不同栽培措施对马铃薯干物质积累与分配的影响

为研究新疆伊犁州昭苏垦区马铃薯不同栽培条件下干物质积累规律,指导马铃薯生产实践,采用两因素(覆膜、密度)随机区组设计,于马铃薯不同生育期取样,测定各器官干物质积累量。结果表明:覆膜栽培可使马铃薯生育期提前,干物质积累显著高于露地栽培,各器官在不同栽培模式下干物质积累趋势基本相同。不同处理下干物质在各器官中的分配,随生长中心的转移而发生变化。     

密度对饲用玉米干物质积累和分配的影响

以饲用玉米品种为材料,研究密度对干物质积累与分配的影响.结果表明:单位面积内叶片干物质积累量在整个生育期先增加后降低,茎秆干物质积累量、子粒干物质积累量及干物质积累总量呈增加趋势;各器官单位面积干物质积累量随密度的增大变化趋势不同;生育前期以叶片为分配中心,生育中期以茎秆为主,生育后期生长中心为子粒,并因密度和品种而异.     

高蛋白大豆生长发育及干物质积累分配对密度的响应研究

以高蛋白大豆冀豆12为材料研究了株高、叶面积指数、干物质积累分配及产量对种植密度的响应。结果表明:随密度的增加,株高和最大叶面积指数呈上升趋势,单株干物质积累量和各器官干物质积累量逐渐减小。群体干物质积累量随着生育进程表现为先增加后下降趋势,鼓粒期达到峰值,鼓粒期以后开始下降;群体干物质积累量随密度升高也呈先增加后下降的趋势,以密度22.5万株/hm~2处理最大。密度为22.5万株/hm~2时,群体产量3 736.67kg/hm~2,为最高。     

不同施肥水平对芝麻干物质积累与分配的影响

以‘皖芝1号’和‘豫芝4号’为试验材料,研究不同施肥水平下芝麻干物质积累规律,指导芝麻生产实践。采用两因素（施肥、品种）随机区组设计,于芝麻不同生育期取样,测定各器官干物质积累量。芝麻干物质积累呈现慢-快-慢的变化趋势,各器官在不同施肥水平下干物质积累趋势基本相同。苗期到初花期干物质分配中心以茎叶为主,后期分配中心转向蒴果和籽粒。随着施肥量的增加干物质积累量增加,但是施肥量过高或过低都不利于芝麻获得高产。选择适宜品种,合理施肥,促进干物质的快速积累与分配是芝麻获得高产的关键。     

大豆氮素积累、分配与转移规律的研究

以北丰-14为供试品种,采用五因素三水平实施方案,系统地研究了大豆在不同密度、施肥量处理下,对N素积累转移及分配的规律.结果表明:大豆对植株N素积累过程呈S形曲线变化.N在各器官的分配随生长发育中心转移而变化,结荚期以前,主要分配在叶片中,随着生育进程的推移,N逐渐向荚皮、子粒中转移,植株各部分吸收全N的70%左右最终转移到子粒中,且以叶片向子粒中转移的N素量为最多.     

宁夏引黄灌区玉米高产挖潜群体特征分析

为了探明宁夏玉米高产群体特征以及限制高产的因子。以‘郑单958’和‘先玉335’为供试品种,在密度为121215株/hm~2和110205株/hm~2下对产量及产量构成、关键生育时期的群体光合性能、干物质动态变化等特征进行研究。结果表明:群体叶面积指数(LAI)随生育进程呈单峰曲线变化,吐丝前后达到最大值;光合有效辐射量沿冠层垂直向下呈大幅下降,以120~180 cm处(棒三叶位置)透光率的变化最为明显;整个生育期群体干物质积累动态呈S形曲线,成熟期干物质积累最大;2种不同高产挖潜模式均可获得高产;但‘先玉335’挖潜模式群体结构更为理想,后期氮肥供应不足是产量限制因子。因此认为,‘先玉335’在原密度下,后期通过增施N肥,来增加千粒重和穗粒数,是宁夏进一步提高玉米产量的重要途径。     

大豆子粒中干物质、脂肪和蛋白质积累规律的研究

利用4个不同蛋白质含量的大豆品种为材料,测定子粒中干物质、脂肪和蛋白质的动态变化。结果表明：不同品种大豆子粒中干物质积累呈S形曲线变化;脂肪含量随子粒的形成呈S形曲线变化;蛋白质含量随子粒的形成而逐渐增加,大致呈W形曲线变化。子粒形成后期,脂肪积累量与干物质积累量呈正相关,在子粒干物质快速增长期呈显著正相关;脂肪积累量与蛋白质积累量在子粒形成前期呈正相关,中期负相关,后期呈显著负相关;干物质积累量与蛋白质积累量在子粒形成前期呈正相关,子粒形成中后期呈负相关。     

转Bt基因抗虫棉源库关系及调控效应研究

以转Bt基因抗虫棉晋棉31号为试验材料，研究栽培密度、DPC化控、化肥三因素不同组合对棉花干物质积累分配以及源库活性的调控效应。结果表明，三因素优化组合可以构建源库优化平衡状态。当源库指数处于优化状态时，干物质积累速率大幅度提高，干物质在各器官分配比例相对协调；开花后同化产物向库器官输出率提高，铃置增加；叶源生理活性显著提高，功能叶时间延长。转Bt基因抗虫棉栽培关键在于构建源库优化平衡状态。     

大豆不同群体叶面积指数及干物质积累与产量的关系

以垦农4号和垦鉴21号大豆为试验材料,研究了大豆在３种不同密度条件下的叶面积指数及干物质积累动态与产量的关系。结果表明：各品种在不同群体条件下叶面积指数的变化趋势大致呈一抛物线,叶面积指数与产量的相关性在V3和R1达显著水平,R3、R5和R6达极显著水平;不同种植密度、品种间的干物质积累动态均存在差异;各阶段干物质积累量与产量的关系,在R3呈显著正相关,R5呈极显著正相关;KJ21后期群体发育在高密度下仍能维持较高的叶面积指数和干物质积累量,适合密植。     

水稻地上部干物质分配动态模拟的初步研究

利用不同类型品种的播期试验和氮肥试验对水稻干物质分配指数与发育进程及环境因子的动态关系进行了系统研究,并构建了以分配指数预测地上部各器官干物质分配动态的模拟模型。各器官干物质分配指数均为生理发育时间的函数,同时还受到基因型、播期及N营养水平的调节。模型对不同影响因子的效应进行了较为充分的定量。采用水     

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.