烤烟根系激素水平、GS、PMT对氮素形态的响应

通过水培试验,探讨了不同氮素形态对烤烟苗期根系激素水平与氮代谢酶的影响。研究结果表明,外源铵态氮对烤烟根系及叶片的谷氨酰胺合成酶(GS)具有一定的诱导作用,饼肥浸提液对烤烟叶片GS有激活作用、对根系GS有抑制作用;外源铵态氮对根系烟碱合成关键酶N-甲基腐胺转移酶(PMT)活性有激活作用;不同氮素形态对根系激素的影响不同,纯铵态氮处理的IAA含量最高,纯硝态氮处理的ABA含量最高,铵态氮与硝态氮1∶1处理的ZR含量最高,浸提液对IAA,ABA,ZR,IAA/ABA,ZR/ABA有明显的激活作用。     

饼肥对烤烟叶片发育过程中质体色素降解及相关酶类活性的影响

采用盆栽方法研究了饼肥对烤烟叶片发育过程中色素降解及相关生理变化。结果表明，饼肥处理叶绿素、叶绿素酶活性、总类胡萝卜素整个生育期含量均较高；无机肥处理在烤烟叶片发育过程中叶绿素的a/b比例保持基本恒定，而饼肥处理促进叶绿素a的代谢。饼肥对新黄质前中期起促进积累作用，中后期起促进代谢作用；饼肥显著促进叶黄质、β-胡萝卜素积累；对紫黄质的影响两处理效应大致相同。无机肥处理的脂氧合酶（LOX）活性在烤烟发育前期高于饼肥处理，30 d后一直低于饼肥处理。饼肥调整了发育末期类胡萝卜素类物质组分比例和色素与相关酶类的关系。     

饼肥配施对烤烟发育过程中叶片光合特性的调控效应研究

研究了饼肥用量对烤烟发育过程中叶片光合特性的影响。结果表明,随着饼肥用量的增加,烟叶的叶绿素含量在增加,叶片的PSⅡ最大光化学效率和潜在活性,PSⅡ的实际光化学效率以及qp都有增加的趋势,最终导致叶片净光合速率的提高。而且试验表明,适当的增施饼肥有利于改善叶片的光合功能,提高叶片的光合速率,但是继续增施饼肥反而不利于光合能力的改善,更不利于荧光动力学参数的优化。     

定向发酵饼肥对烤烟各器官氮含量及氮分配的影响研究

试验以研究定向发酵饼肥对烤烟各器官氮含量及分配的影响规律为目的,用以判断发酵饼肥供氮能力强弱。以‘龙江911’为试材,采用田间小区试验设计,3个处理,分别为纯施无机化肥、50%发酵饼肥与50%无机化肥混合施用、100%施用发酵饼肥,所有处理氮磷钾施用量分别为52.50 kg/hm2、52.50 kg/hm2、105.00 kg/hm2,3次重复,研究根系、茎、叶片内氮含量和分配的变化。结果表明：根系含氮量随着生育期延后而降低,施用饼肥处理氮含量与对照相差0.02%~0.05%,无显著差异;茎内氮含量饼肥处理与对照相差0.01%~0.05%,各处理之间无显著差异;下部叶饼肥处理与对照相差0.08%~0.26%,各处理之间无显著差异;中部叶饼肥处理与对照相差0.03%~0.18%,各处理之间无显著差异;上部叶施用发酵饼肥处理含氮量显著低于对照;施用发酵饼肥处理不会改变烤烟各器官内氮分配的比例。综合分析认为,定向发酵饼肥供氮能力可以达到与无机肥相似的效果,施用比例可以达到50%~100%。     

水分亏缺对烤烟光合特性和氮代谢的影响

通过真空表式土壤张力计监测土壤水势,以正常氮处理的烟株为对照,对生育后期由于施肥过多而严重影响烟叶品质的烤烟K326和NC89,进行有控制的水分亏缺处理,研究以水控氮对烤烟光合特性和氮代谢的影响,探讨以水调肥改善烟叶品质的生理原因。结果表明：两种氮肥营养下,土壤水分亏缺降低了叶片的净光合速率和蒸腾速率,而施高氮较好的抑制了这种下降;适度的土壤水分亏缺抑制了硝酸还原酶的活性,降低了中上部叶全氮的含量,从而有效抑制了高氮营养下烤烟成熟期的氮代谢。     

氮素水平对不同基因型小麦旗叶光合特性和子粒灌浆进程的影响

在池栽条件下，研究了不同施氮水平对强筋小麦8901和弱筋小麦1391生育后期旗叶叶绿素含量、光合速率、灌浆速率和产量的影响。结果表明，两品种表现为随施氮量的增加，叶绿素含量、光合速率都有增加的趋势，但是过量氮肥又使它们降低。在本试验条件下，两品种均以中氮处理(240kg／hm^2)光合速率大，灌浆进程合理，产量水平高。研究发现，强筋和弱筋小麦生育后期叶光合特性和子粒灌浆进程差异显著；旗叶光合速率和叶绿素含量及子粒产量呈正相关。     

饼肥与沼渣配比对烤烟生长发育及其内在品质的影响

采用室内分析与大田试验相结合的方法,研究分析了沼渣与饼肥不同配合比例对烤烟生长发育及品质的影响。结果表明:在饼肥与沼渣氮素含量1∶1施用时,可以增加烟株叶片数、株高、叶长和叶宽,提高烟株的抗病性,促进烤烟生长发育,缩短烤烟生育期1~6 d;根、叶和全株干物质重量在饼肥与沼渣不同配比处理间的差异达到5%的显著水平,茎干物质重在处理间差异不显著;饼肥氮素含量较高的处理烟株干物质含量较高,烟叶产量和产值也较高;沼渣氮素含量较高的处理烟叶均价和等级结构较高;饼肥与沼渣氮含量1∶1施用能够兼顾烤烟产值和等级结构,还可以提高烟叶外观质量,增强烤烟内在化学成分协调性,改善感官评吸的香气质和香气量等。     

苗期土壤水分亏缺后玉米光合生理的恢复

通过模拟土壤水分亏缺试验,研究了玉米在土壤水分亏缺后光合生理的恢复机制.结果表明:不同处理玉米光合生理在复水后30 d内均可以恢复正常生长.轻度亏缺处理玉米叶片气孔导度和蒸腾强度在复水后0～10 d可恢复正常,光合速率和胞间CO2浓度在复水后10～20 d恢复正常,但叶绿素荧光参数(Fv/Fm、Fv/Fo、qP、qN)和叶片光合色素含量的恢复相对较为缓慢.重度水分亏缺处理玉米光合生理指标恢复滞后于轻度亏缺处理.轻度亏缺处理复水后玉米净光合速率的恢复主要受气孔因素影响,重度水分亏缺处理玉米净光合速率的恢复在复水0～10 d主要受非气孔因素影响,复水10 d后主要受气孔因素影响.     

配施有机肥对烤烟若干生理代谢的影响

通过黄泥田土盆栽试验研究了烤烟配施五种有机肥料对烟株旺长初期若干生理代谢的影响,结果表明：配施五种有机肥的烟叶NR活性均随有机氮比例增加而提高;配施鸡粪和稻草的烟叶光合色素含量随有机氮比例增加而增加,而饼肥、牛粪和猪粪则相反;配施鸡粪、饼肥和稻草的烟叶游离氨基酸和可溶性蛋白质含量随有机氮比例增加而增加,而牛粪和猪粪则相反;配施鸡粪、饼肥和牛粪的烟叶可溶性总糖含量随有机氮比例增加而增加,而猪粪和稻草则相反。     

烟苗生长发育对不同氮源形态的响应

为探讨不同形态氮源对烟苗素质和生长发育的影响，以烤烟新品系HN2146为参试材料，采用水培试验研究硝酸铵、硝酸钙、硫酸铵和尿素4种不同形态氮源对烟苗生长发育特性的影响。结果表明，烟苗最大叶面积以硝酸钙处理最大，为100.4cm2；烟苗叶和根系蛋白质含量以硫酸铵处理最高，分别为151.452和79.367μg/g FW；硝酸还原酶活性表现为硝酸钙>硝酸铵>硫酸铵>尿素处理；烟苗对氮的吸收能力表现为硝酸铵>硫酸铵>硝酸钙>尿素处理。通过对不同处理烟苗相关农艺性状和生理特性指标的主成分分析，其综合得分表现为硝酸钙>硝酸铵>硫酸铵>尿素处理。可见以硝态氮和铵态氮作为唯一氮源对烟苗生长发育的效果较好，而以尿素作为唯一氮源的效果最差，本研究结果为不同氮源在烤烟育苗培育上的应用提供了理论依据。     

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.