Sep 2011, Volume 5 Issue 3
    

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  • RESEARCH ARTICLE
    Chengjin GUO, Jincai LI, Wensuo CHANG, Lijun ZHANG, Xirong CUI, Shuwen LI, Kai XIAO

    A complete set of chromosome substitution lines with genetic background of Chinese Spring (CS) were used to determine the effects of each chromosome on utilization efficiencies of nitrogen, phosphorus, and potassium in wheat (Triticum aestivum L.). In each line, only one pair of chromosomes in CS genome was substituted by the corresponding one of donor Synthetic 6x. Under normal growth conditions supplied with enough inorganic nutrients, the dry mass per plant and the utilization efficiencies of nitrogen (N), phosphorus (P), and potassium (K) in plants varied largely among CS, Synthetic 6x, and the chromosome substitution lines (1A–7A, 1B–7B, and 1D–7D). Of these, 1A substituted by the chromosome 1A of Synthetic 6x (other lines are the same as 1A hereafter) had the highest plant dry mass and the accumulative amount of N and K, and 1B behaved to have the highest plant accumulative P amount. 1D and 4D had the lowest accumulative P amount and plant dry mass, respectively. 4B showed the lowest plant accumulative N and K. Thus, chromosome 1A of Synthetic 6x contains major genes endowing plant capacities of higher dry mass, accumulative N and K, whereas chromosome 1B of Synthetic 6x carries major genes improving plant accumulative P capacities. The lines, together with CS and the donor, could be classified into three groups including high-efficiency, mid-efficiency, and low-efficiency based on plant dry mass. Regression analysis suggested that there are significantly positive correlations between plant dry mass and the accumulated amount of N, P, and K. Further, there are positively significant correlations among the plant accumulative N amount and some plant traits and physiological parameters, as well as positively significant correlations between the accumulative amount of P and K and the photosynthetic rate (Pn).

  • RESEARCH ARTICLE
    Muhammad IQBAL, Mueen Alam KHAN

    Cotton growers face a problem of low cotton yield in late planting (after sunflower and maize). The objective of our study was to determine the effects of planting date, plant spacing (plant density), and genotypes on seed cotton yield and its components, ginning outturn (GOT%), and fiber quality traits (fiber length and fiber fineness). Five planting dates (May 1, May 15, May 30, June 15, and June 30), three plant spacings (15, 30, and 45 cm), and three cotton genotypes (CRS-6070, CRS-738, and CIM-496) were evaluated for seed cotton yield with its components and fiber quality traits. The results showed that monopodial branches/plant, sympodial branches/plant, number of bolls/plant, and seed cotton yield differed significantly among different planting dates, plant spacing, and genotypes. While the boll weight was significantly different among genotypes only. GOT%, fiber length, and fiber fineness were different significantly among planting time and cotton genotypes, which were not significantly affected by plant spacing. Cotton grown in early planting dates had higher seed cotton yield (4874 and 4653 kg/hm2) at the highest plant spacing (45 cm). While late sown cotton (June 15 onward) gave higher seed cotton yields (2068 and 1889 kg/hm2) at the lowest plant spacing (15 cm). GOT%, fiber length, and fiber fineness improved significantly in late planting and not affected from plant spacing. From our present study, it is concluded that high seed cotton yield can be achieved at high plant spacing in early planting while at low plant spacing in late planting.

  • RESEARCH ARTICLE
    Xinyan WEI, Lifeng LIU, Shunli CUI, Huanying CHEN, Jingjing ZHANG

    More molecular markers for potential use in peanut genetic research were developed. A total of 92403 EST sequences of peanut (Arachis) in the NCBI database were downloaded and analyzed. 2594 SSRs distributed in 2267 non-redundant EST sequences were detected, with tri-nucleotide motif (65.54%) as the most abundant motif type followed by di-nucleotide motif (28.10%). Among the 92 repeat types, the top eight motif types were AG/TC (20.1%), AAG/TTC (11.8%), AAT/TTA (10.1%), AGG/TCC (6.6%), AGA/TCT (6.3%), AT/TA (5.9%), ACT/TGA (3.8%), and ATG/TAC (3.7%) with higher frequency. A total of 237 primer pairs were successfully designed based on the 2267 SSR-ESTs using DNA star software.

  • RESEARCH ARTICLE
    Xirong CUI, Yongsheng ZHANG, Fanghua ZHAO, Chengjin GUO, Juntao GU, Wenjing LU, Xiaojuan LI, Kai XIAO

    A transcript-derived fragment (TDF) showing up-regulated expression under low Pi stress and being identical to an uncharacterized phosphate transporter gene TaPT2-1 was cloned in wheat. TaPT2-1 was 2075 bp in length and encoded a 568-aa polypeptide. Transmembrane prediction analysis suggested that TaPT2-1 had 13 conserved transmembrane domains. TaPT2-1 shared much higher similarities to other four homologs from Arabidopsis thaliana, Solanum tuberosum, Capsicum frutescens, and Solanum melongena. The expression of TaPT2-1 was root specific and low Pi inducible, suggesting that it plays roles in roots and is involved in the Pi acquisition under Pi-starved condition. The promoter region of TaPT2-1 was cloned based on genome walk analysis. Several types of cis-regulatory elements, such as low Pi responding and tissue specific, were identified in TaPT2-1 promoter. The transgenic tobacco plants with the integrated TaPT2-1 promoter GUS were generated, and GUS histochemical staining analysis in the roots and leaves of the transgenic plants was performed. The results of GUS staining in roots and leaves under various Pi supply conditions were in accordance with the TaPT2-1 transcripts detected based on RT-PCR analysis. Taken together, the distinct expression of low Pi-induced and root-specific TaPT2-1 suggested that it could be used as the potential gene resource on generation of elite crop germplasms with high Pi use efficiency in the future.

  • RESEARCH ARTICLE
    Junyi CHEN, Li XU

    H+ is a root secretion that affects P acquisition and P-use efficiency (PUE) under deficient phosphorus in maize. The secretion of H+, difference value of H+ between deficient and normal phosphorus (DH), and relative H+ (RH) as well as the quantitative trait loci (QTLs) associated with these traits were determined for a F2:3 population derived from the cross of two contrasting maize (BoldItalic L.) genotypes, 082 and Ye107. By using composite interval mapping (CIM), a total of 14, 8, and 9 distinct QTLs were identified for H+, DH, and RH, respectively. Most loci of QTLs for traits H+, DH, and RH had different cross environments. It showed that H+ secretion possessed an environment-sensitive and multi-gene nature. The gene × environment interaction was actually reflected by H+ secretion. One region for QTL of trait H+ was detected at the interval of bnlg2228-bnlg100 (bin 1.08) on chromosome 1. Coincident QTLs in the important genomic region reflected the cross phosphorus levels, different cross growth stages, and two different cross environments. The QTL explained 10% to 14% total phenotypic variance of H+. Therefore, the above segment (bnlg2228-bnlg100) (bin 1.08) identified on chromosome 1 may be used in the future for MAS to improve the phosphorus efficiency in maize.

  • REVIEW
    Chengjin GUO, Wensuo CHANG, Juntao GU, Xiaojuan LI, Wenjing LU, Kai XIAO

    Nitrogen (N) is one of the most important inorganic nutrients in plants, and its less availability is an important limiting factor for plant growth in most agricultural systems. In this essay, the following aspects on nitrate transporters (NRT) in plants, such as the uptake features of nitrate(NO3-) mediated by roots, molecular characterization of NRTs, expression patterns and transcription regulation mechanisms of NRT genes, and functions of NRTs in plants, have been reviewed. Further studies of the molecular characterization, expression patterns, transcriptional regulation mechanisms, and functions of plant NRTs will provide a more detailed insight to understand the molecular mechanism of nitrate intake and nitrate transportation in plants. In the meantime, the researches on plant NRTs have potential roles for the improvement of nitrogen use efficiency (NUE) in crop production, as well as for the promotion of sustainable development in the agricultural ecosystem.

  • RESEARCH ARTICLE
    Yuxia DONG, Jihong XING, Jiao JIA, Qiaoyun WENG, Zhimin HAO, Jingao DONG

    Using a PCR homology approach, DNA and cDNA sequences of calcium/calmodulin-dependent protein kinase (CaMK) gene of Botrytis cinerea were obtained. Southern blotting result displayed that CaMK was single copy in the genome of B. cinerea. The cDNA sequence of CaMK revealed an open reading frame of 2190 nucleotides encoding a 730 amino acid protein with predicted molecular weight of 81.8748 kDa. The genomic sequence of CaMK revealed the same ORF interrupted by six introns. Bioinformatics analysis showed that this protein had the distinctive features that characterize CaMK ATP binding region signature and serine/threonine protein kinase active-site signature. Pharmaceutical analysis displayed that the CaMK specific inhibitor, KN-62, could inhibit conidial germination, pathogenicity and herbicidal activity of B. cinerea BC4 strain. It was suggested that CaMK played an important role in regulating conidial germination, pathogenicity and herbicidal activity of B. cinerea.

  • RESEARCH ARTICLE
    Shan LI, Yongsheng ZHANG, Yanan WANG, Chunqi LIANG, Wenchao ZHEN

    Soil-borne diseases of wheat are getting more and more serious in the wheat/maize rotation growing system in northern China. A multifunctional microorganic strain called B1514 was found to have an inhibitory effect against major pathogens of winter wheat soil-borne diseases, have the ability to decompose maize straw, and have the ability to utilize the straw for multiplication. The strain was processed into bacterial agent HAD-1. Field experiments were conducted from 2008 to 2010 to test the control effect of HAD-1 on the major wheat soil-borne diseases, on decomposing ability to maize straw, and on reproductive capacity. Results showed that HAD-1 had significant control effects on sharp eyespot, take-all, and root rot on wheat. The control efficacy at wheat jointing stage was 59.63% to 72.59%, 57.64% to 59.29%, and 54.48% to 63.25%, respectively. The yield loss decreased by 8.67% to 11.70%. The population numbers of the strain B1514 increased 2.68×107–4.83×107 times during the wheat growing season. HAD-1 significantly accelerated the decomposition rate of maize straw in the soil. The decomposition rate increased by 18.7% to 24.3% during wheat growing season.

  • RESEARCH ARTICLE
    Morteza SABERI, Alireza SHAHRIARI, Farajollah TARNIAN, Mohammad JAFARI, Hanie SAFARI

    Seed priming technique has been known to improve germination and seedling emergence under different environment stresses. The objective of this study was to evaluate the effectiveness of seed priming in improving the seed germination and seedling vigor of Agropyron elongatum and Bromus inermis in response to five concentrations of the allelopathic extract of Thymus kotschyanus (0, 5%, 25%, 50% and 75%) under laboratory conditions. Pretreatments included gibberellic acid (250, 500 and 1000 ppm), potassium nitrate (0.1%, 0.2% and 0.3%) and salicylic acid (100, 200 and 300 mg/L). This experiment was carried out as a factorial experiment based on a completely randomized design with four replications. The results showed that seed germination, germination speed and seedling vigor were significantly decreased (P<0.01) by increasing extract concentrations of Thymus kotschyanus allelopathic compounds in unprimed seed (control) compared with primed seeds. Seed priming enhanced germination percentage, germination speed and initial growth. Overall, the results of this study showed that the response of both species to pretreatment of seeds was positive. Therefore, pretreatments of seeds with the aforementioned chemical stimulators before planting can significantly reduce the negative effect of allelopathic compounds in Thymus kotschyanus during the germination stage and contribute to plant establishment by increasing germination speed and growth of embryos.

  • RESEARCH ARTICLE
    Jihong XING, Ye ZHANG, Jing ZHANG, Qiaoyun WENG, Jiao JIA, Jingao DONG

    Identification of genes related to flowering-time in Arabidopsis is very important and meaningful contribution to the flowering process control. One late flowering mutant plant, which exhibits 60-day delay in flowering, was screened from Arabidopsis library of T-DNA insertion. Southern blotting was used to confirm the single copy of exogenetic T-DNA in the genome of the mutant. The flanking sequence of T-DNA insert was obtained by TAIL-PCR and then analyzed by BLAST to confirm that the insertion site locates at the sixth exon of AT2G19520.1 (FVE gene). FVE is considered as a classical flowering time gene in Arabidopsis. It is a component of the autonomous pathway that encodes AtMSI4, which is a putative retinoblastoma-associated protein. The late-flowering mutant is named as fve-4, which is similar to fve-3 of Columbia and allelic with fve-1 and fve-2 of Landsberg erecta. The fve-4 mutant’s delay of flowering was longer than that of fve-3 mutant, whose T-DNA insertion is located at the first exon of FVE gene, suggesting that the sixth exon of FVE gene may play a more important role in the control of floral transition.

  • RESEARCH ARTICLE
    Defang ZENG, Renjie TU

    Traditional seed-coating agents are widely used, and their accumulative toxicity in soil brings a great hazard to natural environment and human health. In this study, a novel cucumber seed-coating agent was prepared from natural polysaccharide, fertilizer and microelement, etc. Results indicated that the agent had an excellent control effect on pests and increased yield by 8.5% to 9.3%, while the material cost was decreased by 16.7% compared with the traditional toxic seed-coating agent. In addition, the toxicity of the novel agent was also lower than that of traditional ones. Therefore, the application of the novel agent for cucumber is an appropriate option for controlling pests and replacing high toxicity ones.

  • RESEARCH ARTICLE
    Jing ZHANG, Jihong XING, Jingao DONG

    The timing of floral transition is tightly controlled by a combination of endogenous and environmental signals. One early flowering mutant plant was screened from Arabidopsis library of T-DNA insertion to accelerate flowering under short-day condition, and a related-gene EFS1 (AT4G36680.1) was isolated and identified as a novel flowering-time gene of Arabidopsis in our preliminary studies. To investigate the function and the specific mechanism of EFS1 in the flower process control, the RNAi expression vector containing EFS1 gene-specific sequences in the sense and antisense orientations was constructed and transferred into Arabidopsis by using the floral-dip method, with 11 transgenic plants obtained through hygromycin B screening and PCR assays. The results showed that the expression level of EFS1 in transgenic lines was significantly lower than that in wild type and efs1 mutant. The flowering time of the efs1 mutant and RNAi transgenic plants was much earlier than that of wild-type plants. This result further verified that the EFS1 gene played an important role in flowering, and its specific mechanisms need further study. These work provided a foundation to further regulatory mechanisms of EFS1 in the control of floral transition.

  • RESEARCH ARTICLE
    Bin ZHAO, Meng ZHENG, Zhiying SUN, Zhiyong LI, Jihong XING, Jingao DONG

    Botrytis cinerea is one of the important phytopathogenic fungi. Cloning of the genes related to their development and pathogenicity is fundamental to the pathogen control. A mutant (BCt160), which produces abnormal conidia and no sclerotia, was identified from Botrytis cinerea mutant library generated by Agrobacterium tumefaciens-mediated transformation (ATMT). Southern blotting analysis showed that one T-DNA insertion occurred in the genome of the mutant. TAIL-PCR (thermal asymmetric interlaced PCR) and bioinformatic analysis indicated that the exogenous T-DNA insertion occurred in the second exon of a putative gene BC1G_12388.1, named as BcDR1 (B. cinerea development-related gene 1). The function analysis of BcDR1 gene showed that the BcDR1 was related to development, morphological differentiation, and pathogenicity of B. cinerea, suggesting that BcDR1 gene was required for the development and pathogenicity of B. cinerea.

  • RESEARCH ARTICLE
    Xinchao WANG, Liang CHEN, Yajun YANG

    Tea is an important economic crop in China. About 2665 accessions of tea germplasm (Camellia spp.) are conserved in the China National Germplasm Tea Repository. However, only a small fraction of the collections have been exhaustively used in tea plant improvement programs. The objective of the present study was to develop a core collection of tea plant to enhance the utilization of genetic resources in improvement programs and simplify their management. For this purpose, based on the cultivated region grouping and phenotypic trait data, a core collection of tea plant was established using logarithm proportion and Ward’s cluster method. Approximately 20% of the accessions were then randomly selected from these distinct groups to form a core collection of 532 accessions. Different statistical methods including comparison of mean using Newman-Keuls test, variance using Levene’s test, and frequency distribution using Chi-square test for the traits validated that the variation present in the initial collection was retained in the core collection. The Shannon-Weaver diversity index for different traits was also similar in the core and initial collection. The phenotypic correlations among different quantitative traits that may be under the control of coadapted gene complexes were also preserved in the core collection. This core collection will play an important role in the utilization of tea germplasms.

  • RESEARCH ARTICLE
    Chaohong ZHANG, Yuan LIU, Mengjun LIU, Decang KONG

    The occurrence of fruit shrink disease in Ziziphus jujuba Mill. ‘Linyilizao’ was investigated from 2006 to 2009 in Cangxian of Hebei Province, Taiyuan, and Taigu of Shanxi Province, and the pathogens were isolated from the diseased fruits sampled from both Cangxian and Taiyuan in 2006 and 2007. The pathogens in leaf, fruit, and shoot collected from Cangxian were isolated from June to October in 2008 at 30-day intervals. The incidence of the disease varied significantly with location and year, and the highest incidence was observed in Cangxian during 2006. Three kinds of key pathogens were isolated from the fruits from July to September, i.e., Alternaria alternata Keissler (mainly in July), Phoma destructiva Plowr. (mainly in September), and Fusicoccum sp., of which A. alternata was the most dominant. In leaves, both A. alternata (much more dominant) and P. destructiva could be isolated throughout June to October, but no Fusicoccum sp. was found. At the white-ripening stage of fruit, the isolation rate of A. alternata was the highest in leaves (36.67%), followed by extension shoot (6.67%) and fruit (1.11%) while that of P. destructiva was the highest in extension shoot (31.11%), followed by fruit (13.33%) and leaf (12.22%), with Fusicoccum sp. isolated only in extension shoot (2.22%). The frequency of isolating two or three kinds of above three pathogens together was very low, with the highest rate (19.30%) found in A. alternata and P. destructiva from leaves in July.

  • RESEARCH ARTICLE
    Xiaona ZHANG, Zide ZHANG, Lei WANG, Zhenliang ZHANG, Jing LI, Congzhi ZHAO

    The postharvest physiology of strawberry was investigated to study the effects of ozone on weight loss rate, ascorbic acid, respiration rate, peroxdase (POD) activity, catalase (CAT) activity, and malondialdehyde (MDA) content during cold storage. The strawberries were treated with ozone of 0 ppm (control), 2 ppm, 4 ppm, and 8 ppm, respectively. The results indicated that the treatment of 4 ppm ozone could inhibited the decrease of ascorbic acid, POD activity, and CAT activity, and reduced weight loss rate and MDA content. The treatment delayed the senescence of strawberry, with a significantly lower respiration rate. Thus, the best concentration of ozone was 4 ppm, and ozone treatment could be a good candidate for maintaining postharvest quality of strawberry and provide a longer storage life.

  • RESEARCH ARTICLE
    Qian WANG, Wei ZHAO, Zhimin HAO, Jingao DONG

    Intracellular signal transduction pathways including MAPK, Ca2+, and cAMP signal transduction pathways play important roles in regulating growth, development, and pathogenesis of phytopathogenic fungi. Protein kinase A (PKA) is a key enzyme in cAMP signaling pathway. The transcription level of the gene encoding catalytic subunit of PKA in Setosphaeria turcica under different culture conditions was analyzed by the semiquantitative RT-PCR method. The expression level of PKA-c gene was the lowest on the medium containing sucrose and starch as the carbon source, and it was distinctly inhibited by Cu2+, but it was independent of nitrogen source. After the addition of different concentrations of sorbitol, it showed the positive correlation between the inhibition affection and concentrations. However, the highest expression was observed in response to NaCl (0.9 mol/L). This research enriched the biological information resource of filamentous fungi and laid a foundation for the functional analysis about signal transduction pathway in phytopathogenic fungi.

  • RESEARCH ARTICLE
    Fuqiang HE, Hongxia WANG, Zhihua ZHANG

    The existence of a long juvenile phase is found seriously to affect the early-stage economic benefits of later mature walnuts (Juglans regia L.). Studies on LFY, a key gene controlling floral transition and flower differentiation, may be helpful in solving the problem. This study reports the identification and characterization of a JrLFY gene from Juglans regia L., a homolog of FLORICAULA/LFY. The gene was isolated from flower buds of precocious walnut cultivar Zhonglin No. 5 by RT-PCR and RACE. The cDNA sequence of JrLFY (GenBank accession no. GU194836) was 1496 bp and contained an ORF of 1158 bp. Its corresponding genomic sequence (GenBank accession no. HQ019159) showed that the JrLFY contained three exons and two introns. The predicted amino acid sequence of the gene consisted of 385 amino acids and had a conserved region in the C-terminal when being aligned with sequences of other LFY homologs. Phylogenetic analysis showed that the LFY protein of walnut was close to those of hickory and chestnut. These studies will lay a foundation for understanding the mechanism of early fruiting and preparation for transfer of the JrLFY as a transgene to later mature walnuts.

  • RESEARCH ARTICLE
    Asit Baran MONDAL, Abdullah Al MAMUN

    To study the effect of foliar application of urea fertilizer on the growth and yield of tomato and to find out the optimum concentration of foliar application of urea for maximum growth and yield of tomato, an experiment was conducted with different concentrations of foliar application of urea fertilizer, namely, 2500, 5000, 7500, and 10000 ppm. The experiment was laid out by a randomized complete block design (RCBD) with four replications. Results showed that different yield components and yield of tomato were influenced by the foliar application of different concentrations of urea. The maximum plant height (132.6 cm), number of leaves (30.73), number of green leaves per plant at harvest (21.08), days to first flowering (28.94), number of flower clusters (11.89), number of flowers (75.18), fruit clusters (5.81), fruits per cluster (4.14), and fruits per plant (21.49); length (4.72 cm), diameter (6.58 cm), and weight of individual fruit (151.0 g) were significantly influenced by the 10000 ppm concentration of foliar application of urea fertilizer. The 10000 ppm application gave the highest yield (63.69 t/hm2) with the lowest (28.48 t/hm2) in the control treatment. The yield per plant as well as per hectare increased with increasing concentrations of foliar application of urea fertilizer.

  • RESEARCH ARTICLE
    Yitian SHAO, Cunli ZHANG, Ying GUO, Pengzhou XI, Jie GUO

    Soluble dietary fiber (SDF) is an extract from spent residue of BoldItalic Sieb. et Zucc fruit by ultrasonic. The conditions of the experiment optimized with response surface methodology were ambient temperature of 70.3°C, the ratio of solvent to solid being 30 mL/g, and processing time of 110 min under the ultrasonic wave frequency of 40 kHz and ultrasonic power of 250 W. The best aggregative indicator, incorporating the yield of BoldItalic SDF (CSDF), the content of SDF, and light transmittance (%, at 620 nm) of SDF, was predicted to be 12.7845 according to the fitting equation. After UV sterilization, 0.25% (w/v) dispersion of CSDF in mineral water presented a good light transmittance (94.9%) and shelf-life (over 2 months). It had no smell and tasted good. The left residue was extracted with caustic soda to get hemicellulose.

  • RESEARCH ARTICLE
    Waseem SHAHRI, Inayatullah TAHIR, Sheikh Tajamul ISLAM, Mushtaq Ahmad BHAT

    A study was undertaken to assess the effect of different storage temperatures on senescence and postharvest performance of isolated flowers of Ranunculus asiaticus L.. The main aim of the work was to develop a cost-effective storage protocol to reduce the postharvest losses and to bring out the transportation of cut flowers of R. asiaticus. The flowers were subjected to two different storage treatments, dry storage and wet storage, and their postharvest performance was compared under laboratory conditions. For this purpose, the buds were harvested at 8:00 AM at loose bud stage (Stage II of flower development). The harvested buds were cut to a uniform size of 15 cm and processed for dry or wet storage. For dry storage, the buds were packed after wrapping them in moistened filter papers and kept at 5oC and 10oC. For wet storage, the buds were held in distilled water in separate glass beakers kept at 5oC and 10oC, respectively. A separate set of buds each for dry and wet storage was kept at room temperature (15±2)oC. After 72 h storage, the buds were kept at room temperature in distilled water. The average life of an individual flower that opened fully was about 4–5 days. The buds kept under wet storage at 5oC and 10oC for 72 h maintained their premature status, while the buds held at room temperature for 72 h generally bloomed. All the buds stored dry maintained their premature status irrespective of storage temperature. Storage of buds for 72 h at 5oC, followed by transferring to distilled water improved the longevity by about 5 to 6 days. Cold storage treatment before transferring to holding solution improved floral diameter, membrane integrity besides maintaining higher fresh and dry mass of flowers, sugar content, soluble proteins, and phenols. Our results suggested that wet and dry storage of premature buds of R. asiaticus for 72 h at 5oC, followed by placing them in distilled water, improved the cut flower longevity and can be used as effective postharvest storage treatments for this beautiful cut flower.

  • RESEARCH ARTICLE
    Shunli WANG, Zhanfeng LI, Youliang MA, Hu DENG, Liping SHANG

    An online extraction method for monitoring CO2 concentration during soil respiration is described based on the assay of gas pump and gas extraction with a dynamic air chamber. Also, a study is done on the relationship between data collected from online CO2 measurement and time, as well as the curve fitting. This method uses the optimization algorithm to extract the CO2 concentration in the soil respiration chamber, and sets up a mathematical model for online soil CO2 concentration extraction. It is verified that the extraction method is feasible with the automatic site detection. This method, which can reduce the volume of data redundancy and improve data reliability, has a high reference value for the similar characteristics of online data extraction, compared with the traditional CO2 detection methods during soil respiration.

  • RESEARCH ARTICLE
    Chunying MA, Chunsheng LIU, Wenquan WANG

    A full length cDNA encoding HMGR (designated as GuHMGR) was isolated from liquorice (Glycyrrhiza uralensis) based on degenerated PCR and genome walking. The full length cDNA of GuHMGR was 2330 bp with a 1518-bp open reading frame (ORF) encoding a 505-aa polypeptide. Bioinformatics analysis indicated that there were two trans-membrane domains in GuHMGR. A molecular model of tertiary structure showed that GuHMGR is a novel HMGR with a similar spatial structure to other plant HMGRs. The deduced polypeptide of GuHMGR has an isoelectric point (pI) of 6.41 and a calculated molecular weight of about 54.7 kDa. Sequence comparison and phylogenetic tree analysis showed that GuHMGR had the highest homology with HMGRs from Pisum sativum and Medicago truncatula, indicating that GuHMGR belongs to the plant HMGR group. Expression analysis showed the similar amount of transcript level of GuHMGR in roots and leaves, suggesting that this gene was expressed constitutively in plants. Therefore, this novel HMGR gene would possibly provide a new strategy for studying the glycyrrhizin metabolism at the molecular level in the future.

  • RESEARCH ARTICLE
    Yanghui WANG, Jianlou MU, Jie WANG

    Uniform design methodology and response surface methodology were used to determine the optimum conditions for hawthorn-Yali pear wine. By using uniform design, the effects of fermentation temperature, sugar content, the ratio of hawthorn to pear, soaking time of hawthorn, additional volume of SO2, and yeast dosage on sensory quality were investigated, which indicated that the first three aspects were of great significance to the sensory quality. By using three-factor, three-level response surface methodology, a prediction model was established in the form of quadratic polynomial regression equation, with the best processing conditions hereby determined under the conditions of fermentation temperature (25.18°C), sugar content (22.00%), the ratio of hawthorn to pear (21.19:100), and the alcohol degree (11.05 (V/V %)).