correlation coefficients between vitamin E and hydroxyl radical scavenging ability were only 0.17. Conclusion The hydroxyl radical scavenging ability are strongly correlated with the contents of rutin, quercetin, isorhamnetin, kaempferol, myricetin and naringenin, which were helpful to promote the scavenging of hydroxyl radicals in seabuckthorn fruit.
Analysis on Structure and Diversity of Bacterial Community of the Second-instar Ericerus pela Nymph Based on 16S rRNA High-throughput Sequencing
2019, 32(5): 34-41. doi: 10.13275/j.cnki.lykxyj.2019.05.005
[Abstract](3342) [FullText HTML] (1738) [PDF 2022KB](31) [Cited by] ()
Objective To investigate the variation and diversity of symbiotic bacteria both in the second-instar male and female of Ericerus pela . Method The V3-V4 region of the 16S rRNA was performed using high-throughput sequencing technology. Uparse software was used to cluster the qualified labels. Species annotation was taken by using the Mothur and SILVA's SSUrRNA database to analysis the differences in species abundance and diversity between male and female symbiotic bacteria. Result There were 1798646 qualified labels identified in this experiment. Cluster analysis was performed with 97% similarity as the standard, and 1 334 OTUs (operational taxonomic unit) were obtained. After the annotation, 14 phylums, 29 classes, 60 orders, 109 families, 165 genera, and 55 species were obtained. E. pela is significantly different from the other insects. For the second-instar nymph, Rickettsia (85.740% in female, 95.462% in male) was the dominant bacteria while Buchnera and Wolbachia were absent. A total of 386 symbiotic bacteria were identified in the second-instar nymphs. Conclusion The endosymbiotic bacteria of E. pela are quite different from that of other insects. Rickettsia has an absolute advantage in the second-instar nymph of E. pela . Rhizobiales and Bacillales with nitrogen fixation, Sphingomonadales which can synthesize carotenoids, are the subdominant bacteria and occupy a certain proportion in symbiotic bacteria. The unique phenomenon of the E. pela symbiotic bacteria may be related to its unique biological habits, ecological characteristics and nutrition.
2019, 32(5): 42-50. doi: 10.13275/j.cnki.lykxyj.2019.05.006
[Abstract](2919) [FullText HTML] (1844) [PDF 4805KB](53) [Cited by] ()
Objective To study the phenotypic traits of persimmon germplasm resources in Zhejiang Province and the geographical distribution characteristics of persimmon fruit. Method By measuring 23 fruit traits of 73 persimmon germplasm resources in Zhejiang Province, the phenotypic traits and their relations were explored. The fruit shape was classified by principal component analysis (PCA) and PCA score, and the geographical characteristic distribution of fruit shape were analyzed. Result The phenotypic traits of persimmon fruit varied greatly, and the coefficient of variation was from 10.05% to 48.45%. The mean values of fruit mass, fruit volume, fruit longitudinal and transverse area, fruit longitudinal length, fruit transverse length and fruit shape index were 103.34 g, 108.44 cm3, 26.58 cm2, 26.54 cm2, 5.91cm, 5.84 cm and 1.03, respectively. The mean values of seed mass, seed volume, seed length, seed width, seed thickness, seed shape index, seed quantity and the volume ratio of seed to fruit were 0.90 g, 0.97 cm3, 21.80 mm, 11.43 mm, 5.07 mm, 1.94, 4.30 and 4.24%, respectively. The mean values of pith mass, pith volume, pith height, pith top width, pith base width, ratio of height to top width of pith, ratio of height to base width of pith, and the volume ratio of pith to fruit were 2.11 g, 2.62 cm3, 28.65 mm, 6.32 mm, 12.16 mm, 4.80, 2.50 and 2.67%, respectively. Correlation analysis showed that the correlation coefficient of fruit, seed and pith size was between 0.36 and 0.78. The correlation coefficients of fruit shape index with seed shape index, ratio of height to top width of pith and ratio of height to base width were 0.86, 0.90 and 0.88, respectively, which indicated that the size of fruit parts had a positive correlation and the shape had similarity. 16 original phenotypic traits was analysed by PCA, and the first two principal components (75.64%) showed the size and shape indicators of persimmon phenotypic traits. The coincidence rate of the PCA score map and phenotypic traits was higher, which can well represent the size and shape index of the fruit phenotypic traits. Therefore, the phenotypic traits of fruit were divided into four categories:large fruit with long shape, small fruit with long shape, small fruit with flat shape and large fruit flat-shaped. The flat-shaped fruit accounted for 66.67% in Hangzhou-Jiaxing-Huzhou Plain, mainly the large fruit with flat shape (41.67%); the large fruit with long shape accounted for 41.67% in the western Zhejiang hilly area; the flat fruit shape accounted for 71.43% in the Jinhua-Quzhou Basin, and the southern Zhejiang Province was dominated by small fruit with long length (48%). Conclusion The fruit phenotypes of persimmon germplasm resources in Zhejiang Province are rich, and there are correlations between the size and shape of each part of persimmon fruit. The long-shaped fruits mainly distribute in mountain area, while the flat-shaped fruit in plain.
Comparison of Photosynthetic Physiological Traits of Quercus variabilis Seedlings among Various Provenances after Southward Movement
2019, 32(5): 51-57. doi: 10.13275/j.cnki.lykxyj.2019.05.007
[Abstract](2763) [FullText HTML] (1627) [PDF 1335KB](52) [Cited by] ()
Objective To explore the differences in photosynthetic physiological traits among Quercus variabilis provenances responding to alternative habitat, and to provide reference for introduction and cultivation of excellent germplasm of Q. variabilis. Method Five Q. variabilis provenances coming from Pinggu of Beijing, Neixiang of He'nan Province, Zigui of Hubei Province, Yongxiu of Jiangxi Province and Chengbu of Hu'nan Province, were collected and cultured in the region beyond the species' southmost range (Heshan of Guangdong Province) to determine the photosynthetic physiological indices of different provenances. Result The potential maximum net photosynthetic rate of Chengbu provenance was significantly higher than the provenances at mid-high latitudes (Zigui and Pinggu) (P < 0.05). Yongxiu provenance showed higher apparent quantum efficiency, while Zigui provenance showed the lowest. The relative chlorophyll content of Neixiang and Chengbu provenances was significantly higher than that of Yongxiu provenance. Primary light energy conversion efficiency of PSII (Fv/Fm) and potential activity of PSII (Fv/F0) differed slightly among provenances, indicating that all these Q. variabilis provenances did not sustain obvious stresses and could adapt to the new habitat. Moreover, dark respiration rate, light saturation point, light compensation point, Rubisco enzyme maximum carboxylation rate, maximum electron transfer rate, photorespiration rate, as well as growth parameters and chlorophyll fluorescence parameters such as electron transfer rate, photochemistry quenching coefficient and non-photochemistry quenching coefficient were comparable. Conclusion The similarities and differences of photosynthetic physiological traits of Q. variabilis from different provenances are related to their own genetic factors and strong environmental adaptability to new habitat.
2019, 32(5): 58-66. doi: 10.13275/j.cnki.lykxyj.2019.05.008
[Abstract](2799) [FullText HTML] (1290) [PDF 3761KB](55) [Cited by] ()
Objective To study the molecular characteristics and expression pattern of constitutive photomorphogenesis and dwarf of Phyllostachys edulis ( PeCPD ), a kind of the key rate-limiting enzymes in biosynthesis of brasinosteroids, aiming at revealing the role of PeCPD in regulating the rapid growth of bamboo shoots and the response to light induction and stresses. Method Primers were designed based on the CPD homologous sequence of PH01003419G0030 in the Bamboo Genome Database (BambooGDB) and used for PeCPD cloning. The bioinformatics method was used for further analyses, including the gene structure, the cis-elements, the basic physicochemical properties and the conserved domains of the protein encoded by PeCPD , the evolutionary relationships, and the gene expression patterns in different tissues. Quantitative real-time PCR (qRT-PCR) method was used to analyze the gene expression in different height shoots and that in leaves and roots under the circadian rhythm light conditions and stresses of drought and cold. Result PeCPD , a homologous gene of CPD in Ph. edulis was obtained, which cDNA was 1 584 bp in full-length including 5' untranslated region (UTR) 110 bp, 3' UTR 64 bp and coding sequence (CDS) 1 410 bp. The corresponding genomic sequence to the CDS was 2 796 bp containing 6 exons and 5 introns. PeCPD encoded a 470 aa protein with a molecular weight of approximately 52.2 kDa and the theoretical isoelectric point of 9.063. At the same time, the upstream sequence of PeCPD (1 999 bp) was obtained, which was completely consistent with the sequence in the database. Besides the basic elements of the promoter, the upstream sequence of PeCPD also contained a variety of environmentally relevant action elements, such as LTR involved in low temperature response, MBS in response to drought, and light responsive elements (AE-box and TCT-motif). Phylogenetic analysis based on the CPD amino acid sequences showed that Ph. edulis was clustered together with the monocotyledon plants such as Oryza sativa, Zea mays, Setaria italica and Brachypodium distachyon , which was closed to B. distachyon . Expression pattern analysis based on the transcriptome data demonstrated that PeCPD expressed obviously different in the seven tissues of Ph. edulis , with the highest level in 20 cm shoot and the lowest in root. The result of qRT-PCR showed that the expression level of PeCPD in shoots increased with the increasing height of bamboo shoots, those in leaves under the circadian rhythm light conditions demonstrated an increasing trend in the daytime and a decreasing trend at night (darkness). Under both drought and cold stresses, the expression of PeCPD in leaves and roots all showed similar trends of rising at first and falling then. Conclusion CPD homologous gene ( PeCPD ) is obtained from Ph. edulis . The PeCPD is constitutively expressed in Ph. edulis . Moreover, its expression level in shoots increases with the increasing height of bamboo shoots, which suggests that PeCPD may regulate the growth of bamboo shoots by participating in the biosynthesis process of brasinosteroids. The expression of PeCPD in leaves shows circadian rhythm changes, indicating that it may be involved in the photomorphogenesis of Ph. edulis. The expression changes of PeCPD under drought and low temperature stresses indicate that PeCPD is helpful to improve the ability of bamboo to adapt to stresses.
Effects of Soil Straw Mulching and Cultivation on Enzymes and Nutrients in Phyllostachys edulis Plantation Soil
2019, 32(5): 67-73. doi: 10.13275/j.cnki.lykxyj.2019.05.009
[Abstract](2448) [FullText HTML] (1365) [PDF 783KB](48) [Cited by] ()
Objective To reveal the response of soil enzymes and soil nutrients to soil surface mulching in Phyllostachys edulis plantation and the relationship between them. Method The 0~50 cm soil layer of bamboo stands, located in Huangyan District of Taizhou City (Zhejiang Province) were selected to investigate the difference among three treatments, i.e. straw mulched continuously for two years with soil turning, without soil turning, and natural growth with no intervention (CK). Result The results show that:(1) The polyphenol oxidase activity in the soil of Ph. edulis plantation mulched with or without soil turning was lower compared with the CK, especially in soil depth of 0~20 cm. Compared with the CK, the activity of soil peroxidase in Ph. edulis plantation treated with mulching and soil turning decreased with a significant level in soil depth of 0~10 cm and that treated with mulching without soil turning also decreased except the soil layer of 10~20 cm in depth. However, the activities of both urease and sucrase improved compared with the CK. (2) After soil straw mulching, the soil nutrient content of the plantation treated by mulching with or without soil turning increased. The nutrient contents of the mulching and soil turning increased at first and then decreased in the 0~10 cm soil layer, and reached the maximum at 10~20 cm soil layer; there was a significant difference in total N between mulching without soil turning and mulching with soil turning in depth of 0~30 cm soils. (3) There was a correlation between soil enzyme and soil nutrient. Both urease and sucrase had a significant positive correlation with soil nutrient, but a negative correlation between polyphenol oxidase and soil nutrient. Peroxidase had a negative correlation with soil organic matter, available P and had no significant correlation with other soil nutrients. Conclusion Soil surface mulching has significant effect on soil enzyme activity and soil nutrient content of Ph. edulis plantation, short-term surface mulching can significantly improve soil fertility and fertility of straw mulched with soil turning is better than that of straw mulched without soil turning.
Analysis of Spatial-temporal Pattern of Forest Net Primary Productivity of the Great Khingan in Inner Mongolia
2019, 32(5): 74-82. doi: 10.13275/j.cnki.lykxyj.2019.05.010
[Abstract](3143) [FullText HTML] (1718) [PDF 3541KB](96) [Cited by] ()
Objective To analyze the spatial and temporal distribution patterns and driving factors of forest productivity in Daxing'anling of Inner Mongolia by model simulation. Method The optimized and calibrated physiological parameters of the ecological process model, the Biome-BGC, performed in a previous study were applied to simulate the long-term (from 2003 to 2012) forest net primary productivity (NPP) over the Daxing'anling region in Inner Mongolia. Based on forest dendrochronological measurements, the simulated NPPs were validated at a regional scale. Result The simulated forest NPPs from the calibrated Biome-BGC model had high reliability with R2=0.81 and RMSE =48.73 g·m-2·a-1. From 2003 to 2012, the forest NPP ranged from 219.3 to 399.5 g·m-2·a-1, of which coniferous forest NPP ranged from 218.6 to 414.9 g·m-2·a-1, broadleaved forest 213.7 to 412.3 g·m-2·a-1 and mixed forest 188.3 to 404.7 g·m-2·a-1 respectively. The correlation between forest NPP and temperature and solar radiation was higher ( R2 was 0.55 and 0.49), and the precipitation and relative humidity was lower. Conclusion In time series, the annual average of forest NPP in this area shows a slow growth trend, while the spatial distribution shows the characteristics of high in the north and low in the south and east. The implementation of "Natural Forest Conservation Project" is the main factor driving the increase of forest NPP in this area, while fire decreases forest NPP, which results in the spatial and temporal differences of NPP in this area. The differences of NPP in different forest types are mainly affected by temperature and solar radiation.
2019, 32(5): 83-90. doi: 10.13275/j.cnki.lykxyj.2019.05.011
[Abstract](3214) [FullText HTML] (2082) [PDF 2523KB](74) [Cited by] ()
Objective To establish the inversion models of biomass components for Larix olgensis plantation using Airborne LiDAR. Method Compatible models were established by combining dummy variable and nonlinear seemingly unrelated regression based on the biomass data of 64 trees in 40 sample plots of L. olgensis plantation. The canopy height indices and density indices were calculated from LiDAR point cloud data. Then the models based on these biomass components from field data and LiDAR indices were built using multivariate linear regression(MLR) and random forest regression (RF). The biomass model validation was accomplished by Jackknifing technique. Result (1) There was a significant (P < 0.05) or extremely significant (P < 0.01) correlation between biomass components and Hinterval, H80, D10, and D20 which were screened using MLR. (2) The models had good estimation precision with R2>0.82 and R2>0.91 for MLR and RF, respectively. (3) The relationship between LiDAR variables and biomass could be reflected well by relative importance ranking of variables by both MDI and MDA method. Conclusion There is a good correlations between biomass components and LiDAR indices. RF shows stronger ability about fitting goodness and generalization, while MLR can make clearer interpretation of the relationship between LiDAR indices and biomass components. The present situation of L. olgensis plantation can be accurately reflected using inversion models, and the underestimation of component biomass will increase with the increase of stand age.
2019, 32(5): 91-98. doi: 10.13275/j.cnki.lykxyj.2019.05.012
[Abstract](3053) [FullText HTML] (2184) [PDF 5025KB](79) [Cited by] ()
Objective Beijing was taken as the research field to discuss the extraction methods for classification of multi-type wetlands in large areas. Method Object-oriented multi-scale segmentation algorithm and spectral difference segmentation were used to segment the Landsat8 OLI image, and stratified sampling method was used to generate random training samples and validation samples by Google Earth high-definition image and manual interpretation results for 2015. Subsequently, CART Decision Tree was constructed to extract wetland information by combining spectral, shape, texture features and topological relation. The results were compared with maximum likelihood method and object-oriented and nearest neighbor method. Result Using object-oriented and CART Decision Tree, the total accuracy of the results was 88.05%, and the Kappa coefficient was 0.844. Compared with the object-oriented and nearest neighbor, the overall accuracy and Kappa coefficient showed less difference, but for some wetland types, such as rivers and swamp, the accuracy increased by 10% to 20%; the total accuracy was nearly 30% higher than that of the maximum likelihood classification, and the Kappa coefficient increased by 0.355. Conclusion Object-oriented and CART Decision Tree is a fast and effective method for wetland classification in the areas with wide distribution, multi-types and quantities of wetland.
Effects of Shading on Growth, Photosynthesis and Chlorophyll Fluorescence Parameters in Leaves of Quercus virginiana Seedlings
2019, 32(5): 99-106. doi: 10.13275/j.cnki.lykxyj.2019.05.013
[Abstract](2853) [FullText HTML] (1529) [PDF 2380KB](43) [Cited by] ()
Objective To discover the response to light intensity of Quercus virginiana, and the effects of different levels of shading on growth, photosynthesis and chlorophyll fluorescence parameters. Method Three light levels (full light-100% natural light, moderate shading-50% natural light and high shading-25% natural light) were set in greenhouse by covering different layers of shading net. The growth, chlorophyll content index, photosynthesis and chlorophyll fluorescence parameters were determined during the experiment. Result The results showed that the height growth of seedlings increased significantly (P < 0.05) under moderate shading condition, while no obvious change was observed in the growth of basal diameter. Under high shading conditions, the height growth changed a little compared with control, whereas the growth of basal diameter was inhibited significantly (P < 0.05). Under moderate shading, the dark respiration rate (Rd), light compensation point (LCP) and light saturation point (LSP) declined and whereas increased significantly under high shading, which showed that moderate shading might be helpful to improve the light use efficiency and increase the dry mass accumulation in leaves of Q. virginiana. There were no obvious changes in apparent quantum yield (α) and the maximum net photosynthetic rate (Pmax). Further analysis of chlorophyll fluorescence parameters showed that PSII primary energy conversion efficiency (Fv/Fm) and photochemical efficiency of PSII in the light (Yield) remained a reasonable range under two light levels, which indicated that the PSII activity might be not damaged. Conclusion These results indicate that Q. virginiana could tolerate certain shading conditions, however, high shading was considered to be detrimental to the accumulation of dry matter, and light condition with more than 50% natural light would be recommended during the silviculture and nursery cultivation.
Analysis of Carotenoids Compounds and Their Biosynthesis Pathways in Flowers of Three Dendrobium Species
2019, 32(5): 107-113. doi: 10.13275/j.cnki.lykxyj.2019.05.014
[Abstract](3372) [FullText HTML] (1682) [PDF 1625KB](36) [Cited by] ()
Objective To investigate the composition content and structure of carotenoids in yellow flower of native Dendrobium species and their biosynthesis pathways, thus proving references for further investigation of the floral pigment mechanism and molecular breeding of Dendrobium. Method The flower color in yellow petals and labellum of Den. chrysotoxum, Den. densiflorum and Den. thyrsiflorum were observed according to the Royal Horticultural Society Color Card (RHSCC). Besides, the carotenoids in the petals and labellum in 3 Dendrobium species at full opening stages were determined using UPC2-MS/MS. Based on the results of UPC2-MS/MS, the biosynthesis pathways of carotenoids in Dendrobium were proposed. Result The result indicated that the floral color of the 3 Dendrobium species could be divided into white group and pale yellow-yellow-golden yellow group. Totally, 8 kinds of carotenoids were detected from the petals and labellum in the 3 Dendrobium species, respectively, including β-carotene, α-cryptoxanthin, β-cryptoxanthin, violaxanthin, lutein, antheraxanthin, zeaxanthin and lutein-5, 6-epoxide. According to the results of quantitative analysis, white petals of Den. thyrsiflorum contained the lowest carotenoids (52.26 μg·g-1). The content of carotenoid increased with the enhancement of yellow color and the carotenoid compounds in the golden yellow labellum of Den. thyrsiflorum was the highest, reaching 3 810.89 μg·g-1. Among 3 carotenoids contained cultivars, the lutein was majorly contained in pale yellow petals of Den. thyrsiflorum, while golden yellow labellum of Den. densiflorum and Den. thyrsiflorum majorly contained α-cryptoxanthin, lutein and lutein-5, 6-epoxide. Yellow petals of Den. chrysotoxum contained violaxanthin, lutein and antheraxanthin. Conclusion The carotenoids in pale yellow and golden yellow petals are mainly α-carotene and its derivatives, while that in bright yellow petals are mainly β-carotene and its derivatives. Regulation of the LCYE genes which may cause carotenoid biosynthesis will result in flower color change in yellow flower of Dendrobium.
Effects of Nitrogen, Phosphorus and Potassium Ratio Fertilization on Growth and Leaf Nutrient Absorption of Moringa oleifera
2019, 32(5): 114-120. doi: 10.13275/j.cnki.lykxyj.2019.05.015
[Abstract](2797) [FullText HTML] (1627) [PDF 1386KB](43) [Cited by] ()
Objective To determine the nutrient requirement and leaf nutrient uptake of Moringa oleifera. Method Field experiment was carried out, and seven treatments, i.e. N80, N80P20, N80K40, P20K40, N80P20K40, N60P20K60 and no fertilization (CK) were set up to analyze and confirm the effects of the different nitrogen, phosphorus and potassium ratio on growth and leaf nutrient absorption of M. oleifera. Result Under different ratio of nitrogen, phosphorus and potash fertilizer treatments, M. oleifera grew quickly at the beginning and then grew slowly. The highest value of plant height, crown width and fresh leaf biomass and the second highest value of ground diameter appeared in N80. The plant height and ground diameter increment under N60P20K60 treatment, and fresh leaf biomass under N80K40 treatment were second only to N80 treatment. Different nitrogen, phosphorus and potassium ratio fertilization promoted the accumulation of total nitrogen and total phosphorus in M. oleifera leaves, but reduced the total potassium content. Except for N80, the chlorophyll content in leaves under other treatments were lower than that of the CK, and the chlorophyll content of high-nitrogen treatments were higher than that of P20K40 and N60P20K60, and the chlorophyll content under N80P20 treatment was higher than that under N80K40 treatment. Conclusion The impact of nutrient elements on the growth of M. oleifera follows the order of N>K>P, the impact on chlorophyll content in M. oleifera leaves follows the order of N > P > K, and the nutrient element content in M. oleifera leaves follows the order of N > K > P. According to the results of the main growth indicators of M. oleifera and the nutrient absorption of leaves, the optimal fertilization ratio is the combination of N80, and the fertilization treatment is suitable for M. oleifera in young and fast-growing stages.
2019, 32(5): 121-129. doi: 10.13275/j.cnki.lykxyj.2019.05.016
[Abstract](2817) [FullText HTML] (1372) [PDF 4992KB](31) [Cited by] ()
Objective To study the function of the homologous gene of brassinolide receptor BRI1 (JcBRI1) in the development of Jatropha curcas flower. Method The CDS of JcBRI1 gene was cloned by RT-PCR, and inserted into the prokaryotic expression vector pET-30a(+). The prokaryotic expression protein was identified by LC-MS/MS, and the protein structure was analyzed by bioinformatics tools. The qRT-PCR was carried out to detect the transcriptional level of JcBRI1 in the critical developmental stages of flower. Result The length of JcBRI1 CDS was 3 591 bp, which was predicted to encode a piptide of 1 196 amino acids. The results of LC-MS/MS detection and protein structure analysis of prokaryotic expression products showed that this protein is J. curcas BRASSINOSTEROID INSENSITIVE 1. qRT-PCR was carried out to investigate the expressive patterns of JcBRI1 in different developmental stages of flower. It seems that higher transcriptional level of JcBRI1 is likely to promote the development of the megaspore mother cell in female flower. Conclusion The JcBRI1 gene is the homologous gene of brassinolide receptor protein BRI1, it probably participates in the division process of the megaspore mother cells during the flower development of J. curcas.
2019, 32(5): 130-135. doi: 10.13275/j.cnki.lykxyj.2019.05.017
[Abstract](2885) [FullText HTML] (1506) [PDF 2447KB](26) [Cited by] ()
Objective Pathogenicity investigation of the Phytophthora was carried out among the main fruit tree species in Xinjiang wild forest to understand the possible causes of the decline of wild fruit forest in Xinjiang and the potential risks caused by Phytophthora. Method By inoculating mycelium plugs artificially on the in vitro leaves, collections of Phytophthora:Phytophthora plurivora, P. gonapodyides, P. lacustris, P. gregate, P. sp. from Xinjiang were inoculated in the health leaves of apple, apricot, hawthorn, and walnut trees, respectively, and observing and recording the disease spot size one week later. Two-way analysis of variance (ANOVA) was implemented to find the differences among the treatments by software R. Result There were significant differences in the size of disease spots after inoculation of 5 Phytophthora strains on 4 host leaves. Among them, P. plurivora and P. lacustris had larger lesions after inoculation on leaves which were 18.68 cm2 and 14.14 cm2. Among the host plants, the leaves of walnut and apricot trees had larger disease spots which were 18.68 cm2 and 9.55 cm2. Conclusion The Phytophthora pathogenicity on the leaves of apple, apricot, hawthorn and walnut is in the order of P. plurivora > P. lacustris > P. gregate≈P. gonapodyides > P. sp. Among leaves of the 4 host trees (apple, apricot, hawthorn and walnut), the susceptibility to the 5 Phytophthora strains mentioned above is in the order of walnut > apricot > hawthorn > apple.
2019, 32(5): 136-141. doi: 10.13275/j.cnki.lykxyj.2019.05.018
[Abstract](3325) [FullText HTML] (1573) [PDF 2388KB](50) [Cited by] ()
Objective Using narrow-band vegetation index and texture information to classify images, and to explore the potential of vegetation index and texture information for tree species classification under cloud shadows. Method Vegetation indices and texture features were used to recombine a new image. Reflectance images and recombination images were classified by support vector machine classifier. By comparing the classification results, the potential of narrow band vegetation indices, texture information and other characteristics in the classification of forest in cloud shadow was explored. The band used to calculate the texture information was selected by the optimum index factor (OIF), and the number of bands selected were band 31(0.67 μm), 51(0.86 μm) and 55(0.89 μm). Tree species training samples were selected based on high resolution aerial photographs. The Support Vector Machine (SVM) method was adopted to classify the reflectivity images and the feature images after recombination. The classification results were verified by filed data, the overall accuracy and Kappa coefficient were used as the evaluation indices for classification accuracy. Result Compared with the classification result of reflectance image, the combination of vegetation index and texture information significantly improved the classification accuracy. The overall accuracy and Kappa coefficient were 90.4% and 0.88, which increased by 18% and 0.2 respectively. The classification accuracy of individual tree species was also significantly improved. It can be seen from the confusion matrix that when using the reflectance image for classification, the Pinus koraiensis is misclassified as P. sylvestris. However, using vegetation index, the error was significantly reduced. Conclusion It is concluded that the forest in cloud shadow area can be classified based on the narrow band vegetation index (NDVI 705, mSR 705, mNDVI 705, VOG1, VOG2, REP) and texture information and the classification result is better than the reflectance image does.
2019, 32(5): 142-148. doi: 10.13275/j.cnki.lykxyj.2019.05.019
[Abstract](2949) [FullText HTML] (1874) [PDF 6166KB](58) [Cited by] ()
Objective To explore the forest change detection method used to update the forest resource database rapidly and to monitor the dynamic changes in forest harvesting and renewal in a short period. Method The research area was set in the plantation of Shangsi County, Guangxi Zhuang Autonomous Region, where the plantation area changed frequently and rapidly and was under integrated management. The GF-2 remote sensing images of two phases were used as data sources. The image difference values of the red band, near-infrared band and NDVI were also exploited respectively. The threshold was determined based on the distribution function. The changes in the research area were detected rapidly. The changing area and the change type were extracted based on the detection. Result The detection accuracy of the three feature differences are as follows:NDVI difference method showed the best, the red band difference method was the second, and the near-infrared band difference method was the worst. The overall accuracy of NDVI was 87.12%, and the Kappa coefficient was 0.76. Conclusion This method can be applied to quickly detecting the changes and can be used to update the forest resource database.
2019, 32(5): 149-156. doi: 10.13275/j.cnki.lykxyj.2019.05.020
[Abstract](2603) [FullText HTML] (1738) [PDF 1131KB](53) [Cited by] ()
Objective To study the breeding and directional cultivation of high-quality Catalpa fargesii clones by investigating the growth (tree height, DBH, individual volume) and trunk shape traits (branch degree, branch angle, crown, bark thickness, sharpness) of C. fargesii clones. Method The analysis of genetic variation, variance and repeatability of several traits were carried out using 33 five-year-old C. fargesii clones. The optimal clones were selected by principal component analysis and membership function method. Result The height, diameter, and individual volume of C. fargesii were significantly or extremely significantly different among the clones, and the repeatability was between 0.456 and 0.592. There were significant or extremely significant differences among clones with average sharpness P1 and P3 which had moderate repeatability (0.479 and 0.415). In the genetic correlation analysis, there was a significant or extremely significant positive weak correlation between individual volume and crown, bark thickness and average sharpness P1, the correlation was 0.178-0.263. According to different breeding objectives, the selection of clone was carried out by principal component evaluation and membership function method. The optimal clones selected by the two methods were combined. Conclusion There was abundant genetic variation among the traits of the 5-year-old C. fargesii clones, and the growth traits are controlled by the genetic control in the middle and have good genetic improvement potential. The growth traits of C. fargesii clones are independent of the trunk shape traits and can be individually oriented. 6 C. fargesii clones are selected as fast-growing and high-yield varieties; 4 clones are selected as high-quality timber clones; and 4 can be considered as the clones improved both in growth and trunk shape traits and is suitable to be extended locally.
2019, 32(5): 157-164. doi: 10.13275/j.cnki.lykxyj.2019.05.021
[Abstract](3011) [FullText HTML] (1501) [PDF 1343KB](34) [Cited by] ()
Objective To construct DNA fingerprints of Casuarina equisetifolia clones and to provide the references for cultivar identification, cultivar variety right protection, and genetic breeding. Method Twelve EST-SSR primers with clear and stable amplified products were selected from 71 primers. The 12 primer pairs were used to identify the cultivars of 109 clonal samples collected from coastal shelterbelts of South China using touchdown PCR and capillary electrophoresis genotyping method through matching genotyping results of 9 standard reference cultivars. A DNA fingerprint identification system of C. equisetifolia clones based on EST-SSR molecular markers and multi-primer combination method was established. Result In this study, totally 50 alleles were detected from 12 primers, where the allele number of each locus ranged from 3-6 and the average value was 4.2, and 2-5 clones can be identified by single locus. According to identification results, 109 clone samples were identified as 22 clones, including 9 reference cultivars and 13 unknown clones, suggesting that repetitive naming of clones was common in different regions. After further optimization by multi-primer combination method the valid molecular marker decreased to 7 primers, that a 7-digit numbers fingerprinting was established to identify the clones of C. equisetifolia, in which each clone can obtain a 7-digit numbers fingerprinting code. Conclusion The DNA fingerprints of 22 clones can be used for the identification of C. equisetifolia clones. This study demonstrates that some clones are repetitive named and the reality of insufficient clone for afforestation. South China will enforce to strengthen breeding and selection work of new clone cultivars of C. equisetifolia.