籼型水稻两用核不育系2136S的选育

在低纬度、高海拔的贵阳自然低温条件下,按照广适应性籼型水稻两用核不育系选育的光温指标进行严格鉴选,成功地选育出了具有起点温度低(23.5℃),稳定不育期长和可育期自交结实率高的籼型水稻两用核不育系2136S。本文报道了2136S的选育过程及其主要特性。     

短日、低温粳稻不育新种质8608S的育性遗传初析

迄今,国内外水稻科研工作者已发现多个籼型短日、低温诱导不育系和长日、高温诱导不育系,而粳型短日、低温不育系却少见报道。最近,中国农业科学院和江苏省农业科学院联合选育出粳稻短日低温敏核不育新种质8608S,其在长日高温条件正常结实,在短日低温条件下不育;遗传分析表明:8608S的不育性受一对隐性基因控制,且与农垦58S和培矮64S中的长日、高温不育基因存在非等位关系;该两用核不育系可降低长日、高温不育系的育性起点温度,对增强两系杂交稻田间制种安全性和提高杂种结实率有重大生产意义。     

低温敏核不育系与光温敏核不育系杂交后代育性遗传的初步研究

go543S是低温诱导花粉不育的隐性核不育水稻,农垦58S是长日高温诱导花粉不育的隐性核不育水稻。为了研究诱导花粉不育条件相反的隐性不育基因之间的关系,用低温敏核不育水稻go543S与光温敏核不育水稻农垦58S以及由农垦58S衍生的光温敏核不育系7001S、培矮64S、长选3S配制4个杂种F₁,结果表明在自然长日高温、短日低温和不同人工光、温处理条件下杂交F₁的花粉均为不育,自交结实率为0,没有像go543S或农垦58S的育性转换期。分别用go543S、农垦58S作父本与杂种F₁回交,回交组合中像父本具有育性转换期的不育株的比例约50%,与杂种F₁一样的终生不育株约50%,符合隐性基因回交1∶1的分离比。     

水稻雄性核不育的类型及各生态区选育两用核不育系的技术策略

水稻核雄性不育可分为显性核雄性不育和隐性核雄性不育两大类。隐性核雄性不育可分为普通核雄性不育、光敏核雄性不育、温敏核雄性不育和光温互作核雄性不育四类。光敏核雄性不育有长日不育型和短日不育型两种。温敏核雄性不育有高温不育型和低温不育型两种。华南地区以选育不育临界低于２４℃的高温不育型温敏核不育系为主,长江中下游地区应以选育不育临界低的长日不育型光敏核不育系为首选育种目标,而北部地区宜选用低温不育型温敏核不育系。     

自然生态法鉴定水稻光温敏核不育系雄性不育起点温度的研究

本试验是将8个新水稻光温敏核不育系置于湖南怀化进行分期播种,让其在自然条件下充分表现,以选育出雄性不育起点温度低、育性稳定、综合农艺性状好、易于繁殖制种的水稻光温敏核不育系.结果表明:糯S、粳38S、C40S、9771S、德早S、H155S、怀4S雄性不育起点温度在23.5℃左右,而德es雄性不育起点温度在23.5℃～24℃之间.文章对水稻光温敏核不育系鉴定方法进行了探讨.     

水稻两用核不育系C815S繁殖特性研究

研究表明,C815S在长日照条件下最佳繁殖条件是采用冷水串灌温度20.5～22.0℃的低温冷水连续串灌15d,冷水串灌深度为18～22cm。C815S在海南陵水繁殖,育性敏感期若安排在2月5日前,安全系数在90%以上;若安排在2月6～13日间,则安全系数将近80%。提出了C815S海南冬繁与冷水串灌繁殖相结合,是降低水稻低温敏核不育系繁殖风险的另一重要技术途径。     

割茬再生处理对培矮64S育性的影响

对光温敏核不育水稻培矮64S进行了割茬再生处理,比较了再生稻与同期抽穗的头季稻的育性差异,结果表明:无论是长日高温下还是短日低温下,割茬再生处理均可明显提高培矮64S花粉可育度;短日低温下,割茬再生处理对培矮64S套袋自交结实率的提高有一定的效果,但幅度远小于花粉可育度而长日高温下割茬再生处理对培矮64S套袋自交结实率基本无影响.     

农垦58S基因源及其衍生后代与农垦58和湘早籼13号杂交F2育性变化规律的研究

以光敏核不育系农垦58 S基因源及其衍生的温敏核不育系W6154S和培矮64S,在长日高温条件下分别与农垦58和湘早籼13号杂交,在长日高温条件下对各杂交F2进行单株花粉镜检,分析其育性变化规律,利用不同的育性划分标准对各不育系进行遗传分析,研究遗传背景等因素对杂交F2育性变化规律的影响.结果显示光温敏核不育水稻杂交F2育性分离是很复杂的,其中遗传背景是影响核不育基因表达的重要因素,核不育基因的表达可能受多个不同调控位点的影响,从而各不育基因在不同的遗传背景下表达的程度不同.     

两用核不育水稻7436s的温敏感白苗标志性状的遗传及其育性研究

具有温敏感白苗标志性状两用核不育水稻７４３６Ｓ，在长日高温条件下表现不育，短日低温可育，该材料在１０天苗龄内的苗色具有明显温敏感性，即高温苗色正常绿色，低温表现白色，其临界温度为２６．１℃左右，但随着苗龄天数继续增加在低温下生长的白苗能逐渐趋向正常绿色，而不会逆转；该温敏感白苗标志性状受一对隐性单基因控制。     

水稻野败胞质低温敏两用系新种质的初步研究

水稻低温敏两用系新资源３６３Ｓ是从三系杂交稻威优６３Ｆ２代分离群体中筛选培育的,具有野败不育胞质。在２４℃以下低温诱导表现稳定不育,２６℃以上高温诱导可育,这两种温度条件下其花粉育性与小穗育性表现一致;在２４～２６℃范围内,随温度升高,可染花粉增加,但小穗仍表现败育;短日处理有提高结实率的作用;恢保关系与目前使用的野败类型三系不育系基本一致。该不育基因可能与农垦５８Ｓ系统的光温敏不育基因不等位。     

冷冻干燥速溶蛋花汤的加工技术

介绍了运用冷冻干燥技术进行速溶蛋花汤的加工,研究了生产工艺、特点以及影响产品质量的主要因素。试验表明,采用冷冻干燥技术加工的速溶蛋花汤,具有营养丰富、风味独特、方便快捷等特点。     

Measuring of Quantity of Matter-mass and the Measuring of Inertia of Matter-momentclm

A new definition of inertia,i.e. the momentum is the measuring of inertia of matter, is proposed. The article through and etc., subjects, the correctness of the new notion of inertia:The monentum is the measuring of inertia has been demonstrated, and the unsolved contradictions of the traditional definition of inetia. And the mass is the measuring of inertia has been revealed.     

香蕉遗传转化方法研究进展

香蕉是热带亚热带发展中国家重要的粮食作物和碳水化合物来源。但近年来,香蕉生产受到严重的病虫危害。大多数香蕉栽培品种是三倍体,生长周期长,而且不孕。由于没有种子,给繁殖和育种带来一定的困难。遗传转化技术的发展为香蕉品种的改良提供了一种有效的手段。香蕉的遗传转化方法有电激法、基因枪法、农杆菌介导法等。农杆菌介导法的应用是香蕉品种改良的一个重大突破。香蕉遗传转化的外植体也发展到多种,有原生质体,胚性细胞悬浮系,分生组织,以及横切薄片等。近几年,随着分子生物学的发展,出现了转化效率更高,重复性更好的香蕉遗传转化技术。如农杆菌和基因枪结合法,离心辅助农杆菌介导法、真空渗透技术等。这些新技术新方法的出现,必将推动香蕉产业高速发展。     

壳聚糖对石榴果汁澄清效果的影响

利用壳聚糖的絮凝作用对壳聚糖在甜石榴汁澄清中的应用效果进行了研究,试验结果表明,壳聚糖用量为0.3g/L、澄清时间为60min、温度为35℃时,甜石榴汁透光率可达85%以上,且通过对壳聚糖处理前后可溶性固形物、总酸、VC等营养成分含量的比较,确定以上工艺参数为甜石榴汁澄清的最佳选择。     

新疆布尔津县土地利用格局特征研究

基于RS与GIS技术,利用景观生态学理论及景观格局指数对布尔津县土地利用现状进行定量分析。结果显示为：（1）布尔津县以草地、林地为主要景观类型,镶嵌着耕地、水域等景观类型。（2）四个分区（即高山区、丘陵区、平原区、荒漠区）的林地资源组成差异明显,耕地、居民、交通及工矿用地集中分布在丘陵区和平原区（3）从各项指数来看,高山区的多样性指数较低;平原区是受人文因素最多的区域,景观优势度低,各种土地利用类型比例差异不大,有利于生态可持续发展,但要合理的开发利用;荒漠区生态环境相对脆弱,要加强生态环境的保护与改善。通过该研究对布尔津县的土地利用现状作一个了解,为该县乃至整个地区的景观规划和可持续发展战略提供科学依据。     

酸枣幼根原生质体的制备

以生长6～9 d的酸枣种子幼根为试验材料,0.7 mol·L-1甘露醇作为渗透压稳定剂、pH值5.5～6.0、28℃恒温水浴条件下,以光学显微镜观察的水解总时间、初始产生原生质体的时间、原生质体产量及细胞碎片量为指标,研究通过酶水解来制备酸枣幼根原生质体的方法.结果表明,在含1％果胶酶+4％纤维素酶R-10+3％纤维素...     

影响核桃贮藏品质因素的分析

介绍了几种核桃贮藏方法,综述了影响核桃贮藏品质的几个主要因素,以及针对上述影响因素提出若干解决对策.     

Efficiency of water use of early plantings of sunflower

Rain fed crop production in Mediterranean environments depends to a large extent on strategies that avoid the intense summer drought. Early plantings of sunflower have given consistently higher yields in such environments, but the basis for such yield increases has not been explored. We conducted two field experiments at Cordoba (Spain) to investigate the effects of an early and a late planting date on the components of water-limited crop productivity; namely, water use (T), water use efficiency (TE) and harvest index (HI) of sunflower. The results were generalized by simulating rain fed sunflower yields, under early (1 January) and late (15 March) plantings, for a 25-year period with the aid of a simulation model of the Ceres type (OILCROP-SUN) which has been validated in Cordoba. Experimental seed yields of early plantings in 1989 and 1996 were 2.0 and 3.0 t ha⁻¹, while late plantings yields were 1.3 and 2.4 t ha⁻¹, for the 2 years. Average simulated yields were 2.7 ± 1.1 and 1.9 ± 0.7 t ha⁻¹ for early and late plantings, respectively. For the 2 years, T of early plantings was higher than that of late plantings, but the response of TE and HI to planting date was not the same in the two experiments. In the simulation exercise, T and TE of early plantings were consistently higher than those of late plantings, while there were no differences in the HI for the two planting dates. We conclude that early plantings of sunflower increase rain fed yields by increasing both T and TE, while the impact of planting date on HI very much depends on the crop water stress pattern, which is quite variable from year to year even in the predictable Mediterranean environment.     

Establishment of High-frequency Regeneration System of Explants of Alfalfa

The cotyledon and hypocotyl of eight varieties of alfalfa( Medicago sativa L. )are used to study the effect of different cultivation procedures and genotypes on embryogenic callus and embryoid induction,plant development and transplant of alfalfa.The varieties of alfalfa with high embryoid induction rate and high differentiation rate are screened. A high frequency regeneration system for alfalfa tissue culture is established:which is benifical to the gene transformation of alfalfa.     

Laboratorial Method of Determining Limit of Yielding of Material

Based on the relation between the incipient yield pressure and the limit of yielding in cylinder according to the elastic disabled rule, a laboratorial method of determining limit of yielding of material is designed and a set of experimental data were gained by the method. The incipient yield pressure of the cylinder is gained by analyzing the experimental data, and then the limit of yielding is gained. The laboratorial method has a good reliability as the experimental value has a little error to the theory value. It has a definite engineering signification and theory value to research the mechanical capability of material and the disabled rule of high pressure vessel.