小麦花粉离体萌发培养体系的筛选

为了准确检测小麦花粉活性,以5个常规小麦品种为材料,4种花粉离体萌发培养体系为候选方法,通过比较不同体系花粉萌发率差异,从而找到最佳的小麦花粉离体萌发培养体系。结果表明：小麦成熟花粉在20%蔗糖+10%PEG4000+40mg/LH3BO3+3×10-3mol/LCa(NO3)2+10mg/LVB1中28℃培养30min,通过镜检观察,可诱导萌发频率高达90%以上。同时,经过K型小麦不育系、保持系和F1材料的鉴定,表明上述培养基适合于小麦花粉离体萌发,能够准确检测小麦花粉活性。     

Physiology of Drought Tolerance in Wheat (Triticum aestivum L.)

Correlation between lysine, tryptophan and prolamine contents during maturation of the maize kernel
Changes in the contents of total nitrogen, prolamine, tryptophan and protein bound lysine, and the relative nutritive quality of proteins were studied during the maturation of three normal maize varieties, grown under the same topographical and agrotechnical conditions, in two successive crop years.
Total nitrogen was determined according to Kjeldahl's method, prolamine by the turbidity test, lysine by Carpenter's method and tryptophan was assessed fluorometrically.
A significant decrease (p = 0.01) in total nitrogen, tryptophan and bound lysine content in the dry grain matter was found in the late milk and early dough ripeness stages of the maize kernel. Parallel with the decrease in these components, the relative nutritive quality of proteins also decreased during maturation. Prolamine, which was present in the early milk stage in low quantities, increased significantly (p = 0.01) with kernel maturity, reaching the highest level in the early dough ripeness stage. During further kernel maturation no significant changes in the components studied were observed. The correlation coefficients between the contents of prolamine and total nitrogen, lysine and tryptophan, during the ripening of maize kernel were highly significant (p = 0.001): -0.891, -0.938, -0.856, respectively in the first crop year and –0.844, -0.833, -0.867, respectively in the second crop year.     

Effect of Mutagenic Treatments on Somaclonal Variation in Wheat (Triticum aestivum L.)

Different wheat genotypes were treated with gamma-rays, sodium azide (SA) and EMS before tissue culture and immature embryos from M₁ plants or plants shortly after exposure to gamma-rays were used to initiate callus culture. Thousands of plants were regenerated and used to investigate the effect of mutagenic treatments on the regenerated plants and somaclonal variation in the M₃R₂ and M₂R₂ generations. The results showed that mutagen-induced damage in terms of reduction in plant height, fertility and spike length were not outstanding in the regenerated plants as compared with the untreated control. In the M₃R₂ generation, only SA treatment had significantly higher frequencies of somaclonal variations than the control. Increases in the variation frequencies were observed when explant embryos were irradiated with 2.5 and 5 gy gamma-rays and the highest frequency appeared when embryos were exposed to 5 gy gamma-rays on the 5th day after anthesis. Increased variation spectra also resulted from mutagenic treatments and most of the variants recovered were unsuitable for plant improvement.     

转反义TRX s基因对小麦萌发过程中储藏蛋白降解的影响

以转反义TRX s基因豫麦18和对照（豫麦18）为试材,测定了小麦种子萌发过程中胚乳内thiocalsin、苹果酸脱氢酶、谷丙转氨酶的活性以及游离氨基酸含量的变化。结果表明,反义TRX s基因的导入能够增加对thiocalsin和苹果酸脱氢酶的抑制,降低其活性,使储存蛋白更难于被降解,谷丙转氨酶增高的速度减慢,种子氨基酸代谢减弱。说明蛋白质代谢缓慢是转反义TRX s基因小麦抗穗发芽的一个主要原因。     

小麦籽粒颜色与抗氧化作用

以抗活性氧活力单位、抗超氧阴离子活力单位和总抗氧化活力单位为指标，研究了白、红、紫、深紫、紫黑、蓝等不同颜色小麦籽粒的抗氧化能力，并分析了其与色素、黄酮等抗氧化物质含量和抗氧化酶活性之间的关系。结果表明，小麦籽粒颜色与其抗氧化活性之间存在着非常密切的关系，蓝、紫黑、深紫、紫等黑粒小麦籽粒的抗氧化能力高于白粒和红粒小麦。黑粒小麦的总黄酮、氨基酸、Vc、类胡萝卜素等抗氧化物质含量和SOD等抗氧化酶活性高于普通白粒和红粒小麦；并且籽粒色素含量、总黄酮含量、总氨基酸含量以及SOD活性与3个抗氧化能力指标显著或极显著正相关，Vc和类胡萝卜素含量与3个抗氧化指标之一或之二显著或极显著正相关，说明色素、黄酮、SOD、Vc和氨基酸等是蓝、紫黑、深紫、紫等黑粒小麦的抗氧化能力强于白粒和红粒小麦的主要物质基础。     

Agronomic and Physiological Study of Cold and Flooding Tolerance of Spelt (Triticum spelta L.) and Wheat (Triticum aestivum L.)

Flooding of soil occurs all over the world in areas of crop production. The resulting lack of available oxygen in the soil can hinder the establishment of field crops such as wheat ( Triticum aestivum L.) and thus lead to a decrease in yield. The current study compares the tolerance of spelt ( Triticum spelta L.) and wheat to wet and cold stress during germination and early growth. Two specific traits seem to be related to the superior early flooding tolerance of spelt: (1) fast growth of the coleoptile, which reaches the soil surface rapidly, thus reducing the time span of hypoxia sensitivity, independent of temperatures between 10 and 20 °C; (2) the improved physiological adaptation for coleoptile growth under hypoxia is probably due to lower oxygen consumption between germination and emergence. Because of this high level of flooding tolerance, spelt would also be a good source for breeding for stress tolerance in wheat. These findings will help to detect quantitative trait loci (QTL) for characters such as growth rate, flooding tolerance and oxygen consumption in future studies. A marker-assisted introgression of spelt into wheat is necessary to avoid combination with undesirable agronomic traits of spelt.     

N2激光和氮离子注入对小麦一些性状的影响

以粉质,中杆,无芒小麦辐３６为材料,分别用Ｎ２激光,氮离子注入和Ｃｏ＾６０－γ射线三种诱变因素处理,对第二代植株高度有影响,经前二者处理的对株高有提高趋势,氮离子注入的,二代出现高杆植株占７２．６％,１焦耳Ｎ２激光处理的在二代中有４５．５％是高杆,Ｃｏ＾６０－γ射线处理Ｍ２株高明显变矮,７９ｃｍ以下的单株占总株为数中４６．３％,在芒性变异上出现顶芒和长芒类型,处理间诱变效果顺序为γ射线〉１焦耳Ｎ２     

小麦幼胚的脱分化状态及再生性能研究

通过对30个品种（系）的研究，确立了小麦幼胚最佳取材时期的种子形 态指标：在幼种子发育到嫩绿色，脊部由光亮转变为无光泽并具一层绒毛时，幼胚刚好发育到透明的后期和半透明前期。该时期仅有几个小时。探讨了不同基因型的幼胚的致密愈伤组织诱导状况及其继代保持和分化能力，并获得了良好的再生体系。使得致密愈伤组织诱导率达到91％，在14d时分化频率达到96．7％，70d时分化频率仍可达62％。并就温室材料和大田材料以及不同年份大田材料的致密愈伤组织的继代保持和分化能力进行了比较。     

Morphological Traits Associated with Lodging Resistance of Spring Wheat (Triticum aestivum L.)

Throughout the world, lodging in cereals causes great losses in yield each year. A two year field study was conducted to determine the relationship of morphological traits to lodging resistance in spring wheat ( Triticum aestivum L.) breeding lines and to find easily measurable traits related to lodging resistance. A set of 15 breeding lines, representing a wide range of combinations of plant height and lodging resistance, was evaluated.
During the first year, 29 morphological traits were measured at two growth stages and correlated with the lodging score. Higher correlations were found for traits measured at anthesis (DC 65) than for traits measured at maturity (DC 92); most of the fresh weight traits correlated better to lodging resistance than did the corresponding dry matter parameters. During the second year the six traits of plant height, stem length, stem diameter, ear weight, stem weight and stem weight per cm were measured at anthesis and correlated with the lodging score.
From the pooled data of four experiments, significant correlations between the lodging score and single morphological traits were found for stem diameter and stem weight per cm. Thicker stems and heavier stems (mg per cm) were indicative for better lodging resistance. Stem diameter and stem weight cm⁻¹ explained 48.5 % and 49.7 %, respectively, of the phenotypic variation in lodging resistance. Multiple linear regression equations indicated that 77.2 % of the variation in lodging resistance was based on stem weight cm⁻¹ and on the weight of the ear.     

Identification of Powdery Mildew Resistance Genes in Common Wheat (Triticum aestivum L.)

Major genes for resistance to powdery mildew were analysed in 24 Czechoslovakian wheat cultivars and, in part, in their parents. For this purpose individual isolates of the pathogen, able to differentiate host lines with known resistance genes, were selected. Eight of nineteen winter wheat cultivars do not possess any major resistance gene. Three cultivars have one and seven have two genes. One cultivar carries a combination of three genes (Pm2, Pm4b, Pm8). The most common resistance genes are Pm4b, Pm5 and Pm8. Pm2 is once combined with Pm6. Only one of five spring cultivars lacked a major resistance gene. Mlk is once present alone and twice combined with Pm5. There is one spring cultivar with a novel combination of three genes: Pm1, Pm5 and another gene needing further characterization. The observations are discussed with additional results of parent lines and further information on pedigrees.     

Preliminary Diallel Analysis of Anther Culture Response in Wheat (Triticum aestivum L.)

A four-parent complete dialleld mating-set of three Triticum aestivum L. cultivars ‘Edwall’, ‘Chris’ and ‘Spillman’, and an alloplasmic line of ‘Selkirk’ in Aegilops variabilis Eig. cytoplasm was used. Genetic components among total variation for callus induction, green plant percentage and green plant yield werr 92%, 80% and 77%, respectively, but lower (36%) for plant regeneration. General combining ability (GCA) variance components and narrow-sense heritabilities estimated for callus induction, green plant pereentnge and green plant yield were 74%, 66%, and 53%, and 0.68, 0.54 and 0.43. respectively. Specific combining ability (SCA) variancw was calculated as 85%) of total genctie variation for plant regeneration. Significant reciprocal effects for callus induction. green plant percentage and green plant yield were observed.     

壳寡糖对PEG胁迫下小麦种子萌发、幼苗生长及渗透调节物质的影响

以小麦品种郑引1号为试材,探究不同浓度壳寡糖溶液(COS,5、25、50、100、200 mg·L^-1)浸种和叶面喷施对20%PEG胁迫下小麦种子萌发、幼苗生长、氧化损伤、渗透调节物质含量及脯氨酸代谢的影响。结果显示,PEG胁迫下小麦种子发芽势、发芽率、发芽指数、活力指数、幼苗叶片相对含水量、株高、根长、地上部和根部干重、干物质相对增长率、叶绿素和游离氨基酸含量较ck明显降低,叶片类胡萝卜素、超氧阴离子(O·2^-)、丙二醛(MDA)、可溶性蛋白、葡萄糖、蔗糖、脯氨酸含量和吡咯琳-5-羧酸合成酶(P 5 CS)、脯氨酸脱氢酶(ProDH)活性明显提高。外源适宜浓度的COS溶液处理可明显促进PEG胁迫下小麦种子的萌发和幼苗的生长,降低叶片O·2^-、MDA含量和ProDH活性,提升叶片相对含水量、叶绿素、类胡萝卜素、渗透调节物质含量及P 5 CS、鸟氨酸δ-氨基转移酶(δ-OAT)活性,以COS浓度为100 mg·L^-1效果最佳。可见,外源适宜浓度COS溶液处理能增强小麦幼苗的渗透调节能力,减轻20%PEG胁迫对种子萌发和幼苗生长的抑制效应,降低叶片氧化损伤,在一定程度上提高了小麦的抗逆性。     

Nitrate Assimilation and Nitrogen Harvest in Uniculm 'Gigas' Wheat (Triticum aestivum L.)

Contribution of the upper laminae designated as 7, 8 and 9 (flag), to the total reduced nitrogen was determined by two different methods; integration of nitrate reductase activity over the entire growing season of individual laminae, and laminae removal at ear emergence. The values obtained by these methods were: 20, 14, and 12 %, and 23, 15, 12 %, respectively. The in vivo nitrate reductase activity was relatively higher in the lamina 9, which contributed an extra 8 % towards total reduced nitrogen when the other laminae were removed from the shoot. No such compensatory response was observed when either lamina 7 or 8 was retained.     

NaCl胁迫对燕麦与小麦幼苗生长及其营养吸收的影响

采用水培的方法,研究了NaCl胁迫对燕麦和小麦幼苗生长及其营养吸收的影响,旨在为全面比较两种作物的耐盐性以及高效利用内蒙古地区的盐碱地提供基础信息。结果表明:与对照相比,低浓度NaCl处理(40 mmol/L)促进了燕麦的株高、生物量的增加,当NaCl浓度分别达到60 mmol/L与80 mmol/L时,明显降低了小麦与燕麦的株高、生物量,其中小麦较燕麦下降幅度大;随着NaCl浓度的增加,燕麦幼苗茎叶、小麦幼苗根中全N含量有所下降,而燕麦与小麦植株中全P含量有所增加;燕麦与小麦植株中K+、Ca2+含量、K+/Na+、Ca2+/Na+比值随NaCl浓度的增加迅速降低,且小麦的降低效应大于燕麦,在同一处理NaCl胁迫下燕麦的K+/Na+高于小麦。     

转基因小麦后代HMW-GS组成的变异研究

转基因技术应用于作物品种改良,要求外源基因稳定整合与表达,并且生物环境和自身遗传背景不被干扰[1].目前流行的植物转基因方法,需经历基因转移、组织培养再生植株和转基因植株的选择与繁殖等环节,每个环节都有可能产生不可预测的变异.有些变异与外源基因导入有关.Bregitzer等(1998)应用基因枪法获得转基因大麦,认为重要农艺性状抽穗期的延长是转化步骤引起了体细胞无性系变异[2].但有些变异与外源基因导入无关.Phan等(1996)把转基因水稻植株中基因组变异归因于组织培养[3].Barro等(2002)在田间评价转基因小麦的农艺性状时,没有发现因转化或组培引起表型变异[4].转基因植物在有性繁殖过程中,多拷贝外源基因也会对自身遗传背景产生影响[5].表型变异的原因可能是特定生化过程或蛋白质发生了质或量上的变化,但很少见遗传转化对植物内源非靶蛋白质影响的报道.     

6—BA对小麦种子萌发过程中所受盐害的缓解作用

本文以小麦为材料,研究盐分胁迫对小麦种子萌发的影响以及6－BA对小麦种子萌发过程中所受盐害的缓解作用。结果表明,6－BA能够相对提高盐分胁迫条件下前发的小麦胚乳内α－淀粉酶、蛋白酶的活力和可溶性糖、游离氨基酸、可溶性蛋白质的含量,提高小麦发芽数量、速度和质量;在1．2％NaCl盐分胁迫条件下,当6－BA的浓度为1×10(-5)mol／L时对小麦种子萌发过程中所受盐害的缓解效果最好。     

Specific and General Adaptation and Yield Stability of Wheat (Triticum aestivum L.) Genotypes

Mean grain yield performance of 12 wheat and one triticale genotypes were measured at four locations over four consecutive years, using a randomized complete block design with four replications. The genotypes used were commercial cultivars and advanced lines from different wheat breeding projects located in different areas in Iran. Two locations were in semiarid regions and the other two locations in the temperate zones. The combined analysis of variance indicated highly significant genotype-environment (GE) interactions. From combinations of locations and years three sets of environments were generated. Set I and set II, each, consisted of eight environments (two locations and four years) representing semiarid and temperature environments, respectively. Set III consisted of 16 environments including both semiarid and temperate conditions. Set I and set II were used to measure specific adaptation of the genotypes while set III was employed for measuring general adaptation. The methods of Eberhart and Russell (1966) were used for partitioning GE interactions. The mean square associated with the heterogeneity of regression was highly significant under all sets of environments. These observations indicated that a major part of GE interaction could be accounted for by differences in the regression of the individual genotypes. All the genotypes had significant regression mean square under set I, set II, and set III environments, with the exception of two genotypes under set II. However, mean yields, regression coefficients, and the mean squares associated with deviation from regression greatly varied over the sets of environments. Only three genotypes, a commercial cultivar and two new advanced line, were identified as having specific adaptation and yield stability to semiarid environments. Among all the genotypes, only a commercial cultivar was identified as adapted and stable to temperate conditions. Two of the three genotypes which were adapted to semiarid environments also showed general adaptation to set III environments. However, the mean yield of these two genotypes under semiarid conditions (set I) were significantly greater than their respective mean yields under set III environments. Thus, wider adaptability was compensated by lower mean yield. The present study indicates that, while a wide range of environments is necessary and recommended for measuring general adaptation reactions and yield stability of various genotypes, one should not ignore the possibility of finding some genotypes with specific adaptation to specific environments and thus maximizing yield production. Stable genotypes with general of specific adaptation should be utilized in breeding projects in order to develop even more desirable lines.     

普通小麦D染色体组微卫星分子标记遗传差异研究

本研究采用微卫星(SSR)分子标记技术, 对我国不同生态区的6个春小麦品种(系)及北方冬麦区的17个冬小麦品种(系)D染色体组的遗传多样性进行了分析. 结果显示, 23个微卫星引物在23份材料间共扩增出65个等位基因, 平均每个引物为2.9个. 分析发现, 冬小麦群体内检测到的等位基因数(60个)及平均遗传距离(0.4504)明显高于春小麦(48