Genetic Diversity Analysis of Balsam Pear （Momordica charantia L.） by ISSR Marker

[Objective] The aim was to explore the relationship between the classification and regional distribution of balsam pear.[Method] In the research,30 varieties of balsam pear were analyzed by ISSR marker.[Result] The research showed that 172 bands were amplified by 18 primers,in which,132 bands were polymorphism and the polymorphic proportion was 76.7％.All of the samples can be divided into four categories by UPGMA analysis.[Conclusion] The results indicated that the classification of balsam pear is similar as varieties＇ regional distribution,which will be useful for genetic relationships analysis and parents selection in hybridization breeding.     

Experiment on Tissue Culture Technique of Saposhnikovia divaricata （Turcz.） Schischk

The study aimed to optimize the induction and differentiation medium by exploreing different tissue culture of Saposhnikovia divaricata （Turcz.） Schischk. In tissue culture with the root, stem segments, young leaf, cotyledonary node and axillary bud of Saposhnikovia divaricata （Turcz.） Schischk as explants, a lot of plantleles were obtained and the corresponding plant regeneration-system was established. The results showed that when use MS＋1.0 mg·L^-1 6-BA＋0.2 mg·L^-1 NAA as callus induction medium, the cotyledonary node had the highest bourgeon rate, and its callus was better than any others; MS＋2 mg·L^-1 6-BA＋0.4 mg·L^-1 NAA was the best adventitious buds induction medium, and the best adventitious buds induced condition was 3% sucrose as carbon source, illumination for 12-14 h·d^-1 and pH 5.8, The best rootage medium was 1/2 MS＋0.5 mg·L^-1 NAA.     

Development of Alfalfa （Medicago sativa L.） Regeneration System and Agrobacterium-Mediated Genetic Transformation

The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on regeneration were compared. The better callus forming frequency obtained from hypocotyls of Xinjiang Daye is 88.5% and regeneration frequency is 9.8% in our initial experiments. To further optimize regeneration system for genetic transformation, we therefore changed concentrations of plant growth regulators and supplemented with glutamine into callus-induction and shoot-regeneration media. Callus forming frequency and shoot differentiation frequency were increased to 100%. The time taken to generate transgenic plants （16 weeks） was shorter than that for previouse procedure （25 weeks） and regeneration frequency was promoted to 15.1%. The results show that addition of glutamine is particularly important for shortening period of regeneration and promoting regeneration frequency. For study of genetic transformation of alfalfa, Agrobacterium tumefaciens-mediated transformation of Xinjiang Daye was developed based on this optimized regeneration system. The plant expression vector carrying two glutamine synthetases （GS 1 and GS2） and △1-pyrroline-5-carboxylate synthetase （P5CS） gene was used for alfalfa in vitro transformation. Six transgenic alfalfa plantlets with resistance to PPT were obtained. The introduction of foreign genes into plants was assessed in the transformants by PCR analysis and Southern hybridizations.     

Study on the Mechanism of Browning of Pomegranate （Punica granatum L. cv. Ganesh） Peel in Different Storage Conditions

Peel browning of pomegranate fruit is the key problem during storage. The mechanism of it during storage in relation to the technology of the browning control was studied in this paper. The effects of storage temperature, gas component and pH value on peel browning of sweet pomegranate fruit in Lintong, Shaanxi Province, China, were investigated. Change in tannin content was measured and the relationship between the activities of ascorbic acid oxidase （AAO）, polypenoloxidase （PPO）, peroxidase （POD）, catalase （CAT） and peel browning was analysed. The results showed tannin was the basic substance of pomegranate peel browning. The activities of the browning index of peel were correlated positively with AAO, PPO and POD, correlated negatively with CAT activity. Application of intermittent warming for 24 h at （15 ± 0.5）℃ every 5 days for pomegranate fruit storage under the conditions of pH 4.0, （5.0± 0.5）℃ and 5.0% CO2 ＋ 8.0% O2 ＋ 87.0% N2 gas component could delay browning, with the browning index being 0.15 after 120 days of storage. Enzymatic tannin denaturation was the main cause that led to peel browning of pomegranate fruit during storage. The browning control of pomegranate fruit peel was effective using intermittent warming storage with suitable pH, temperature and gas component.     

Effects of Environmental Temperature on the Regeneration Frequency of the Immature Embryos of Wheat （Trificum aestivum L.）

The immature embryos （IEs） of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4℃ daily cooler for a short period time for its use in plant tissue culture or transformation experiments. This study aimed to investigate the effects of environmental temperature, cryopreservation storage temperature, and heat shock culture （HSC） temperature on the regeneration frequency of wheat IEs. Results indicated that environmental temperature significantly affected the induction of embryonic calli. The optimum total accumulated temperature （TAT） during the time of anthesis and sampling for regeneration of these tissues was around 280℃ for spring wheat type cv. CB037 and approximately 300℃ for winter wheat type cv. Kenong 199. Regeneration ability obviously declined when the highest environmental temperature was over 35℃ for 1 d or a high temperature between 30 and 33℃ lasted for 5 d during anthesis and sampling. This finding was verified by culturing the freshly isolated IEs under different temperatures from 29 to 37℃ in different controlled growth incubators for 5 d; the IEs almost completely lost regeneration ability when the temperature rose to 37℃. Cryopreservation of-20℃ caused the wheat samples lost ability of producing callus or embryonic callus in a few days, and cryopreservation of-10℃ more than 10 d made the regeneration potential of the tissues dramatically declined. Comparatively, the temperature that best maintained high regeneration ability was -5℃, at which the materials can be maintained for around 1 mon. In addition, the preservation of the immature samples at -5 or -10℃ inhibited the direct germination of the IEs, avoiding the embryo axis removing process. Our results are useful for ensuring that field collection and cryopreservation of the wheat IEs are done correctly to enable tissue culture and genetic transformation.     

Identification of Organic Substances Associated with Tissue Senescence in Upland Cotton （Gossypium spp. L.） Based on GC-MS Analysis

Premature senescence in crop production,especially occurred at the late growth stage,generally results in a reduction in yield and quality.Therefore,it is beneficial for yield and quality to properly delay senescence of plant tissues during the late developmental stage.In this study,it was observed that the chlorophyll content and photosynthetic rate were gradually decreased along leaf growth progression,and the rates of reduction were promoted by drought.Based on gas chromatography-mass spectrometry (GC-MS) analysis,total eight,five,seven,and five kinds of organic compounds that putatively associated with the tissue senescent progression were identified in leaves,fruit branches,petals,and sepals,respectively.It was found that the identified organic compound,such as α-pinene,β-pinene,and pentadecane were present in different tissues.Among the total ten organic substances identified to be related with the leaf senescence,half were specifically detected in the drought treatment.These results suggest some biochemical pathways associated with the leaf senescence are distinctly regulated by drought.The identified organic compounds in the tested tissues showed three types on the performance pattern based on the contents along with the senescent progression,including gradually increasing,decreasing,and a curve with one single peak.Thus,during the senescence process in tissues,a subset of metabolic substances occur modifications on the quantities,reflecting a complicate biochemical reactions are initiated via the senescence signals.Further analysis of the important organic substances will be helpful for elucidation of the tissue senescence mechanism at the biochemical level and provide a new insight of the senescence signaling transductions in cotton.     

Effect of Three Different Growth Media on Yield and Oil Constituents of Rosemary （Rosmarinus officinalis L.） under Protected Agriculture Conditions

Medicinal plants provide an important source of cure since ancient time. Poor soil resources, scarce and saline water and the harsh environment limited the production of plants in the Arabian Gulf countries. This study aimed to investigate the production potential of rosemary （Rosmarinus officinalis L.） grown on different growth media under greenhouse conditions. Three growth media agricultural soil, compost and hydroponic system were used, whereas tuff （inert volcanic material） was used as substrate. The result indicated that the high salinity of the agricultural soil limited growth and oil yield in rosemary. Shoot height increased in 11 weeks, by 62%, 65% and 114% in plants grown in agricultural soil, hydroponic system and compost, respectively. Na content in plants grown in agricultural soil was significantly higher than in plants grown in the other treatment. Essential oil yield in plants grown in compost exceeded those in agricultural soil by 114%. Essential oil content （0.66%-1.5% w/w） and chemical constituents concentrations did not change significantly with growth media. The main constituents, more or less, are comparable to essential oils constituents reported from other countries. In comparison, better yields are obtained for individual components of the oils of plants grown under our green house conditions. This study demonstrated the great potential of commercial production of rosemary in the greenhouse without compromising the oil quality and oil yield.     

吉林省玉米生产省域尺度上比较优势研究

从播种面积指数、单产指数、效益指数以及综合比较优势指数的角度分析了吉林省玉米生产的比较优势。结果表明,和全国其他省份相比,吉林玉米播种面积指数和单产指数具有明显的比较优势,2002~2006年5年平均分别位于全国第1位和第4位;效益指数和全国平均水平相比不具有比较优势,2002~2006年5年平均位于全国第14位;综合比较优势指数具有明显的比较优势,2002~2006年5年平均位于全国第4位。在此基础上,提出吉林省发展玉米生产的对策建议。     

吉林省玉米生产省域尺度上比较优势分析及建议

从播种面积指数、单产指数、效益指数以及综合比较优势指数的角度分析了吉林省玉米生产的比较优势,结果表明,和全国其他省份相比吉林玉米播种面积指数和单产指数具有明显的比较优势,1997—2001五年平均均位于全国第三位;效益指数和全国平均水平相比具有比较优势,和全国优势省份相比不具有比较优势,1997—2001五年平均位于全国第十二位。综合比较优势指数具有明显的比较优势,1997~2001五年平均位于全国第四位。在此基础上,提出吉林省发展玉米生产的对策建议     

吉林省玉米生产县域尺度比较优势分析

根据比较优势理论,应用综合比较优势指数法,对吉林省玉米生产县域尺度比较优势进行了测定和差异分析。结果表明,吉林省玉米生产不同县域之间综合比较优势存在着很大的差异,吉林省应当引导各县域按照比较优势的原理进行玉米生产结构的调整,实现玉米生产的合理布局和专业化生产,以充分发挥玉米生产的比较优势。     

河北省蛋鸡综合比较优势指数变迁及生产布局优化研究

为了优化河北省各地市蛋鸡产业布局,分析了河北省各地市1996 ～ 2013年蛋鸡生产综合比较优势指数.结果表明,河北省蛋鸡综合比较优势由南向北、由西向东逐渐减弱,南部的邯郸、邢台、沧州、衡水、石家庄具有较强的综合比较优势,北部地区和东部的张家口、承德、秦煌岛和唐山综合比较优势较弱.河北省各地市禽蛋综合比较优势指数呈现层级发展,各层级之间综合比较优势指数表现出极显著差异,层级内除秦皇岛和承德外均无显著差异.建议在蛋鸡产业综合比较优势较强的区域在科技、财政和政策等方面给予重点扶持,综合比较优势较弱的地区应综合考虑各类畜产品综合比较优势,给予不同程度重视.     

我国玉米生产地区比较优势研究

利用灰色系统评估方法,基于比较优势理论,选取2008—2014年我国20个玉米主产省份的相关数据,对其玉米生产的比较优势进行测算,得出2014年河北省、内蒙古自治区、黑龙江省和山东省在玉米生产上具有比较优势;同时,分析了不同省份比较优势的形成原因,结合供需情况、生产结构调整等问题,提出我国玉米生产的对策。     

吉林省普通玉米品种品质现状分析

[目的]分析吉林省普通玉米品种主要营养品质的变化趋势。[方法]对1995~2006年吉林省育成的普通玉米品种的品质指标(脂肪含量、蛋白质含量及淀粉含量)进行分析。[结果]普通玉米的粗蛋白含量为8.06%~13.97%,平均10.37%;粗脂肪含量2.85%~9.70%,平均4.56%;粗淀粉含量62.59%~76.80%,平均71.15%。就年际间变化而言,粗蛋白含量变异较大,但整体呈比较平稳趋势;脂肪含量整体呈下降趋势且变异较大;粗淀粉含量整体比较稳定且呈上升趋势。就省内不同地区而言,粗蛋白含量除通化和白山地区较低外(9.99%),其他地区基本相当,变辐为10.13%~10.48%;延边地区粗脂肪含量较高,为5.42%;通化和白山地区的玉米品种粗淀粉含量较高,为72.01%。[结论]吉林省普通玉米品种品质指标偏低,不同品种间变异比较大,品质改良潜力很大。     

吉林省玉米品种容重浅析

选择吉林省目前生产中应用的140个玉米品种,分为早熟组、中熟组、中晚熟组、晚熟组、耐密组、高油组、青贮组和特用组共8组,在吉林省中部半湿润区、西部半干旱区设3个试验点,系统地研究了吉林省玉米品种容重概况,通过在生态区间、品种组间、品种组内计算与分析,获得了各品种的容重差异及容重显著高于对照的高容重玉米品种。     

吉林省玉米生产波动的影响因素与稳产对策

吉林省作为我国重要的玉米主产区,探讨其玉米生产波动问题有着重要的现实意义.本文对吉林省1990-2010年玉米生产的波动情况进行了分析,结果表明:吉林省玉米生产是在不稳定的波动中增长的,其波动周期频度较高,长度不规则,波动幅度剧烈.并从自然因素、农业政策、玉米市场、科学技术等角度,剖析了吉林省玉米生产波动的影响因素;进而从加强玉米生产基础设施建设、建立健全灾害防控体系和玉米市场体系等方面,提出了防御和平抑吉林省玉米生产超常波动的对策.     

充分发挥吉林省的优势大力发展农村经济

从十一届三中全会以来吉林省农村经济取得的成就入手,提出了发挥吉林省的优势,进一步发展农村经济的对策。     

吉林省玉米超高产品种探讨

围绕吉林省玉米超高产的品种类型、关键特征特性、产量构成参考指标等方面进行探讨。并针对超高产品种主要问题提出了育种对策。