Conditions and Stimulation for Germination in Glycyrrhiza uralensis Fisch Seeds

Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on seed germination and mechanical and chemical scarification on breaking the seed coat. Seeds were collected in 2004, 2005, and 2006, placed in Petri dishes, and incubated at constant temperature 20, 25, and 30℃, and alternating temperature 15-25, 20-30, 15-30, and 20-35℃ under either an 8h photoperiod or total darkness for 28 consecutive days. Different methods were used to break the dormancy owing to hard seededness in this species such as chemical scarification by immersing in concentrated sulphuric acid for 5, 10, 15, 20, 25, 30, 45, and 60 min, in 0.2% KNO3 solution to saturate the seedbed, and prechilling for 7 d at 7℃ and mechanical scarification by cutting. The results showed that alternating temperature at 20-30℃ with 8 h photoperiod and 16 h darkness was optimum for G. uralensis seed germinating in the laboratory. Hard seeds were broken by concentrated sulphuric acid soaking or mechanical scarification by cutting. Germination of seeds harvested in two different years was both promoted by immersing for 30-45 min in concentrated sulphuric acid. KNO3 solution was ineffective for reducing hard seeds. During seed germinating, the first count was on the 7th day and the last count was on the 14th day.     

Influences of Seed Source,Pre-chilling,Light and Temperature on the Germination of South African Pelargonium sidoides

Pelargonium sidoides DC is used in herbal medicine for the treatment of various infections. The roots are being indiscriminately harvested for local and export trade and the collection rate is becoming unsustainable. Seed germination dynamics of this species was studied with the aim to reveal factors that influence its survival in the wild in order to adopt the appropriate germination conditions for use in ex-situ propagation and conservation program. Germination was affected by age of seeds, temperature and pre-chilling conditions. Temperature higher than 25 oC reduced germination by 60%. When seeds of P. sidoides were subjected to pre-chilling treatment for seven days, there was a significant drop in final germination by 29% compared to the other treatments. Although, final germination was not affected by different light treatments, continuous light significantly promoted germination velocity Seeds harvested from the plants grown in the green house performed better in germination than those collected from the field. The ecological implications of these observations on the propagation and conservation ofP. sidoides are discussed.     

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.     

Enhancement of Arachidonic Acid Production by Mortierella isabellina Through Protoplast Regeneration Mutagenesis

A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast regeneration mutagenesis. The results showed that a commixture enzyme (cellulase and glusulase) at the concentration of 4%, enzymolysis temperature at 30℃ and enzymolysis time on 7.5 h were the optimal conditions, in which the lethality of M. isabellina spores was 78.4%. After mutagenesis and re-s...     

The Effect of Washing and Inhibitor on Cathepsin Activity of Silver Carp

The effect of washing and temperature on the activity of cathepsins of Silver carp was studied. The result showed that the activity of cathepsin L was higher than those of cathepsin B and H. The total catalysis activity of these three enzymes was the highest at 55 C after washing. The inhibiting effect of soybean protein and potato starch on cathepsin L also had been studied,the results showed that soybean protein and potato starch could decrease activity of cathepsins L significantly.     

Constitutive Overexpression of Myo-inositol-1-Phosphate Synthase Gene (GsMIPS2) fromGlycine soja Confers Enhanced Salt Tolerance at Various Growth Stages inArabidopsis

The enzymemyo-inositol-1-phosphate synthase (MIPS EC 5.5.1.4) catalyzes the first step ofmyo-inositol biosynthesis, a product that plays crucial roles in plants as an osmoprotectant, transduction molecule, cell wall constituent and production of stress related molecule. Previous reports highlighted an important role of MIPS family genes in abiotic stresses particularly under salt stress tolerance in several plant species; however, little is known about the cellular and physiological functions ofMIPS2 genes under abiotic conditions. In this study, a novel salt stress responsive gene designatedGsMIPS2 from wild soybean Glycine soja07256 was functionally characterized contained an open reading frame (ORF) of 1 533 bp coding a peptide sequence of 510 amino acids along with mass of 56 445 ku. Multiple sequence alignment analysis revealed its 92%-99% similarity with other MIPS family members in legume proteins. Quantitative real-time PCR results demonstrated thatGsMIPS2 was induced by salt stress and expressed in roots of soybean. The positive function ofGsMIPS2 under salt response at different growth stages of transgenicArabidopsis was also elucidated. The results showed thatGsMIPS2 transgenic lines displayed increased tolerance as compared to WT andatmips2 mutant lines under salt stress. Furthermore, the expression levels of some salt stress responsive marker genes, including KIN1,RD29A, RD29B,P5CsandCOR47 were significantly up-regulated inGsMIPS2 overexpression lines than wild type andatmips2 mutant. Collectively, these results suggested thatGsMIPS2 gene was a positive regulator of plant tolerance to salt stress. This was the first report to demonstrate that overexpression ofGsMIPS2 gene from wild soybean improved salt tolerance in transgenicArabidopsis.     

Cardinal temperatures and required biological days from sowing to emergence of three millet species （common,foxtail, pearl millet）

The modeling of germination and seedling emergence is required for the construction of a simulation model of three species of millet （panicum miliaceum, pennisetum galucum and setaria italica）. This study provides the necessary temperature parameters to model these processes. For this purpose, different non-linear regression models including fiat, logistic, quadratic, sigmoidal, dent-like, segmented, beta and curvilinear were used. Root Mean Square of Errors, coefficient of determination and regression coefficients of predicted values versus observed were used to find the appropriate model. Investigating regression coefficients indicated that dent-like model has the least RMSE and a coefficient （RMSE=0.000009, a=0.0006） and the biggest R2 and b coefficient （R2=0.96, b=0.98） in common millet. These coefficients were （RMSE=0.01, a=0.005） and （R2=0.94, b=0.97）, and （RMSE=0.004, a=0.05） and （R2=0.99, b=0.99）, for beta in foxtail and pearl millet, respectively. According to these coefficients, dent-like, was chosen as the best model to describe the response of common millet germination to temperature （Tb=7~C and Tc=49.50℃）. Also beta, was chosen for foxtail millet （Tb=7℃, Tc=49.50℃）. Beta, was chosen as the best model for pearl millet （Tb=6.5 ℃ and To=4 ℃ ）. These parameters can be used in millet simulation models to predict sowing to emergence duration based on a thermal time concept. Also, required biological days from sowing to emergence using these models varied from 3.57, 4.29 and 5.54, for common millet, foxtail millet and pearl millet, respectively.     

Pilot Study of Drought Resistance for Maize at Budding Stage

The drought resistances of 44 maize germplasms at budding stage were studied with 19.2% polyethylene glycol(PEG-6000)in order to provide new germplasm resource for drought resistance breeding of maize.The results showed there were five extremely high drought resistance germplasms,20 germplasms with high drought resistance,and 19 germplasms with medium drought resistance.The significance testing was also used to demonstrate that the germination index(GI)and germination of drought resistance index(GDRI)of N4,N54-1 and Wuming No.1 were dramatically remarkable than others.The conclusion was that the 44 maize germplasm had good drought resistance and could be used as germplasm resource of the drought resistance breeding of maize,which had a great value of development and utilization.     

Characteristics of Microencapsulated Nutritional Oil for Infant Formula Food

Nutritional oil for infant formula food was microencapsulated by the spray drying method with coating materials including maltodextrin （MD）, soy protein isolate （SPI）, and emulsifier （soy lecithin）. Vegetable oil blend was prepared by mixing coconut oil, safflower oil and soybean oil at a ratio to achieve a fatty acid profile comparable to human milk fat （HMF）. The fatty acid composition of the product was determined by capillary gas chromatograph. As a result, the composition was as close as possible to that of HMF, it could be used for infant fomular food to make up some deficiencies of milk powder in nutrition and functional properties. Furthermore, the glass transition temperature （Tg） of the wall material was determined by DSC and its Tg was 66.42℃. It provided a theoretical basis for the storage of the product at the normal temperature.     

Studies on the Correlations Between Isoflavone Contents in SoybeanSeed and the Eco-Physiological Factors

The soybean cultivar Yudou25 was sown at 5 locations of Henan Province on 13 different dates in 2001 and 2002. The data of isoflavone contents for the 109 samples of soybean seed and 33 eco-physiological factors including meteorological factors, soil nutrition and altitudes were received and used for statistical analysis. The step-wise regression was used to screen the correlated factors, which significantly effected isoflavone contents. Results showed that 9 eco-physiological factors were highly correlated with isoflavones. Low mean temperature, high diurnal temperature range at seed filling and maturity, more sunlight hours and low mean temperature at emergence were favorable to isoflavone accumulation. The rainfall at emergence showed a nonlinear relationship with isoflavone content and its optimum value was 75 mm for isoflavone formation. Low diurnal temperature range at branching, high organic matter and low sulfur content in soil were suitable for the formation of isoflavones. The isoflavone contents would not be affected by other eco-physiological factors in this study.     

不同化学药剂处理对金铁锁(Psammoilene tunieoidesW. C. Wu et C. Y, Wu)种子萌发的影响

 珍稀濒危药用植物金铁锁(Psammoilene tunieoides W．C．Wu et C．Y,Wu)种子经浓度为25%次氯酸钠 (NaClO)溶液消毒处理和利用0.01%赤霉素（GA3）处理后,置于恒温20,25℃和变温20℃（16h）～30℃(8h)条件下进行发芽试验,探寻金铁锁种子的最适发芽温度和发芽习性;利用0.1%,0.5%,1.0%的硝酸钾（KNO3）溶液和10%,20%,30%的PEG6000溶液,分别渗透调节引发处理金铁锁种子,时间分别为8,12h 和16,24,32h,引发温度为20℃,对经引发处理后的金铁锁种子进行发芽试验,比较上述不同化学药剂和引发处理对金铁锁种子发芽力和种子活力的影响。结果表明：金铁锁种子萌发的最适温度为恒温25℃,第15天发芽结束时发芽率为86%;经0.01% GA3,KNO3和PEG6000溶液渗透调节引发处理金铁锁种子都能显著地提高金铁锁种子的发芽力和种子活力（P＜0.05）,其中0.1%的KNO3渗透引发处理8,12h和20%的PEG6000渗透引发处理24h,金铁锁种子的发芽势、发芽率、发芽指数、活力指数等指标均达到了最大值。     

串叶松香草种子的萌发条件

在实验室进行了串叶松香草种子适宜萌发条件和净度分析样品最低重量的研究，探讨了光照（黑暗为对照）、温度（１５℃、２０℃、２５℃和３０℃恒温，１５／２５℃、２０／３０℃和２５／３５℃变温）和发芽床（纸上ＴＰ、纸间ＢＰ和砂上ＴＳ）等因素对种子萌发的影响。结果表明：串叶松香草种子最适萌发条件为２５℃恒温、１５／２５℃和２０／３０℃变温（８ｈ高温，１６ｈ低温），高温时段（恒温在白天）设光照，和砂上（ＴＳ）及纸上（ＴＰ）发芽床；初次和末次计数时间分别以第５ｄ（或第６ｄ）和第１４ｄ为宜；种子的幼苗发育可归入双子叶植物子叶出土类型；净度分析样品最低重量是７０ｇ     

不同处理方式对野生凤仙种子发芽特性的影响

为野生凤仙的进一步引种驯化及开发利用提供参考,研究不同采种期、贮藏温度和赤霉素(GA3)浓度浸种对滇水金凤野生种子发芽的影响。结果表明:昆明地区滇水金凤种子的最佳采集时期为10月,在贮藏过程中种子不宜常温(22℃)久藏,而冷藏(2℃)能保持较高的发芽率,贮藏30d时种子的发芽率、发芽势和发芽指数最高,分别为75%、48%和20.60,且出苗整齐;不同浓度GA3浸种可不同程度提高滇水金凤种子的发芽率和发芽势以及活力指数,同一浓度随浸种时间延长呈先升后降趋势,其中以GA3250mg/L浸种16h的效果最好,其发芽率、发芽势、发芽指数和活力指数分别为97%、92%、40.55和64.47。     

持续高温对大豆品种萌发及幼苗生长的影响

通过人工控温,在大豆萌发期和幼苗生长期,对10个栽培大豆品种和2个野生大豆材料实施38℃持续高温处理,研究了持续高温对大豆品种萌发及幼苗生长的影响。结果表明：持续高温对大豆种子萌发没有显著影响,但对幼苗生长的影响达到了显著水平,且不同品种间存在差异。大豆品种的抗高温特性与籽粒大小、蛋白质含量和脂肪含量显著相关。野生大豆的抗高温能力远远高于栽培大豆。     

环境因素对新疆不同地区田旋花种子萌发的影响

【目的】研究环境因素对新疆不同地区田旋花种子萌发的影响,为制定有效的杂草防除技术提供理论依据。【方法】通过室内测定,研究温度、盐碱度、干旱、pH值等环境因子对新疆阿拉尔市和新和县两个点田旋花种子萌发的影响。【结果】阿拉尔市、新和县田旋花种子在5～50℃恒温范围内,随着温度的升高发芽率先升高后降低;田旋花种子最低发芽温度为5℃,当温度上升到30～40℃,两个县市的田旋花种子发芽率均达到最大值,种子在15℃/5℃～45℃/35℃的变温条件下均可发芽,且当温度为40℃/30℃时发芽率最高。盐碱胁迫可降低田旋花种子的发芽率,当NaCl浓度大于300 mmol/L或NaHCO₃浓度大于250 mmol/L时,两个县市的田旋花种子不能萌发;同时,田旋花种子的萌发受水势的影响较大,随着水势的增加,田旋花种子的发芽率逐渐降低,当水势达-0.6 MPa时,新和县田旋花种子已不能萌发,当水势达到-1.0 MPa时,阿拉尔市田旋花种子的萌发率仅为2%;pH值5～10,两个县市的田旋花种子均能正常萌发。【结论】室内模拟实验条件下,温度、盐碱和水势均是影响新疆不同地区田旋花种子萌发的关键环境因素,而农田生态系统中,干旱胁迫和pH不是限制田旋花萌发的主要因素。     

不同处理方法对樟叶越桔种子萌发的影响

为了提高樟叶越桔种子的萌发率,以在六盘水采集的樟叶越桔种子为材料,对其进行种子萌发试验,研究了不同水浴温度浸种(常温、40℃和60℃)、不同浓度赤霉素(GA_3)溶液浸种(200、1000、1500 mg/L)、不同浓度硼酸溶液浸种(0.2%和0.5%)和不同培养温度(15、20、25、30、35℃)等处理对樟叶越桔种子萌发的影响。结果表明:常温水浴浸种与40℃水浴浸种条件下种子萌发率差异不显著,60℃水浴温度过高,浸种后的种子丧失生命活力;GA_3浸种处理能显著促进种子萌发,缩短发芽时间,且萌发率随浓度增加而增加,最大萌发率达68.67%,而硼酸浸种无明显作用;不同培养温度条件下的萌发率差异显著,在15~30℃条件下,种子都能发芽,但萌发适宜温度为15~25℃,最适温度为20℃,最大萌发率达65.33%。     

温度与日长对山桐子萌芽成枝的影响

为了解环境信号对山桐子形成轮生枝的影响,以1年生山桐子苗木作为试验材料,研究温度与日长对山桐子顶侧芽萌发成枝的影响。设置3个温度和3个日长分别进行组合试验,共9组处理,同时以自然处理为对照,每10d观测1次顶芽萌发高生长过程中侧芽萌发成枝的时间、数量和生长量等指标。结果表明,25/15℃和30/20℃变温条件下,日长对山桐子顶芽萌发高生长过程影响差异不显著;25℃恒温条件下,12、16h日长时山桐子顶芽萌发高生长过程均呈断续高生长过程,而20h日长下却呈连续高生长过程,12h下高生长量最大,与16h差异达到显著水平。25/15℃变温条件下16、20h日长可以诱导侧芽萌发进行后发枝生长,日长越长分枝数越少,侧枝生长量越大;30/20℃变温条件下日长必须高达20h才会出现侧芽萌发成枝现象;25℃恒温条件下,3种日长处理的山桐子苗木均萌发成侧枝。郑州气候条件下,山桐子苗木顶芽萌发后生长至5-6月,芽内叶原基全部展开并进入新叶原基形成和缓慢展开期时,顶端优势转换为侧端优势,外界温度和日长等环境信号有利于诱导侧芽萌发成枝,而7-8月高温期日长又变短,很难再诱导侧芽萌发成枝,导致每年集中形成一轮后发枝,进而形成分层型树冠。     

温度、光照及盐分对喜盐鸢尾种子萌发的影响

研究温度、光照及盐胁迫对喜盐鸢尾（Iris halophila Pall．）种子萌发的影响,筛选种子萌发的适宜条件.光照12h/黑暗12h 交替时喜盐鸢尾种子萌发最适温度为10℃/20℃,最终发芽率为86．66％±0．58％,亚适宜温度为15℃/25℃;其种子萌发对光照不敏感,属于光中性种子;盐分浓度50 mmol/L 时促进种子萌发,200~800 mmol/L时发芽率随盐浓度的增高而降低,800 mmol/L NaCl 胁迫下的种子复水后恢复发芽率为60％.温度是影响喜盐鸢尾种子萌发的重要限制因子;光照对喜盐鸢尾种子萌发有一定的促进作用,但差异不显著（P ＞0．05）;与其他盐生植物相比,喜盐鸢尾表现出较强的耐盐性,其种子萌发特性体现出对盐生环境的适应性.     

生殖生长期温度对大豆各器官维生素E及其组分含量影响

研究以α-生育酚含量水平不同的两个大豆品种北丰9(高)和龙选1号(低)为试验材料,在大豆生殖生长期利用光照培养箱以三个温度处理(28~34℃、22~28℃、16~22℃),研究不同温度对大豆茎、叶、荚皮、籽粒维生素E含量影响。结果表明,随温度升高,大豆茎中α-生育酚、γ-生育酚和维生素E总含量降低(P0.01),叶片中α-生育酚和维生素E总含量降低(P0.01),籽粒中γ-生育酚、δ-生育酚和维生素E总含量降低(P0.01),而籽粒中α-生育酚增加(P0.01)。中等温度(22~28℃)更有利于大豆荚皮中δ-生育酚和VE总含量积累,而低温(16~22℃)不利于α-生育酚和γ-生育酚积累。高温条件能提高α-生育酚从叶、茎和荚皮向籽粒中转化运输率(P0.01),有利于大豆籽粒中α-生育酚含量积累。