玉米亲子代锌铁吸收和分配的研究

以玉米子粒高锌铁含量自交系NXR22（母本）、子粒低锌铁含量自交系NXR12（父本）及其配制的杂交种（F₁）为供试材料,比较双亲及其后代不同穗位的叶片、茎秆及子粒中锌和铁含量、积累量在吐丝期与成熟期间的差异,解析亲子代锌铁吸收与分配特征。研究结果表明:不同基因型玉米叶片、茎秆、子粒中锌铁含量和积累量存在显著差异。F₁不同穗位的叶片和茎秆锌铁含量介于双亲之间,且偏向于子粒锌铁含量高的亲本;锌铁积累量显著高于双亲,表现出明显的杂种优势。从吐丝期到成熟期3个供试材料不同穗位的叶片和茎秆锌铁含量和积累量均表现出一定程度的增加。F₁子粒中锌含量及积累量偏向于母本,表现出杂种优势;铁含量介于双亲之间,更偏向于母本。     

氮磷钾配施对杂交玉米禾玉9566农艺性状、产量与养分吸收利用的影响

为优化玉米氮磷钾施用,提高玉米产量和肥料利用效率,开展了杂交玉米禾玉9566氮磷钾配施试验,探讨氮磷钾配施对玉米农艺性状、产量和养分吸收利用的影响。结果表明:氮磷钾配施能有效改善农艺性状,优化产量构成因子,主要是增加穗粒数,从而提高产量,对玉米产量的影响作用为氮磷钾。施氮、钾能提高玉米子粒和茎叶中氮、钾含量,施氮促进植株对氮磷钾的吸收利用,施钾可提高玉米子粒对氮、磷养分吸收量;氮磷钾三因子中促进养分吸收积累作用表现为氮钾磷。氮磷钾配合施用,可有效提高玉米植株对养分的吸收积累,子粒中氮、磷含量和子粒氮磷钾各养分吸收量均为最高,全株养分吸收总量也最高;每100kg经济产量N、P2O5、K2O养分吸收量分别为2.02、0.90、2.21kg,氮、磷、钾肥料利用率为33.28%、15.43%、48.79%,氮、磷、钾肥农学效率分别为13.07、5.59、3.34kg/kg。     

土壤肥力和灌水组合对小麦植株-土壤系统氮素平衡的影响

采用15N示踪技术，在池栽群体条件下，研究了三种土壤肥力和两种灌水量组合对冬小麦生产系统氮素平衡的影响，结果表明：（1）不同处理氮肥的当季吸收利用率变化在39.08%~53.08%，土壤残留率在21.80%~33.59%之间，损失率变化幅度为18.81%~34.62%，植株吸收积累氮素中的29.88%~47.55%来自肥料；证明，采用不同土壤肥力和灌水量组合来调控小麦生产系统的氮素平衡具有较大的空间。（2）随土壤肥力的提高，植株吸收的总氮和土壤氮量显著增加，但营养体滞留量增加，向子粒的分配比例减少；而对肥料氮的吸收量则表现为中肥>高肥>低肥；氮肥损失率表现为低肥>高肥>中肥，残留率无明显变化，说明土壤肥力达到本实验的中等水平后再继续提高，会给肥料氮的吸收利用带来不利影响，但可有效降低对肥料氮的依赖。（3）增加灌水量在不同土壤肥力条件下均可促进对总氮的吸收量，但对土壤氮吸收的促进作用远高于肥料氮，同时也提高了肥料氮的损失率、降低了土壤残留率和向子粒的分配率。（4）提高土壤肥力和增加灌水量均可提高小麦的经济产量、生物产量和土壤A值，降低收获指数；子粒蛋白质含量随肥力的提高而增加，随灌水的增加而下降。     

超级稻施肥量与插植方式研究 Ⅰ．不同施肥量对一季超级杂交稻产量及生长的影响

试验以准两优527和两优293为材料,设不同施氮量处理（135、180、225kg／hm^2）,研究了施肥量对一季超级杂交稻的增产效应,结果表明：抽穗期稻穗、叶片和茎秆的干物质积累分配比例为1：1．5：3～3．5,干物质积累主要在茎秆;成熟期籽粒的干物质重迅速增加,是稻草干物质重的1倍以上。准两优527前期叶面积指数和后期干物质积累均高于两优293;不同施肥量对一季超级杂交稻产量及产量构成的影响存在品种间差异,其中两优293的有效穗、每穗颖花数、结实率和千粒重较低,3种施肥水平处理间连续两年产量差异不大,说明施氮量在135～225kg／hm^2范围内,能满足超级杂交稻生长对氮素养分的需要;不同施肥量处理间植株氮素含量和氮素吸收量差异不大,但品种间略有差异,准两优527成熟期植株氮素吸收量为165．8～188．7kg／hm^2,抽穗期达到总吸收量的72．4％～80．3%,两优293植株氮素吸收量为154．3～170．8kg／hm^2,抽穗期达到82．0%～89．0％,说明准两优527后期仍有较强的氮素吸收能力;磷素和钾素的测定结果与氮素相似。     

辽宁中部地区玉米机械粒收质量及其限制因素研究

研究和明确制约机械粒收质量的因素,对于辽宁省玉米机械粒收技术的推广和生产转型升级具有重要意义。2015-2017年在辽宁省中部的铁岭县蔡牛镇、沈北新区黄家村和海城市耿庄开展了5组玉米机械粒收试验与示范,通过对41个参试品种57个品次粒收质量指标的测试与评价,结果表明：（1）子粒破碎率均值为11.38%,5组试验均高于国家标准≤5％的要求,破碎率偏高是目前辽宁机械粒收存在的主要质量问题;（2）收获产量损失率平均为3.93%,低于国家标准≤5％要求,但不同试验组间差异较大,变幅为0.78%~12.60%,部分田块机械粒收产量损失较大;（3）57个品次样本子粒含水率与破碎率、杂质率的相关系数分别为0.596和0.454,均达到极显著水平,子粒含水率高是导致破碎率和杂质率高的重要因素;（4）产量损失主要来自落穗损失,占总损失量的63.2%~92.5%,落穗损失与植株倒伏倒折密切相关;（5）10月中下旬（10月13日至10月21日）收获,87.2%的参试品种子粒含水率可下降至25%以下,处于适宜机械粒收水分范围。本研究认为,辽宁中部地区热量资源丰富、玉米适采期长,10月中下旬收获时子粒含水率不是当前制约机械粒收质量和技术推广的首要因素,而后期茎秆衰老慢和抗玉米螟、茎腐病品种的选育,控制倒伏与落穗的技术措施应引起关注。     

Pb在小麦植株内吸收、分配和累积的研究

通过大田试验，研究了Pb在小麦植株中的吸收、分配和累积的动态变化规律。结果表明，在小麦整个生长过程中，不同部位Pb含量和Pb累积量随着时间的推移而变化，但从总体上看是根〉茎〉子粒。在灌浆末期，各部位Pb含量从大到小依次为：根〉废弃物〉叶〉茎〉叶鞘〉颖片〉穗轴〉子粒，地上各部位Pb累积量从大到小依次为：废弃物〉茎〉叶鞘〉颖片〉叶〉子粒〉穗轴。从结果还可以看出，小麦植株中较易富集Pb的部位是根、废弃物、茎和叶，而子粒中Pb含量和累积量均比较低。小麦在生殖生长阶段的Pb吸收量大于营养生长阶段；拔节一抽穗期和灌浆初期一灌浆中期Pb吸收量及吸收速率显著高于其他时期。     

施用钾肥对春玉米产量及品质的影响

以黑龙江省2个主栽的玉米品种嫩单12和兴垦3为试验材料,研究了不同钾肥用量对春玉米生育期、植株性状和产量性状以及子粒品质的影响.结果表明,施用钾肥对春玉米生长发育具有促进作用,可使生育期提前,秸秆坚硬,抗倒伏能力增强,有利于光合产物的形成和积累,增加百粒重、穗粒数、穗长,减少秃尖长,有效提高玉米产量.同时,可改善春玉米子粒品质,提高粗脂肪含量.     

黄淮海区域现代夏玉米品种产量与资源利用效率的差异分析

品种改良对夏玉米单产的提升有重要贡献,但目前对现代夏玉米品种间产量形成差异的原因尚不明确。本研究在商河国家农作物品种展示示范中心设置大田试验,选用我国黄淮海区域近年来审定或将要审定的390个玉米品种,于玉米完熟期进行植株取样,测定不同品种产量及其构成因素、完熟期干物质积累与分配、氮素的积累、分配与利用以及光温利用效率,探究不同夏玉米品种的产量及资源利用效率的差异及其形成原因。不同品种的夏玉米产量存在显著差异,收获穗数、穗粒数和千粒重对产量的直接通径系数分别为0.57、1.00和0.88,表明品种间产量差异主要由穗粒数的变化影响。植株的干物质和氮素的积累与分配均对夏玉米产量有极显著影响,与籽粒产量<7 t hm^–2的品种相比,7.0～8.0、8.0～9.0、9.0～10.0、10.0～11.0和>11.0 t hm^–2产量范围内的品种植株群体总干物质积累量分别提高了12.25%、20.52%、29.61%、40.11%和54.04%;籽粒氮素积累量分别提高了16.62%、24.85%、38.45%、48.42%和68.41%;籽粒干...     

潮盐土条件下不同小麦品种（系）子粒品质差异分析

为探明潮盐土条件下不同小麦品种（系）间的子粒营养物质含量及其积累过程,以小麦品种连麦7号、淮麦33和小麦品系连麦抗1为材料,研究了潮盐土条件下小麦子粒蛋白质及其组分含量、氨基酸积累量、淀粉含量及灌浆期间的动态变化。结果表明,连麦7号蛋白质总量及各组分含量均显著高于其他2个品种（系）,醇溶蛋白和谷蛋白含量在3个品种（系）间均存在显著差异。不同小麦品种（系）各氨基酸积累量,以谷氨酸积累量最高。连麦7号18种氨基酸积累量均高于淮麦33和连麦抗1,以脯氨酸差异最大。连麦抗1谷氨酸和苏氨酸积累量高于淮麦33。子粒灌浆期间淀粉含量表现为连麦抗1>淮麦33>连麦7号,其中总淀粉和支链淀粉含量随子粒发育先升高后降低,而直链淀粉含量不断增加。综合以上结果,在潮盐土条件下,连麦7号的子粒品质优于淮麦33和连麦抗1。     

水稻不同器官氮积累及转化效率与氮素利用效率的关系

【目的】分析灌浆过程中不同器官的氮素含量和积累及分配变化与氮素利用效率的关系。【方法】在田间试验条件下,研究了10个水稻基因型的各组织器官氮素积累、分配利用与氮素利用效率间的相互关系。【结果】在籽粒灌浆过程中穗中的氮素含量品种间没有显著的差异而鞘叶和茎中的氮素含量主要在灌浆后期呈显著的差异。穗中氮素积累的增加伴随着鞘叶和茎的氮素积累的下降,尤其是鞘叶更明显,植株总吸氮量在器官中的分配比例随籽粒灌浆进程穗中氮素比例增加伴随鞘叶和茎的氮素比例减少。同样,穗、鞘叶、茎的氮素积累量和分配比例籽粒灌浆后期品种间呈显著的差异。籽粒灌浆不同时期的氮素利用效率品种间呈显著差异,其中成熟期氮素利用效率与成熟期穗和鞘叶氮素含量、鞘叶的氮素积累量和鞘叶氮素分配比例呈显著的负相关,与灌浆中后的穗氮素积累分配比例呈显著的正相关。【结论】在水稻氮高效育种工作中,结合组织氮素进行选择,可有效地提高选择效果     

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.