关中小麦白粉病发生规律研究

1983～1991年的研究表明,白粉病菌主要在凉爽阴湿的沿山地区自生麦苗上越夏;夏季多雨凉爽年份,在平原秋作物覆盖地自生麦苗上偶尔也有零星白粉病发生。浸染自生麦苗的菌源,主要是夏季存活期内的有性世代,病残体上的分生孢子无作用。自生麦苗上的分生孢子,是侵染冬麦秋苗的来源;12月上旬停止侵染。秋苗上的菌丛,12月上旬停止产孢,下旬菌丝停止生长,以菌丝主要在茎基叶鞘上越冬;2月上旬菌丝复苏,3月份是病害开始发展期,4月份是普发期,5月份是盛发期;春季病情与雨量、雨日密切相关。     

基因枪转化小麦愈伤组织的影响因素研究

以小麦愈伤组织为受体材料,用基因枪法将报告基因GUS和目的基因Psag12-IPT导入小麦中。GUS基因表达检测表明,金粉用量越高,转化频率越高;质粒DNA用量以2.0μg/枪最佳;随着愈伤组织培养时间的延长,GUS基因瞬时表达呈明显下降趋势,至第28天以后趋于稳定。另外,GUS基因瞬时表达检测应在24h内进行。     

Histology and Ultrastructure of Incompatible Combination Between Puccinia striiformis and Wheat Cultivars with Low Reaction Type Resistance

The incompatible combinations between races of Puccinia striiformis and wheat cuitivars withlow reaction type resistance were examined by means of fluorescent microscopy, differential interference con-trast microscopy and electron microscopy. The incompatible combinations consisted of wheat cultivar Niuzhuteplus CY28, Hybrid46 plus CY29 and Tianxuan882 plus CY29, while the compatible combination was wheatcultivar Huixianhong plus CY28. The observation revealed a striking difference in the fungal development andthe host responses between susceptible and resistant wheat cuitivars following infection by the pathogen. Themain histological manifestation of the pathogen development in the resistant wheat cultivars include inhibitionof hyphal growth, delay of hyphal branching and colony formation, decrease of formation of haustorial mothercells and haustoria, and occurrence of host cell necrosis. The observation by electron microscopy demonstratedthat a series of abnormal changes occurred in intercellular hyphae, haustorial mother cells and haustoria dur-ing pathogen development in the resistant wheat cultivars. The cytoplasm became more electron-dense and vac-uoles in the cytoplasm increased in number and size. The cell walls of hyphae, haustorial mother cells werethickened irregularly. The organeiles were disorderly distributed in the cytoplasm and the haustorial mothercells and haustoria lost their physiological function. In the final stage of the pathogen development, the inter-cellular hyphae, haustorial mother cells and haustoria became necrotic and collapsed. The structural defensereactions such as formation of cell wall apposition, collar and encasement of haustorium were essentially morepronounced in the infected wheat leaves of the resistant cultivars than in the susceptible one. In addition, therelationship between the host resistance expression and the histological and cytological features occurred in theincompatible combination was discussed in this paper.     

山羊草及普通小麦遗传多样性的研究

使用微卫星荧光标记-全自动基因分析仪(3700 DNA Analyzer)，用43对D染色体组引物标记76份普通小麦、粗山羊草、拟斯卑尔脱山羊草和尾状山羊草品种和材料，将其结果进行聚类分析，共聚成四类：普通小麦被聚成一类，粗山羊草被聚成两类，拟斯卑尔脱山羊草、尾状山羊草和部分来自巴基斯坦的粗山羊草聚成一类。聚类结果与现有的植物学分类的结果相一致。     

普通小麦-百萨偃麦草染色体易位的选育与鉴定

 利用染色体C 分带、基因组原位杂交和花粉母细胞减数分裂分析的方法 ,从普通小麦中国春与中国春 百萨偃麦草双倍体回交BC1F5 代中选育出 5份纯合易位新种质 ,分别为 :含 1对易位染色体并添加 1对百萨偃麦草完整染色体的Tj0 1和Tj0 2 ;添加 1对易位染色体的Tj0 3 ;含 1对易位染色体并添加 1对百萨偃麦草某一染色体臂端着丝粒染色体的Tj0 4和含 1对易位染色体并添加 2对百萨偃麦草完整染色体的Tj0 5。这些易位染色体的易位断点均不在着丝粒处 ,能稳定传递 ,且所涉及的植株生长和结实均正常。推测在该回交后代中小麦与百萨偃麦草染色体之间发生了自发的部分同源重组 ,这将有利于百萨偃麦草优异基因向普通小麦的转移与利用     

小麦、偃麦草和小偃麦同工酶及蛋白质的比较研究

本文采用聚丙烯酰胺凝胶电泳法,比较分析了小麦、天蓝偃麦草和小偃麦的酶酯同工酶、过氧化物酶同工酶和可溶性蛋白质。结果表明,不同属的酶谱是不同的。小麦和天蓝偃麦草的同工酶和可溶性蛋白质具有属的特异性。小偃麦兼有小麦和天蓝偃麦草的酶带,是不同于小麦和天蓝偃麦草的八倍体新类型。5个小偃麦划分成两种不同的类型,中_1和中_2属于第一种类型,中_3、中_4和中_5属于第二种类型。酯畴同工酶和过氧化物酶同工酶可以做为研究种属间关系和分类的一项生化指标。     

冬小麦根系对水分胁迫期间和胁迫后效的响应

 为揭示土壤水分胁迫期间和胁迫后效对植株根系生物量累积的影响，本文以冬小麦为对象，利用温室盆栽试验结果对其做了分析。结果表明，土壤水分在胁迫期间和胁迫后效对根重的抑制量不同，主要受胁迫程度和胁迫持续时间的影响；在胁迫期间，不同水分处理的根重抑制量源于此期间的胁迫强度，且重度胁迫处理大于中度胁迫处理；在胁迫解除后，尽管胁迫后效对根重的影响仍表现在相应时段的胁迫强度上，但是短期胁迫处理大于长期胁迫，中度胁迫大于重度胁迫处理；分析不同水分胁迫条件下的冬小麦根系的受抑制状况，集中表现为在短期胁迫和长期中度胁迫处理中，根重抑制量主要归因于胁迫后效应作用下的胁迫强度；而长期重度胁迫处理对根的抑制量源于胁迫期间的胁迫强度。结合前期的成果可见，水分胁迫对根生长的影响是源于前一个生育期已形成的基础、此生育期的环境响应以及前一个生育期环境效应的滞后作用的综合结果。     

QTL for grain yield and yield parameters in winter wheat(Triticum aestivum L.)

Field trials with a set of 108 doubled haploid lines(DHs) derived from a cross between the Chinese winter wheat cvs.CA9613 and H1488 were run at Beijing(China).Phenotypic data were recorded for major agronomic yield traits,i.e.grain weight per ear,grain number per ear and thousand grain weight(Tgw) in two field trials at Beijing.Based on the phenotypic data and a genetic map comprising 168 SSR markers,an analysis of quantitative trait loci(QTL) was carried out for yield and yield parameters using the composite interval mapping(CIM) approach.A total of 14 QTL were detected for these traits across two environments.Four of these QTL located on chromosomes 1A and 2B,respectively,exhibited pleiotropic effects.Loci showing pleiotropic effects will be very useful for understanding the homeologous relationships of QTL and designing an appropriate marker-assisted selection programme by multi-trait selection in order to accumulate("pyramide") favorable alleles at different loci.     

不同穗型冬小麦品种灌浆期籽粒中与淀粉合成有关的酶活性变化

 在池栽条件下 ,对豫麦 6 6和豫麦 4 9的籽粒灌浆过程中几个与淀粉合成有关的酶活性变化研究表明 ,开花后 2 5d内 ,大穗型品种豫麦 6 6籽粒中淀粉积累速度比多穗型品种豫麦 4 9慢 ,但开花 2 5d之后情况则相反。豫麦 6 6籽粒中淀粉积累速率的变化呈单峰曲线 ,峰值出现在花后 2 0～ 2 5d ,而豫麦 4 9则呈双峰曲线 ,花后 15～ 2 0d和 2 5～ 30d分别达到峰值 ,且第 1个峰值显著高于第 2个。灌浆期豫麦 6 6和豫麦 4 9籽粒中蔗糖含量与SS(蔗糖合成酶 )活性变化均呈单峰曲线 ,峰值分别出现在花后 2 0和 15d ,整个灌浆期内豫麦 6 6籽粒中蔗糖含量与SS活性均高于豫麦 4 9;豫麦 6 6籽粒中AGPP(腺苷二磷酸葡萄糖焦磷酸化酶 )和SBE(淀粉分支酶 )活性变化均呈单峰曲线 ,峰值出现在花后 2 0d ,而SSS(可溶性淀粉合成酶 )活性变化则呈双峰曲线 ,峰值分别出现在花后 10和 2 0d ,且第 2个峰值显著高于第 1个     

小麦新种质N9659抗白粉病基因的遗传分析

抗性种质"N9659"携带来自野生二粒小麦(资源编号:AS846)的抗白粉病基因,并对陕西关中地区白粉病优势小种表现为高抗。为了研究其白粉病抗性基因的遗传规律,用高感品种辉县红、阿勃、陕160和阿勃21个缺(单)体系分别与N9659进行杂交,并在苗期对F1和F2进行接种鉴定。鉴定结果表明,辉县红×N9659、阿勃×N9659、陕160×N9659杂交组合的所有F1表现为高抗白粉病,F2代的白粉病抗感分离比例均符合3∶1。阿勃21个单(缺)体系和N9659杂交组合的所有F1表现为高抗白粉病,F2代的白粉病抗感比例除组合"阿勃5BM×N9659"偏离3∶1外,其它组合均符合3∶1。表明N9659苗期白粉病抗性由1对完全显性基因控制。