从T461的育成探讨广谱广亲和系的选育

T461是以籼粳中间型品种轮回422为广亲和、野败恢复基因供体,与意大利粳稻Cripto杂交选育成的具有良好一般配合力、广谱广亲和的偏粳型恢复系。T461能恢野败、矮败、印尼水田谷、滇型和BT型等核-质互作型籼、粳三系不育系,与籼型和粳型测验种杂交的结实率非常接近,小穗育性平均在90%以上,表现亲和力强、亲和谱广。在T461的改良过程中,选用多个不同的三系不育系在分离世代检测恢复性和配合力的同时,还能起到鉴定广亲和性的作用,达到获得广谱广亲和的目的。     

水稻显性雄性核不育基因鉴定初报

1978年我所用栽野型组合(萍矮58×华野)F_2中的无花粉型不育株与反交组合(华野×萍矮58)F_4中的正常株杂交,后代出现典败型变异株。经13个世代观察,该不育材料的测交、回交、姊妹交(不育株×可育株)F_1分离出的不育株与可育株呈1∶1;可育株自交后代育性不分离;“不育株”幼穗分化期在高温下(白天平均温度30℃以上)有部分结实,     

(禾鲁)稻与云南稻地方品种亲缘关系的初步研究

穭稻的植株形态及谷粒特性与云南稻的两个粳型地方品种相近,彼此的杂交结实率高于它与籼型品种的杂交结实率。穭稻野生性状较强,在 F_1代中表现显性.F_1植株的花粉育性为1.15—82.1%,与粳型品种杂交时育性较高,又以穭稻为母本时育性高于其反交组合。穭稻种胚酯酶同工酶的酶带与云南稻的粳型品种有些相近。穭稻与云南稻四个品     

梅树结实不稳定因素的观察研究

梅树结实多寡和不稳定性与品种器雌蕊败育有密切关系，败育花的多少是梅品种特性之一；梅品种间授粉亲和力差异大，常有自花不实和异花授粉不亲和以及某些组合正交而反浆亲和等现象；一些品种还有作父本授粉亲岙和作母本接受花粉亲和面的广窄之别。花期气温是制约梅着果率的重要环境因子；品种差异和异地引种不当是影响梅绳索产量的主要因素之一。     

水稻籼粳亚种间杂种不育性的研究进展

克服杂种不育性是利用籼粳亚种间杂种优势的关键。由此对水稻亚种间杂种不育性的原因、细胞学基础及两种主要基因遗传模式进行了总结,并详细综述了利用“亲和基因”克服籼粳杂种不育性的两种有代表性的学说-广亲和基因和特异亲和基因分子定位的最新研究进展,并提出了两“亲和基因”共同利用的初步设想:将聚合了Si等位基因的粳型亲籼系与聚合了不同广亲和基因(中性亲和基因的广亲和力强、亲和谱广泛的粳型品种进行杂交和回交,选育出聚合不同广亲和基因和Si等位基因的粳型亲籼系,再与籼稻品种杂交,真正实现直接利用籼粳亚种间杂种优势。     

利用广亲和品种配制亚种间杂交稻的研究

众所周知,籼粳交F_1表现极明显的优势,但结实率低.广亲和基因的发现.使利用亚种间杂种优势成为可能.袁隆平据此提出了利用广亲和基因培育亚种间杂交稻超高产育种的见解.我们研究了用广亲和品种配制的杂种F_1主要农艺性状的相关关系,各性状对单株产量的重要性及各性状的优势表现.旨在为广亲和品种用于配制亚种间杂交稻的研究提供科学依据.材料和方法广亲和品种为培矮64(籼), CPSLO17(爪哇型),CPSLO(爪哇型),02428(粳).不育系有台中65A,秋光A,黎明A,农虎26A,京越A,黄金A,中作59A,537A,72-75A,垦六人,六南早A,珍籼97A(籼),V20A(籼),29南1号A(籼),协青早A(籼)等.以广亲和品种为父本,以不育系为母本,配制了76个组合,以盐优57为对照.于1990年4月13日播种,6月2日插秧,每一组合为一区,株行距为10cm×20cm,单本植,田间记载生     

高粱 A_2雄性不育系的鉴定 Ⅰ.育性反应

1983～1985年间观察了3份 A_2不育系(A_2TAM428,A_2Tx624,A_2Tx3197)与140份品种测交 F_1的自交结实率。结果表明,A_1不育系的恢复系或保持系,基本上也恢复或保持 A_2不育系的不育性;但也发现某些恢复 A_1不育系结实性的中国高梁地方品种和国外高梁品系却保持 A_2不育系的不育性。这证实 A_2不育系的育性反应确实与 A_1不育系     

水稻温敏核雄性不育系培矮64S广亲和位点S-5的SSR紧密连锁标记

广亲和(WC)是水稻(OryzasativaL.)亚种间杂种优势利用的重要遗传工具。本研究对我国南方大面积推广应用的亚种间两系杂交稻亲本培矮64S的WC基因S-5n进行分子标记定位。从培矮64S//T8/秋光三交F1中选出由263个高育和低育极端类型组成的标记群体,选用来源于CornellSSR连锁图的20个标记和根据GenBank数据库公布的序列合成的9个SSR标记,通过BSA(分离群体分析)法对标记群体进行分析,该S-5位点精确定位于第6染色体上,距SSR标记GXR6和RM276的距离只有0.2cM。培矮64S的S-5n对育性贡献可使小穗结实率从平均43.5%提高到77.5%,贡献率达34.0%,表明它是一个很强的控制广亲和特性的主效基因。本研究所获得的这些紧密连锁标记对分子标记辅助选择培育广亲和水稻品种和基因克隆具有重要的利用价值。     

三种水稻胞质雄性不育恢复基因的比较

用籼型强恢复系密阳46、H804,含广亲和基因S5n的粳型恢复系02428、T984及H921分别与三种水稻雄性不育胞质野败(CMS-WA),矮败(CMS-DA),印尼水田谷败育(暂名CMS-IA)不育系测交,分析各组合F1、F2及BCF1代的育性表现以研究雄性不育胞质恢复性的遗传。密阳46和H804对CMS-WA、CMS-DA、CMS-IA的恢复性均由两对主效恢复基因控制。T984及H921对野败、矮败和印尼水田谷败育均含有一对主效恢复基因。02428对野败和印尼水田谷不育胞质不含恢复基因,对矮败可能含一对弱恢复基因。对矮败胞质雄性不育的恢复基因作了讨论,推测存在强弱差异的可能。籼粳杂种后代育性表现较品种间组合育性表现更易受环境影响。     

水稻广亲和基因S5-n的功能标记开发及其应用

广亲和基因S5-n是能够恢复籼、粳杂种育性的基因,利用常规育种方法回交转育广亲和基因需要通过配组杂种F₁,根据F₁的育性判断和选择S5-n,选育周期长,方法繁琐。因此,在广亲和遗传改良和聚合育种中需要寻找一种快速、简便的广亲和基因检测方法。本研究根据水稻广亲和基因和籼粳S-5等位基因序列存在136 bp缺失的特征,设计了InDel标记S5136。前人研究已经明确02428、Dualr、CPSLO17具有S5-n,分子标记S5136 PCR扩增这3个材料的带型为缺失带型,而不携带广亲和基因S5-n的材料的带型为非缺失带型。利用该标记对3037与02428的F₂群体分析表明,该标记能准确区分S5-n、S5-i纯合及杂合基因型,标记基因型符合1∶2∶1比例,没有发生偏分离现象。利用该标记从554份水稻品种资源(O. sativa L.)和27份普通野生稻(O. rufipogen Griff.)以及24份江淮流域杂草稻资源中筛选出具有缺失带型的资源材料13份,并对其PCR产物测序证实为S5-n,对Kasalath的广亲和性进行了初步验证;从20份02428的高世代育种材料中,筛选到携带广亲和基因S5-n的恢复系2份。该标记可以用于S5-n基因资源筛选、分子标记辅助选择育种和培矮64S为母本的杂交种种子纯度鉴定。     

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.     

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.     

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...     

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.     

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.