2020 Vol. 35, No. 10
Display Method:
2020, 35(10): 1043-1049.
doi: 10.19303/j.issn.1008-0384.2020.10.001
Abstract:
Objective Grain-filling of Tartary buckwheat (Fagopyrum tataricum) was studied to determine the cause of inferior crop yield of tetraploid variety. Method Diploid Tartary buckwheat varieties, Xiaohuang and Liuku 2081, were compared with the tetraploid TB193 and TB198 on grain-filling, starch biosynthesis, root morphology and physiology, agronomic characteristics, and grain yield for the analysis. Result Although both Tartary buckwheat varieties stopped the 100-grain weight increase 25 d after anthesis, the diploid was higher than the tetraploid in that respect. In addition, compared to the tetraploid varieties, the diploid Tartary buckwheat started earlier on the filling initiation; achieved higher peak and average filling rates; reached the maximum grain-filling in a shorter time; showed greater AGPase and SSS activities in grains at early grain-filling stage but lower in the middle and late filling stages; had significantly lower length, surface area, volume, activity, and fluid on the roots, height on the plant, number of branches on the main stem, node count on the main stem, girth between the 1st and 2nd nodes, and 1-2 internode thickness. On average, the diploid Tartary buckwheat was 2.97 times higher on plumpness and 1.23 times higher on yield than the tetraploid counterpart. Conclusion The lower grain filling initiation, filling rate, and starch synthase activity at early filling stage appeared to be the key physiological indicators of the inferior performance of the tetraploid Tartary buckwheat on grain production.
2020, 35(10): 1050-1062.
doi: 10.19303/j.issn.1008-0384.2020.10.002
Abstract:
Objective Mechanism of red bud taro in response to cryotherapy was studied by transcriptome analysis for extended application of the virus-free seedlings at Yanshan, Jiangxi. Method Transcriptomes of virus-free (VF) and virus-carrying (V) red bud taro plantlets that had been cryo-therapeutically treated were analyzed and compared. Result In the VF plantlets, the clean reads were 42 406 188 with a GC content of 54.09%; while, in the V plantlets, the clean reads were 46 818 060 with a GC content of 50.36%. For either group, the FPKM was between 0-2, and the expression density between 0-0.8. There were 23 820 genes commonly expressed in both VF and V, while 4 477 independently expressed in VF, and 10 298 in V. There was a low correlation between VF and V with a coefficient of 0.287, and were 5 282 differentially expressed genes (DEG) in them. Compared to V, VF had 3 011 genes were up-regulated and 2 271 down-regulated. The Go enrichment analysis showed that the differential genes were annotated mainly in the processes of hydrogen peroxide catabolism, hydrogen peroxide metabolism, monocarboxylic acid biosynthesis, and polysaccharide catabolism, metal ion transport, extracellular region, cell wall, external encapsulating structure, intrinsic components of membrane and plasma membrane as well as the activities of nucleic acid binding transcription factor, transcription factor, sequence-specific DNA binding, monooxygenase, iron ion binding, heme binding, etc. The KEGG enrichment analysis indicated that the differential genes were annotated largely to the biosynthesis of phenylpropanoid, flavonoid, stilbenoid, diarylheptanoid, gingerol, carotenoid, isoquinoline alkaloid, ubiquinone, and other terpenoid-quinones, the metabolisms of starch, sucrose, tyrosine, alpha-Linolenic acid, phenylalanine, cyanoamino acid, glycine, serine, threonine, fructose, mannose, galactose, amino sugar, and nucleotide sugar, and the pathways of MAPK signaling-plant, plant hormone signal transduction, pentose and glucuronate interconversions, peroxisome, circadian rhythm-plant, and others, Conclusion The genes of F-box family protein, abscisic acid receptor PYR1, ethylene receptor 2, auxin response factor 1, BZIP transcription factor family protein, peroxidase, catalase 1, superoxide dismutase [Cu-Zn], plant disease resistance response protein, disease resistance protein, disease resistance protein RPS2, disease resistance protein RPS5, disease resistance protein RGA2, disease resistance response protein, retrovirus-related Pol polyprotein from transposon TNT, retrovirus-related Pol polyprotein LINE-1, tobamovirus multiplication protein 3-like, tobamovirus multiplication protein 1, retrovirus-related Pol polyprotein from transposon RE1, sucrose synthase, etc. were the predominant genes in the virus-free red bud taro plantlets that responded to the cryotherapy.
2020, 35(10): 1063-1070.
doi: 10.19303/j.issn.1008-0384.2020.10.003
Abstract:
Objective Tolerance to low-temperature stress of seedlings of 3 Coffea varieties was evaluated using photosynthetic as well as chlorophyll fluorescence indices for an improved prediction on cold-resistance of the plants for breeding and new cultivar introduction. Method Seedlings of 3 varieties of coffee cultivars were treated under 8 ℃ for 0, 24, 48 or 72 h. Effects of the low-temp stress on chlorophyll (Chl), gas exchange indices, and Chl fluorescence measurements of the leaves were monitored. Tolerance of the seedlings to low-temp treatments was evaluated using the membership function method. Result (1) The prolonged low-temp stress caused Chl to initially increase in Coffea liberica and C. arabica seedlings and declined later but decrease continuously in C. canephora. (2) The decreased Pn in seedlings was caused by non-stomatal factors. Pn, Tr, Gs, WUE, and Ls did not significantly differ among the treatments on 3 varieties under low-temp stress but did significantly between the treatments and control. (3) The total initial fluorescence (Fo) on the 3 varieties increased indicating the occurrence of significant damage to PSH. The non-photochemical quenching coefficient (qN) had a firstly-increase-then-decline pattern with the larger decreases on the maximum photochemical efficiency (Fv/Fm), photochemical quenching coefficient (qP), apparent quantum transfer rate (ETR), and actual photochemical quantum yield (ΦPSII) of PSII in C. liberica reflecting a greater damaging effect on its leaves than in the other two varieties. According to the analysis by the membership function method, C. arabica seedlings was most cold tolerant among the three varieties. Conclusion By using the photosynthetic and fluorescence indices on coffee seedlings in combination, the membership function method could accurately determine the low-temp tolerance of Coffea cultivars for breeding and/or new variety selection.
2020, 35(10): 1071-1077.
doi: 10.19303/j.issn.1008-0384.2020.10.004
Abstract:
Objective Linalool synthase gene, LIS, of Dendrobium officinale was cloned. Expression patterns of the gene in flower, leaf, stem, and root at flowering stage as well as those in leaf induced by methyl jasmonate (MeJA) were determined to help decipher the monoterpene metabolism mechanism involved. Method Full-length cDNA of D. officinale LIS (DoLIS) was cloned using RACE-PCR and RT-PCR. Physiochemical properties and amino acid homology were analyzed by ProtParam and BLAST P, and phylogenetic tree constructed by MEGA 6.0. Expressions of DoLIS in the flowers, leaves, stems, and roots of D. officinale at flowering stage, as well as those in the MeJA-treated leaves were determined by quantitative real time PCR. Result The full-length of DoLIS was 2 844 bp with a 2 538 bp ORF encoding 845 amino acids. The protein had a molecular weight of 98.298 KD, a theoretical isoelectric point of 7.04, and an instability coefficient of 46.29. An unstable protein, DoLIS contained a conservative domain of Terpene_cyclase_plant_C1. The phylogenetic analysis showed that DoLIS was closely related to Phalaenopsis equestris (XP_02057697) and clustered in the same branch with the (s)-(+)-LIS of other species. The qPCR results on relative expression of DoLIS indicated that the highest level at flowering stage was found in the leaves. The MeJA induction produced the peak DoLIS expression, which was 3.88-fold of the original, in 5h after the treatment. Conclusion This study cloned the full-length cDNA of DoLIS and discovered the relative expression of the gene to be significantly higher in the leaves than the flowers, stems or roots of a D. officinale plant at the flowering stage. In addition, the expression could be upregulated by MeJA induction.
2020, 35(10): 1078-1085.
doi: 10.19303/j.issn.1008-0384.2020.10.005
Abstract:
Objective To clone MaAQP1 from a drought stressed banana plant using a constructed bait vector, and establish a cDNA library of the transformed drought-resistance gene from single-hybrids yeast cells. Method The promoter of MaAQP1 from a banana plant (Musa acuminat L. AAA group cv. Brazilian) under draught-stress was constructed on the pHIS2 plasmid as the bait to be transformed into yeast cells for the gene cloning. A cDNA library of MaAQP1 in the yeast was subsequently established for the study. Result The MaAQP1 bait vector was successfully constructed. The sequence of the 1 362 bp promoter was cloned and analyzed to show 72 cis-acting TATA-box and CAAT-box core elements as well as elements of MYB, MYC, ERE, and MeJA as well as those of ABA, light, and meristem responses, etc. A drought-resistance cDNA library of 1.25×107 CFU in capacity with an average insert size of about 1 200 bp was established. Conclusion The results provided a basis for screening transcription factors of the cloned MaAQP1 in the yeast single-hybrids to decipher the mechanism of MaAQP1 in response to drought for improving the stress resistance of plants.
2020, 35(10): 1086-1092.
doi: 10.19303/j.issn.1008-0384.2020.10.006
Abstract:
Objective Effects of bagging with paper pouches of different light-transmitting property on fruit color and carotenoids composition of red-flesh Banjintao peaches were investigated. Method Pouches made of yellow-colored, monolayer paper providing 50% light-transmittance and those laminated with a black interior layer to block the sunlight transmission were used to bag the fruits on the peach trees starting 40 d after full bloom. For control, no bagging was applied on the fruits (CK). Chromatic aberration and carotenoid compositions of the peach sarcocarp were measured at 71, 82, 90, and 95 d after full bloom. Result The bagging with 50% light-transmitting pouches on the peaches increased Chromatism B of the sarcocarp initially and followed by a decline, did not affect Chromatism C or H, and decreased Chromatism A 82 d after full bloom. The 2-layer pouches, which allowed no light exposure for the fruits, induced no effect on Chromatism A and C, while reduced Chromatism B and H on the ripened peaches. On the other hand, Chromatism L of the sarcocarp rose upon ripening with or without the bagging. The treatments exerted no significant effect on the bagged peaches on the total carotenoids, β-cryptoxanthin or α-carotene in the sarcocarp either. But, as the fruit was ripening, the bagging caused a reduction in the sarcocarp on β-carotene and significantly increased zeaxanthins under 50% light-transmission, as well as, on xanthophylls when the fruits were not exposed to sunlight. Conclusion In field practice, it was possible to use 50% light-transmitting pouches 40d after full bloom to bag the fruits on Banjintao peach trees to encourage the production of zeaxanthins, or to apply the 2-layer, no-light-transmission pouches to boost the content of xanthophylls in the sarcocarp.
2020, 35(10): 1093-1100.
doi: 10.19303/j.issn.1008-0384.2020.10.007
Abstract:
Objective Physiological responses and cold resistance of Crassulaceae plants under low-temp stress were studied to facilitate selection of germplasms for new variety breeding and cultivation. Method Eight physiological indicators were employed to gage the cold tolerance of 4 varieties of Crassulaceae under the temperature at 9, 6, 3, 0 or −3 ℃. A mathematical model that combined the principal component analysis and the membership function method was formulated for the evaluation, which was subsequently verified by testing the recovery of normal plant growth. Result Crassulaceae plants of different varieties differed significantly in their physiological reactions to the low-temp stress. In general, MDA and Pro contents of the plants increased with decreasing temperature, but soluble sugar, water, and photosynthetic pigment varied among the 4 varieties. Under −3 ℃, Crassula Campfire responded with the greatest increases on relative water content and MDA release, C. oblique Gollum with a mostly stabilized photosynthetic pigment, and Sedum lucidum Obesum with the fastest soluble sugar and Pro accumulations. The 8 physiological indicators were clustered into two principal components that showed a biologically significant cumulative contribution rate of 90.59%. The cold resistance of the varieties was ranked as S. lucidum Obesum＞x Sedeveria Blue Elf＞C. oblique Gollum＞C. Campfire, which agreed with the result obtained by the plant growth recovery test. Conclusion S. lucidum Obesum had a survival rate of 85.5% under −3 ℃ and grew well with stable morphological characteristics after the cold stress treatment. In contrast, C. Campfire was limited in adapting to low temperatures and survived at a rate of merely 25.5% under the same condition.
2020, 35(10): 1101-1110.
doi: 10.19303/j.issn.1008-0384.2020.10.008
Abstract:
Objective Physiological races of Magnaporthe grisea, the major pathogen of rice blast disease in Fujian in recent years, and the rice varieties resistant to the infection were studied to understand the fungal distribution and provide a clue for breeding to prevent the disease. Method Microbial samples from the diseased rice in 17 localities in the province were collected from 2017 to 2019. Monospores were isolated and classified by comparing with 7 species with known identifications. From them, 60 distinctive strains were sprayed indoor on 32 local rice varieties to detect the presence of 9 molecular markers of rice blast resistance genes on the inoculated rice plants. Result Using the 7 specimens with known identification and classification for comparison, the ZA group with an occurrence frequency at 39.48% was found to be the dominant physiological race of rice blast. Inoculation of the 60 physiological races on the 32 rice varieties showed an average pathogenicity rate of 23.28%. The relatively low infection rate suggested that most of the local rice were blast resistant to varying degrees. Subsequently, 15 of the rice varieties with broad resistance spectra were identified. Of which, Longliangyouhuazhan and Liangyou 332 exhibited the broadest spectra and were considered suitable for further applications. Conclusion The dominant physiological race of M. grisea appeared to have gradually changed over recent years from ZB and ZC to ZA group in Fujian. The transformation might relate to the large-scale promotion of the Yongyou rice series during the time. Consequently, it would be prudent in selecting rice varieties with a broad-spectrum on blast resistance for promotion. And, prior to introducing a new variety, an understanding of the origin of pathogenic physiological races would be necessary to preclude areas that are susceptible to the spread of the disease for the cultivation.
2020, 35(10): 1111-1118.
doi: 10.19303/j.issn.1008-0384.2020.10.009
Abstract:
Objective Effect of pesticide application on the growth of Tremella fuciformis and recommendation of maximum residue limits (MRLs) on selected pesticides for the snow fungus cultivation were investigated. Method On the fruiting bodies of a major variety of T. fuciformis, Tr21, 10 pesticides of 8 different types were sprayed separately. Residues and metabolites of each pesticides on the harvested snow fungus were analyzed by GC-MS/MS and LC-MS/MS. A risk assessment was carried out to evaluate the potential long-term dietary exposure to human health risk, then MRLs were recommended. Result Growth of Tr21 was inhibited by the conventional applications of prochloraz emulsifiable oil, pyridaben and acetamiprid micro-emulsion (2 000-4 000 mg·L−1) or isoprocarb emulsifiable oil (4 000 mg·L−1). However, when the recommended formulation and method were used, the pesticide applications not only allowed the fungi grow vigorously, but also reduced the residual levels to within the limits for safe consumption. The MRLs of bifenthrin, acetamiprid, abamectin, prochloraz, imidacloprid, isoprocarb, and pyridaben were recommended as 1, 0.7, 0.1, 0.02, 5, 0.1, and 0.01 mg·kg−1, respectively. Those could provide a protection against the chronic dietary risk in the range from 3.07 to 306.92. Conclusion The above mentioned 7 pesticides could be safely applied for T. fuciformis cultivation under the recommended methods. The dietary exposure to pesticides residues on snow fungus could be acceptable if the pesticide residual levels were lower than recommended MRLs.
2020, 35(10): 1119-1130.
doi: 10.19303/j.issn.1008-0384.2020.10.010
Abstract:
Objective Characteristics and seasonal changes of ammonia-oxidizing microorganism (AOM) community in soils under different land uses on Wuyi Mountains were studied. Method Soil specimens of virgin woodland and tea plantations in evergreen broad-leaf forest growing zones at same latitude on Wuyi Mountains in Fujian were collected for Illumina Hiseq high-throughput sequencing to analyze the relative abundance and diversity of AOMs in the region. The data were applied for a correlation analysis with the physiochemical properties of the local soil. Result (1) An abundant resource of AOMs was found in the soils. The microbial species in soil were similar despite varied land uses. The archaea domain of the AOMs included Unclassified Candidatus Nitrososphaera, Unclassified Crenarchaeota, Unclassified Thaumarchaeota, Nitrosopumilus, and others, while the bacteria consisted of Nitrosomonas, Nitrosospira, Unclassified Nitrosomonadaceae and others. At the tea plantations, a unique species, Nitrosovibrio, was found. (2) The relative abundance of AOMs in the region had significantly changed over time and was affected by the seasons. (3) The environmental factors affected the bacteria and the archaea of the AOM community in soil differently. The major influential factors also varied in accordance with seasons; and, potassium in soil affected mainly the bacteria, while ammonium nitrogen the archaea. Conclusion Regular seasonal changes on the AOM community in the soil of evergreen broad-leaf forest zone on Wuyi Mountains were observed. Although the microbial species in the soils did not differ significantly by the land use, their relative abundance varied significantly seasonally and by the land utilization.
2020, 35(10): 1131-1137.
doi: 10.19303/j.issn.1008-0384.2020.10.011
Abstract:
Objective Rule of H2S played on the growth of barley seedlings under Cd-stress was investigated to understand the mechanism and means to improve Cd-tolerance of the plants. Method Treatment groups of Cd, NaHS, HA, Cd+NaHS, and Cd+HA with addition of CdCl2 at 0.2 mmol·L−1, exogenous H2S donor NaHS at 50 μmol·L−1 or H2S synthesis inhibitor hydroxylamine HA at 1 mmol·L−1 in medium were made for an indoor hydroponic barley seedling growth experiment. Effects of the treatments on the growth, leaf damage, osmotic regulator, antioxidant enzyme activity, chlorophyll content, and photosynthetic characteristics of the seedlings of Jinke 571 barley were monitored. Result The H2S addition in the hydroponic medium lessened the growth inhibition and leaf damage on the seedlings induced by Cd-stress. It increased the root length, plant height, and seedling biomass; decreased the leaf relative conductivity, malondialdehyde (MDA) and superoxide anion (O2−) contents; enhanced the photosynthesis with increased chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate; and, improved the resistance to the external adversity imposed on them with increased osmotic regulatory substances (e.g., soluble sugar, proline, soluble protein) and antioxidant enzymatic activities on SOD, POD, CAT. Conclusion Addition of H2S donor NaHS at 50 μmol·L−1 in hydroponic medium partially alleviated the ill-effects of Cd-stress on the barley seedlings suggesting its potential field application for barley farming to combat the pollution.
2020, 35(10): 1138-1144.
doi: 10.19303/j.issn.1008-0384.2020.10.012
Abstract:
Objective Possibility of growing sesame(Sesamum indicum) and sunflower(Helianthus annuus) crops on the soil polluted by Pb2+, Cd2+, Cr6+, and/or Cu2+ was explored in a hydroponic experimentation in laboratory with the respects of seed germination and seedling growth of the plants. Method Seeds of sesame and sunflower cultivars were planted in hydroponics to examine the effects of heavy metals, Pb2+ (at 0, 5.0, 10.0, 20.0, 50.0, and 80.0 mg·L−1), Cd2+ (at 0, 0.5, 1.0, 5.0, 10.0, and 20.0 mg·L−1), Cr6+ (at 0, 3.0, 5.0, 8.0, 12.0, and 14.0 mg·L−1) and Cu2+ (at 0, 50.0, 100.0, 150.0, 300.0, and 600.0 mg·L−1) on the germination and seedling growth. Result The artificially added heavy metals in the medium decreased the seed germination rates (GR) of both cultivars as the Pb2+, Cd2+, Cr6+, and Cu2+ concentrations increased. The effect was significantly higher on the sesame seeds than the sunflower seeds (P＜0.01). At lower levels of the heavy metal concentrations, the development and morphogenesis of either seeds were significantly affected. However, as the pollutants were increased in the medium (i.e., Pb2+＞80.0 mg·L−1, Cd2+＞20.0 mg·L−1, Cr6+＞14.0 mg·L−1, and Cu2+＞600.0 mg·L−1), normal root or bud formation was inhibited on both cultivars. For the growth of the seedlings, the heavy metals exerted greater reductions with Pb2+ at 5.0-10.0 mg·L−1, Cd2+ at 0.5-20.0 mg·L−1, Cu2+ at 50-300.0 mg·L−1, and Cr6+ at 8.0-12.0 mg·L−1 on the root length of sesame than sunflower plants (P＜0.01), but at 20.0-80.0 mg·L−1 of Pb2+ or 14.0 mg·L−1 of Cr6, the opposite was observed. For the growth of seedling shoots, Pb2+ at 10.0-80.0 mg·L−1, Cd2+ at 5.0 mg·L−1, Cu2+ at 50.0-100.0 mg·L−1 and 600.0 mg·L−1 or Cr6+ at 3.0-8.0 mg·L−1 and 14.0 mg·L−1 inhibited it on sunflower more than on sesame, while the opposite was found with Cd2+ at 0.5-1.0 mg·L−1 or 10.0-20.0 mg·L−1. Conclusion Heavy metals, Pb2+, Cd2+, Cr6+, and/or Cu2+, in a hydroponic medium induced greater germination inhibition effect on the sunflower than the sesame seeds. The growth of roots and buds of sesame seedlings appeared more tolerant to Pb2+ at 20.0-80.0 mg·L−1, Cr6+ at 14.0 mg·L−1, and Cu2+ at 150.0-300.0 mg·L−1 than that of the sunflower counterparts, while the sunflower seedlings were more tolerant to Cd2+ at 0.5-1.0 mg·L−1 and 10.0-20.0 mg·L−1.
2020, 35(10): 1145-1153.
doi: 10.19303/j.issn.1008-0384.2020.10.013
Abstract:
Objective Effects of addition of lactic acid bacteria to the spent substrate of Pleurotus ostreatus cultivation on the fermentation and quality of the feed material for livestock and poultry industry were analyzed. Method Lactic acid bacteria CCZZ1 and HT1 were added alone or in combination (MIX) to the spent culture substrate prior to fermentation. A blank control (CK) was included in the 3-treatment experimentation. Initially, 18 replicates for each testing group were conducted at room temperature. Triplicated analytical data and fermentation process evaluation criteria on the 1st, 3rd, 7th, 15th, 30th, and 60th day were collected for the study. [Result] During the fermentation, the contents of lactic acid, acetic acid, propionic acid, and dry matters increased, while those of hemicellulose, butyric acid, and crude protein declined. And, ammonia nitrogen was significantly lower in MIX than in control (P＜0.05). After fermented for 7 d, the pH of the treatment groups were significantly lower than those of CK (P＜0.05), and reached below 4.2 in 23 d less than it took CK. The acetic acid and dry matter contents in the treatment groups were significantly higher than those in CK (P＜0.05), while lactic acid increased, and crude protein reduced as compared with CK. On the other hand, the contents of ammonia nitrogen, crude ash, soluble carbohydrate, acid washed fiber, neutral water washed fiber, hemicellulose, propionic acid, and butyric acid in the treatment groups did not significantly differ from those in CK. Conclusion The addition of lactic acid bacteria CCZZ1 and HT1 alone or in combination not only improved the quality of the fermented feed made from the spent mushroom culture substrate but also facilitated the fermentation process.
2020, 35(10): 1154-1161.
doi: 10.19303/j.issn.1008-0384.2020.10.014
Abstract:
Objective Fe3O4@SNW-1 was prepared as an adsorbent in the magnetic solid phase extraction (MSPE) to pre-treat samples for HPLC determination on sulfonamides (SAs) in milk. Method A magnetic covalent organic framework (COF) material, Fe3O4@SNW-1, was hydrothermally synthesized to serve as the adsorbent in MSPE for the sample pretreatment. Parameters for the pretreatment, including adsorbent usage, adsorption duration, eluent selection, and elution time that affected the extract recovery, were optimized. HPLC was used to evaluate and determine the validity of the methodology. Result The optimized MSPE applying 2.0 mL ammonia-methanol (5 ∶ 95, V/V) as elution solvent, 60s for desorption, 4.0 mg of Fe3O4@SNW-1 as adsorbent, 120 s for adsorption at pH 6.0 to achieve linearities in the ranges between 10 ng·mL−1 and 100 ng·mL−1 on detecting 5 different SAs with correlation coefficients greater than 0.995. The HPLC detection limit on the SAs was 1.7-2.7 ng·mL−1. The daytime RSDs of 5 extraction replicates on the SAs (50 ng·mL−1 each) were 2.8–4.7%. The recovery rates on the SAs varied from 72.0% to 95.0%. Conclusion The proposed HPLC method with the MSPE sample pretreatment was convenient, rapid, specific, and effective for the determination of trace amounts of SA residues in milk.
2020, 35(10): 1162-1170.
doi: 10.19303/j.issn.1008-0384.2020.10.015
Abstract:
Objective The dissolved components in the brews of Fujian white teas were investigated. Method 4 local white tea products of 2 cultivar varieties and 2 quality grades were brewed by the standard procedures for sensory evaluation on white tea. The components in the 3 series of brewed teas were analyzed. Result (1) After 3 series of brewing the average total dissolved amounts of the components were 9.56 g·hg−1 for polyphenol, 4.78 g·hg−1 for catechin, 4.26 g·hg−1 for soluble sugar, 3.98 g·hg−1 for theabrownine, 3.59 g·hg−1 for thearubigin, 3.26 g·hg−1 for caffeine, 2.38 g·hg−1 for amino acid, 0.45 g·hg−1 for flavone, and 0.12 g·hg−1 for theaflavin, the average total dissolved rates of the components were 78.95% for caffeine, 70.71% for flavone, 66.69% for amino acid, 63.98% for theabrownine, 63.23% for theanine, 61.97% for thearubigin, 55.77% for polyphenol, 53.27% for soluble sugar, 43.31% for EGCG, 40.42% for catechin, and 31.34% for theaflavin. (2) Except for thearubigin and soluble sugar, all the other components decreased in their dissolved amounts and rates from the 1st to the 3rd brewing, among which caffeine,amino acid and flavone showed the highest average dissolved rates of 37.13%,31.54%,29.73% respectively in the 1st brewing. (3) Polyphenol, caffeine, flavone or thearubigin differed significantly (P＜0.05) between its dissolved amounts of 3 series of brewing of the same sample.The dissolved rates of caffeine and amino acid decreased significantly by more than 9% in one more brewing, while the dissolved rates of the components generally did not show regular differences between the varieties and the grades. Conclusion The dissolved amounts and rates of the components tested, except for thearubigin and soluble sugar, declined from the 1st to the 3rd brewing. In 3 consecutive brewing, due to differences in solubility, caffeine, flavone and amino acid rapidly leached, polyphenol and theanine partly dissolved, and less than 50% of catechin, EGCG and ECG in the dry leaf dissolved in 3 brewings.
