小麦生理型雄性不育花药中能量相关基因表达

为揭示小麦(Triticum aestivum L)生理型雄性不育机理, 以化学杂交剂SQ-1为诱导剂,构建了普通小麦西农1376不育和可育等生理系,用RT-PCR 技术分析了3-磷酸甘油醛脱氢酶（GAPDH）和NFUDP4基因在不同发育时期的不育和可育花药中的表达差异。结果表明,与同期对照相比,GAPDH和NFUDP4基因在不育花药单核期到三核期均下调表达,其中在大量花粉粒败育的单核期,GAPDH下调表达尤为显著。因此,小麦生理型雄性不育花药败育过程中,一方面由于GAPDH基因表达受抑制,使糖酵解受阻导致能量供应不足;另一方面,NFUDP4基因下调表达,可能引起线粒体某一Fe-S 族蛋白装配需要的分子骨架减少而使其数量不足,从而可能引起Fe-S族蛋白参与的生化反应减弱,如呼吸链电子传递受阻引起能量供应不足,与小麦生理型雄性不育具有一定关系。     

化学杂交剂诱导的雄性不育花药组织内源激素的变化

实验以Ｋ７８－１Ｂ和Ｔ０００２Ｂ为材料，分别用化学杂交剂ＳＣ２０５３和ＢＡＵ２诱导完全和部分雄性不育，测定了花粉败育过程中花药组织各种内源激素的变化。结果表明花药组织内源ＩＡＡ、ＤＨＺＲ水平都低于对照，ＺＲ和ＡＢＡ含量高于对照，变化幅度与喷施杂交剂的量密切相关，ＩＰＡ与ＧＡｓ的变化因小麦基因型，杂交剂种类及剂量而异，这说明化学杂交剂可能了内源激素的含量从而导致了雄性不育的发生，有助于进一步阐明化学     

小麦生理型雄性不育系中反式烯脂酰-CoA还原酶基因(TaECR)的克隆及表达分析

超长链脂肪酸(VLCFAs)代谢在花药发育中发挥着重要的作用,而反式烯脂酰-CoA还原酶(trans-2,3-enoyl-CoA reductase,ECR)是催化超长链脂肪酸合成的脂肪酰-CoA延长酶之一.为进一步研究杀雄剂SQ-1诱导小麦雄性不育的机理,根据己报道二穗短柄草(Brachypodium distachyon)ECR基因,采用电子克隆获得序列并设计引物,从小麦(Triticum aestivum)中克隆ECR的开放阅读框cDNA序列,命名为TaECR,将该序列提交至GenBank,登录号为KC222053.序列分析表明,TaECR基因编码310个氨基酸,具有反式烯脂酰-CoA还原酶的经典结构域.表达分析表明,TaECR基因在小麦花药、颖片、叶和根中均有表达,其中在根中的表达量最底;与可育系相比,TaECR基因在生理型不育系三核期中表达急剧下调,在单核期和二核期表达趋势无显著变化,并与其蜡质积累量变化趋势基本一致,这表明TaECR基因调节的超长链脂肪合成途径可能参与了SQ-1诱导的败育过程.     

小麦T型雄性不育恢复基因的遗传分析及RAPD标记

2114是一个携带有来自小伞山羊草的恢复基因的T型恢复系，为研究该恢复系恢复基因的遗传，我们将恢复系2114与3个不育系ND44A、D8442A、D北15A杂交，通过调查三个组合的F2代群体育性分离对恢复基因进行了遗传分析。分析表明除了一对主效基因控制外，2114 性同时又受微效基因的影响，而且2114中携带有恢复基因的易位染色体在不同遗背景中雄配子的传递率不同。以ND44A／2114的F2代分离群体为作图群体，利用分离群体分组分析法（Bulked Segregant Analysis,BSA），用460个随机引物对2114中的T型细胞质雄性不育恢复基因Rf6进行RAPD分析，筛选到10个可在亲本间扩增出多态性的引物，其中OPI18经多次重复能在亲本间及不育和可育池间扩增出稳定的多态性片段OPI181260。进一步对F2群体的147个单株分析表明：OPI181260与恢复基因Rf6的遗传距离为3.4cM。     

将新的人工雄性不育基因导入小麦栽培品种的研究初报

利用ＰＤＳ－１０００型氢气基因枪将我们构建的雄性不育基因导入小麦栽培品种的幼胚愈伤组织,经含除草剂Ｂａｓｔａ的抗性培养基分化和生根筛选后得到２７株绿苗,ＰＣＲ和Ｓｏｕｒｈｔｅｍ检测均发现有３种株呈阳性,初步表明基因已整合到小麦的基因组中,转化频率达０．２％左右。     

小麦细胞质雄性不育与花药组织内源激素的关系

利用间接酶免疫（ＥＬＩＳＡ）检测技术，测定了Ｋ，Ｔ型小麦细胞质雄性不育系及其相应保持系分发育过程中花药组织生长素，细胞分裂素，脱落酸，赤霉素四大类内源激素的动态变化，结果表明，不讼是Ｋ型还是Ｔ型细胞质雄性不育系，在花粉败育过程中与其相应保持系相比在比花组织中均表现为ＩＡＡ，ＩＰＡ，ＧＡ３ＧＡ４含量的下降ＺＲ，ＤＨＺＲ，ＡＢＡ含量的上升，据此认为内源激素含量的变化与小麦雄性不育的发生密切相关。     

小麦雄性不育与叶片中内源激素含量的关系

实验通过对叶片中内源激素含量的分析发现,在花粉发育过程中,核质互作雄性不育（ＣＭＳ）和化学杂交剂（ＣＨＡ）诱导的雄性不育与其相应的可育材料相比,叶片中各种内源激素的水平分别在不同时期发生了明显的变化,主要表现为吲哚乙酸（ＩＡＡ）,赤霉素类（ＧＡ４）含量的降低,脱落酸（ＡＢＡ）含量的增加,这种变化与小麦基因型,ＣＨＡ种类及其浓度有关,在不同发育时期,不育系,恢复系及其杂种Ｆ１叶片中各种激素含量都有明     

小麦T型细胞质雄性不育恢复基因Rf1和f4的SSR标记分析

为进一步探讨小麦(Triticum aestivum L.)T型细胞质雄性不育(T-CMS)育性恢复的遗传机理,并为利用T型不育系选育强优势杂交小麦分子辅助育种提供理论与技术支撑,本研究以小麦ms(S)矮抗58/R113的F2代分离群体中的极端可育株和极端不育株分别建立恢复池和不育池,采用分布于小麦第一染色体群(染色体1A、1B和1D)及第六染色体群(染色体6A、6B和6D)上的196对SSR引物进行扩增筛选.结果表明,(1)位于1AS染色体上的3个SSR标记和位于6BS染色体上的4个SSR标记均在亲本和基因池间扩增出了稳定的多态性差异条带;(2)定位群体验证结果表明,恢复基因Rf1与1AS染色体上Xgwm136、Xgpw7062和Xgdm33标记的遗传距离分别为4.8、9.6和13.7 cM,3个标记与Rf1之间的顺序依次为Xgdm33、Xgwm136、f1、Xgpw7062; (3)恢复基因Rf4与6BS染色体上的Xgpw1079、Xgwm193、Xgpw7011和Xgwm508标记的遗传距离分别为3.4、6.8、13.7和21.5 cM,4个标记与Rf4之间的顺序依次为Xgpw 011、Xgpw1079、Rf4、Xgwm19和Xgwm508.研究还表明,T-CMS恢复系R113的育性是由Rf1和f4两对主效恢复基因和多对微效基因共同控制的,筛选的上述7个SSR标记可直接用于T型或者类似T型,如S型杂交小麦分子标记辅助育种,可有效提高对应恢复系的选择效率.     

旱地覆膜对冬小麦花后14C-同化物转运分配的影响

利用14CO2示踪研究了覆膜对旱地冬小麦花后14C-同化物在灌浆期转运分配的影响。结果表明,花后同化的14C在标记后24h约78%已储存在茎鞘和穗轴中,11%已转运至籽粒,11%还滞留在叶片中;成熟时叶片的14C-同化物几乎都外运了,茎鞘和穗轴中还滞留约28%,70%已转运分配到籽粒中。覆膜小麦的14C-同化物向籽粒的转运比对照慢。另外,研究还表明覆膜小麦花后叶片的叶绿素含量比对照高,MDA含量比对照低,叶片衰老延缓,同化能力强,干物质多,籽粒产量高。因此,覆膜使小麦增产的原因在于小麦中前期生长加快,后期衰老延缓,同化能力增强,最终使得同化的干物质总量大大增加;但并不促进同化物向籽粒的转运分配。     

黄淮冬麦区主栽小麦品种根系的生理特性比较

采用盆栽试验方法,以黄淮麦区主栽的23个小麦品种为材料,以根系活力、根中全氮含量和根中可溶性糖含量为指标进行聚类分析。结果表明, 23个小麦品种的根系生理特性可归为3个类群:根系生理活性旺盛型(A类群);根系生理活性中等型(B类群);根系生理活性较弱型(C类群)。本研究条件下,根系生理活性中等型综合表现较好,主要表现为根系活力较强,根中氮含量和可溶性糖含量较高,获得的籽粒产量较高,是较为理想的育种材料。研究结果为黄淮冬麦区当前主栽品种的合理利用、新品种选育以及高产优质高效栽培提供了理论参考。     

外源DNA导入小麦后雄性不育变异的初步研究

利用浸泡法将外源λDNA导入普通小麦品系 81 45 2 7,获得不育变异株 ,稳定为不育系 ,简称D型不育系。该不育系小花结构具有显著特点 ,多数小花子房数目增加 ,花药数目减少 ,而且二者之和并非恒定为 4。多子房小花一般位于穗的中部 ,而顶部和基部小花未发现多子房现象。多子房小花的主子房位于小花的中央 ,副子房着生于主子房的周围。子房的发育进程不同步 ,主子房发育较早 ,体积较大 ;副子房发育较慢 ,而且未发育成熟即退化萎缩。花药多呈短棒状、月牙状等畸形状态 ,且多数在早期即退化萎缩 ,无生活力花粉。杂交试验表明 ,该不育系为细胞质雄性不育系 ,不育度达 99% ,受体品系 81 45 2 7可作其保持系。不育系与鲁麦 1 4号的杂种一代在穗长、每穗小穗数和穗粒数等性状上存在一定程度的杂种优势 ,单株产量较鲁麦 1 4号增加 1 1 6%。     

小麦RPL21基因同源克隆与表达分析

为了解60S核糖体蛋白L21(ribosomal protein L21,RPL21)的基因组结构和表达模式,以GenBank数据库中小麦RPL21基因的部分序列为信息探针,采用RT-PCR和PCR技术从小麦多子房株系幼穗中克隆了RPL21基因的cDNA与DNA片段,并对该基因在小麦多子房近等基因系间的表达差异和多子房...     

Mineral Uptake of Mycorrhizal Wheat (Triticum aestivum L.) under Salinity Stress

The hypothesis was that arbuscular mycorrhizal (AM) fungi are able to alleviate salt stress on plant growth by enhancing and adjusting mineral uptake. The objectives were to determine (1) the effects of soil salinity on mineral uptake by different wheat genotypes and (2) the effectiveness of different mycorrhizal treatments on the mineral uptake of different wheat (Triticum aestivum L.) genotypes under salinity. Wheat seeds of Chamran and Line 9 genotypes were inoculated with different species of AM fungi including Glomus mosseae, G. intraradices, and G. etunicatum and their mixture at planting using 100 g inoculum. Pots were treated with the salinity levels of 4, 8, and 12 dS/m before stemming. Different arbuscular mycorrhizal treatments, especially the mixture treatment, increased wheat mineral uptake for both genotypes. Although Line 9 genotype resulted in greater nutrient uptake under salinity stress, Chamran was more effective on adjusting sodium (Na⁺) and chloride (Cl^?) uptake under salt stress.     

小麦籽粒胚乳淀粉合成酶基因表达及酶活性分析

为研究小麦籽粒淀粉合成酶基因表达与酶活性的特征,选用4个淀粉含量差异较大的普通六倍体小麦新春24、E28（高淀粉含量组）和宁春16、安农9912（低淀粉含量组）为试验材料,采用实时荧光定量RT-PCR ,对灌浆期籽粒淀粉合成酶相关基因的表达进行研究,并对其表达量与相应酶活性的相关性做了分析。结果表明,束缚态淀粉合成酶基因(GBSS)、可溶性淀粉合成酶基因(SSS)、淀粉分支酶基因( SBE)、淀粉去分支酶（DBE）基因均呈单峰曲线变化。利用实时荧光定量PCR技术检测9个基因在不同淀粉含量的4个供试品种花后不同时期的相对表达量,结果表明,花后6d这些基因开始表达,在灌浆的中期（花后12~18d不等）有表达的小高峰,但在不同时期,2个高淀粉含量的品种中各种酶活性及其酶基因的相对表达量均比2个低淀粉含量的品种相对较高;这些基因表达谱与酶活性相关分析显示, 除GBSS外其他几种淀粉合成酶基因均与相应酶活性呈显著或极显著正相关,而且GBSS酶活性到达峰值时间稍迟于DBE、SSS、SBE等酶,说明DBE、SSS、SBE基因可能主要通过转录水平来控制籽粒淀粉的合成,而GBSS基因可能主要通过转录后水平来控制籽粒淀粉的合成。     

Boron-Calcium Synergically Alleviates Aluminum Toxicity in Wheat Plants (Triticum aestivum L.)

The effects of B and Ca treatments on root growth, nutrient localization and cell wall properties in wheat ( Triticum aestivum L.) plants with and without Al stress were investigated. Seedlings were grown hydroponically in a complete nutrient solution for 7 d and then treated with B (0, 40 μM), Ca (0, 2,500 μM), and Al (0, 100 μM) in a 500 μM CaCl₂ solution for 8 d. The cell wall materials (CWM) were extracted with a phenol: acetic acid: water (2:1:1 w/v/v) solution and used for subsequent pectin extraction with trans -1,2-diami-nocyclohexane- N,N,N,N -tetraacetic acid (CDTA) and Na₂CO₃ solutions. Boron, Ca, and B + Ca treatments enhanced root growth by 19.5, 15.2, and 27.2%, respectively, compared to the control (pH 4.5). Calcium and B+Ca treatments enhanced root growth with Al stress by 43 and 54%, respectively, while B did not exert any effect. The amounts of CWM and pectin per unit of root fresh weight increased by Al treatment, whereas the Ca and B+Ca treatments slightly reduced the contents of these components. Seventy-four percent of total B, 69% of total Ca, and 85% of total Al were located in the cell wall in the B, Ca, and Al treatments, respectively and 32% of total B, 33% of total Ca, and 33% of total Al were located in the CDTA-soluble and Na₂CO₃-soluble pectin fractions. A more conspicuous localization of B was observed in the presence of Al. Aluminum treatment markedly decreased the Ca content in the cell wall as well as pectin fractions, mainly in the case of the CDTA-soluble pectin fraction. Boron + Ca treatment decreased the Al content in the cell wall and pectin fractions compared to the Ca treatment alone in the presence of Al. It is concluded that the B+Ca treatment enhanced root growth and, B and Ca uptake, and helped to maintain a normal B and Ca metabolism in the cell walls even in the presence of Al.     

ROLE OF SALICYLIC ACID IN REGULATION OF CADMIUM TOXICITY IN WHEAT (TRITICUM AESTIVUM L.)

The present study is focused on the possible mediatory role of salicylic acid (SA) under cadmium (Cd⁺²) toxicity. Cadmium treatments resulted in the inhibition of root dry biomass, root elongation and increased Cd accumulation in roots. Pretreatment of seeds with SA (500 μM) for 20 hrs resulted in protection against Cd, increased root dry biomass, root elongation and minimal accumulation of cadmium. Cadmium chloride (CdCl₂; 0.0, 100, 400 and 1000 μM) produced a significant inhibition in chlorophyll, photosynthetic efficiency [carbon dioxide (¹⁴CO₂)-fixation], relative water content (RWC) and abscisic acid (ABA) content. Pretreatment of seeds with SA alleviated the Cd negative effect on these parameters. A drop in the activities of carboxylating enzymes, phosphoenol pyruvate carboxylase (PEPC, EC 4.1.1.31), and ribulose1,5-bisphosphate carboxylase (RuBPC, EC 4.1.1.39) were observed in Cd treated plants. Pretreatment with SA ameliorated the inhibitory effect of Cd on the studied enzymatic activities. Cadmium applied to salicylic acid free plants increased the level of stress metabolites, malondialdehide (MDA), hydrogen peroxides, and free proline content. Salicylic acid pretreatment decreased the toxic effect level of cadmium manifested by lower lipid peroxidation, lesser production of H₂O₂ and reduction in free proline content. The ultrastructural investigation of the root cells of wheat exposed to different concentrations of Cd for 15 days was carried out. The results indicated that Cd induced several obvious ultrastructural changes such as increased vacuolation, condensed cytoplasm with increased density of the matrix, reduction of mitochondrial cristae, severe plasmolysis, highly condensed nuclear chromatin and increment of disintegrated organelles. Electron dense granules appeared between the cell wall and plasmalemma. In vacuoles, electron dense granules encircled by the membrane were aggregated and formed into larger precipitates, which increase in number and volume as a consequence of excessive Cd exposure. An important issue arising from this study was how the short-term treatment with SA affected several physiological processes, such as plant growth, photosynthesis, and antioxidant defense system. We assume that the beneficial effect of SA during an earlier growth period could be related to avoidance of cumulative damage upon exposure to cadmium. One of the important roles of SA in inducing resistance to various environmental stresses is manifested by its ability to express genes that code for pathogenesis-related proteins or defense-related enzymes. Also, SA could form a complex with Cd that may provide Cd tolerance.     

异源细胞质对小麦雄性不育系主要农艺性状、花粉粒核分裂及花药绒毡层降解的影响

为了更好地利用核质互作小麦雄性不育系并解析不同类型细胞核与异源细胞质互作对花药绒毡层细胞及花粉粒核分裂特征的影响,本研究以2套核(偃师9号细胞核和90-110细胞核)质(K型、B型、S型、V型和Ven型细胞质)互作雄性不育系及其保持系(偃师9号保持系和90-110保持系;偃师9号细胞核属1B/1R类型;90-110细胞核属非1B/1R类型)为材料,调查其主要农艺性状(株高、穗长、穗下节间长和分蘖数),观察不育系及其保持系花药绒毡层降解和花粉粒核分裂特征。结果表明,核质互作雄性不育系细胞核是1B/1R类型或非1B/1R类型时,其农艺性状受细胞质类型的影响,且存在不同程度的差异。S-偃师9号花粉粒核分裂异常发生在单核早期,属典败型;Ven-偃师9号花粉粒核分裂异常发生在单核晚期,属典染杂合型;K-偃师9号和V-偃师9号花粉粒核分裂异常发生在二核期,属染败型;B-偃师9号花粉粒核分裂异常发生在三核期,属染败型。K-90-110与S-90-110花粉粒核分裂异常发生在单核晚期,分别属染败型和圆败型;V-90-110和Ven-90-110花粉粒核分裂异常发生在二核期,V-90-110属染败型,V...     

Effects of P fertilization level on phosphorus uptake and agronomic traits under deficit irrigation in winter wheat (T. aestivum L.)

Abstract

Enhancing the phosphorus (P) use efficiency is critical for the sustainable cultivation of winter wheat. In this study, we investigated the effects of P fertilization level on plant P-uptake and agronomic traits under deficit irrigation, by using two wheat cultivars sharing contrasting water responses (i.e., Jimai 585 and Shimai 22). The high P level treatment (P120) improved plant biomass and P accumulation at each growth stage, grain yields, P remobilization amount to grain (PRA), P remobilization rate (PRR), and P contribution rate (PRR) of the cultivars with respect to the low P treatments (i.e., P90 and P60). Compared with Jimai 585, a cultivar acclimated to affluent water, the drought tolerant cultivar Shimai 22 exhibited similar behaviors on plant biomass, P-associated traits at each stage, and agronomic traits at maturity under P120. However, Shimai 22 was more improvement on P-associated and agronomic traits than Jimai 585 under P60 and P90. P contents were increased whereas moisture contents decreased in soil profile treated by P120 with respect to those by P60. Meanwhile, the soil profile cultivated by Shimai 22 displayed reduced moisture and P contents under P deprivation (i.e., P90 and P60) respect to that by Jimai 585, suggesting the contribution of more consumption of soil P and water storage to improved agronomic traits of Shimai 22. Together, our investigation suggested that suitable P input management positively mediates plant P-associated traits and grain formation capacity under deficit irrigation by improving supply and internal translocation of P across tissues in winter wheat plants.