Our objective was to determine the effect of sugarcane stubble cutting height on the root morphological and physiological characteristics during stem elongation stages. Four stubble cutting heights were tested on cultivar CYZ 07-2800: 5 cm stubble cutting height above soil surface (control), and three stubble cutting heights at or below the soil surface (0-5-10 cm). Stubble cutting height treatments significantly affected the aboveground and belowground sugarcane growth and physiology. The aboveground biomass, root length, root surface area, and root volume of the -5 cm treatment increased significantly compared to of the other treatments (P<0.01) at mid and late elongation. The concentration of malonaldehyde (MDA) in the root was in the order 5 cm >-5 cm > 0 cm >-10 cm, while the activities of superoxide dismutase (SOD), peroxidase (POD), and nitrate reductase (NR) were in the order: 5 cm < 0 cm <-5 cm <-10 cm. The activities of SOD and POD tended to increase with elongation period. The -5 cm treatment increased the growth and physiological attributes of the root system, presumably increasing nutrient use efficiency and delaying root senescence. Due to continuous improvement in mechanical harvesting of sugarcane and limited ratooning ability, harvesting of sugarcane or post-harvest stubble cutting at 5 cm below soil was used to manage the ratoon crop, which significantly increased the yield and a prospect of large-scale adaptation of technology at farmers’ level.
In the present study, the growth and the absorption dynamic parameter of NO3 --N in flue-cured tobacco, which was pretreated in different concentrations of KCl, were investigated with sand culture test. The results showed that compared with low (K1) and high K (K3) treatments, the fresh and dry weight of the shoot and root of the flue-cured tobacco increased under medium potassium (K2) treatments. With the increase of K concentration, the proportion of potassium transported from roots to shoots increased, while the net photosynthetic rate of the flue-cured tobacco had no significant difference in the early growth stage, but increased significantly in the late growth stage. Compared with low (K1), medium K (K2) level increased total root length, total surface area, average diameter and total volume, while high potassium (K3) level inhibited it; the uptake of NO3 --N of the flue-cured tobacco was in accordance with Michelis-Menten equation pretreated with different concentrations of KCl, and the uptake kinetics parameters, Vmax and Km were enhanced with the K pretreatment concentration increased, but the increase range was not consistent. For the high-affinity system, compared with low K (K1) pretreatment, high K (K3) pretreatment decreased the uptake rate of NO3 --N, while medium K (K2) pretreatment increased the uptake rate of NO3 --N, which indicated that the high affinity system of NO3 --N uptake by the flue-cured tobacco was regulated by K level, and appropriate K level pretreatment increased the uptake rate of low concentration NO3 --N. For the low-affinity system, compared with low K pretreatment, medium K (K2) and high K (K3) pretreatment could significantly increase the absorption of NO3 --N, which indicated that the root uptake of NO3 --N of the low-affinity system was less affected by long-term high K environment, while was restrained at long period of low K environment.
A mini-watermelon nursery trial was conducted on substrates with vermicompost replacing peat in different volume ratio, and substrate properties as well as seedling growth were studied. The results showed that with the increase of vermicompost proportion, the pH, electrical conductance (EC), dry and wet bulk density of substrate increased almost gradually, meanwhile the maximum water holding capacity, total porosity and capillary porosity decreased gradually. It might be harmful to substrate physical properties when vermicompost proportion reached or exceeded 50%. With the addition of vermicompost, the quantity of bacteria and fungi in the substrate decreased obviously, especially that of bacteria. The plant height, stem diameter, biomass, root length and root surface area of mini-watermelon seedlings grown in substrate S2 (containing 10% vermicompost) were all the highest. Thus the growth situation and comprehensive evaluation score were all the best. It indicated that the addition of 10% vermicompost in peat was beneficial to improving the mini-watermelon nursery effect. According to the result of correlation analysis, the growth of mini-watermelon seedlings was greatly affected by the physical properties of substrates. Specifically, the stem diameter, root length and comprehensive evaluation score of mini-watermelon seedlings was extremely significant or significant negative correlation to dry and wet bulk density of substrate, while extremely significant or significant positive correlation to maximum water holding capacity, total porosity and capillary porosity.
Three hundred and two ‘Guanximiyou’ pummelo (Citrus grandis) orchards from Pinghe County, the southern region of Fujian Province, China, were selected for this study. The objectives were to determine (i) the primary factors affecting fruit quality and synthetical fruit quality status of ‘Guanximiyou’ pummelo from different regions and soil types, (ii) optimum range of mineral element contents of the leaves for high-quality and high-yield ‘Guanximiyou’ pummelo production, and (iii) nutrition status of ‘Guanximiyou’ pummelo orchards based on Diagnosis and the Recommendation Integrated System (DRIS) method. The results showed that three factors (eigenvalue>1) were extracted by the factor analysis with their cumulative contribution approximated to 69.7%. The first factor was determined by the ratio of soluble solid content to titration acid, total soluble solids and total sugar content, with variance contribution approached to 36.8%. The second factor was determined by sac granulation and juice sac granulated segments, with variance contribution approached to 20.3%. The third factor was determined by fresh weight of whole fruit and titratable acidity with variance contribution approached to 12.7%. The synthetical score of fruit quality in the east of Pinghe County was higher than that in the west of Pinghe County, while the synthetical score of fruit quality in hilly red soil orchards was higher than that in paddy soil. The values of the optimum ranges of mineral elements of the leaves for high-quality and high-yield ‘Guanximiyou’ pummelo production were: N 2.15%-2.80%, P 0.12%-0.17%, K 1.25%-1.85%, Ca 2.10%-4.25%, Mg 0.25%-0.55%, S 0.25%-0.40%, Mn 20-145 mg/kg, Zn 25-50 mg/kg, B 35-135 mg/kg. The DRIS diagnostic results indicated that the most deficient elements for various ‘Guanximiyou’ pummelo regions of Pinghe County were as follows: B, Mg and Ca for the hilly red soil orchards of the east Pinghe County; Mg, N and P for the paddy soil orchards of the east Pinghe County; Zn, Ca and Mg for the hilly red soil orchards of the west Pinghe County; and Zn, K and S for the paddy soil orchards of the west Pinghe County. In conclusion, optimized nutrient management based on new nutrition diagnosis standards and regional difference is essential for achieving high-quality and high-yield ‘Guanximiyou’ pummelo production.
Based on Ipomoea batatas (L.) Lam. with higher (Yushu No.1, Yushu No.27), middle (Yusu No.303, Yusu No.8, Yushu No.99) and lower (Chaoshu No.1) dry matter (DM) content in storage roots, the characteristics of DM accumulation and partition and the correlations with major agronomic traits were studied at 15, 30, 60, 90, 120 d after transplanting. The results indicated varieties with higher DM content in storage roots, compared with the other two types, could accumulate much more DM during the earlier period (15-60 d) with higher increasing rates and ratios of DM partition in aerial parts. The maximum increasing rate of aerial parts was up to 2.31 g/(plant·d) during 60-90 d. The maximum net assimilation rate was up to 12.018 g/(m 2·d) during the earlier and middle periods. DM yield per plant revealed an extremely significant positive correlation with DM accumulation of blades while that revealed no significant correlation with ratios of DM partition in each part during all periods. DM yield of storage roots revealed a significantly or extremely significant positive correlation with ratios of DM partition in storage roots before 60 d. High DM content varieties had the characteristics contributed of DM partition early in storage roots, stable growth of aerial parts during the middle period, and non-decreasing leaf area and dry yield during the later period, which leading to higher yield. The research would lay a solid foundation for sweetpotato quality breeding and industrialization.
This study was conducted to effectively evaluate and utilize the germplasm resources of Erianthus arundinaceum in Guangxi, to expand the genetic basis of sugarcane. The phenotypic traits and genetic diversity of 183 accessions of E. arundinaceum collected from Guangxi were analyzed. Results showed that the genetic diversity of phenotypic traits was low. The genetic diversity index (DI) ranged of 13 descriptive traits from 0.0000 to 1.2349 with an average of 0.3070, with highest for hair groups and lowest for growth ring shape. There was no polymorphicin 4 traits including pipe, aerial root, root primordial and sheath detached. The DI among different regions ranged from 0.2851 to 0.5072, with highest for Qinzhou, followed by Guilin and Chongzuo, and the lowest for Laibin. The coefficient of variation (CV) of 5 numerical traits ranged from 13.54% to 29.11% with an average of 19.59%, with highest for leaf width and lowest for leaf length. The regional CV of 10 regions ranged from 16.48% to 21.92%, with highest for Guilin and the lowest for Baise. Cluster analysis showed that 183 germplasm resources could be clustered into 10 groups. The genetic differentiation among groups was not obvious and had no close relationship with geographical origin and the genetic distance was not closely related to geographical origin. This study revealed the phenotypic specificity and genetic diversity of E. arundinacea in different regions of Guangxi, and provided theoretical reference for collection, conservation and hybridization of E. arundinacea resources.
Forty six Erigeron breviscapus germplasms were collected from Yunnan and Guizhou provinces, and the active constituents were determined for selecting special composition germplasms. Ten active constituents in the germplasms were determined by HPLC (high performance liquid chromatography), the relationships among the contents of different active constituents were revealed by correlation analysis, and the germplasms were classified into different groups by cluster analysis according to the composition of active constituents. Sixteen germplasms with a content of scutellarin (SE) more than 2.5% were the ideal materials for breeding breviscapine-type cultivars, among them, four germplasms with a content of dicaffeoylquinic acids (diCQAs) more than 1% were suitable for breeding Dengzhanxixin-type cultivars. Furthermore, eight germplasms with total flavonoids (TFs) more than 3.5% were suitable for breeding flavone-type cultivars. The content of SE was positively correlated with the contents of diCQAs and TFs, indicating that SE was the selective marker for quality breeding in E. breviscapus. Most germplasms were included in two clades (I and II) by cluster analysis, except one germplasm, which containing equal contents of SE and diCQAs (III). The first clade (I), designed as high TFs-type germplasms, contained higher TFs relative content (more than 80%) and lower diCQAs relative content (less than 15%), while the second clade (II) were characterized by high relative contents of diCQAs (16.9%-28.9%) and lower TFs relative content (less than 80%).
The study was aimed to identify the sucrose-degrading enzymes playing key regulatory roles in the quality formation of sweet potato and the content of carbohydrates (i.e. sucrose, glucose, fructose and starch) in the storage roots of two sweet potato cultivars. The cultivars had large differences in carbohydrate content and enzyme activities. Sucrose synthase (Sus) activity was the highest among the four sucrose-degrading enzymes, followed by cytoplasmic invertase (CIN) and vacuolar invertase (VIN). Cell wall invertase (CWIN) activity was the lowest. Besides VIN, it was found for the first time that there was also a significant positive correlation between CIN activity and hexose content. Cultivar with higher hexose content also had a higher CIN and VIN activity. There was a positive correlation between Sus activity and starch content. CWIN activity was the lowest among the four sucrose-degrading enzymes and its function in quality formation of storage root remained to be elucidated. Sus maight play key regulatory roles in starch accumulation of storage roots, whereas VIN and CIN play key regulatory roles in hexose accumulation.
We studied the effects of temperature stress on the leaf physiological and photosynthetic characteristics of the two-year-old seedling of Medinilla magnifica in plant growth chambers for 48 h. The results showed that under high temperature stress the relative electrolytic conductivity (REC) and catalase (CAT) activity increased in different degrees with the increase of temperature, so do the content of soluble protein, free proline, malondialdehyde. Moreover, the chlorophyll content reduced significantly, the activities of peroxidase (POD) and superoxide dismutase (SOD) decreased. Under low temperature stress the REC and the content of free proline, MDA increased, but the content of soluble protein, chlorophyll and CAT activity decreased slowly. Both the net photosynthetic rate (Pn), stomatal conductance (Gs) and water use efficiency (WUE) decreased, whereas the intercellular CO2 concentrations (Ci) shared u-shaped curves with the decrease or increase of temperature. In addition, transpiration rate (Tr) reduced with the decrease of the temperature. The variation ranges of REC and MDA content were smaller under high temperature stress than those under low temperature stress, and the activities of POD and SOD were higher than those under low temperature stress. The results indicated that the photosynthesis of M. magnifica was inhibited by low and high temperature stress and M. magnifica was more sensitive to low temperature stress.
Different photosynthetic parameters of five native colored-leaf trees in Fujian were determined using an Li-6400 portable photosynthesis system, and the light response curves were drawed. The results showed that at the beginning of light increase, differences in the photosynthetic rate (Pn) between colored-leaf trees were not distinct, however, with the increase in light intensity, great differences in Pn between colored-leaf trees appeared. The stomatal conductance (Gs) of the five colored-leaf trees showed two trends with the increase of light intensity. Sassafras tzumu, Sapium discolor and Euscaphis japonica showed an overall upward trend, while Liquidambar formosana and Sapindus mukorossi showed a first upward and then downward trend till to be stable. The light response curve of transpiration rate (Tr) was basically the same as that of Gs. The intercellular CO2 concentration (Ci) of the five colored-leaf trees decreased rapidly at first and then tended to be stable. The water use efficiency (WUE) increased first and then decreased with the increase of PAR. The LCP ranged from 9.525 μmol/(m 2·s) to 28.018 μmol/(m 2·s), and the LSP ranged from 592.303 μmol/(m 2·s) to 1245.871 μmol/(m 2·s). The five colored-leaf trees were light preferring plants. The ability to use high light for Sassafras tzumu and Sapium discolor was better than the other trees with a higher LCP, LSP and maximum net photosynthetic rate. The ability to use low light for Euscaphis japonica was better with a lower LCP, LSP and maximum net photosynthetic rate.
Changes in PAL activity, total phenol and flavonoid content, total antioxidant capacity and SgPALs expression pattern were analyzed to study the responses of Stylosanthes guianensis cv. Reyan2 to biotic (infectied by Colletotrichum gloeosporioides) and abiotic (drought and salt) stresses. PAL activity increased by 18.58%-123.56% in different tissues under treatments of the three different stresses. The total phenol and total flavonoid content, and the total antioxidant capacity significantly increased by 65.11%-68.00%, 51.00%-76.87% and 83.00%-262.08%, respectively, in the leaf by pathogen infection, drought and salt stress, and similarly increased by 43.77%-51.12%, 45.46%-45.98% and 60.45%-97.89%, respectively, in the root by pathogen infection, drought and salt stress. PAL gene expression patterns showed that the cloned SgPALs genes, except SgPAL4, were up-regulated by anthrax infection in the leaf. The SgPALs genes were up-regulated by drought stress in the root while only SgPAL1 and SgPAL4 were up-regulated in the leaf. Under salt stress, the SgPALs genes were up-regulated in the root, while the SgPALs genes, except SgPAL3, were down-regulated in the leaf.
The molecular mechanism of panicle apical abortion has important theoretical and practical significance for high and stable yield breeding in rice (Oryza sativa L.). The phenotype of a rice panicle apical abortion mutant paa1-2 was observed and the TUTOU1 and PAA1 gene sequences in the mutant paa1-2 were sequenced. Results showed that the degraded phenotype of the mutant paa1-2 at the top of panicle was produced after the 6th stage of early panicle differentiation. The TUTOU1 gene sequence in the mutant paa1-2 was identical to that of wild type. However, there were mutations in the PAA1 gene of the mutant paa1-2. There were four base deletions at 1512-1515 bp, which led to coding mutations and early termination of protein translation. PAA1-2 maight be a new allele of PAA1 gene.
The sequence of the open reading frame of CBF was obtained from reference Solanum melongena genomic sequence in NCBI using the the sequence of CBF gene from Chinese cabbage as a query. The full-length cDNA of CBF was isolated from the leaf of eggplant (primers were designed according to the genome DNA sequence and the EST sequence), and the cloned gene was designated as SmCBF (GenBank No: KY780486.1). Using bioinformatic analysis, the gene was identified as a member of the AP2 gene family, which encoding 211 amino acids with DNA binding site. The cis-acting elements of the promoter sequence of SmCBF gene were analyzed by PlantCARE. One MYC recognition site and one MYB binding site were found, indicating that MYC and MYB might be involved in regulating the expression of SmCBF. Real-time PCR analysis revealed that the expression level of SmCBF gene increased gradually with the prolongation of low temperature treatment time and reached the highest value at 6 h, indicating that SmCBF was induced by low temperature treatment.
In this study, the apical stem of the hermaphroditic strain of papaya seedlings identified by multiple PCR technique was used as the explants to establish and optimize a set of propagation system of papaya seedlings in tissue culture. The problem of rootless seedlings and low survival rate of transplanting were solved. In the experiment, the hermaphrodite plants were identified by multiple PCR and the stem tips were cultured on MS supplement with BA 0.5 mg/L, NAA 0.1 mg/L, sucrose 30 g/L, agar 6g/L (pH 5.8), and cultured at 28 ℃for 30 days. The rootless seedlings were formed and subdivided into small clusters and planted on the strong seedling medium MS supplement with BA 0.5 mg/L, KT 0.25 mg/L, NAA 0.1 mg/L, sucrose 30 g/L, agar 6g/L (pH 5.8), cultured at 28 ℃and 2000 lx for 30 days. The rootless seedlings were inoculated on the 1/2MS supplement with IBA 0.75 mg/L, NAA 0.05 mg/L, KT 0.01 mg/L, sucrose 30 g/L, agar 6 g/L (pH 5.8) medium. After being cultured at 28 ℃and 1500 lx for 20 days. In order to obtain the best rooting rate and survival rate of transplanting, the rootless seedlings were tested with different concentrations of nutrient rooting water and different treatment time. The results showed that the accuracy of multiple PCR technique for sex identification was over 98%. Under the conditions of 50 mg/L nutrient rooting water and 8 h treatment, the rooting rate of ‘Solo’ was 81.1%, and the survival rate of transplanting was 91.1%. The rooting rate of ‘Mihong’ was 60% and the survival rate of transplanting was 86.7%. The results obtained by the technique are superior to those of mature lateral buds, and could be used in the commercial production of papaya seedlings.
Corynespora cassiicola is a plant pathogenic fungus, which is harmful to major tropical crops in China. It has a wide range of hosts, significant morphological differences, diverse symptoms and contains a host-specific toxin, which encoding up to six distinct protein isoforms. In the study, we used public database to construct Cassiicolin genes barcode database of C. cassiicola form major tropical crops in China. At the same time, we established a set of molecular detection techniques with high specificity and sensitivity, which could detect 100 pg/μL target genomic DNA. Then, we systematically detected the isoforms cassiicolin of C. cassiicola, which were isolated from rubber tree, cassava, papaya, melon and vegetable in China. There were only two isoforms Cassiicolin in China, among which the Cas5 isoform Cassiicolin accounted for 94.8%, and had obvious host specificity and was specific and advantage population on rubber tree in China. Phylogenetic tree analysis showed that distinct isoforms Cassiicolin of C. cassiicola was closely related to host origin, but not to geographical origin. The results of the research would significantly contribute to the population genetic structure, dominant population, preservation of C. cassiicola and control strategies.
Diversity analyses were investigated by the high-throughput sequencing to study the composition and diversity of bacterial communities in the rhizosphere soil of Pennisetum giganteum and Arundo donax cv. Lvzhou No. 1. Results showed that the dominant phyla of all samples were Acidobacteria, Proteobacteria, Actinobacteria, Firmicutes, Chloroflexi, Gemmatimonadetes, Nitrospirae, Verrucomicrobia, Planctomycetes. At the class level, nine dominant species were found in all samples, such as Gammaproteobacteria, Alphaproteobacteria, Bacilli, Actinobacteria, Acidobacteria-6, Betaproteobacteria, Acidobacteriia, Ktedonobacteria, Deltaproteobacteria. At the genus level, dominant species were found in all samples, such as Staphylococcus, Saccharopolyspora, Paenibacillus, Serratia, Streptococcus, Rhodoplanes, Acinetobacter, Pseudomonas. The Shannon-Wiener from the samples was 9.05, 8.733, 7.61, respectively. The Simpson index from the samples was 0.01, 0.014, 0.037, respectively. The Chao1 index from the samples was 3145.320, 3647.482, 2329.344, respectively. The result of Alpha diversity analysis showed that the Shannon index, Simpson index and Chao1 index of Juncao increased. The diversity index analysis showed that in the soil samples, the lowest bacterial diversity was in the experimental control soil and the highest bacterial diversity was in the A. donax cv. Lvzhou No. 1 rhizosphere soil. The bacterial diversity in the A. donax cv. Lvzhou No. 1 rhizosphere soil was slightly higher than that in the Pennisetum giganteum rhizosphere soil.
Heortia vitessoides is a major pest of Aquilaria sinensis forests in recent years. In this study, the influence of temperature and supplementary foods on the development and fecundity of the moth were studied. Results showed that the developmental period of all stages and life cycle of H. vitessoides were shortened with increasing temperatures under five constant temperatures (15, 19, 23, 27 and 31 ℃), but it could not complete whole generation development at 11 and 35 ℃. Under the constant temperature, the threshold temperature of egg, larva, prepupa, pupa, preoviposition and whole generation was 8.26, 8.79, 11.97, 11.49, 5.62 and 9.22 ℃ respectively, and the effective accumulated temperature was 150.73, 291.45, 37.23, 138.66, 93.83 and 718.10 d?℃. The moth had six generation per year in Xishuangbanna, Yunnan. Moreover, the moth feeding on 10% sucrose lived longer than that feeding on other sugar concentrations. The result offered a scientific base for rearing in laboratory and forecasting and prevention of H. vitessoides in field.
Bactrocera tau (Walker) is a major pest to Cucurbitaceous and Solanceous vegetables and many fruits of tropical and subtropical areas. Prevention and control of it is very difficult due to its strong resistance and rapid reproduction. To seek effective molecular targets for its control and the action mechanism of parapheromone, transcriptome of B. tau was sequenced and related bioinformatics analyzed using Illumina HiSeq2500 PE125 bp sequencing platform. The clean reads were then de novo assembled into 36 109 Unigenes. Through a similarity search against seven public databases, 21 127 unigenes were annotated. Most unigenes were annotated to Nr database with a success number of 20 948, and the unigenes of B. Tau had the highest homology to those of Ceratitis capitate in species distribution of unigenes in Nr database (59.80%), followed by 14.86% with Drosophila melanogaster. According to GO database, 14 029 Unigenes were classified into 3 categories and 57 sub-types, while searching KOG database, 13 479 Unigenes were sorted in 25 functional groups. Metabolic analysis based on KEGG found 6442 Unigenes involved in 152 metabolite pathways in 5 classes. By further screening and identification, 528 olfaction-related genes of B. tau were obtained. Analysis of odorant binding protein genes of B. tau demonstrated that most of them were typical with 6 conserved cysteine sites and with high homology to those of D. melanogaster, C. capicata, B. cucuribita and B. dorsalis. These results will provid basic information for the research of functional genes related to parapheromone treatment on B. tau as well as the establishment of control measures based on olfactories.
Earthworm (Eisenia fetida) is one of the key bio-indicators of soil health. To evaluate the effects of glyphosateon soil invertebrates, the acute toxicity of glyphosate to earthworms were determined by artificial soil test. Effects of different concentrations of glyphosate on the activities of superoxidedismutase (SOD), catalase (CAT), peroxidase (POD), glutathions S-transferase (GST) and acetylcholinesterase (AChE) in earthworms were measured at different exposure durations. The results of artificial soil test showed that the LC50 of glyphosate to earthworms was greater than 1000 mg/kg (7 d, 14 d), indicating that the acute toxicity of glyphosate was low to earthworms. With the increase of glyphosate concentrations and exposure time, the activity of SOD in earthworms increased first and then decreased; the activity of CAT in earthworms decreased first and then increased; and the activity of POD in earthworms kept decreasing. Compared to the control, the activity of AChE in earthworms exposed to glyphosate reduced significantly after 14 days. The results would provide a scientific basis for rational evaluation and monitoring of soil pollution level caused by glyphosate.
To investigate the pharmacodynamic substance basis of Blumea balsamifera (L.) DC., fifteen compounds were isolated from the EtOAc fraction by silica gel, sephadex LH-20 and ODS-A column chromatography. The structures were determined based on the analysis of the spectroscopic data as 3,3°,5-trihydroxy-4°,7-dimethoxy flavanone (1), 4°,5-dihydroxy-3,3°,7-trimethoxy flavone (2), blumeatin (3), 3,5,3°,4°-tethydroxy-7-methoxy flavone (4), diosmetin (5), 3°,4°,5-trihydroxyl-3,7-dimethoxy flavone (6), isosamicin (7), chrysosplenol C (8), hyperoside (9), isoquercitrin (10), 3°,5,7-trihydroxy-4°-methoxy flavanone (11), sakuranetin (12), pilloin (13), 5,7,3°,4°-tetrahydroxy-3-methoxyflavone (14) and 5-hydroxy-3,7,3°,4°-tetramethoxy flavone (15). Compounds 7, 11, 12 and 13 are isolated from the plant for the first time. Antibacterial test indicated that 1, 3, 6, 8 and 12 displayed different inhibition against three bacteria, and 3 significantly inhibited Staphylococcus aureus subsp. aureus (DSM 799) with a MIC value of 32 μg/mL.
To identify the ingredient in the oil cells of Kaempferia galanga L. and Kaempferia rotunda L. at room temperature, and to avoid sample pretreatment and extractions which can be labor intensive, the work showed the possibility to detect in situ the main components of the essential oils in the two plants oil cells by Raman spectroscopy. Under the DXR laser confocal micro Raman spectrometer, the oil cells could be seen with objective lens of 10×. Different oil cells had similar Raman spectrum. The Raman spectrum of 4-methoxycinnamic acid ethyl ester and benzyl benzoate was obtained. The Raman spectrum of K. galanga L. was correlated very well with that of 4-methoxycinnamic acid ethyl ester, and that of K. rotunda L. was correlated very well with that of benzyl benzoate. The Raman spectroscopy of 4-methoxycinnamic acid ethyl ester and benzyl benzoate was calculated by the density functional theory (DFT). The Raman spectroscopic bands were assignment with the help of calculation. It indicated that the essential principal oil components of K. galanga L. and K. rotunda L. in the oil cells were 4-methoxycinnamic acid ethyl ester and benzyl benzoate.
The composition and content of amino acids in 22 species Dendrobium were determined by an automatic amino acid analyzer, and multivariate statistics analysis were performed to provide a reference for the quality. The most abundant amino acids were aspartic acid, glutamic acid, leucine and arginine; methionine and cystine were the first and second restricted amino acids in Dendrobium. There was a significant difference in the content of amino acid and the composition. Ten in the 22 species of Dendrobium contained 17 amino acids and 7 essential amino acids. No methionine or cystine was detected in 11 species. D. aurantiacum, D. parishii, D. moschatum, D. crepidatum, D. transparens, D. aurantiacum var. were classified as the richest in amino acids based on the recommendation of FAO/WHO. The amino acids could be divided into four groups by quality with principal component analysis and cluster analysis, and Dendrobium were classified into three categories.
The quality characteristics of lotus seed starch have great influence on the processing quality and edible quality of shelled lotus seeds. In this project, the characteristics of the starch in four lotus varieties were compared using scanning electron microscope (SEM), amylose automatic analyzer, X-ray diffractometer (XRD) and Malvern laser particle size analyzer. The quality characteristics of the seed starch of the four lotus varieties during the dough stage and full ripe stage were measured and analyzed. The amylose content, resistant starch content and particle size of lotus seed starch of different maturity stages of the same variety depended on maturity levels, while the crystallization of lotus seed starch with different maturity degrees of the same variety decreased with the increase of the maturity of fresh lotus seeds (except Jingguang No. 1). Among the four varieties, the starch content of Jianxuan No. 17 and Jianxuan No. 35 fresh lotus seeds was higher in the dough stage and full ripe stage, while the content of amylose was much lower, which had a certain effect on inhibiting the starch retrogradation.
The suitable substrate formulation for tobacco seedling cultivation was explored based on spent mushroom substrate (SMS), peat and wormcast, and the application effect of SMS in tobacco seedling cultivation was analyzed. The results showed that T4 treatment group (wormcast∶SMS∶vermiculite∶perlite = 1∶1∶1∶1) had obvious advantages in plant height, root development, soluble sugar, root activity and other growth and physiological indicators compared with market substrate treatment group (peat∶vermiculite∶perlite=2∶1∶1). Multivariate linear regression analysis of physical and chemical indexes of substrate and growth and physiological indexes of tobacco was carried out by SPSS software. The results showed that higher total porosity, available iron content and total potassium content of substrate were beneficial to the growth of tobacco seedlings, while higher electrical conductivity, organic carbon and total nitrogen content were not conducive to the growth of tobacco seedlings. SMS had the advantages of high total porosity, high effective iron, suitable nutrient structure and low cost, but it also had the disadvantages of high conductivity, low bulk density and high organic carbon. It was not suitable to be used as a matrix alone. The proper formulation could give full play to the role of SMS. It is a good substrate material and has broad application prospects.
In order to analyze the effect of tea tree rhizosphere soil chemicals on the soil microbial diversity, the rhizosphere soils from Tieguanyin tea plantations of 0, 3, 9 and 25 years old were extracted and eluted through different polar resins to discuss the autotoxicity of resins eluted and the effect of soil microbial diversity. The results showed that the inhibitory effect of ADS-7 resin eluent on the root length of receptor was the strongest. After the replanted tea trees was treated by ADS-7 resin eluent, the number of bacteria in the tea trees rhizosphere soil decreased with the increase of planting soil age. Correlation analysis result showed that 15 T-RFs from bacterial community were significantly and positively correlated with soil age, which included 31 species of microbes belonging to 8 classes, respectively. Thirty-one microbes could be divided into 4 types according to the function, among them, 19 species of pathogenic bacteria accounted for 61.29%. In addition, 18 T-RFs were significantly and negatively correlated with soil age, which included 31 species of bacteria belonging to 11 classes, respectively. The thirty-one bacteria could be divided into 6 types according to the function, and total percentage of the bacteria to inhibit 83.87%. In brief, after the replanted tea trees was treated by ADS-7 resin eluent, the number of pathogenic bacteria in tea tree pathogenic bacteria, carbon cycle, nitrogen cycle, sulphur cycle and the bacteria to improve the soil quality accounted for rhizosphere soil was great enhanced and the number of probiotics and soil nutrient cycling bacteria decreased significantly as planting soil age increased, which led to the imbalance of soil microbial ecosystem.
In this study, soil microorganisms in different banana growing areas in Guangxi were taken as the research object. Amplicon sequencing technology, Spearman correlation analysis, RDA analysis and other methods were used to determine and analyze the abundance and diversity of soil microorganisms. The effects of physicochemical properties of banana and soil on soil microbial abundance and diversity were discussed. The results showed that the ratio of total OTU of banana soil bacterial samples to that of fungal samples was approximately 2∶1. Fusarium, the genus of the pathogen of banana wilt, accounted for 5.132% to 55.132% of the genus abundance. Spearman correlation analysis showed that there was no significant correlation between Fusarium and soil physicochemical properties. Fusarium had no significant correlation with soil physical and chemical properties. The abundance and diversity of fungi were more easily affected by soil physical and chemical properties and nutrients than bacteria. The single soil physical and chemical properties could not significantly affect the community structure and species composition of soil microorganisms. To a certain extent, soil fungi reflect the degree of disease resistance of banana varieties.
Three interplanting patterns with Pogostemon cablin (Blanco) Benth, Desmodium styracifolium (Osb.) Merr. and Andrographis paniculata (Burm. f.) Nees were arranged to explore the effects of intercropping patterns on the physical and chemical properties and available elements of the rhizosphere soil of Citrus medica L. var. sarcodactylis Swingle. The results showed that interplanting changed soil pH value which ranged from 6.1 (C. medica L. var. sarcodactylis Swingle only) to 6.4 (with P. cablin (Blanco) Benth). Compared with the C. medica L. var. sarcodactylis Swingle group, the soil organic matter content and soil alkaline hydrolysis content decreased under the three intercropping patterns, and the most declining was the D. styracifolium (Osb.) Merr. group, the P. cablin (Blanco) Benth group had no significant difference with C. medica L. var. sarcodactylis Swingle group in soil alkaline nitrogen content. The content of available phosphorus and available potassium in the soil of A. paniculata (Burm. f.) Nees group increased by 8.07% and 3.41%, respectively, indicating that the content of available phosphorus and available potassium in the soil after interplanting with A. paniculata increased significantly. Compared with the C. medica L. var. sarcodactylis Swingle group, the content of exchangeable calcium, magnesium and available copper in the rhizosphere soil of P. cablin (Blanco) Benth decreased, and the content of available zinc, iron, manganese and boron increased; the exchangeable calcium and magnesium in the rhizosphere soil of D. styracifolium (Osb.) Merr. group, the content of available copper, zinc and iron decreased, and the content of available manganese and boron increased. The content of exchangeable calcium, magnesium, available copper and manganese in soil rhizosphere of A. paniculata (Burm. f.) Nees group decreased, and the content of available zinc, iron and boron increased. PCA analysis results showed that alkaline nitrogen, available potassium, available phosphorus, copper, zinc and iron were the characteristic factors affecting the growth of C. medica L. var. sarcodactylis Swingle. At the same time, different intercropping models improved overall economic efficiency. Different intercropping patterns significantly affected the soil physical and chemical properties and trace elements in the rhizosphere of C. medica L. var. sarcodactylis Swingle.
