以滇粳优1号为背景导入系的耐低磷性的初步评价

我国是土壤缺磷的国家,筛选发掘耐低磷的种质具有现实意义。本文利用土壤有效磷含量为8.53mg/kg与5.55mg/kg自然条件,以农业部948项目全球水稻分子育种计划采用的25份种质资源为供体亲本、云南优质高原粳稻品种滇粳优1号为背景构成的311份BC3F3世代和319份BC4F3世代的导入系为材料,分析耐低磷相关性状并以之为指标评价筛选导入系的耐低磷特性。结果表明,分蘖数、有效穂数、穗总粒数是较好的耐低磷筛选和评价指标;以中优早81为供体的1个株系在两试验点均表现耐低磷,还有2个株系仅在宜良试验点表现耐低磷,推断中优早81具有耐低磷特性,所形成的相关3个株系可以作为磷高效品种选育和研究的重要材料。     

转TaEBP基因小麦的回交转育研究

本研究以转TaEBP基因的新春9号小麦T 4代株系为供体,通过回交育种的方法将与抗逆相关的TaEBP转录因子基因导入黄淮麦区的7个主栽或主推小麦品种中,利用温室快速加代和目的基因PCR分子跟踪检测技术,实现了一年四代的快速繁育,在一年内获得了转基因回交三代株系群。PCR分析结果显示,TaEBP基因在杂交F1代植株中阳性率平均在72.3%以上,在6个轮回亲本的回交后代中基本符合1∶1分离比率,在刑麦六号的BC3F2代中呈3∶1分离,外源TaEBP基因的分布符合一对显性等位基因扩增结果的遗传分离比例;PEG-6000胁迫条件下,对3个来自刑麦6号BC3F2代的回交导入系苗期抗性鉴定显示,3个转基因回交导入系的抗旱性明显提高。表明利用转基因材料通过回交转育、快速加代和分子跟踪检测是快速定向改良小麦品种的性状、获得新的转基因小麦的一条有效途径。     

利用MAS技术改良水稻两用核不育系C815S的稻瘟病抗性

为了改良水稻两用核不育系C815S的稻瘟病抗性,本研究以75-1-127(Pi9)、谷梅2号(Pi25)、谷梅4号(Pigm)、天津野生稻(Pi2-1和Pi51(t))、湘资3150(Pi47和Pi48)和魔王谷(Pi49)共6个广谱抗稻瘟病水稻品种为供体亲本,通过分子标记辅助选择育种技术,将稻瘟病抗性基因回交导入C815S。结果表明:改良的6个BC3F1群体除每穗粒数较轮回亲本极显著增加外,其他性状均与轮回亲本保持一致。利用稻瘟病菌株110-2和CHL506对BC3F2改良株系接种鉴定,发现导入了抗病基因的单株抗性增强,表明抗病基因已成功导入到受体亲本中并稳定表达,证实本研究中分子标记辅助选择抗稻瘟病基因是有效的。改良的系列两用核不育系,一方面可用于配制稻瘟病抗性增强的两系法杂交稻新组合,另一方面为进一步培育聚合多个抗稻瘟病基因的不育系提供了材料基础。     

米象对磷化氢的抗性遗传研究

用磷化氢对来自四川三台（SO－6）、广东湛江（SO－3）以及澳大利亚（SO－A）等3个品系的抗性米象进行抗性筛选，对来自海南通什的敏感米象（SO－2）进行单对筛选。分别用这3个抗性品系和一个敏感品系的米象作为亲本进行一系列杂交组合试验，用FAO方法（20小时）测出各个亲本及其F1代杂种（F1）、F1代对敏感亲本的回交（F1－BC）。F1代混交（F2）、敏感亲本雄性与抗性亲本雌性的杂交（F11）、抗性亲本雄性与敏感亲本雌性的杂交（F12）的浓度对数－死亡机率值反应曲线（LC－P）线，并对这些结果进行分析。结果表明：对磷化氢有抗性的米象的抗性遗传为不完全显性、非性连锁的两对或两对以上的常染色体遗传。     

滇粳优1号背景导入系耐低氮的初步评价

耐低氮种质的发掘及其在高原粳稻中应用,有利于提升高原稻区的生产效率并保护环境。在云南高原稻区两种土壤氮素水平下,种植以育成的优质高原粳稻品种滇粳优1号(DJY1)为轮回亲本所形成的2064份导入系,以叶绿素计读数(SPAD)值为指标,评价导入系的耐低氮特性。结果显示:供试导入系的SPAD平均值在两种不同土壤氮素水平下均呈正态分布,且与有效穗和穗粒数极显著正相关;以超出95%右尾概率值为标准,初步筛选出供体亲本为Khazar(BC3F3)和Chhomrong(BC3F4)2个导入系为低氮钝感材料,即耐低氮材料;以小于5%左尾概率值为标准,则推论出供体亲本为Basmati370(BC3F3)、Type3(BC3F3)、Khole-Mavshi(BC3F3)、Ajaya(BC3F3)、Doddi(BC3F3)和鱼秋谷(BC4F3)的6个导入系为低氮敏感材料。这些材料可用于高原稻区耐低氮及氮高效育种及遗传研究。     

野生稻DNA导入后代对稻瘟病的抗性遗传分析

连续多年鉴定了21份普通野生稻(从染色体组)DNA导入后代株系对稻瘟病的抗性,筛选出3个稳定抗病的后代株系2005 D3-60、2005 D3-136和2005 D3-112,以其与感病地方品种白皮稻的杂交F1代和F2代为材料,初步分析了导入后代对稻瘟病菌系01-13-1的抗性遗传特性.研究结果表明:3个组合的F1代对01-13-1菌系全部表现抗病,说明其抗病性都是由显性基因控制的;2005 D 3-60/白皮稻和2005 D 3-136/白皮稻的F2代抗感分离比例为9:7,说明对01-13-1的抗性是由2对显性基因控制,且基因存在互补作用,而05 D 3-112/白皮稻的F2代抗感分离比例为27:37,说明其抗病性是由3对显性基因控制的,基因亦存在互补作用;3个组合正反交的F1代均表现抗病、F1代分离比例相同,说明导入系中抗稻瘟病性状属细胞核遗传.     

欧山羊草高分子谷蛋白亚基向小麦的转入及其遗传规律

欧山羊草具有两个容易用聚丙烯酰胺凝胶电泳与小麦区别的高分子谷蛋白亚基,分别命名为Glu-Aeb1和Glu-Aeb2。采用聚丙烯酰胺凝胶电泳（SDS-PAGE）方法对21份欧山羊草与小麦杂交后代BC2F6和15份BC2F5与小麦杂交F0种子的谷蛋白亚基组成进行了鉴定。实验结果表明,36份材料全部都有欧山羊草高分子谷蛋白亚基的转入。Glu-Aeb1在BC2F6和杂交组合F0中的传递频率分别为59.52%和20.94%。而Glu-Aeb2在BC2F6和杂交组合F0中的传递频率分别为40.48%和22.96%。     

水稻高世代回交导入系耐盐性的遗传研究

水稻是一种对盐敏感的作物，盐分是限制水稻产量的主要因子之一。本研究利用广泛推广种植的杂交籼稻的亲本珍汕97（ZS97）和测序粳稻品种日本晴（Nipponbare）杂交、回交构建的导入系，对水稻的耐盐性进行遗传研究。用88份导入系作苗期盐胁迫（0．3％氯化钠）处理试验，发现6份导入系的耐盐性同受体亲本ZS97有显著差异，其中5份导入系耐盐，1份对盐敏感。图示基因型分析表明5份导入系中含有少数外源导入片段及耐盐相关的基因。     

回交高代选择导入系的纹枯病抗性与抗旱性的遗传重叠研究

利用来自抗旱性较好的供体亲本（BG300和BG304）、具有两种遗传背景（IR64和特青）的水稻高代回交（BC2）抗旱选择导入系，通过人工接种的方法鉴定纹枯病抗性，考察纹枯病抗性与抗旱性之间可能存在的遗传重叠。通过与受体亲本的纹枯病抗性表现比较发现，具有特青背景的抗旱选择导入系倾向于纹枯病抗性的降低，而IR64背景的抗旱选择导入系则倾向于纹枯病抗性的增强。基于基因型与表型的方差分析共鉴定到6个与纹枯病抗性相关的位点，其中QSbr6在不同供体和背景的两个群体中分别检测到，而QSbr10则在同一供体的两个遗传背景下均检测到；有3个位点（QSbr6、QSbr8和QSbr10）与同一群体中检测到的抗旱性位点位置相近，很可能是两种抗性重叠的遗传基础。尽管方差分析的方法在选择导入系的非选择目标性状相关位点的鉴定中存在相当程度的偏低估计，本研究所检测到的纹枯病抗性位点，特别是那些与抗旱性重叠位点的分子标记以及相关的抗性株系仍将为进一步的水稻纹枯病抗性和抗旱性的多抗性育种和深入的遗传重叠研究提供有用的信息和材料。     

几个普通小麦品种中9个位点上控制Kamal腥黑粉病的加性基因

由Tilletia india引起的Kamal腥黑粉病（KB）是1931年由Mitra在印度Kamal地区发现的，是小麦的一种重要病害；其病原菌会在灌浆籽粒中形成大量的真菌孢子。本试验将4个抗性原种（HD29、W485、ALDAN‘S’／IAS 58、H567．71／3＊PAR）与高度敏感品种WH542杂交，然后用其衍生的群体研究了Kamal腥黑粉病（KB）抗性的遗传。用于筛选KB反应的植株材料由来自全部抗性X敏感性组合的F2、BC1、重组自交系和来自6个抗性X抗性组合的重组自交系以及双亲和F1代构成。     

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.