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。     

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。     

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。     

金农油1号高产综合农艺措施数学模型研究

应用二次回归正交旋转组合设计,通过建立数学模型的优化与解析,对杂交油菜品种金农油1号产量与密度、氮肥、磷肥、钾肥四因素的定量关系进行系统研究.结果表明:在4因素中,对金农油1号产量的影响效应大小依次为氮肥＞密度＞磷肥＞钾肥;要获得≥250 kg/hm2的产量,其最佳栽培措施组合是:密度13.2万～15.0万株/hm2,施氮量262.5～330.0 kg/hm2,施磷量102.3～119.6 kg/hm2,施钾量102.3 ～ 129.2 kg/hm2 .     

种植密度与施氮量对玉米顺单 6 号 干物质积累量及产量的影响

为探究玉米品种顺单6号的适宜种植密度及施氮量,设置3个种植密度和4个施氮水平,采用随机区组设计,研究不同密度及施氮量对顺单6号叶面积、干物质积累、穗部性状及产量的影响。结果表明,当种植密度与施氮量分别为60000株/hm^2与210kg/hm^2时,玉米干物质积累量最大,叶面积及叶面积指数大小适宜,千粒重较大,产量最高,为10547.06kg/hm^2。综合分析认为玉米品种顺单6号在贵州安顺地区适宜种植密度和施氮量分别为60000株/hm^2与210kg/hm^2。     

不同种植密度和施氮量对‘泸糯8号’产量的影响

为了确定‘泸糯8号’高产高效栽培适应的种植密度和施肥量,运用群体生理学的方法,采用两因素四水平完全组合试验设计,研究了不同种植密度和施肥量对杂交糯高粱‘泸糯8号’产量的影响。结果表明,密度低于11.25万株/hm2时,杂交糯高粱的产量随密度的增加而增加;超过11.25万株/hm2时,杂交糯高粱的产量又随密度的增加而减少。当施氮量低于纯氮187.5 kg/hm2时,杂交糯高粱的产量随施氮量的增加而显著增加,当施氮量高于187.5 kg/hm2时,杂交糯高粱的产量随施氮量的增加无显著增加。随着密度的增加,杂交糯高粱的穗粒数、千粒重、倒5叶叶面积、茎粗均显著减少（小）,株高则显著变高。随着施氮量的增加,杂交糯高粱的穗粒数、倒5叶叶面积、茎粗均随之增加而增加,千粒重则是先增加后减小。当施氮量超过纯氮150 kg/hm2时,株高随施氮量的增加而降低。由此得出,处理A3B3即种植密度为11.25万株/hm2,施肥量为纯氮187.5 kg/hm2最为适宜。     

密度和施氮量对超高产夏玉米干物质积累和产量形成的影响

为明确种植密度和施氮量对超高产夏玉米干物质积累和产量形成的影响,以夏玉米品种农单902为研究材料,于2013年在河北省藁城市进行了密度(设5.25万,6.00万,6.75万,7.50万,8.25万株/hm~2共5个水平)和施氮量(300,375,450 kg/hm~2共3个水平)的二因素裂区试验。结果表明,密度和施氮量对干物质积累量和产量性状的互作效应不显著。同一施氮量下,随密度增加,干物质积累量和每公顷穗数逐渐增加,但收获指数、穗粒数、千粒质量逐渐减小,吐丝后干物质积累量、吐丝后干物质贡献率及产量则先增加后减少。密度对果穗秃尖长、穗粒数的影响最大,对穗行数的影响最小。同一密度下,随施氮量增加,各生育时期的干物质积累量(除拔节期)、吐丝后干物质积累量、收获指数、籽粒产量及3个产量构成因素都是先增加后降低,以施氮量375 kg/hm~2最高。本研究条件下,以种植密度6.75万,7.5万株/hm~2,施氮量375 kg/hm~2的处理产量构成因素最为协调,获得了最高的产量,分别为12 797.3,12 425.5 kg/hm~2。     

氮密调控对冬小麦籽粒产量及氮素利用效率的影响

为探究氮肥用量和种植密度对冬小麦籽粒产量和氮素利用效率的互作效应,2017—2018年在大田定位试验条件下,以‘矮抗58’为试验材料,设置112.5、150、187.5 kg/hm² 3个种植密度,0、180、240、300 kg/hm²4个施氮水平,研究了氮肥用量和种植密度对小麦干物质积累转运、籽粒产量及氮素利用效率的影响。结果表明,同一种植密度下,花后贮藏干物质的转运量及对籽粒产量的贡献率随施氮量的增加呈先升后降趋势,而花前趋势相反;冬小麦群体分蘖数、穗数、穗粒数和产量随施氮量的增加呈升高趋势,然而千粒重和氮肥利用效率随施氮量的增加呈降低趋势。可以通过提高种植密度来减小施氮量降低对小麦产量和氮素利用效率的负面影响。因此,适宜氮肥用量与种植密度可提高小麦籽粒产量和氮素利用效率。在本试验条件下,施氮量240 kg/hm²与种植密度150 kg/hm²相匹配是获得更高产高效的最优组合。     

栽培措施对粮饲兼用型玉米粗纤维积累的影响

采用3因素最优饱和设计,系统地研究了氮肥、磷肥与种植密度3因素对不同收获时期粮饲兼用玉米粗纤维变化的影响。结果表明,散粉至乳熟期,各器官粗纤维含量均呈增加趋势,器官间以茎鞘粗纤维含量最高,叶片和雌穗相差不大。随着密度、施氮量和施磷量增加,叶片、茎鞘中粗纤维分配量呈下降趋势,而雌穗中粗纤维分配量以中等密度和施氮、磷量水平下较低。从营养品质角度考虑,呼和浩特地区粮饲兼用型玉米适宜的收获期为乳熟末期,优化栽培措施为种植密度5200~5700株/hm2,施氮量（纯氮）260~330 kg/hm2,施磷量（P2O5）110~150 kg/hm2。     

种植密度和施氮量对桂育9号农艺性状及产量的影响

为了探讨水稻品种桂育9号在广西中西部地区的最佳种植密度和施氮量,采用2因素4水平裂区试验设计,测定相关农艺性状和叶面积指数及产量。结果表明,种植密度对最高苗数和结实率有极显著影响（P<0.01）,对有效穗数和千粒重有显著影响（P<0.05）;施氮量对农艺性状及产量影响不显著,A3B2处理的农艺性状最佳,产量最高（7 550kg/hm ²）。在广西中西部地区种植桂育9号时,种植密度以3.0×10 ⁵蔸/hm ²、每蔸2苗、施氮量165kg/hm ²为宜。     

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.