麦田杂草节节麦染色体核型分析研究

对麦田杂草二倍体节节麦（Triticum tauschii L．）的植株形态特征及根尖细胞染色体核型作了分析，并和六倍体普通小麦（Triticum aestivum L．）中国春核型作比较。结果表明，节节麦的核型公式为2n=2X=14=10M＋4SM（2SAT），在第4号染色体上有一对随体。节节麦染色体组和普通小麦中国春D组全套染色体类型相同，表明这两组染色体具有较强的同源性；但二者在染色体相对长度和臂比值上表现出一定的差异，表明该地区节节麦未参与普通小麦的起源。     

一个花粉辐射诱导的小麦-簇毛麦相互易位染色体系的分子细胞遗传学研究

利用⁶⁰Co-γ-射线处理小麦-簇毛麦6V单体添加系花粉，并给中国春授粉，在一个M1单株减数分裂中期Ⅰ检测到一个由2条小麦-簇毛麦易位染色体和一条完整小麦染色体构成的三价体，说明参与易位的2个小麦片段均来自同一条小麦染色体，推测两条易位染色体由相互易位产生。将其中涉及外源大片段的易位染色体称为外源大片段易位（large alien segment translocation, LAST），涉及外源小片段的称为外源小片段易位(small alien segment translocation, SAST)。对后代中两个易位染色体均纯合的植株（LAST’’+SAST’’, 2n = 44）进行顺次C-分带和GISH研究，结果表明外源大片段易位染色体为T7BS-6VS•6VL，外源小片段易位染色体为T6VS-7BS•7BL，易位断点分别位于7B染色体短臂约FL0.60处及6V染色体短臂约FL0.70处。在M2代群体中检测到7种染色体组成类型，比例为3(LAST’’+SAST’’)∶20(LAST’+SAST’)∶2(LAST’’+SAST’)∶1(LAST’+SAST’’)∶1LAST’∶2SAST’∶22(0型)，其中外源大片段和外源小片段易位染色体往往相伴出现。抗病鉴定结果显示抗白粉病基因位于外源大片段易位染色体T7BS-6VS•6VL上。对LAST’+SAST’型（2n = 43）M₂代单株花粉母细胞减数分裂的GISH研究结果显示，88.5%的后期Ｉ或末期Ｉ细胞中出现T6VS-7BS•7BL和T7BS-6VS•6VL的共分离。此外，在个别后期Ｉ细胞中观察到外源大片段易位染色体T7BS-6VS•6VL发生落后和着丝粒断裂现象，并在LAST’型单株（2n =42）的自交后代中筛选到一个通过着丝粒断裂-融合产生的外源小片段插入易位T7BL•6VS-7BS，这为利用外源大片段易位进一步创制携带抗病基因的小片段插入易位提供了新的思路。还分别获得了T7BS-6VS•6VL和T6VS-7BS•7BL的纯合易位系。     

基于寡核苷酸探针套painting的小麦“中国春”非整倍体高清核型及应用

基于寡核苷酸探针套painting的染色体鉴定技术简单、经济和高效,可以促进小麦品种及亲缘物种染色体识别和变异体鉴定,提高染色体工程效率。我们前期开发了寡核苷酸探针套,包含p As1-1、p As1-3、AFA-4、(GAA)10和p Sc119.2-1共5个探针。本研究通过一次荧光原位杂交(FISH),对源于17个非整倍体的18份材料分析发现,其中14个染色体组成正确,可以清晰识别相应的缺体、四体和端体。还构建了基于寡核苷酸探针套涂染的、能准确识别3个基因组和7个部分同源群染色体的高清核型,发现4个非整倍体发生变异,其中从N5BT5D中鉴定出一个可能的小片段相互易位系T6AS·6AL-6DL和T6DS·6DL-6AL。进一步对7个地方品种、10个栽培品种(系)和1个人工合成小麦分析,发现15条染色体存在多态性,涉及6条B组(除4B)、5条A组(除1A和3A)和4条D组(1D、2D、4D和7D)染色体,可以清晰识别我国小麦生产上广泛应用的3种易位类型(T1RS·1BL、T6VS·6AL及相互易位T1RS·7DL和T7DS·1BL),省去了基因组原位杂交(GISH)程序。另外,对5个亲缘物种分析发现,该探针套可以识别栽培一粒小麦、硬粒小麦Langdon、荆州黑麦、长穗偃麦草(2n=2x=14)全部和中间偃麦草30条染色体,并构建了这5个物种的核型。本研究结果证实该寡核苷酸探针套可以有效用于小麦及亲缘物种染色体鉴定,高清晰的中国春非整倍体核型为小麦染色体工程提供了参考标准。     

小麦-黑麦1RS/1BL新易位系的创制和分子细胞遗传学鉴定

利用普通小麦（Triticum aestivum L．）品种小偃6号与黑麦（Secale cereale L．）品种德国白粒杂交，选育出一批带有黑麦抗病性状的小偃6号类型种质材料。应用连续C-分带-基因组原位杂交（sequent C-banding-GISH）技术对上述材料进行染色体组成分析，筛选出2个小麦-黑麦1RS/1BL纯合易位系BC152-1-1和BC01-89-1。其中，BC152-1-1（2n=42）除含有1对1RS/1BL易位染色体外，未见其他染色体变异；BC01-89-1（2n=43）除含有1对1RS/1BL纯合易位染色体外，还附加1条两端缺失的3R染色体。高分子量麦谷蛋白亚基（HMW-GS）组成分析和品质分析结果表明，BC152-1-1和BC01-89-1不仅含有来自小偃6号的14＋15优质亚基，而且其蛋白质含量、湿面筋含量和SDS沉降值等品质性状都得到显著改良。     

基于寡核苷酸探针套painting的中国春非整倍体高清核型及应用

基于寡核苷酸探针套painting的染色体鉴定技术简单、经济和高效, 可以促进小麦品种及亲缘物种染色体识别和变异体鉴定, 提高染色体工程效率。我们前期开发了寡核苷酸探针套, 包含pAs1-1、pAs1-3、AFA-4、(GAA)₁₀和pSc119.2-1共5个探针。本研究通过一次荧光原位杂交(FISH), 对源于17个非整倍体的18份材料分析发现, 其中14个染色体组成正确, 可以清晰识别相应的缺体、四体和端体。还构建了基于寡核苷酸探针套涂染的、能准确识别3个基因组和7个部分同源群染色体的高清核型, 发现4个非整倍体发生变异, 其中从N5BT5D中鉴定出一个可能的小片段相互易位系T6AS·6AL-6DL和T6DS·6DL-6AL。进一步对7个地方品种、10个栽培品种(系)和1个人工合成小麦分析, 发现15条染色体存在多态性, 涉及6条B组(除4B)、5条A组(除1A和3A)和4条D组(1D、2D、4D和7D)染色体, 可以清晰识别我国小麦生产上广泛应用的3种易位类型(T1RS·1BL、T6VS·6AL及相互易位T1RS·7DL和T7DS·1BL), 省去了基因组原位杂交(GISH)程序。另外, 对5个亲缘物种分析发现, 该探针套可以识别栽培一粒小麦、硬粒小麦Langdon、荆州黑麦、长穗偃麦草(2n=2x=14)全部和中间偃麦草30条染色体, 并构建了这5个物种的核型。本研究结果证实该寡核苷酸探针套可以有效用于小麦及亲缘物种染色体鉴定, 高清晰的中国春非整倍体核型为小麦染色体工程提供了参考标准。     

利用白茅花粉有效地诱导小麦单倍体

小麦和野生杂草白茅（Imperata cylindrica）进行种间杂交后通过去掉白茅染色体得到高频率的小麦单倍体。对其根系进行细胞学分析后发现，再生植株的体细胞染色体数为21。小麦的所有F1代与白茅的杂交都获得了单倍体再生植株，这暗示小麦与白茅杂交后代的基因型具有非专性特性。观察了与白茅杂交的小麦F1杂种形成种子的变异（44．9～84．5％），形成胚的变异（15．1～47．7％），以及再生率的变异（27．0～75．0％）。     

三种黑麦种质的染色体FISH核型分析

为了解黑麦染色体的FISH核型特点,本研究使用Oligo-pSc119.2-2、Oligo-pSc200和Oligo-pSc250探针对3种黑麦(MAD黑麦, WR7黑麦和C718黑麦)染色体进行了双色FISH分析,结果发现3份黑麦的7对染色体上,Oligo-pSc119.2-2红色信号强且丰富,广泛分布于染色体端部及中部等。Oligo-pSc200和Oligo-pSc250绿色信号强,主要位于染色体端部及近端部。3份黑麦每条染色体的Oligo-pSc119.2-2信号分布较为相似,但是Oligo-pSc200和Oligo-pSc250信号的差别较大。MAD黑麦和WR7黑麦染色体上的Oligo-pSc200和Oligo-pSc250信号比C718黑麦多且强。MAD黑麦和WR7黑麦的FISH核型较为相似,它们与C718黑麦的差别较大。通过本试验了解到3份黑麦的FISH核型之间存在遗传多样性,建立了3份黑麦的FISH核型,这将有助于该种质在麦类作物遗传育种上的利用和深入研究。     

普通小麦中国春和Sava单体的繁育行为

从１９９１年至１９９４年对普通小麦品种中国春和Ｓａｖａ两套单体的繁育行为进行研究。观察表明，在分析的６６８株中国春单体自交种子中，５５．３％为单体，４１．０％为二体，３．２＾％为缺体。检查了６３０株Ｓａｖａ单体自交种子根尖染色体数目，其中单体，二体和缺体株频率分别为５２．７％，４２．６％和３．８％。观察到的其他类型非整倍体的三体，四体，单端体和双单体，频率不超过１％。     

普通小麦中国春-百萨偃麦草异染色体系的分子标记分析

综合利用HMW-Glu亚基、STS、SSR和RFLP等分子标记对普通小麦中国春、百萨偃麦草、中国春-百萨偃麦草双二倍体和11个中国春-百萨偃麦草异染色体系进行了分析。结果表明，14对SSR、10对STS引物和6个RFLP标记可以特异追踪百萨偃麦草染色质。C7-17及其后代株系C7-17-2等编码百萨偃麦草特异HMW-Glu亚基，添加染色体涉及与小麦第１部分同源群染色体部分同源的1J；1对STS、3对SSR和1个RFLP探针可以特异追踪二体附加系CH05中的百萨偃麦草染色体，并揭示最初根据分带核型确定的J3与小麦第2部分同源群染色体具有较高的部分同源性；2对STS、1个RFLP探针和1对SSR可以追踪CH09的外源染色体，并揭示最初确定的J7与小麦第3部分同源群染色体具有较高的部分同源性；1对STS和1个RFLP探针在CH03、CH04和CH34中具有相同的多态，3个附加系可能添加了相同染色体，最初确定的J₁、J₂和J_?与小麦第7部分同源群染色体具有较高的部分同源性；3对SSR引物可以特异追踪CH12中附加的大片段易位染色体和CH11中的小片段易位染色体，推测易位可能涉及同一条百萨偃麦草染色体。发现13个标记（5个STS、3个RFLP探针和5个SSR）可以追踪未涉及到的4J和5J等染色体。     

一种野生燕麦的染色体核型分析

对安徽风阳地区麦田里的一种野生燕麦的染色体核型进行了分析，结果如下：该物种的染色体数为2n=42，各染色体间形态差异明显，但均为中着丝粒染色体（m）或近中着丝粒染色体（sm），最长与最短染色体相对长度比为2．34，并在全套染色体中的第9号和16号染色体上发现了2对随体，核型公式为2n=6x-42=22m＋20sm（2SAT），核型类型舅比较对称的2B型。同时讨论了燕麦作为小麦遗传改良的重要种质资源，对普通小麦远缘杂交和品质改良的意义。     

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.