Frontiers of Agriculture in China

ISSN 1673-7334

ISSN 1673-744X(Online)

CN 11-5729/S

   Online First

Administered by

Current Issue

, Volume 3 Issue 4 Previous Issue    Next Issue
For Selected: View Abstracts Toggle Thumbnails
Research articles
Establishment of transgenic cotton lines with high efficiency via pollen-tube pathway
Haina ZHANG, Fanghua ZHAO, Yuxin ZHAO, Chengjin GUO, Cundong LI, Kai XIAO
Front. Agric. China. 2009, 3 (4): 359-365.  
https://doi.org/10.1007/s11703-009-0036-8

Abstract   PDF (8835KB)
The transformation method via pollen-tube pathway has great potential roles in crop molecular breeding. In this paper, the effects of genotype, exogenous DNA concentration injected, and the flower positions in plant on cotton genetic transformation mediated by pollen-tube pathway were evaluated. It was found that there were no obvious differences on the boll setting rate and transformation efficiency between the cultivars 33B and 99B. However, the DNA concentrations and the flower positions largely affected the transformation efficiency. The putative transgenic plants derived from boll seeds injected with binary expression vector pCAMBIA3301 DNA were all to be PCR positive. On the other hand, the expression levels of reporter gene Gus varied dramatically, including high, middle, and nontranscripts detected. Both the GUS activity of the transgenic plants and the intensity of histochemical GUS staining in the representative transgenic plants were in accordance to those of the transcripts of reporter gene Gus. The selection of high quality and suitable concentration of exogenous DNA and the injection of the DNA in basal flowers at the middle fruit branches are important factors for improving the cotton transformation efficiency. The transformation method via pollen-tube pathway established in this study has provided an efficient genetic transformation technique in cotton breeding.
References | Related Articles | Metrics
Accumulation and distribution of selenium in some vegetable crops grown in selenate-Se treated clay loam soil
Karaj S. DHILLON, Surjit K. DHILLON,
Front. Agric. China. 2009, 3 (4): 366-373.  
https://doi.org/10.1007/s11703-009-0070-6

Abstract   PDF (156KB)
A greenhouse experiment was conducted to study the accumulation of selenium by some vegetable crops commonly grown in the Indian Punjab. Eleven vegetable crops were raised in an alkaline clay loam soil treated with different levels of selenate-Se, i.e., 0, 1.25, 2.5 and 5.0mg·kg−1 soil. Dry matter yield of both edible and inedible portions of different vegetable crops decreased with increasing Se level in soil except potato (Solanum tuberosum), radish (Raphanus sativus) and cauliflower (Brassica oleracea var. botrytis) which recorded 10%―21% increase in inedible dry matter at 1.25mg·kg−1 Se soil. Application of 5mg·kg−1 selenate-Se soil resulted in complete mortality in the case of radish, turnip (Brassica rapa) and brinjal (Solanum melongena). Some vegetable crops including tomato (Lycopersicum esculentum), cauliflower and pea (Pisum sativum), though, survived the toxic effect at the highest concentration of Se yet did not bear any fruit. Potato and spinach (Spinacea oleracea) proved to be highly tolerant crops. Selenium concentration in the edible as well as inedible portions of all the vegetables increased with an increase in the level of applied Se. Selenium accumulation in the edible portion of vegetable crops in the no-Se control ranged from 2.2 to 4.9mg·kg−1 Se dry weight. At 1.25mg·kg−1 Se soil, the edible portion of radish accumulated the greatest concentration of Se (38mg·kg−1 Se dry weight) with that of onion (Allium cepa) bulb the lowest (9mg·kg−1 Se dry weight). Inedible portions of vegetables accumulated Se 2―5 times more than that absorbed by edible portions. Total Se uptake by edible portions of different vegetables was the greatest at 1.25mg·kg−1 Se soil, ranging from 7 to 485 µg∙pot−1. The results suggest that vegetable crops vary in their sensitivity to the presence of selenate-Se in soil. Vegetative portions were several times richer in Se than other parts of vegetable crops.
References | Related Articles | Metrics
Evaluation of phenotype and genetic diversity of maize landraces from Hubei Province, Southwest China
Kai WEI, Hao ZHANG, Xianfeng XU, Zuxin ZHANG, Hewei DU, Yiqin HUANG,
Front. Agric. China. 2009, 3 (4): 374-382.  
https://doi.org/10.1007/s11703-009-0075-1

Abstract   PDF (141KB)
The intelligent exploitation of maize landraces for maize breeding requires a detailed knowledge of genetic and historical relationships among these populations and an understanding of the partitioning of genetic diversity among populations. In this study, the diversity of 102 maize landraces from Hubei Province was evaluated on the basis of phenotype data (collected over two years) and simple sequence repeat (SSR) data. The results showed that significant differences in important traits were present among the landraces, especially in kernel weight and ear height. The comparison of the yield components of two elite populations, BSSSC9 and Suwan2, with those of landraces indicated that the ear length of 28 landraces, the kernel weight of 35 landraces, the row number per ear of 11 landraces, and the kernel number of 3 landraces were better than those of the two elite populations, implicating that abundant genetic diversity and favorable genes were accumulated within these landraces. Thirty-six SSR markers revealed a total of 179 alleles in 102 landraces, with an average of 4.97 alleles per loci, and 0.4362 polymorphism information content (ranging from 0.3141 to 0.5601). Cluster analysis based on the phenotypic data and SSR data divided the 102 landraces into two or three major groups. Integrating the phenotypic data and SSR diversity, we suggested that abundant genetic variability and specific alleles were contained within the set of landraces. A few landraces (including Batangbai, Bairihui, Dongjingbai, and Huangyumi) with large genetic diversity and specific favorable characteristics could be selected for further research and utilization.
References | Related Articles | Metrics
SRAP marker reveals genetic diversity in tartary buckwheat in China
Yanqin LI, Xiaoling FAN, Tonglin SHI, Quanbin ZHANG, Zongwen ZHANG,
Front. Agric. China. 2009, 3 (4): 383-387.  
https://doi.org/10.1007/s11703-009-0071-5

Abstract   PDF (101KB)
Sequence-related amplified polymorphism (SRAP) marker was employed to analyze genetic diversity of 10 accessions of tartary buckwheat selected from a wide geographical area in China. Of the total 30 primer combinations investigated, 26 could amplify clearly and consistently. They produced a total of 285 fragments, of which 235 (82.5%) were polymorphic bands. Among the 26 primer combinations, five could discriminate all the genotypes used in this study. Based on the molecular data, the genetic similarity coefficients varied from 0.61 to 0.78 and calculated using the NTSYSpc published by Nei and Li (1979). The cluster analysis revealed that the 10 accessions were better to be grouped into two major clusters at a similarity level of 0.69. Moreover, the accessions collected from the same province turned out to be grouped in the same cluster, which indicated some geographical relationships. It also proved that the SRAP marker system was useful in identification and genetic diversity analysis of tartary buckwheat.
References | Related Articles | Metrics
Root distributions in tillage layers and yields of pumpkin and oil sunflower in an intercropping system
Junhua ZHANG, Wei HUANG, Fenglu ZHANG, Lifeng ZHANG,
Front. Agric. China. 2009, 3 (4): 388-396.  
https://doi.org/10.1007/s11703-009-0053-7

Abstract   PDF (1826KB)
Studies on the distribution of roots of pumpkin and oil sunflower in tillage layers and their relations with their above-ground biomass in an intercropping system were conducted by digging roots by layers, combined with DT-Scan and the WinRHIZO root analysis system, during harvest in the plateau of the northwest part of Hebei Province, China. The results of analyzing roots and ratio of root to shoot showed that oil sunflower had an advantage over pumpkin in the intercropping system. Root dry weight of oil sunflower in treatments of pumpkin intercropped with one row (J1) and two rows of oil sunflower (J2) was, respectively, 2.5 and 1.83 times that of sole oil sunflower cropping (YD); the root length was 1.25 and 1.27 times, the root surface area was 1.20 and 1.14 times, and the root volume was 1.53 and 1.44 times that of sole oil sunflower cropping, respectively. As oil sunflower was dominant in absorbing nutrition and water in the intercropping system, the growth and development of pumpkin were restricted. Root dry weight of pumpkin in sole cropping (ND) was 1.5 and 1.9 times as much as that in treatments of J1 and J2 in a 0- to 40-cm soil layer, with the root length, surface area, and volume being 1.02 and 1.13, 1.04 and 1.26, 1.22 and 1.22 times that of treatments of J1 and J2, respectively. The root and the above-ground biomass of intercropped pumpkin with oil sunflower were lower than those in sole pumpkin cropping, while those of oil sunflower were the opposite. Root density of pumpkin decreased in power function with the soil layers, while it decreased by exponential function in oil sunflower. It was concluded that sole pumpkin cropping rather than pumpkin-oil sunflower intercropping is the suitable planting regimen in this area.
References | Related Articles | Metrics
Cytological effects of different mutagens in soybean [ Glycine max (L.) Merrill]
Mudasir Hafiz KHAN, Sunil Dutt TYAGI,
Front. Agric. China. 2009, 3 (4): 397-401.  
https://doi.org/10.1007/s11703-009-0065-3

Abstract   PDF (4546KB)
The effect of gamma rays, ethyl methane sulphonate, and their three combinations on various cytological parameters in M1 generation was studied in two soybean cultivars, Pusa-16 and PK-1042. Combined treatments exhibited high meiotic abnormalities in Pusa-16 as compared with the individual treatments of ethyl methane sulphonate and gamma rays. In PK-1042 the highest frequency of meiotic abnormalities was exhibited by gamma rays, while in Pusa-16 the frequencies of univalents were high as compared with other meiotic abnormalities. Fragments/bridges, laggards, ring and rod bivalents were other types of meiotic abnormalities that were noticed in both the cultivars. The frequencies of irregular cells in the two cultivars were high in combined treatments followed by ethyl methane sulphonate and gamma rays. The highest percentage of pollen sterility was exhibited by the combined treatments and the lowest was exhibited by gamma rays. In Pusa-16, the increase in doses of gamma rays and ethyl methane sulphonate increased the pollen sterility percentage, while in the combined treatments, the increase was noticed up to the intermediate dose and then gradually decreased at higher doses. On the other hand, in PK-1042 the increase in ethyl methane sulphonate dose increased sterility percentage, while no definite trend was noticed in gamma rays and combined treatments.
References | Related Articles | Metrics
Characterization of promoter expression patterns of OsNrt2.1 , a nitrate transporter gene of rice ( Oryza sativa L.)
Zhenlong XU, Chengsheng MENG, Chengjin GUO, Hairong XU, Kai XIAO, Yanzhen ZHOU, Wenjing LU, Juntao GU,
Front. Agric. China. 2009, 3 (4): 402-412.  
https://doi.org/10.1007/s11703-009-0047-5

Abstract   PDF (8991KB)
Nitrate is one form of available nitrogen nutrient, and its uptake and transport in plants was mediated by nitrate transporters. It is important to elucidate the transcription mechanism of nitrate genes at the molecular level. In this study, the promoter of OsNrt2.1, a rice nitrate transporter gene previously cloned in our group, has been characterized. Based on PLACE online analysis, some important cis-regulatory elements were identified. Under the control of the full length fragment of OsNrt2.1 promoter (P-2047), the expression of the reporter gene Gus was up-regulated when exposed to low nitrogen. Promoter deletion analysis indicated that the low nitrate responding elements located at position −524 to −1 and −980 to −525. Several cis-regulatory elements such as CIACADIANLELHC and −10 promoter element, located at positions of −524 to −1, −980 to −525, −1487 to −981, and −2047 to −1488 in P-2047, were possibly involved in the circadian regulation of the OsNrt2.1 gene. Sugar signaling and sugar-responsive motif WBOXHVISO1 and TATCCAOSAMY were also identified in P-2047, suggesting that the exogenous sugar variations resulted from the photosynthesis changes were related to the up-regulated expression of Gus during the day time. It is guessed that the expression pattern of Gus with low-nitrate inducible and diurnal rhythm was partly, at least, via the mediation of Ca2+ signal transduction pathway. Owing to its regulation pattern with low nitrate inducible and typical circadian pattern, the OsNrt2.1 promoter maybe has a potential role in the generation of transgenic crop varieties with high-N use efficiency in the future.
References | Related Articles | Metrics
Cloning and expression analysis of a ribosomal protein S7 in wheat under the stress of Puccinia triticina
Aihua YAN, Yunwei ZHANG, Lifeng ZHANG, Dongmei WANG,
Front. Agric. China. 2009, 3 (4): 413-418.  
https://doi.org/10.1007/s11703-009-0077-z

Abstract   PDF (1379KB)
A gene was isolated from the suppression subtractive hybridization (SSH) cDNA library of wheat by reverse northern blotting. Full length cDNA was obtained by RACE technique, and the result showed that all sequences consisted of 471 bp and encoded 157 amino acid. Subsequently, the gene expression was enhanced according to quantity real-time PCR (qRT-PCR) in response to leaf rust stress as the time over. All the results above suggested that the gene might play important role in wheat hypersensitive response (HR) to leaf rust.
References | Related Articles | Metrics
Strawberry FaEtr2 gene RNAi expression vector construction and genetic transformation
Chunli SONG, Junlian MA, Xia TANG, Zide ZHANG, Zhixia HOU,
Front. Agric. China. 2009, 3 (4): 419-424.  
https://doi.org/10.1007/s11703-009-0057-3

Abstract   PDF (189KB)
The short hairpin RNA (shRNA) expression vector of the FaEtr2 gene was constructed by inserting the sense fragment into the constructed antisense vector of FaEtr2 (pBI121-Anti-Etr2) in sense orientation. The constructed RNA interference (RNAi) expression vector was transformed into Agrobacterium fumefeciens LBA4404 and used to infect strawberry leaves. Using in vitro plantlet leaves as explants, the transformation conditions of All-Star strawberry were studied systemically. The results showed that infecting the leaves with A. fumefeciens resuspension liquid of OD600 = 1.0 by pre-culturing for 3 d, co-culturing for 3 d, infecting for 10 min, and adding acetosyringone (AS) 50―100 µmol·L−1 was suitable for genetic transformation of All-Star strawberry. Seven lines of transgenic plants were preliminarily identified by PCR and β-glucurondiase (GUS) histochemical staining.
References | Related Articles | Metrics
Establishment and application of bioassay method for screening fungicides against cucumber powdery mildew
Hongmin REN, Yanan WANG, Keqiang CAO, Jianjian WEI,
Front. Agric. China. 2009, 3 (4): 425-430.  
https://doi.org/10.1007/s11703-009-0066-2

Abstract   PDF (8118KB)
Sphaerotheca fuliginea Poll., a pathogen causing powdery mildew in cucumber, was used as a target for establishing a bioassay method for screening fungicides. Different cucumber varieties, seedling ages, spore culturing times, and inoculation concentrations were tested. The results showed that a highly susceptible variety “Xinchangchunmici” was a suitable cultivar for bioassay test, with the appropriate seedling age of 5―10 d, the spore culturing-time of 10―15 d and the spore concentration of 30―40 spores per field of vision (10 × 10 times under microscope) in the suspension. Cotyledon-spraying method, and leaf-disc method were compared for bioassay and Trypan Blue staining method was used for detecting thedevelopment of S. fuliginea on the leaf surface. Based on the bioassay system established above, the protective effect of chrysophanol on the development of S. fuliginea was evaluated using cotyledon-spraying method. The results showed that chrysophanol reduced the disease index effectively and the protective EC50 value was 33.36 μg·mL−1.
References | Related Articles | Metrics
Evaluation of two-dimensional gel electrophoresis-based technology on plant calmodulin isoforms
Chunyan HOU, Aihua YAN, Jie ZHANG, Hui ZHOU, Shuchao LV, Dongmei WANG,
Front. Agric. China. 2009, 3 (4): 431-434.  
https://doi.org/10.1007/s11703-009-0072-4

Abstract   PDF (1523KB)
The two-dimensional gel electrophoresis-based technique is commonly used in protein analysis and identification. Though this technique is powerful, mature and sensitive there still remain some questions regarding its ability to characterize different types of proteomes. Different calmodulin isoforms play different roles in response to varying external stimulant signals during plant development, but their advanced structures are too small to be distinguished and purified at protein level. In this paper, a two-dimensional gel electrophoresis-based technology was investigated to identify different calmodulin isoforms, which will lay a foundation for subsequent researches.
References | Related Articles | Metrics
A review on starch changes in tobacco leaves during flue-curing
Zhaopeng SONG, Tongshuai LI, Changrong GONG,
Front. Agric. China. 2009, 3 (4): 435-439.  
https://doi.org/10.1007/s11703-009-0076-0

Abstract   PDF (78KB)
This article discusses a range of studies on starch changes in tobacco leaves during flue-curing. Important effects resulting from using different flue-curing equipment and techniques on starch content are presented. It concludes that future researches should be focused on the structure and physico-chemical properties of tobacco starch during the curing process.
References | Related Articles | Metrics
Effects of human sex hormones and gonadotropins on the development of worker bee larvae ( Apis mellifera L.)
Bin ZHOU, Ke ZHANG, Jiatong DING, Manhong YE, Yawen WU,
Front. Agric. China. 2009, 3 (4): 440-445.  
https://doi.org/10.1007/s11703-009-0074-2

Abstract   PDF (240KB)
Worker bee larvae of Apis mellifera L. were fed artificially in an incubator under controlled temperature and relative humidity conditions. Our results showed that (35.5±0.1)°C with a relative humidity of (85±5)% was suitable for the growth of worker bee larvae. A gradually increasing content of pollen and honey, accompanied by decreasing the content of royal jelly in diet, met their fundamental needs. With environmental and nutritional needs basically met, larvae got a similar growth rate to that under natural conditions. Four kinds of human hormones, i.e., estradiol, testosterone, follicular stimulating hormone, and luteinizing hormone, were added into the daily diets of worker bee larvae at different concentrations. Their growth curves were perfectly fitted by binomial fitting complex models. Effects of a single hormone and the combinations of different hormones with a follicular stimulating hormone on the development of worker bee larvae were evaluated. Our results indicated that the development of worker bee larvae at early stage was affected greatly by exogenous hormones. Larvae of 65–89h old were particularly sensitive to the effects of sexual and gonadotropic hormones, and interactions between different hormones were detected.
References | Related Articles | Metrics
Comparative study on antibiogram of Vibrio spp. isolated from diseased postlarval and marketable-sized white leg shrimp ( Litopenaeus vannamei )
Seong Wei LEE, Musa NAJIAH, Wee WENDY, Musa NADIRAH,
Front. Agric. China. 2009, 3 (4): 446-451.  
https://doi.org/10.1007/s11703-009-0068-0

Abstract   PDF (136KB)
This paper compared antibiotic sensitivity between Vibrio spp. isolated from diseased postlarval and marketable-sized white leg shrimp (Litopenaeus vannamei). Recently, white leg shrimp become target species of shrimp culture among shrimp farmers in Malaysia to replace tiger shrimp (Penaeus monodon) culture. However, the baseline information on antibiogram of pathogenic bacteria especially Vibrio spp., the causative agent of vibriosis in white leg shrimp culture is not well established. Therefore, this study was conducted to reveal the antibiogram of Vibrio spp. isolated from diseased postlarval and marketable-sized white leg shrimp. The information gained from this study is useful for shrimp farmers in selecting appropriate antibiotic during disease outbreak. Antibiogram of present bacterial isolates was determined through disk diffusion method against 21 antibiotics (oxolinic acid 2µg, ampicillin 10µg, erythromycin 15µg, furazolidone 15µg, lincomycin 15µg, oleandomycin 15µg, amoxicillin 25µg, colistin sulphate 25µg, sulphamethoxazole 25µg, chloramphenicol 30µg, doxycycline 30µg, florfenicol 30µg, flumequine 30µg, kanamycin 30µg, nalidixic acid 30µg, novobiocin 30µg, oxytetracycline 30µg, tetracycline 30µg, nitrofurantoin 50µg, fosfomycin 50µg, and spiramycin 100µg). A total of 47 Vibrio spp. isolates (Vibrio parahaemolyticus, 24, and V. alginolyticus, 23) from postlarval white leg shrimp and 49 Vibrio spp. isolates (Vibrio parahaemolyticus, 13, Vibrio
References | Related Articles | Metrics
Effects of Echinacea purpurea extract on the immunological response to infectious bursal disease vaccine in broilers
Aituan MA, Wanyu SHI, Xiaofei NIU, Meng WANG, Xiuhui ZHONG,
Front. Agric. China. 2009, 3 (4): 452-456.  
https://doi.org/10.1007/s11703-009-0039-5

Abstract   PDF (84KB)
Echinacea purpurea is among the most widely used herbal medicines throughout Europe and North America for the prevention or treatment of infectious diseases. However, there have been few reports on the effect of the herb in chickens. In order to investigate the immunomodulatory effect of Echinacea purpurea in fowls, 150 seven-day-old broilers were randomly divided into five groups (30 in each group). Birds in Groups A, B, and C were orally given Echinacea purpurea extract once a day at low (0.1g, Group A), medium (0.5g, Group B), and high (1g, Group C) doses for seven days, while Group D and Group E, assigned as control Group I and control Group II, respectively, were given distilled water in the same amount as Groups A, B, and C. Broilers in Groups A, B, C, and D were normally immunized with infectious bursal disease (IBD) vaccine at 14-day-old, whereas Group E was neither treated with Echinacea purpurea extract nor vaccinated. Results indicated that antibody titers were higher (P<0.01) in the three Echinacea purpurea extract treated groups (Groups A, B, and C) compared with Group D on days 21, 28, 35, and 42 after treatment. The antibody titer raised more strikingly in groups treated with higher doses of Echinacea purpurea extract (0.5g and 1g) than lower dose (0.1g). The IL-2 level in peripheral blood was significantly higher in Groups B and C compared with Group D (P<0.01 on day 21 and P<0.05 on days 28 and 35). No significant difference was observed between Group A and Group D. The TNF-α content in Group B was significantly higher than that of Group D (P<0.01 on day 21 and day 28, P<0.05 on day 35). Birds in Group C also showed a higher TNF-α content than Group D (P<0.05 at the three measuring dates). These results indicated that Echinacea purpurea extract significantly enhanced IL-2 and TNF-α production and antibody titers to the IBD vaccine. The Echinacea purpurea extract was also found to increase the feed conversion ratio.
References | Related Articles | Metrics
Construction of a variable regions gene library of antibody against Eimeria acervulian merozoite of chicken
Yuelan ZHAO, Lei ZHANG, Li GUO, Yongzhan BAO, Jianhua QIN,
Front. Agric. China. 2009, 3 (4): 457-465.  
https://doi.org/10.1007/s11703-009-0067-1

Abstract   PDF (380KB)
Antigens of Eimeria acervulina merozoites were prepared and purified. BALB/C mice were inoculated with the merozoite soluble antigens of E. acervulina. The total RNA was extracted from the spleen cells of the immunized BALB/C mice. The first chains of cDNA were synthesized by reverse transcription with Oligo (dT)15 Primer, using extracted RNA as a template. The variable regions of heavy chain (VH) and light chain (VL) genes were amplified by PCR with gene-specific primers. The results showed that the genes of amplified VH and VL were about 420 bp and 390 bp, respectively. PCR products were purified by agarose gel DNA purification kit, and then the VH and VL gene libraries were constructed, respectively. The purified products were cloned into PGM-T vectors. The cloned plasmids were transformed into Escherichia coli TOP10. The colonies were selected on ampicillin-containing agar plates and the plasmids were isolated from several independent clones. The selected colonies were sequenced using Sanger’s dideoxy sequencing method. Nucleotide sequences of the VH and VL genes were compared with the published VH and VL sequences from the BALB/C mice. The sequences were confirmed with mouse antibodies. As expected, the sequence differences between VH/VL and the corresponding germline genes were identified and predominantly localized in complementary determining regions. The sequence analysis results of partial clones indicated that the constructed gene libraries of VL/VH had a good diversity.
References | Related Articles | Metrics
Preparation and physicochemical property of chicken yolk immunoglobulin (IgY) against porcine transmissible gastroenteritis virus (TGEV)
Jinghui FAN, Yuzhu ZUO, Tanqing LI, Xiaobo ZHANG,
Front. Agric. China. 2009, 3 (4): 466-470.  
https://doi.org/10.1007/s11703-009-0054-6

Abstract   PDF (109KB)
Oral administration of immunoglobulin prepared from the egg yolk of hens immunized with porcine transmissible gastroenteritis virus (TGEV) has been demonstrated to reduce piglets mortality significantly in our previous studies. In the present study, we investigated the stability of chicken yolk immunoglobulin (IgY) specific to TGEV by measuring the remaining activity by ELISA. The results showed that the IgY was stable between pH 4 and pH 11. In the incubation with pepsin at pH 4 and pH 6, about 90% and 100% of the IgY activity remained, respectively. IgY activity could remain approximately 80% at 60°C for 30 min, suggesting that pasteurization can be applied to sterilizing the product. The stability of IgY at 25ºC and freezing-thawing treatment indicated that the IgY was easy to be conserved. These results highlight the attractive potential application of IgY as the antibodies of oral administration for treatment of TGEV infections.
References | Related Articles | Metrics
Nutrition and feed strategies for sustainable swine production in China
Daiwen CHEN,
Front. Agric. China. 2009, 3 (4): 471-477.  
https://doi.org/10.1007/s11703-009-0059-1

Abstract   PDF (85KB)
China is the largest swine producer in the world. Although the China swine industry has made great progress in the past, it faces many problems according to the requirement of sustainability. This article summarizes the current situation and problems of the swine industry in China and proposes nutrition and feed strategies for the sustainable development of swine production with emphasis on available practical approaches and future research focuses.
References | Related Articles | Metrics
Strategies for enhancing DNA vaccine potency by targeting antigen-presenting cells
Xingxing WANG, Fei ZHONG, Nan LI, Dongmei HAN, Sumin PAN, Xiujin LI,
Front. Agric. China. 2009, 3 (4): 478-485.  
https://doi.org/10.1007/s11703-009-0073-3

Abstract   PDF (122KB)
The potency of DNA vaccines to stimulate the immune response, especially the T-cell immune response against viral infections and tumors, depends mainly on the ability of antigen-presenting cells to process and present DNA-encoded antigens. Targeting the specific antigen to antigen-presenting cells is believed to be a crucial step for eliciting the T-cell response. Many strategies for enhancing DNA vaccine potency by targeting antigen-presenting cells have been developed. In this article, we generally introduce a T cell immune system and reviewe some strategies that recently develop for enhancing DNA vaccine potency.
References | Related Articles | Metrics
A poplar chimera with stable differentiation regulation
Jun ZHANG, Jinmao WANG, Haiyong LIANG, Minsheng YANG,
Front. Agric. China. 2009, 3 (4): 486-492.  
https://doi.org/10.1007/s11703-009-0069-z

Abstract   PDF (15588KB)
Populus shenzhou, a chimera, is divided into three types: A, B, and C. Among them, Type B is the chimera of Type A and Type C. Type B of P. shenzhou, as a progenitive material was cut and differentiated stably into Type A, Type B, and Type C, at an average differentiation rate of approximately 79.6%, 18.3%, and 2.2%, respectively. The studies on SSR identification of P. shenzhou showed that all tissues, including the bud, leafstalk, leaf nervation, phloem, and xylem, were a chimera. There were two kinds of color roots of the three types. The rufous roots were identified as Type A tissue and the yellow roots as Type C tissue by the SSR molecular markers.
References | Related Articles | Metrics
20 articles