光敏色素与光敏感雌性不育苎麻育性转换的关系

利用红光（R）/远红光（FR）逆转的标准试验技术，对光周期敏感雌性不育苎麻（PFSR）进行长暗期（14 h/d）光间断处理。结果表明R间断诱导雌性败育，延迟现蕾和开花；而FR可以逆转R的效应，使雌性可育；暗间断对雄性的育性没有明显影响。暗示光敏色素是PFSR雌性育性光敏性的光受体。     

水稻光周期敏感雄性不育性的遗传研究

湖北光周期敏感核不育水稻(HPGMR)在长日照(LD)条件下,表现完全的雄性不育,而在短日照(SD)条件下表现为可育。这种受日照长度调控的育性转换特性可以稳定遗传。石明松、冯云庆、卢兴桂等的研究报道都认为光敏核不育性受一对隐性基因控制,与细胞质无关,还存在具修饰作用的微效基因,朱英国则认为光敏核不育     

水稻雄性败育初探

水稻雄性育性通常受一对可育基因和质、核间相应诱导物质(RNA)共同作用,质、核间育性诱导物质的协调与否,能影响基因性状的表达,目前三系中的“不育”系就多为这种类型。“光(温)敏核不育”则还受一对光(温)敏育性基因及相应的光(温)敏核诱导物质(RNA)共同作用,在特定光(温)条件下能表现可育,条件不具备时则表现为“不育”。因这两种“不育”均非不育基因作用,实质上应是败育。     

光敏核不育水稻农垦58S花粉败育过程中Ca2+-ATPase的变化

运用电镜细胞化学技术(铅盐沉淀法),对长日照条件下光敏核不育水稻农垦58S和可育株系58N花药发育的不同时期进行了Ca²⁺-ATPase定位研究。结果表明,Ca²⁺-ATPase颗粒在可育与不育水稻的花药壁、花粉及药隔中的出现时间和数量具有明显差异。可育花药在花粉母细胞时期,药壁细胞内出现Ca²⁺-ATPase颗粒,至单核花粉后期,解体的绒毡层细胞和乌氏体表面分布大量的Ca²⁺-ATPase颗粒;与可育材料相比,不育花药在花粉发育的同时期,Ca²⁺-ATPase颗粒在药壁各层细胞内不仅出现的时间滞后,且分布的数量较少,到二核花粉时期(花粉已畸形空瘪),药壁表皮细胞的液泡膜上、绒毡层细胞质中及乌氏体表面才出现明显的Ca²⁺-ATPase颗粒。可育花粉单核早期,花粉细胞内线粒体膜上有少量的Ca²⁺-ATPase分布;单核花粉中期,花粉外壁上有少量的Ca²⁺-ATPase分布;到单核花粉后期,Ca²⁺-ATPase颗粒大量分布在花粉外壁、内壁及细胞质膜和细胞核中。而不育花粉在单核花粉发育中都未见Ca²⁺-ATPase的分布,到花粉败育空瘪时才出现明显的Ca²⁺-ATPase颗粒,但数量较可育花粉同期同部位少。可育花药药隔细胞中Ca²⁺-ATPase在花粉母细胞减数分裂期就有分布,而不育花药到单核花粉早期药隔中才有少量的Ca²⁺-ATPase分布。由此推测,水稻不育系在其花粉发育中,由于细胞壁和质膜上Ca²⁺-ATPase颗粒出现时间滞后和数量减少影响到细胞膜钙泵将Ca²⁺由胞质向胞外转运的功能,致使胞质内Ca²⁺过多积累,导致花粉败育。     

湖北光周期敏感核不育水稻农垦58s花药中的某些生化代谢特点

湖北光周期敏感核不育水稻农垦58s单核早期的不育花药的线粒体呼吸速率和LOX活性分别较可育株低11.9％和5％,而单核晚期相应较可育株低18.4％和17.3％。花药发育从单核期至三核期,可育花药的AsA和GSH含量增高,而不育花药仅分别相当于可育株的35—55％和22—32％,并有脂质氢氧化物积累。随着花药发育,可育花药的AsA-POD,GR和6-GPDH活性逐有增高,至三核期达到最高。而不育花药,随花粉败育,在单核早期至三核期,AsA-POD,GR和6-GPDH活性逐渐降低,至三核期,其活性分别为可育株的26％,22％和19％,不育花药的ME和MDH活性亦较可育株低。IDH活性在单核晚期为可育株的47—80％。细胞还原势低是不育花药特征之一。低的还原势可能导致活性氧代谢失调和花药不育。     

试议光周期敏感雄性核不育种质的评价

作者认为，仅凭群体不育株率、不育度、不育期与可育期结实率评价光敏核不育种质是不充分的，应当注重依据已知的光周期效应指数（ＰＥ）、温度效应指数（ＴＥ）、完全败育临界日长值等育性转换参数以及育性转换的稳定性进行评价与分类     

Triticum spelta 1BS染色体对K型小麦不育系花粉发育的影响

利用非1B/1R与1B/1R类型小麦雄性不育系及保持系, 对2类K型不育系及其保持系花粉发育过程中丙二醛含量、花粉细胞膜透性、SOD活性、花粉发育形态等几个方面进行比较研究。结果表明,2类型小麦不育系花粉丙二醛含量和花粉提取液电导率从减裂期到散粉成熟期变化趋势基本一致,都呈上升趋势,而保持系在花粉发育全过程中2项指标都基本保持平稳。2类型不育系SOD活性从单核期到三核期都一直呈下降趋势。与保持系相比, 2类不育系的SOD活性从单核期到二核期均显著高于其相应的保持系,三核期均低于其相应的保持系,且呈继续下降趋势。推断2类不育系的败育过程和败育时期基本一致,花粉败育的关键时期可能均为单核期到三核期。但花粉发育形态的染色观察表明,非1B/1R不育系从二核期出现花粉形态异常,而1B/1R不育系到三核期才出现,似乎又反映出非1B/1RK型不育系花粉败育稍早于1B/1RK型不育系。     

普通小麦T型,V型和K型细胞质雄性不育系花粉败育机理的细胞学研究

从细胞学的角度对小麦８３（２１）３５核背景的Ｔ型、Ｖ型和Ｋ型细胞质雄性不育系的花粉败育机理进行了研究。发现三类不育系的小孢子发生过程基本正常，Ｔ型不育系的花粉主要在小孢子后期发生败育，以典败型和圆败型为主；Ｖ型不育系的花粉主要在小孢子后期至二细胞花粉期败育，以圆败型和浅染败型为主；而Ｋ型不育系的花粉主要在二细胞花粉后期至三细胞花粉期败育，以浅染败型和深染败型为主。药室合并现象普遍发生是Ｔ型不育系花药的一个突出特点，而Ｖ型和Ｋ型人育系花药各壁层的发育是正常的。核质发育关系不协调是不育系花粉败育的根本原因。细胞学观察结果可以作为不育细胞质类型划分的一项参考指标。     

水稻雌性半不育突变体M21的细胞学研究和基因的初步定位

水稻雌配子的发育直接影响水稻的育性。由于雌配子败育的机理复杂,使得雌性不育的分子机理研究一直未取得突破性进展。本研究以EMS诱变获得的半不育突变体M21为研究材料,采用细胞学技术发现M21是由胚囊部分败育造成的。以M21//M21/N22回交群体BC1F1为作图群体全基因组分析,构建全长为2674.2 cM的遗传图谱,包含了189对SSR标记,平均遗传距离为14.1 cM;复合区间作图法(CIM)进行QTL定位,在第11号染色体检测到一个新的雌配子半不育QTL qPS-a,初定位在标记RM26761和RM26841之间,其贡献率为20.2%。本研究有助于进一步探究水稻雌性半不育的遗传机制。     

温光敏核不育小麦C412S的育性转换及其APRT基因的表达

以选育的小麦(Triticum aestivum L.)温光敏核不育系C412S为试材,以C412S回交转育时的受体亲本C412为常规品系对照,通过分期播种试验研究了其育性转换特性。用涂抹压片法观察减数分裂和小孢子发育进程,用半定量RT-PCR技术分析不育与可育条件下不同发育时期的幼穗中腺嘌呤磷酸核糖基转移酶基因(APRT)的表达水平。结果表明,通过调整播种期改变雄性发育的温光条件,C412S表现出完全不育—高不育—半不育—正常可育的育性转换特性。C412S花粉败育的高峰在单核小孢子晚期,主要表现圆败型不育。C412S的育性敏感期是从花粉母细胞形成期到成熟花粉期,其中最敏感的时段是花粉母细胞形成期到减数分裂期。与对照相比,C412S的APRT1基因序列有个别碱基变异,但编码氨基酸序列没有变化。在花粉母细胞形成期至单核期,与晚播可育条件相比,早播不育的C412S幼穗中APRT基因转录水平下调,因此认为,其育性转换与幼穗中APRT基因转录水平有一定关系。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.