毕单18号高产配套栽培技术研究

通过四因素二次回归正交旋转组合试验,对杂交玉米新品种毕单18号在黔西北地区的高产配套栽培技术进行了研究。建立了该品种籽粒产量与4个主要栽培因子N、P、K肥施用量和种植密度之间的数学模型;解析数学模型,分析了各因子对产量的影响;通过模拟寻优,筛选出毕单18号在黔西北海拔1 400m左右地区的高产配套栽培技术为:籽粒产量在9 953.1kg/hm2以上的种植密度53 934～55 365株/hm2,施纯N 298.4～357.0kg/hm2,施P2O5144.25～169.3kg/hm2,施K2O18.5～42.3kg/hm2。     

杂交玉米新品种毕单18号高产配套栽培技术研究!

采用四因素二次回归正交旋转组合设计,对杂交玉米新品种毕单18号在黔西北地区的高产栽培配套技术进行了研究。建立了该品种产量与4个主要栽培因子种植密度(X1)和N(X2)、P(X3)、K(X4)肥施用量之间的数学模型。解析数学模型,分析了各因子对产量的影响;通过模拟寻优,筛选出毕单18号在黔西北海拔1 300m左右地区产量在9 000.0kg/hm2产量以上的适宜栽培方案为:密度53 307～54 639株/hm2;N肥(纯N)用量221.2～268.8kg/hm2;P肥(P2O5)用量46.6～90.5kg/hm2;K肥(K2O)用量109.8～146.5kg/hm2。     

山区高油玉米高产优质栽培模式研究

为探索在黔西北山区种植高油玉米高产优质的栽培模式，促进山区种植业结构调整，采用多元二次正交回归旋转组合设计，研究了高油玉米产量、产油量与四个主要栽培因子——种植密度及N、P、K肥施用量之间的关系，建立了数学模型，解析了各因素对产量、产油量的效应，通过计算机模拟寻优，筛选出了黔西北山区高油玉米高产优质的农艺综合方案：密度62463～63710株/ hm2；N肥（纯N）321.79～359.04kg/hm2；P肥（P2O5）319.94～345.32 kg/hm2；K肥（K2O）293.64～333.30 kg/hm2。     

杂交玉米‘毕单17号’在高海拔地区的高产栽培技术研究

为使‘毕单17号’在高海拔地区获得高产,通过采用二次回归通用旋转组合设计的方法,对‘毕单17号’产量及其主要栽培因子--种植密度及N、P、K肥施用量之间的关系进行研究,并根据所得数据建立数学模型,解析各因子对产量的效应,通过计算机模拟寻优。结果表明,‘毕单17号’产量≥ 9850.00 kg/hm2的栽培因子优化组合方案为：密度65805~70620 株/hm2,施纯N量449.85~485.1 kg/hm2,施P2O5量273.75~326.25 kg/hm2,施K2O量224.64~323.85 kg/hm2,且对产量的影响顺序为：密度 > 氮肥（纯N） > 磷肥（P2O5） > 钾肥（K2O）,且氮、钾肥有一定的互补作用。     

高海拔地区优质苦荞黔苦2号高产高效农艺措施数学模型研究

采用四因子五水平二次旋转回归组合设计,以密度和氮、磷、钾肥施用量四因子为研究对象,以苦荞种植产量和经济效益为研究目的,对优质苦荞黔苦2号的高产、高效和栽培技术进行栽培试验.结果表明：优质苦荞黔苦2号产量要达到190kg/667 m2以上,栽培模式为：密度8.44万～8.9万株/667 m2,施纯N 5.28～5.77 kg/667 m2,P2O5 3.48～4.48 kg/667 m2,K2O5.14～6.46kg/667 m2;当纯收益达到170元/667 m2以上时,栽培模式为：密度8.88万～9.48万株/667 m2,施纯N 5.03～5.7kg/667 m2,P2O5 2.14～3.45 kg/667 m2,K2O 1.54～2.84kg/667m2.四因子对产量和经济效益影响程度大小依次为N肥＞密度＞P肥＞K肥;因子间互作效应分析,N肥施用量是影响苦养黔苦2号产量和纯收益的关键措施.     

稻田春玉米高产高效施肥技术研究

针对湖南省改部分双季稻田为春玉米—杂交晚稻的种植制度 ,作者对稻田春玉米高产高效施肥技术进行了研究。结果表明 :稻田种植春玉米的产量在 6 0 0 0kg/hm2 的施肥技术为 :施N180kg/hm2 ,P2 O56 0kg/hm2 ,K2 O 12 0kg/hm2 ,并以基肥和穗肥二次施用 ,即全部P ,K肥及 1/ 2N作基肥 ,1/2N作穗肥 ,穗肥施用时期 ,中、早熟种 (叶片数在 16～ 17片叶 ) ,在 9叶全展施用增产效果较好 ;迟熟品种则在 10～ 11叶施用增产效果较好。产量在 75 0 0kg/hm2 以上的施肥技术为 :施肥水平应以施N2 2 5～ 30 0kg/hm2 ,P2 O570～ 10 0kg/hm2 ,K2 O15 0～ 2 0 0kg/hm2 ,N素按基肥∶攻秆肥∶穗肥 =1∶1∶2的比例施用为宜 ,攻秆肥在 4～ 5叶全展施用 ,穗肥中、中熟种在 9叶全展施用 ,迟熟品种则在 10～ 11叶施用     

肥料与密度对玉米农艺性状和产量的影响

此试验通过研究N、P、K、有机肥的配合施用和种植密度对玉米农艺性状和产量的影响,为玉米高效高产提供理论依据和指导。试验采用二因素裂区设计,设主区肥料因子为A共4个水平,即A1（N：150 kg/hm2、P2O5：90 kg/hm2、K2O：45 kg/hm2）;A2（N：300 kg/hm2、P2O5：180 kg/hm2、K2O：90 kg/hm2）;A3（N：450 kg/hm2、P2O5：270 kg/hm2、K2O：135 kg/hm2）;A4（N：450 kg/hm2、P2O5：270 kg/hm2、K2O：135 kg/hm2、有机肥7200kg/hm2）。设副区密度因子为B共6个水平,即B1：108000株/hm2、B2：96000株/hm2、B3：84000株/hm2、B4：72000株/hm2、B5：60000株/hm2、B6：48000株/hm2。共24个处理,3次重复。结果表明：肥料和密度对玉米农艺性状和产量有显著影响。在4个肥料处理中,A4处理在穗长、穗粗、穗粒数、百粒重、产量都是最高值。密度对穗长、穗粗、穗行数、百粒重及产量都有显著和极显著影响,基本上都是随着密度的增高穗长、穗粗、穗粒数、百粒重在降低,但产量却是逐渐增加,在密度为96000株/hm2时产量最高,随后密度进一步增加产量下降。综合考虑肥料和密度因子,A4B2组合产量最高（12513.0 kg/hm2）。     

密度肥料对玉米种兴农单1号产量影响

为研究兴农单1号高产配套栽培技术,采用用二次回归正交旋转设计,开展不同密度、不同肥料对兴农单1号产量影响的研究,结果表明,密度和N肥对该品种的产量影响较为显著,P肥和K肥对产量影响为不显著;产量以密度为3 300株/667m2、N肥为20kg、P肥为15kg、K肥为10kg时产量最高。     

优质高产杂交玉米毕单4号栽培技术模式研究

采用二次回归通用旋转组合设计方法,研究毕单4号产量及其产量构成因素与密度及N、P、K肥施用量的关系,建立了产量及其产量构成因素与密度及N、P、K肥施用量之间的回归数学模型。通过计算机仿真试验和模拟寻优,提出了毕单4号获得10t/hm2以上的优化栽培方案：密度64714～70285株/hm2,N261.65～335.36kg/hm2,P2O5225.00kg/hm2,k2O108.45～191.55kg/hm2。产量与产量构成因素的相关及通径分析表明,在合理密植保证单位面积有足够穗数的基础上,主攻穗粒数,增加粒重,对毕单4号实现高产有积极的促进作用。     

密度与施肥对不同玉米品种产量的影响

为探索适宜普洱地区玉米高产栽培的优化农艺措施,以云瑞47、云优105两个玉米杂交种为材料,研究不同类型玉米品种在不同密度和不同施肥水平下产量的变化规律.结果表明：不同品种产量差异显著,在相同密度和施肥水平上云优105高于云瑞47;云优105栽培密度在82500株/hm2和施肥水平N37 kg/hm2、P2O5 225kg/hm2、K2O270 kg/hm2处理下产量最高;云瑞47栽培密度82 500株/hm2和施肥水平N375 kg/hm2、P2 O5 225 kg/hm2、K2O270 kg/hm处理下产量显著高于其它处理.     

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.