草铵膦对大豆胚尖不定芽形成的影响

本文以大豆黑农37、吉育91和淮豆4号3种基因型的胚尖为外植体,研究草铵膦7种浓度对大豆不同基因型胚尖不定芽形成的影响。结果表明,大豆3种基因型表现出对草铵膦的耐性不同。吉育91耐性较强,淮豆4号耐性较差。依大豆基因型的不同,草铵膦浓度在0.6mg/L或1.2mg/L时抑制大豆胚尖不定芽形成。本研究为以Bar基因作为选择标记的大豆胚尖遗传转化奠定了基础。     

棉花基因枪茎尖转化研究

对棉花茎尖轰击转化的多种因素进行了分析,建立了较为完善的基因枪茎尖转化体系,使抗性转化率达到4.7％～9.4％,转化周期缩短至2～3个月,改进了抗性筛选程序,建立了4次筛选法,获得91株抗生素抗性植株;同时对部分植株目的基因的表达量进行了初步的遗传分析。结果表明,茎尖的轰击状态与抗性筛选程序对转化周期与转化率具有决定性作用。     

棕色棉茎尖基因枪遗传转化

为了建立高效的棉花茎尖遗传转化体系,以棕色棉品种新彩棉5号为材料,采用茎尖培养和基因枪遗传转化方法,通过对凝固剂种类、活性炭含量、卡那霉素浓度、渗透处理时间、轰击压力、轰击距离等因素的优化,建立了棕色棉新彩棉5号茎尖基因枪遗传转化技术体系。结果表明,不同凝固剂种类、活性炭含量、卡那霉素浓度、渗透处理时间、轰击压力和轰击距离对棕色棉茎尖转化率有明显影响。最佳的遗传转化体系为:前渗处理4 h,轰击压力7.586 MPa(1100 psi),轰击距离9 cm,轰击后恢复培养4 d,然后在MSB+8 g·L~(-1)琼脂+125mg·L~(-1)卡那霉素筛选培养基中筛选25 d。获得抗性芽后,在添加1 g·L~(-1)活性炭的生根培养基中诱导抗性芽生根,并获得抗性再生植株。通过PCR和q PCR检测,5200个茎尖共获得16株阳性转基因植株,转化率为0.31%。该技术体系的建立为棕色棉的遗传转化奠定了基础,为彩色棉育种提供了新的材料。     

农杆菌介导大豆胚尖转化体系的研究

以大豆"黑农37"胚尖为外植体,利用农杆菌介导法将抗除草剂基因EPSPS转入大豆,并对转化各培养阶段6-苄氨基腺嘌呤(6-BA)浓度进行了优化。结果表明:在预培养和共培养培养基中加入较高浓度6-BA有利于抗性芽的诱导;1mg/L6-BA和0.2mg/L吲哚丁酸(IBA)配合使用有利于抗性芽的伸长且提高了抗性芽的再生率;将抗性芽添加在1mg/L IBA的培养基中培养7d后转入不加任何激素的培养基中生根快且移栽后成活率高。PCR结果初步证明将EPSPS基因转入到大豆中。     

苹果SnRK2基因家族的鉴定和生物信息学分析

SnRK2（蔗糖非发酵1型相关蛋白激酶2）是植物特有的一类Ser/Thr 类蛋白激酶,参与植物体内多种信号途径的转导,在植物逆境生理过程中扮演了重要的角色。本文利用隐马可夫模型搜索和系统建树的方法,在苹果基因组中鉴定出了16个SnRK2基因家族成员,然后从系统发生、理化性质、二级结构、motif、C末端序列和EST等方面对其进行了预测和分析,并分析了苹果与拟南芥、水稻、玉米等的SnRK2基因家族之间的关系。结果表明,苹果中鉴定的基因与拟南芥、水稻、玉米所有的SnRK2蛋白一起分成了3个亚族。系统发生、motif和C末端序列分析表明,苹果SnRK2蛋白激酶家族具有较高的保守性。本研究为苹果SnRK2基因家族生物学功能的研究奠定了生物信息基础。     

基因枪轰击转化棉花茎尖分生组织影响因素的探讨

以农大KB18的茎尖分生组织为受体材料,利用基因枪轰击法将植酸酶基因(PhyA)导入棉花茎尖分生组织,经过再生、筛选、分子检测等过程获得若干转基因植株。通过研究碳源、外源激素、活性炭、轰击距离和轰击次数以及茎尖的恢复培养与抗性筛选等,建立了较为完善的棉花基因枪茎尖转化体系。结果表明,植株再生率与再生培养基的成分,如激素的有无、活性炭的含量和碳源等有关,轰击距离以及筛选程序中卡那霉素的起始筛选时间、筛选浓度和浓度梯度等因素对转化周期和转化率有直接影响。     

适于基因枪转化的棉花茎尖培养及筛选体系初探

将棉花种仁无菌培养40～60h,制备茎尖分生组织,培养在无激素MSB培养基上,直接再生完整植株。植株再生率与品种基因型差异较小,与再生培养基的成分相关。棉花茎尖分生组织制备的优劣与基因枪转化率密切相关。筛选培养过程中,卡那霉素的起始时间和浓度梯度等因素对转化率有直接影响。还描述了非转化植株的表现,探讨了抗生素最高筛选压的确定等问题。     

影响基因枪轰击转化棉花胚性愈伤的因素初探

本研究就基因枪法转化棉花胚性愈伤过程中的影响因素进行了探讨。结果表明,2,4 D在愈伤启动阶段很重要,而在胚性愈伤诱导阶段要尽量少加或不加,IAA的浓度比KT低时,有利于胚性愈伤的产生。胚性愈伤的表观状态、轰击次数和轰击距离是基因枪转化成功的关键因素。通过GUS基因在棉花胚性愈伤中的瞬间表达证明,在轰击前4h,轰击后16h采用0.3mol·L 1的甘露醇做渗透处理,轰击距离9cm,轰击次数2次,效果最好。     

以棉花茎尖分生组织为受体进行基因枪轰击转化的研究

以棉花茎尖分生组织为受体进行基因枪遗传转化,在不受宿主基因型范围和操作时间的限制等方面优于农杆菌介导法和花粉管通道技术。影响棉花茎尖分生组织基因枪遗传转化率的因素较为复杂,轰击前,外植体制备需考虑茎尖分生组织的取材时间、下胚轴保留的长度、外源生长调节剂及活性炭的使用量,以保证其正常生长;轰击后,抗生素筛选的浓度、筛选培养基的转换时间和抗性苗的壮苗也会影响转化效率;此外,DNA和钨粉或金粉的质量、基因枪参数及操作等对转化效果都有一定的作用。除对影响茎尖分生组织基因枪转化率的因素分析以外,还对近年来在棉花茎尖分生组织遗传转化中的最新动态进行了综述,并对目前存在的问题加以讨论。     

大豆胚尖不定芽诱导影响因子的研究

以大豆胚尖为外植体,研究基因型、浸种时间和诱导时间对胚尖不定芽诱导的影响。结果表明,7个基因型大豆不定芽诱导率变化在35.0%~83.3%之间,黑农48适合于大豆胚尖不定芽再生系统;合丰35成熟种子诱导不定芽产生以浸种48h效果最好;黑农48诱导96h时不定芽诱导率达100%,诱导96h和84h大豆胚尖可形成较多的不定芽。     

Transpiration Dynamics in Cadmium-Treated Soybean (Glycine max L.) Plants

Soybean ( Glycine max L.) plants, cv Richland, were grown during 30 days in a nutrient solution. After this period the plants were treated with a 50 μM Cd(NO₃)₂ solution. Sap flow rate and stomatal conductance were monitored during 4 consecutive days; at the end of this period relative water content and stomatal width and length were determined on fully expanded leaves. On the second day from the Cd treatment sap, flow rate and stomatal conductance in the treated plants were reduced to 60% of the control plants. Stomatal conductance kept on decreasing up to the fourth day. Cadmium decreased the leaf relative water content and the reduction in the stomatal closure was supported by an increase in the L/W ratio of the stomata. Root water uptake should be the primary mechanism reduced by Cd stress in soybean, and this reduction is consistent with the decrease in transpiration rate and with the stomatal closure.     

Mineral Nitrogen Availability and Isoflavonoid Accumulation in the Root Systems of Soybean (Glycine max (L.) Merr.)

Isoflavonoids, as plant-to-bacteria signal molecules, play an important role in the establishment of the soybean ( Glycine max (L.) Merr.)– Bradyrhizobium japonicum nitrogen (N) fixing symbiosis. They are essential to the development of effective root nodules and responsible for inducing the nod genes of B. japonicum . Because N affects a broad range of infection events, especially the symbiotic events occurring within 18 h of inoculation, it is reasonable to hypothesize that mineral N disrupts the interorganismal signal exchange between soybean host plants and B. japonicum . High performance liquid chromatographic (HPLC) analysis of root extracts of soybean, inoculated with B. japonicum or not, grown with various levels of mineral N in the rooting medium were performed to test this hypothesis. The results of these studies indicated that: (1) at early plant growth stages (before the onset of N fixation), a strong negative relationship between N application and soybean root isoflavonoid (genistein and daidzein) concentrations existed; (2) although isoflavonoid (genistein and daidzein) concentrations in both inoculated and non-inoculated soybean root systems were generally decreased by N application, at very low N levels (10 mg N l⁻¹) genistein in the non-inoculated plant roots was not decreased relative to the 0 N plants; (3) averaged over all mineral N treatment levels and sampling times, inoculation of soybean with B. japonicum increased root daidzein concentrations (P > 0.05), but did not affect genistein. Overall, N application reduced the isoflavonoid concentration of soybean root systems, which probably plays a part in the regulation of soybean nodule formation by available N.     

Growth and Development of Soybean (Glycine max [L.] Merr.) Cultivars under Shade in Coconut Garden

The growth and development of seven soybean cultivars were studied under shade in a coconut garden. Higher shoot height, internodal elongation and lower leaf area index were the most significant growth changes noticed under shade. Leaf net photosynthesis, crop growth rate and seed yield were also reduced under shade. The cultivars CO 1, UGM 30 and UGM 37 recorded higher yield under shade when compared to other cultivars tested.     

大豆幼荚子叶原生质体培养及植株再生

本文研究了13个栽培大豆（Glycine max L.）品种原生质体培养的再生能力。从大豆幼荚子叶酶解游离原生质体,用Gellan Gum进行株状包埋,悬浮在含2,4-D 0.1-0.2mg/L,BA0.5-1.0mg/L的改良MS液体培养基中,原生质体培养3天后开始第一次分裂,以后持续分裂。供试基因型间的10天植板率差异显著,变幅为33-67%。30天内形成大量的     

Transgenic fertile plants of soybean [Glycine max (L.) Merrill] obtained from bombarded embryogenic tissue

This work describes the production of transgenic, fertile plants of soybean [Glycine max (L.) Merrill]. The transformation method combines the advantages of somatic embryo genesis with the efficiency of particle bombardment of tissues that have a great capacity for in vitro proliferation and regeneration. The results described here represent the first report of transformation of soybean cultivars recommended for commercial growing in South Brazil using somatic embryogenesis, and may open the field for the improvement of this crop in this country by genetic engineering. This revised version was published online in August 2006 with corrections to the Cover Date.     

Interaction Amongst Soybean [Glycine max (L.) Merrill] Genotype, Soil Type and Inoculant Strain with Regard to N2 Fixation

The nitrogen (N₂)‐fixing bacterial inoculant strain for soybean [Glycine max (L.) Merrill] is not indigenous to South African soils. The interaction between soybean genotype, soil type and inoculant strain, however, has a definite influence on soybean production and compatibility should be optimized. This paper reports a growth chamber study using three different soybean genotypes (Barc‐9, Avuturda and Talana), three Bradyrhizobium japonicum inoculant strains (WB108, WB112 and WB1) and three soil types (Avalon, Arcadia and sand) to evaluate the effectiveness of N₂ fixation by different genotype × soil type × inoculant strain combinations, using different measuring parameters. These parameters included nodule fresh mass (NFM), amount of N₂ fixed (P_fix), as determined by the ureide method, seed protein content (SPC), average seed mass per plant (SMP) and average foliar N content (FNC). The comparison amongst the three‐way interactions, genotype × soil type × inoculant strain, did not differ significantly for the parameters used. Significant two‐way interactions were soil × inoculant for FNC, P_fix and SMP; soil × genotype for FNC and SMP, and inoculant × genotype for FNC (P < 0.05). The soil × inoculant strain interaction was significant for P_fix (P < 0.05). NFM, P_fix, FNC, SMP and SPC correlated positively with soil pH and negatively with soil clay content and soil NO₃^– and NH₄⁺ content (P < 0.05). SPC was significantly different (P < 0.05) for soil type, genotype and inoculant strain. P_fix and NFM did not reflect the protein content of the seeds, indicating that nodule evaluation should be used with caution as a N₂ fixation parameter. Low soil pH and high mineral N content inhibited N₂ fixation. NFM correlated negatively with the clay content of the soil. This finding confirms that soybean production in South Africa can be improved by appropriate selection of genotypes and inoculant strains for their compatibility in different soils.     

Effect of Salinity Stress on Growth and Nutrient Composition of Three Soybean (Glycine max L. Merrill) Cultivars

Soil salinity is a major limitation to legume production in many areas of the world. The salinity sensitivity of soybean was studied to determine the effect of salinity on seed germination, shoot and root dry weights, and leaf mineral contents. Three soybean cultivars, Lee, Coquitt, and Clark 63, were planted in soils of different salinity levels. The electrical conductivity (EC) of the soils used in this experiment was 0.5 dS m^?1. The soil salinity treatments were 0.5, 2.5 4.5, 6.5 and 8.5 dS m^?1. Saline drainage water from a drainage canal with an EC of 15 dS m^?1 was used to treat the soil samples in order to obtain the desired salinity levels. Germination percentages were recorded 10 days after planting. Shoot and root dry weights of 45‐day‐old plants were measured. Nutrient concentrations for Na⁺, K⁺, Ca²⁺, Mg²⁺ and Cl^? were determined. Germination percentages were significantly reduced with increasing salinity levels. The cultivar Lee was less affected by salinity stress than Coquitt and Clark 63. At 8.5 dS m^?1 a significant reduction in plant height was found in all three cultivars. However, Lee plants were taller than plants of the other two cultivars. Salinity stress induced a significant increase in leaf sodium (Na⁺) and chloride (Cl^?) in all cultivars. However, the cultivar Lee maintained lower Na⁺ and Cl⁺ concentrations, a higher potassium (K⁺) concentration and a higher K⁺/Na⁺ ratio at higher salinity levels than Coquitt and Clark 63. Saline stress reduced the accumulation of K⁺, calcium (Ca²⁺) and magnesium (Mg²⁺) in the leaves of the cultivars studied. This study suggests that Lee is the most tolerant cultivar, and that there is a relationship between the salt tolerance of the cultivar and macronutrient accumulation in the leaves.     

大豆苗期耐低磷性及其QTL定位

利用来自波高和南农94-156（耐低磷种质）的重组自交系群体NJ(SP)BN（151个家系）通过盆栽试验研究与耐低磷有关的性状,并进行耐低磷性状的QTL定位。初步结果表明,不施磷处理的总干重主要由单株P吸收量决定,而与磷利用效率无关;而单株P吸收量与根干重、根效率均极显著正相关,单株P吸收量变异的76.2%由根效率决定。不施磷处理的根冠比（R/S）显著增加主要是茎干重无显著变化而根干重显著增加所致。在D1b+W、F、G、N和O等5个连锁群上共检测到7个QTL与耐低磷有关。分别可解释所对应性状表型变异的4.8%~17.0%,其中5个QTL的增效基因来自亲本波高,2个QTL的增效基因来自亲本南农94-156。     

紫外线-B辐射增强对大豆生长、发育、色素和产量的影响

在田间条件下，模拟20%平流层臭氧层的减薄，研究了增强紫外线-B辐射(280～320nm)(UV-B)对10个大豆品种生长、发育、色素和产量的影响。结果表明：(1)增强的UV-B辐射使一些大豆品种的物候期发生改变。(2)明显降低多数品种光合作用色素和类胡萝卜素的含量，增加所有品种类黄酮类化合物的含量。(3)大豆品种的株高、根茎叶生物量     

Influence of Root-Applied Epibrassinolide and Carbenoxolone on the Nodulation and Growth of Soybean (Glycine max L.) Seedlings

24-Epibrassinolide belongs to the brassinosteroid family of plant hormones, and carbenoxolone is a synthetic analogue of glycyrrhizic acid that inhibits enzymes important in steroid and prostaglandin action in animals. The effect of these compounds on root nodulation, root growth and shoot growth of Glycine max (L.) Merr. cv. Tracy M was examined. Epibrassinolide reduced total nodulation, plant wet weight, root length, shoot length, first internode length and number of lateral roots. Effects were observed at concentrations as low as 0.1 μ M . Carbenoxolone reduced lateral root formation, but did not reduce nodule numbers, root length or weight, nor stem length or weight.