水稻栽培品种淀粉合成相关基因来源及其对品质的影响

为了明确高产水稻品种中与淀粉合成相关基因的性质，为稻米品质改良提供指导。严长杰等以53个典型的籼粳品种和近年育成的高产水稻品种为材料，分析了供试品种的理化品质和RVA谱特征，并利用根据籼粳基因组序列差异设计的Wx、Sbe1、She3基因的分子标记，检测了53个水稻品种的基因型，并分析了3个基因位点的遗传学效应。结果表明，3个分子标记均能很好地区分3个位点上等位基因的籼粳来源，根据3个位点的基因型可将53个品种分为6种类型。单个基因遗传效应分析表明：在不同基因型品种间淀粉的理化特性（AC，GC，RVA）存在显著或极显著差异，3个基因的联合效应在不同基因型组合间也存在显著的差异。     

水稻淀粉合成相关基因对稻米RVA谱特征的影响

以优质粳型糯稻苏御糯为供体，品质较差的籼稻桂朝2号为轮回亲本，构建了BC₂F₄群体，通过发展分子标记，研究了淀粉合成相关基因Wx、Sbe1、Sbe3、Isa、Pul、SssⅠ等对稻米淀粉RVA谱特征的影响。结果表明Wx基因对RVA谱8个特征值的表现均起主要作     

利用基因示踪分子标记对水稻淀粉合成基因进行功能分析

细粒粘连淀粉合成酶、淀粉分支酶1和淀粉分支酶3是关系到水稻胚乳中淀粉生物合成的3种主要酶。为了鉴定籼稻品种93-11和粳稻品种日本晴基因组数据库中的同源区域，已经使用了编码相应淀粉分支酶1和淀粉分支酶3的Sbe1、Sbe3基因的通用序列。使用序列多样性来开发出基因示踪标记，以便区分这两个位点Sbe1和Sbe3中的籼稻等位基因和粳稻等位基因。     

小麦籽粒淀粉分支酶同工酶基因型与酶活性关系研究

测定了71个小麦品种的籽粒淀粉分支酶活性,并采用非变性聚丙烯酰胺凝胶电泳（Native-PAGE）,鉴定了分支酶同工酶的基因型,以明确小麦籽粒淀粉分支酶（SBE）各同工型等位基因的分布特点和基因型组成,阐明分支酶活性与分支酶同工酶基因型的相关性。结果表明,分支酶有SBEⅠ和SBEⅡ两个基因位点,SBEⅡ位点未显现多态性,SBEⅠ位点存在多样性。在SBEⅠ位点鉴定出A、B、D_ⅰ和D_ⅱ共4个等位基因位点,各等位基因位点出现频率分别为9.9%、76.1%、95.8%和57.8%;共检测到9种基因型,其中基因型D_ⅰD_ⅱB、D_ⅰB和D_ⅰD_ⅱ有较高的分布频率,分别为45.1%、28.2%和8.5%。从单一位点分析,分支酶活性与SBEⅠ位点有显著的相关性,与SBEⅡ位点相关性不显著。由此可见,小麦籽粒胚乳淀粉分支酶同工酶不同基因位点和基因型对酶活性具有不同的遗传效应。     

水稻Wx复等位基因基于PCR的功能标记开发与利用

直链淀粉含量是影响稻米食味品质的重要因素,主要由蜡质基因(Wx)调控,Wx基因座存在Wxa、Wxb、Wxin、Wxmw等多个复等位基因,通过分子标记辅助选择(marker-assisted selection,MAS)培育中低直链淀粉含量的水稻品种是提高稻米适口性的重要途径。Wx复等位基因的功能由单碱基核苷酸多态性(single nucleotide polymorphisms,SNP)决定,其检测依赖于测序或酶切,存在耗时多、费用昂贵等缺点。为提高选择效率,本文利用Wx复等位基因的SNP差异和四引物扩增受阻突变(tetra-primer ARMS-PCR)原理,进行PCR功能标记的开发。引物设计过程中,针对扩增效率低和非匹配的延伸2个技术难题,提出了调整错配位点的解决方案,成功开发了基于PCR技术的两对功能性标记Waxygt-ARMS2和Waxyac-ARMS2,可以准确区分上述复等位基因型,且具有操作简单、耗费较低的特点。利用新开发标记对辽宁省育成的部分水稻品种进行Wx基因型检测的结果表明,40份辽宁育成品种均携带Wxb基因,遗传基础单一。上述结果为利用Wx基因位点的分子标记培育中低直链淀粉含量的水稻品种,改良辽宁省水稻品种的食味品质提供了技术支撑。     

利用分子标记鉴定水稻品种的Wx等位基因及其与直链淀粉含量的关系

应用Wx基因的微卫星标记484/485和PCR-AccⅠ分子标记对93份籼、粳水稻品种（系）的Wx基因的多态性进行了研究,并探讨了不同基因型与直链淀粉含量的关系。484/485扩增结果表明,该微卫星标记表现为3种基因型,即Wx1Wx1、Wx2Wx2和Wx3Wx3,其中籼稻以Wx1Wx1和Wx3Wx3为主,粳稻以Wx2Wx2为主,具有Wx1Wx1和Wx2Wx的品种（系）直链     

人工老化对不同Wx基因型稻米品质及RVA谱的影响

为了解不同Wx基因型稻米在贮藏过程中的食用蒸煮品质和RVA谱变化,采用高温高湿人工加速老化方法,对5个携有不同Wx等位基因水稻品系的种子在87.5%相对湿度和42℃条件下分别处理0、5 d、10 d、15 d、20 d、25 d和30 d。结果显示,经高温高湿老化处理后,稻米直链淀粉含量、碱消值和胶稠度的变化不大,而RVA谱特征值在整个老化过程中存在较大波动。总体来看,消减值的变异系数最大,达20.71%;其次是崩解值和回复值,分别达到17.52%和14.25%;峰值时间和起浆温度的变异系数最小,只有2.34%和0.91%。不同Wx基因型稻米RVA特征值在老化过程中的稳定性并不一致。其中,Wxt基因型稻米的最高黏度和崩解值变异幅度最小;Wxg1基因型稻米的热浆黏度、消减值、回复值和峰值时间最为稳定;Wxg2基因型稻米冷胶黏度的波动最小。本研究结果,可为今后在水稻品质耐储藏实践中延缓稻米品质的劣变提供理论依据和参考。     

RVA谱在稻米蒸煮食用品质评价及遗传育种方面的研究进展

在稻米的品质改良中,利用粘度速测仪测定稻米淀粉粘度特性作为估计稻米食用品质一个很重要指标。这种测定具有测定简单快速和用量小的特点。美、日等发达国家已经广泛水稻品质育种中应用。中国在近些年开始应用。对稻米淀粉RVA谱在稻米蒸煮食用品质评价,稻米淀粉RVA谱遗传及在育种上应用的研究进展进行了总结并提出了一些可能研究利用方向。RVA谱能较好地区分AAC相似的品种的食味。RVA与稻米食味、米饭质地以及其它与米饭食味相关的理化指标均密切相关,已经在杂交育种和诱变育种等育种上应用。RVA谱主要受单基因（Waxy）加性效应控制,可在F4代及其以后种子进行选择。不同地点环境对RVA谱影响很大。     

稻米淀粉品质遗传与改良研究进展

本文介绍了稻米淀粉品质性状的含义和主要内容,较全面地总结了直链淀粉含量、糊化温度、胶稠度、RVA谱、支链淀粉结构、淀粉膨胀体积以及淀粉凝胶的质构和老化特性等性状的遗传研究进展.总结了淀粉品质与其它品质性状与农艺性状的遗传相关性,环境条件(灌浆结实期气温)及基因型×环境互作效应对稻米淀粉品质的影响,及分子辅助选择与基因工程技术改良稻米淀粉品质的研究进展.今后淀品质研究应集中在淀粉品质相关性状形成的基因网络解析、淀粉基因分子标记挖掘、淀粉品质的多基因聚合育种及淀粉品质分子设计的数据库建设.通过应用基础研究以及相关技术集成,特别是分子设计(聚合)育种技术的实践,有望培育出淀粉品质符合市场要求的优良品种.     

粳稻精米脂肪含量和组分对蒸煮品质的影响及其对氮素的响应

选用6个穗型不同的粳稻品种,采用7个氮肥处理,研究了精米中脂肪含量和组分对稻米直链淀粉含量和RVA特征值的影响及其对氮素的响应。结果表明,水稻精米中脂肪含量及组分存在显著的基因型差异。小穗型品种宁粳1号、早丰9号和武育粳3号精米中粗脂肪含量和淀粉脂(SL)含量分别大于或等于与之对应的大穗型品种宁粳2号、徐稻4号和9522; 精米中非淀粉脂(NSL)含量小穗型品种宁粳1号、早丰9号和武育粳3号均小于或相近于与之对应的大穗型品种宁粳2号、徐稻4号和9522。氮素对精米脂肪含量及组分的影响小于基因型,而且对于不同的基因型水稻氮素对脂肪的调控作用不同。精米中粗脂肪含量及各脂肪组分含量与直链淀粉含量(AC)及RVA特征值关系密切。精米中粗脂肪含量与脱脂前后的崩解值(BDV)呈极显著负相关,SL与直链淀粉含量(AC)、脱脂前后的消减值(SBV)和回复值(CSV)均呈显著或极显著负相关。从这些结果可以看出,精米中脂肪含量尤其是SL含量对稻米的蒸煮食味品质有显著影响,提高精米中SL含量能够提高稻米的蒸煮食味品质。     

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.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

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...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

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.     

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...     

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).     

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...     

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.     

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.