A Method Suitable for Extracting Genomic DNA from Animal and Plant——Modified CTAB Method

[Objective] The study aimed to introduce a rapid and effective method that is suitable for extracting genomic DNA from animal and plant. [Method] The genomic DNAs were extracted from tender leaves of 24 peanut cultivars and from the liver,lung and kidney of white mouse through the specifically modified CTAB method. The DNAs were run on agarose gel,next detected by DNA/Protein analyzer. Finally PCR amplification was conducted to detect the quality of DNAs extracted using the modified CTAB method. [Result] The clear and orderly bands were observed in gel detection,and the values of OD260/OD280 for DNAs extracted via modified CTAB method were between 1.77-1.83. The DNAs performed well in PCR amplification. [Conclusion] The DNAs extracted by modified CTAB method could satisfy the requirement of PCR amplification.     

Davana： A New Host Plant for Ralstonia solanacearum from India

Ralstonia solanacearum infecting Davana （Artemisia pallens Wall.） from commercial nurseries in India was isolated on modified semi selective media （SMSA）. Here, we report a new host for Ralstonia solanacearum i.e. davana. It has huge demand in medicinal and aromatic industries. Isolate was confirmed as race-l, biovar-3 by morphological, physiological, biochemical and pathogenicity studies. Two sets of primers （OLI 1 ＆ Y2 and Y 1 ＆ Y2） were used in this study. Further, the identity of the isolate was confirmed by serological diagnostic kit obtained from International Potato Research Center, Lima, Peru and single chain variable fragment antibody specific to Ralstonia solanacearum used to confirm the casual organism.     

Plant regeneration and genetic transformation in switchgrass——A review

Switchgrass is native to the tallgrass prairie of North America. It is self-incompatible and has varied ploidy levels from diploid(2x) to dodecaploid(12x) with tetraploid and octoploid being the most common. The high yielding potential and the ability to grow well in marginal lands make switchgrass an ideal species as a dedicated biomass producer for lignocellulosic ethanol production. Genetic transformation is an important tool for studying gene function and for germplasm improvement in switchgrass, the genome of which has been sequenced recently. This paper intends to provide a comprehensive review on plant regeneration and genetic transformation in switchgrass. We first reviewed the effect of explants, basal medium and plant growth regulators on plant regeneration in switchgrass, which is a prerequisite for genetic transformation. We then reviewed the progresses on genetic transformation with either the biolistic or Agrobacterium-mediated method in switchgrass, and discussed various techniques employed to improve the transformation efficiency. Finally we reviewed the recent progresses on the use of genetic transformation in improving biomass quality such as the reduction of lignin, and in increasing biomass yield in switchgrass. We also provided a future perspective on the use of new genome editing technologies in switchgrass and its potential impact on regulatory processes.     

Prokaryotic Expression of Gly-GIn Dipeptide and Its Bioactive Analysis： A Novel Method for Short Peptide Production

Small bioactive peptides, with diverse biological functions, have received increasing attention as physiologically beneficial substances in animal production. The main obstacle to wide application of small bioactive peptides is a lack of costeffective methods for mass production. In this study, we mass-production method for small bioactive peptides. used glycyl-glutamine （Gly-Gln） as a test case to develop a novel The oligonucleotide encoding Gly-Gln pro-peptide （Gpp） was designed and synthesized. Gpp includes 3 Gly-Gln dipeptides and 2 enzymatic sites for pepsin and trypase, allowing direct digestion and absorption of Gly-Gln in the gastrointestinal tract. The Gpp oligonucleotides were linked to generate an oligomeric oligonucleotide segment containing 12 tandem copies of Gpp. This 12Gpp segment was cloned and expressed in Escherichia coli vector pET32a. By optimizing culture conditions [0.1 mmol L^-1 isopropyl-β-D- thiogalactopyranoside （IPTG）, 50 μg mL^-1 ampicillin （Amp）, 30℃ for 12 h], the thioredoxin fusion peptides reached 40% of total bacterial protein. After purification, the fusion protein was fed to Kunming mice to determine its effect on mouse immune function. The results showed that similar to Gly-Gln dipeptide, Gpp polymer protein could significantly suppress the proliferation of T and B lymphocytes in blood and spleen, and additionally could significantly improve interleukin-2 （IL-2） and interleukin-6 （IL-6） secretion of blood and spleen lymphocytes. These effects were not observed in mice fed a 2 amino acids mix （glycine and glutamine）. These evidences indicated that an efficient digestion of Gpp polymer protein could be achieved when ingested into the animal gut. The expression system in this study provides a potential production method for not only Gly-Gln dipeptide but also other short bioactive peptides.     

A Preliminary Study on Systems Engineering-Based Method for the Evaluation of Allelopathic Potential in Crops and Its Application

The objective of this study was to develop a method to assess and analyze the total allelopathic potential of crop germplasm and to test this method on four winter wheat accessions commonly planted in the Loess Plateau. A systems engineering model was developed and used to evaluate the total allelopathic potential of crop cultivars. In addition, a method for quantifying the total allelopathic potential in crop accessions was presented. Total allelopathic potential of four winter wheat accessions from the Loess Plateau was estimated and compared using a systems theory approach. The model assessed allelopathic potential in different parts of the plants from the time wheat turned green in spring until maturity. Results from these models indicated that the four wheat accessions had very weak allelopathic potential. Allelopathic potential declined in the order Xiaoyan 22 〉 Ningdong 1 〉 Fengchan 3 〉 Bima 1. This system engineering evaluation method allows for the assessment of allelopathic potential among crop varieties. It will help plant breeders to select and develop allelopathic crop accessions that combine weed suppression properties with agronomic traits related to yield and quality.     

Comparison of energy consumption and economic performance of organic and conventional soybean production——A case study from Jilin Province,China

Modern agriculture heavily depends on energy consumption, especially fossil energy, but intensive energy input increases the production cost for producers and results in environmental pollution.Organic agricultural production is considered a more sustainable system, but there is lack of scientific research on the energy consumption between organic and conventional systems in China.The analysis and comparison of energy use between the two systems would help decision-makers to establish economic, effective and efficient agricultural production.Thus, the objectives of the present study are to analyze energy inputs, outputs, energy efficiency, and economic benefits between organic and conventional soybean(Glycine max(L.) Merrill) production.A total of 24 organic farmers and 24 conventional farmers in Jilin Province, China, were chosen for investigation in 2010 production year.Total energy input was 71.55 GJ ha–1 and total energy output was 96.18 GJ ha–1 in the organic system, resulting in an energy efficiency(output/input) of 1.34.Total energy input was 9.37 GJ ha–1 and total energy output was 113.4 GJ ha–1 in the conventional system, resulting in the energy efficiency of 12.1.The huge discrepancy in energy inputs and respective efficiencies lies in the several times higher nutrient inputs in the organic compared to the conventional production system.Finally, the production costs ha–1 were 33% higher, and the net income ha–1 25% lower in the organic compared to the conventional soybean production system.It is recommended to improve fertilizer management in organic production to improve its energetic and economic performance.     

A Friendly Bridge between Hunan and the World——Opening Speech for the Official Publication of HASTN

At the time when the new millennium comes, I am very delighted at the news that Hunan Agricultural Science & Technology Newsletter(HASTN) in English edition officially starts publicatiou. We think it will certainly establish another more friendly bridge between our Hunan Province and foreign countries in scientific and economic exchange and cooperation during the mportant days when our People's Republic of China is ready to enter the WTO.     

Segregation Characteristics and Their Correlation Analysis on Plant Characters of F2∶3 Family Lines from A Normal Maize x High-Oil Maize Inbred Cross

[目的]研究由优良普通玉米自交系8984与高油玉米自交系GY220杂交构建的F23家系的分离特征及其相关性.[方法]在夏播环境条件下对8个植株性状进行分析.[结果]F2∶3家系间各性状均存在极显著的差异,并呈连续性正态分布,存在明显的双向超亲分离;株高与穗位高、顶高、穗上叶片数、叶面积、雄穗长和雄穗分枝数,穗位高与顶高、穗上叶片数、叶面积、雄穗长和雄穗分枝数,顶高与顶高/株高、穗上叶片数、叶面积、雄穗长和雄穗分枝数,顶高/株高与穗上叶片数,穗上叶片数与叶面积、雄穗分枝数,叶面积与雄穗长间均呈显著或极显著的表型和遗传正相关;顶高/株高与株高、穗位高、叶面积和雄穗分枝数间均呈显著或极显著的表型和遗传负相关.[结论]该研究可以为高油玉米育种及其相关性状的分子遗传研究提供一定的科学依据.     

Water Resource Management and Its Role in Development of Integrated Mountainous Agriculture——A Case from Ningnan County of Sichuan Province

This paper reviewed rainwater collection and water resource management in Ningnan County in southwestern mountain of China,as a case study for solving the problems of water management in a simple and sustainable way. In this mountainous agriculture system,private agricultural enterprises were introduced into local mountain agriculture to solve capital fund shortage for the construction of rainwater harvesting system. Agreement was signed by private agriculture enterprises with the target farmers to subscribe for the household agriculture production at a protection price. Cash invested by the enterprise and subsidy from the government were collected for purchasing materials,while the farmers supplied labors for the construction of water harvesting systems. The system solved the share of input and benefits between the local government,enterprise and household farms successfully. In addition,the micro water harvesting tanks and micro irrigate systems extend quickly in this mountainous county. Up to 2007,more than 12 000 rainwater harvesting tanks had been established and more than 8.5×104 hm2 dry arable land accounting for nearly 75% of the total arable land had been irrigated efficiently. Per capita income of farmer had been increased by 14 times in the past 20 years. Considerable potential for further improvement in implementation of the models for solving water shortage and water resource management in mountain region maybe depend on more local private agriculture enterprises and households than the government.     

A Simple Method for the Isolation and Purification of 2,4-Dihydroxy-7-Methoxy-2H-1,4-Benzoxazin-3（4H）-One （DIMBOA） from Maize （Zea mays L.） Seedlings

2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA), the dominant benzoxazinoid hydroxamic acid in maize (Zea Mays L.), serves as important factors of resistance against insects and microbial diseases, allelochemicals used in competition with other plants. In this paper, a novel and simple method for the isolation and purification of DIMBOA from maize seedlings was developed. Frozen shoots from 7-d-old maize seedlings (1 000×g) were firstly defrosted and then were directly homogenized and extracted with ethyl acetate. The macerate was allowed to stand at room temperature (25±2)°C for 1 h to allow enzymatic release of DIMBOA from DIMBOA-glucoside. Then the ethyl acetate phase was filtered, dried and evaporated to dryness. The resulting light-tan, semicrystalline residue was stored at -20°C for 24 h. Upon recrystallization from acetone-hexane, a relative higher yield (0.58 g) of pure DIMBOA crystals was obtained compared with the yield afforded by Woodward methodology (0.26 g).     

The causes and impacts for heat stress in spring maize during grain filling in the North China Plain——A review

High-temperature stress(HTS) at the grain-filling stage in spring maize(Zea mays L.) is the main obstacle to increasing productivity in the North China Plain(NCP). To solve this problem, the physiological mechanisms of HTS, and its causes and impacts, must be understood. The HTS threshold of the duration and rate in grain filling, photosynthetic characteristics(e.g., the thermal stability of thylakoid membrane, chlorophyll and electron transfer, photosynthetic carbon assimilation), water status(e.g., leaf water potential, turgor and leaf relative water content) and signal transduction in maize are reviewed. The HTS threshold for spring maize is highly desirable to be appraised to prevent damages by unfavorable temperatures during grain filling in this region. HTS has negative impacts on maize photosynthesis by damaging the stability of the thylakoid membrane structure and degrading chlorophyll, which reduces light energy absorption, transfer and photosynthetic carbon assimilation. In addition, photosynthesis can be deleteriously affected due to inhibited root growth under HTS in which plants decrease their water-absorbing capacity, leaf water potential, turgor, leaf relative water content, and stomatal conductance. Inhibited photosynthesis decrease the supply of photosynthates to the grain, leading to falling of kernel weight and even grain yield. However, maize does not respond passively to HTS. The plant transduces the abscisic acid(ABA) signal to express heat shock proteins(HSPs), which are molecular chaperones that participate in protein refolding and degradation caused by HTS. HSPs stabilize target protein configurations and indirectly improve thylakoid membrane structure stability, light energy absorption and passing, electron transport, and fixed carbon assimilation, leading to improved photosynthesis. ABA also induces stomatal closure to maintain a good water status for photosynthesis. Based on understanding of such mechanisms, strategies for alleviating HTS at the grain-filling stage in spring maize are summarized. Eight strategies have the potential to improve the ability of spring maize to avoid or tolerate HTS in this study, e.g., adjusting sowing date to avoidHTS, breeding heat-tolerance varieties, and tillage methods, optimizing irrigation, heat acclimation, regulating chemicals, nutritional management, and planting geometric design to tolerate HTS. Based on the single technology breakthrough, a comprehensive integrated technical system is needed to improve heat tolerance and increase the spring maize yield in the NCP.     

A major pathway for carbon and nitrogen losses — Gas emissions during storage of solid pig manure in China

This study investigated the carbon (C) and nitrogen (N) gas emissions (N₂O, NH₃, CO₂ and CH₄) from solid pig manure management in China. Gas emissions were quantified from static piles over 60 days during summer in China's Yangtze River Basin, using Drager-Tube and static chamber-gas chromatography techniques. High emissions of NH₃ and N₂O were observed at the early stage of storage, but high emission of CH₄ occured later during storage. Overall, 62% of the total C in the original pile was lost; CO₂ and CH₄ emissions accounted for 57 and 0.2% of C lost respectively. Over the same time, 41% of the total N in the original pile was lost; NH₃ and N₂O emissions accounted for 15 and 0.3% of N lost respectively. The volatilization of NH₃ during storage in summer was 4.56 g NH₃ per kg dry weight. The total greenhouse gas (GHG) emissions during storage accounted for 67.93 g CO₂ equivalent per kg dry weight; N₂O and CH₄ contributed to 46 and 55% of total GHG emissions respectively. Given China's major role in pig production, further attention should given to pig manure management to mitigate its contribution to atmospheric pollution.