提高小麦X玉米杂交产生单倍体胚的频率

Laurie和Bennett（1986）用普通小麦与玉米杂交，并进行幼胚培养，获得了小麦单倍体植株。但要真正用于育种实践，必须首先获得较高并且相对稳定的得胚率。目前报道的单倍体胚诱导频率差异较大，最高的已达48．6％，最低的不足10％（顾坚等，2005）。本实验通过在2，4-D中加入不同体积浓度的二甲基亚砜，研究其对得胚率的影响。     

提高小麦×玉米杂交产生单倍体胚的频率

Laurie和Bennet(t1986)用普通小麦与玉米杂交,并进行幼胚培养,获得了小麦单倍体植株。但要真正用于育种实践,必须首先获得较高并且相对稳定的得胚率。目前报道的单倍     

日本臭菘体细胞胚胎发生及植株再生体系的建立

以日本臭菘幼叶为外植体,应用均匀设计法筛选其最适合的胚性愈伤组织及胚性细胞复合体诱导、体细胞胚胎发育及植株再生的培养基配方,建立日本臭菘体细胞胚胎发生体系。结果表明,LS+6-BA 1.0 mg/L+2,4-D 2.0 mg/L+IAA 0.1 mg/L适宜日本臭菘幼叶胚性愈伤组织及胚性细胞复合体诱导,诱导率为98%;LS+6-BA 0.50 mg/L+NAA 0.10 mg/L+IAA 0.10 mg/L最适宜体胚发育及植株再生,体胚萌发率为100%,萌发的体胚在发育培养基上继续培养42 d后全部发育成完整植株。对不同阶段培养材料的形态结构及超微结构的观察证明,成功建立了日本臭菘体细胞发生及植株再生体系。     

辐照花粉促进普通小麦与窄颖赖草属间杂交的研究

通过研究小麦基因型、γ射线辐照剂量、授粉时期等对普通小麦与窄颖赖草（ Ｌｅｙｍ ｕｓ ａｎｇｕｓｔｕｓ） 杂交结实率的影响和不同幼胚抢救方法,首次较为完善地建立了运用核辐射促进普通小麦与窄颖赖草属间杂交的配套方法程序,即选用适宜小麦基因型Ｊ １１ 作母本,用适宜剂量（５ ～９ Ｇｙ） 的γ射线辐照窄颖赖草花粉,在适宜授粉时期（ 去雄后１ｄ 、散粉前２ ～３ｄ） 授粉;采用胚 愈伤组织二步成苗法进行幼胚抢救。     

基因枪法转化小麦幼胚瞬时表达

自Vasil et al．（1996）利用基因枪将获得小麦对除草剂Basta具有抗性的再生植株以来，基因枪介导的小麦遗传转化研究发展很快（Altpeter et al．，1996）。在小麦基因枪转化中，优化基因枪转化因素，提高转化效率仍然是基因转化的关键问题。本实验研究了不同金粉用量、质粒DNA浓度及轰击枪数对小麦幼胚瞬时表达的影响，通过GUS染色和细胞压片，分析了gus基因的瞬间表达。     

影响玉米幼胚愈伤组织再生率的因素分析

为探讨影响玉米幼胚愈伤组织的再生率的因素,本试验以3个优良玉米自交系为材料,对影响幼胚的胚性愈伤组织诱导率、克隆指数和分化率的因素进行了研究。结果表明,3个玉米自交系幼胚的愈伤诱导率差异极显著。 生长环境对975-12影响显著,对18-599和416051影响不显著。18-599和416051的胚大小为2mm时II型胚性愈伤组织的诱导率最高,而975-12在胚大小为2.5mm时II型胚性愈伤诱导率最高。3个自交系的克隆指数和分化率一般在第3或第4代时达到最大值。综合分析表明,18-599和416051这2个自交系具有愈伤组织诱导率高、克隆能力强、易分化的优点,是玉米转基因研究中具有潜在利用价值的优良自交系。     

不同培养基对小麦×玉米杂种胚离体培养成苗的影响

为了提高小麦远缘杂交单倍体胚植株再生频率,剥取胚龄16～20d的小麦单倍体胚无菌条件下接种到不同配方的培养基.结果表明,直径＜ 500μm的小胚在1号培养基、直径＞500 μm态的较大胚于2号培养基能一步成苗直接发育成具有丛生芽和健壮根的幼苗;若把丛生幼芽分开后分别转移到1/2 MS基础培养基,则可分化增殖为多株麦苗.小胚培养基配方为:1/2MS +0.1mg·L-12,4-D+0.2mg·L-1 BA +300mg· L-1 LH(水解乳蛋白)+50g·L-1蔗糖+7g L-1琼脂,pH =5.8,成苗率71％;大胚培养基配方为:1/2 MS +0.1mg· L-12,4-D+0.2mg·L-1BA +30g· L-1蔗糖+7g·L-1琼脂,pH值5.8,成苗率83％以上,以上培养基维生素部分为正常MS培养基维生素加入量的2倍.适宜于小麦单倍体胚再生和繁殖的生长素效果:2,4-D＞IBA＞IAA,培养基加入2,4-D后经继代培养途径形成单倍体植株生长旺盛,根系发达,增加了单胚再生植株数和植株丛生苗数量,有利于大幅度提高胚成苗率以及染色体加倍效率,从而提高远缘杂交单倍体育种水平,缩短小麦新品种生产周期.     

玉米不同部位愈伤组织诱导及植株再生的比较研究

为建立稳定高效的玉米再生体系,选用6个玉米常用自交系的成熟胚、幼胚、茎尖和幼嫩叶段作为外植体,在含有不同外源激素的培养基中诱导愈伤组织及植株再生,比较研究这6个玉米自交系的诱愈率和分化率,并观察愈伤的形态。结果表明,在适宜的培养条件下,不同基因型、不同外植体均能分化出苗,但其再生率差别较大,其中玉米幼胚的诱愈率和分化率最高,其次为茎尖、成熟胚,幼嫩叶段相对较低。不同外植体的培养基类型和外源激素的浓度配比有着很大的不同,且不同基因型的愈伤差异也较大。本研究筛选出了3个愈伤胚性良好、分化率较高的玉米基因型辐80、综31和Mo17。玉米茎尖、成熟胚和幼嫩叶段的再生均找到了适宜的培养条件,完全能够代替幼胚作为愈伤组织诱导的初始材料,该结果为建立一套高效稳定的玉米再生体系提供了理论依据和技术参考。     

辐照花粉对小麦与中间偃麦草杂交及其胚胎发育的影响

用γ射线辐照中间偃麦草散粉期的穗,用其花粉授予普通小麦“J-11”和“中国春”,研究不同剂量辐照花粉对普通小麦与中间偃麦草杂交结实率、杂交种子含胚率、杂种幼胚培养和杂种幼苗获得率的影响。结果表明,5~9Gy低剂量γ射线略提高了中国春×中间偃麦草的结实率,表现出低剂量辐射的刺激效应,但对J-11×中间偃麦草却未表现出刺激效应。所有剂量的辐射对杂种幼胚均有伤害作用,杂交种子含胚率、杂种幼胚成苗率随剂量增加而下降。30Gy处理时有12.9%~14.5%的杂种幼胚发育成了植株,但该剂量应用到小麦中难以获得后代。在50~100Gy高剂量γ射线处理杂交种子胚发育不良,通过幼胚培养未能得到植株。将花粉辐照技术与幼胚拯救技术、花药培养技术有效结合,可以快速获得突变体,提高诱变育种效率。     

苹果叶柄体细胞胚胎发生

以苹果栽培品种嘎拉试管苗带柄叶片为材料,接种于附加不同浓度BA和蔗糖及不同氨基酸的MS培养基上,诱导叶柄产生体细胞胚和再生嫩梢。研究显示,附加BA 1.5mg/L的MS培养基是叶柄形成体细胞胚进而发育成嫩梢的适宜培养基。培养基中蔗糖浓度调控叶柄的分化类型,浓度在5～10g/L时,叶柄由体细胞胚途径分化嫩梢,浓度为20g/L时,叶柄同时由体细胞胚和器官发生途径形成嫩梢,浓度30g/L以上时,叶柄由器官发生途径分化嫩梢。4种氨基酸中,L-脯氨酸和谷氨酰胺促进叶柄体细胞胚形成,以L-脯氨酸促进效果最好。     

Electron capture gas-liquid chromatographic method for the simultaneous analysis of 2,4-D, dicamba, and mecoprop residues in soil, wheat, and barley.

A method has been developed for the simultaneous analysis of 2,4-D (2,4-dichlorophenoxy-acetic acid), dicamba (2-methoxy-3,6-dichloro-benzoic acid), and mecoprop (MCPP; 2-[(4-chloro-o-tolyl) oxy] propionic acid) residues in soil, wheat, and barley. Soil and crop samples are extracted with acidic acetone and methanol, respectively. The extracts in diethyl ether are esterified with diazomethane and cleaned up by passing through a Florisil column. Extracts are analyzed by gas-liquid chromatography, using an electron capture detector to determine 2,4-D and dicamba residues. Mecoprop in the extract is not detected at low levels of concentration. However, bromination of the extract increases the response of the electron capture detector to mecoprop. The method is sensitive to about 0.05 ppm 2,4-D and dicamba and 0.5 ppm mecoprop. Recoveries of these 3 herbicides added to soil, wheat, and barley samples at 0.05, 0.1, 0.5, and 1.0 ppm levels were between 65 and 93%. The method was used for the simultaneous analysis of 2,4-D, dicamba, and mecoprop residues in wheat, barley, and soil samples obtained from fields sprayed with the herbicide formulation Kil-Mor.     

提高小麦×玉米杂交产生单倍体胚频率的研究

为了提高小麦×玉米杂交单倍体胚的产生频率，采用了2,4-D中含有不同体积浓度的二甲基亚砜和不同的激素处理组合两种方法诱导小麦×玉米产生单倍体，研究其对得胚率的影响。结果表明，就平均得胚率而言，在二甲基亚砜激素浓度处理中，最佳的二甲基亚砜体积浓度为3.0%（得胚率为17.0%），而且各不同浓度的处理均高于对照（9.7%）；在不同激素配比试验中，2,4-D+3%二甲基亚砜单独处理的得胚率（7.3%）﹥2,4-D两次处理(6.9%)﹥2,4-D与2,4-D+3%二甲基亚砜配合处理(5.5%)﹥2,4-D一次处理(2.9%)。     

紫花苜蓿组织培养体系的建立

通过外植体类型、生长素和细胞分裂素浓度等因素对紫花苜蓿愈伤组织诱导、分化影响的试验,建立了高效的紫花苜蓿组织培养体系,即以真叶为外植体,在MS+0.2mg/L2,4-D+0.01mg/LNAA+0.2mg/LKT培养基上进行愈伤组织的诱导,诱导率可达到100%,愈伤组织继代2～3次,然后在MS培养基上分化,分化率可达90%。分化苗转入1/2MS培养基进行生根,形成完整的组培苗。愈伤组织诱导的正交试验表明,2,4-D浓度是影响苜蓿愈伤组织诱导率的主要因素,其次是外植体类型、NAA浓度、6-BA浓度和KT浓度;对苜蓿愈伤褐化率影响较大的因素是外植体类型,其次是KT、2,4-D、6-BA、NAA浓度。外植体类型对愈伤组织诱导率和褐化率的影响均达到极显著水平(P0.01);生长素(2,4-D、NAA)对苜蓿愈伤组织的诱导作用大于细胞分裂素(6-BA、KT)。分化试验表明,紫花苜蓿愈伤组织分化的主要决定因素是愈伤诱导培养基的激素配比。     

Laboratory incubation studies of chlorophenoxyacetic acids in chernozemic soils

The relative persistence of 2,4-D, MCPA and 2,4,5-T in some Saskatchewan soils was assessed under laboratory conditions. Under moist conditions, 2,4-D and MCPA showed half-life times of between 14 and 41 days but the MCPA half-life was usually 1 or 2 days longer. 2,4,5-T exhibited a half-life period over twice the length of the other chemicals. The half-life times were directly correlated to microbial plate counts, the larger numbers of soil microorganisms being associated with shorter residence times. Half-lives depended on soil moisture content and the best moisture levels for chemical loss appeared to be just less than field capacity. The use of ¹⁴C in 2,4-D incubation studies showed that the initial cleavage of the 2,4-D molecule was associated with the ether linkage and was not a decarboxylation.     

Single-laboratory validation of EPA Method 8150 for determination of chlorinated herbicides in hazardous waste

Method 8150, published in the second edition of Test Methods for Evaluating Solid Waste, Manual SW-846, required optimization, ruggedness testing, linearity determinations, precision tests, bias testing, gas chromatographic/mass spectrometric confirmation, and quality control guidelines for validation of the protocol. This single-laboratory validation, which is applicable to the determination of the herbicides dicamba, silvex, 2,4-D, 2,4-DB, 2,4,5-T, dinoseb, MCPP, MCPA, and dichlorprop in hazardous waste extracts, was completed and is described in this report. Final ruggedness testing of the optimized procedure gave a mean recovery of 89.3% with a standard deviation of 4.3%. Percent relative standard deviations are less than 10 (n = 20, each analyte) over a 10(2) linear range of concentration for MCPP and MCPA and over a 10(3) linear range of concentration for the other target herbicide esters. Instrumental detection limits for electron capture detection and mass spectrometric identity confirmation were determined and found to be matrix-dependent.     

空竹悬浮细胞系的建立

竹子悬浮细胞培养比较困难,本研究首次获得空竹悬浮细胞.以空竹种胚为材料诱导愈伤组织,建立稳定的悬浮细胞培养体系;通过固体培养法获得悬浮细胞来源的愈伤组织,可为竹类悬浮细胞系遗传转化或诱变后单克隆的筛选提供材料.空竹种胚在3/4MS+500mg/L脯氨酸+500mg/L谷氨酰胺+300mg/L胰蛋白胨+3.0mg/L 2...     

Proteome-level differences between auxinic-herbicide-susceptible and -resistant wild mustard (Sinapis arvensis L.)

To identify proteins that may be involved in mediating auxinic herbicide resistance (i.e., resistance to dicamba, picloram, 2,4-D), we compared the proteomes of an auxinic-herbicide-susceptible (S) and -resistant (R) wild mustard (Sinapis arvensis L.) biotype at different developmental stages. Using two-dimensional electrophoresis and mass spectrometry, we identified 11 seedling and leaf proteins that showed reproducible differences in expression between the S and the R wild mustard biotype following application of dicamba. Our proteome-level studies revealed the increased expression of the enzyme peptidylprolyl cis-trans isomerase (PPIase), which has recently been implicated in auxin signal transduction. Juglone, an inhibitor of PPIase, interfered with the normal ability of R seeds to germinate in the presence of dicamba, whereas S seeds did not germinate in the presence of dicamba or dicamba plus juglone. When R and S plants (3-4 leaf stage) were treated with dicamba, S showed typical auxinic herbicide effects (e.g., epinasty) whereas R did not. However, the concomitant application of dicamba and juglone to greenhouse-grown R plants produced morphological changes that were consistent with known auxinic-herbicide-induced symptoms. This is the first report suggesting the potential involvement of differential expression of PPIase in mediating auxinic herbicide resistance.     

INDUCTION OF SOMATIC EMBRYOS AND REGENERATION OF PLANTLETS FROM RICE ROOTS

<正> The number of somatic embryos and regenerated plantlets were directly induced from irra-diated rice roots of the variety Taipei 309(Oryza sativa L.).For the induction of somatic em-bryos,the suitable age of roots was no more than 7 days after seed culture on the medium and thesections near tip were more vigorous than those near base of a root;the number of somatic em-bryos induced by the media with 1.11mg/L2,4-D plus 0.47mg/L NAA and 2.21mg/L 2,4-Dplus 1.86mg/L NAA was much higher than that induced by 1.11mg/L 2,4-D alone;10～20 Gyand 40 Gy of γ irradiation were the most favourable for increasing somatic embryo number onthe media of 2.21mg/L 2,4-D plus 1.86mg/L NAA and 1.11mg/L 2,4-D plus 0.47mg/L NAAor 1.11mg/L 2,4-D alone respectively.The highest number of regenerated plantlets was fromthat cultured on the medium of 1.11mg/L 2,4-D plus 0.47mg/L NAA and irradiated with 30～40 Gy of γ rays.     

糯性和半糯性水稻品种成熟胚组织培养力的比较

为建立江苏优质糯性水稻品种的成熟胚再生技术体系,以非糯粳稻南粳44为对照,选择糯稻品种苏御糯和半糯性品种南粳5055为研究材料,以其成熟胚为外植体,分别从愈伤组织的诱导、继代、分化和植株再生进行了比较,研究糯性水稻的成熟胚再生技术。结果表明,以M8为基本培养基,添加同样的激素组合(蔗糖3%,琼脂0.8%, 2,4-D 3mg/L,KT 0.1mg/L,ABA 0.2mg/L),诱导20d,苏御糯出愈率为98.81%,南粳5055为81.00%,均比对照南粳44的 99.32%略低,而且3品种的出愈快慢有差异,与对照南粳44相比,苏御糯的和对照相当,表现出愈较快,而南粳5055则比较慢。在分化过程中,以MS为基本培养基,添加不同浓度的激素组合(蔗糖3%,琼脂1%,山梨醇1.5%,2,4-D 0.1~0.4mg/L,6-BA 1~2mg/L),苏御糯和南粳5055在0.1mg/L 2,4-D和2mg/L 6-BA组合中分化率达到最高,分别是86.54%和56.5%,而对照南粳44只有21.42%,但南粳44在0.2mg/L 2,4-D和3mg/L 6-BA组合中的分化率最高,达到了66.67%。不同基因型的最高再生率分别为:苏御糯87.5%,南粳44 78.38%,南粳5055 65.3%。     

Physiological and biochemical characterization of quinclorac resistance in a false cleavers (Galium spurium L.) biotype

The physiological and biochemical basis for quinclorac resistance in a false cleavers (Galium spurium L.) biotype was investigated. There was no difference between herbicide resistant (R) and susceptible (S) false cleavers biotypes in response to 2,4-D, clopyralid, glyphosate, glufosinate-ammonium, or bentazon. On the basis of GR(50) (growth reduction of 50%) or LD(50) (lethal dose to 50% of tested plants) values, the R biotype was highly resistant to the acetolactate synthase (ALS) inhibitor, thifensulfuron-methyl (GR(50) resistance ratio R/S = 57), and quinolinecarboxylic acids (quinclorac R/S = 46), resistant to MCPA (R/S = 12), and moderately resistant to the auxinic herbicides picloram (R/S = 3), dicamba (R/S = 3), fluroxypyr (R/S = 3), and triclopyr (R/S = 2). The mechanism of quinclorac resistance was not due to differences in [(14)C]quinclorac absorption, translocation, root exudation, or metabolism. Seventy-two hours after root application of quinclorac, ethylene increased ca. 3-fold in S but not R plants when compared to controls, while ABA increased ca. 14-fold in S as opposed to ca. 3-fold in R plants suggesting an alteration in the auxin signal transduction pathway, or altered target site causes resistance in false cleavers. The R false cleavers biotype may be an excellent model system to further examine the auxin signal transduction pathway and the mechanism of quinclorac and auxinic herbicide action.