两种浓度营养液下水培生菜和小白菜生长特性及品质研究

比较了2个生菜品种和2个小白菜品种在两种浓度(0.5剂量、1.0剂量)营养液中水培的叶片数、叶部横径、株高、叶绿素含量、根系、单株鲜重、Vc含量和硝酸盐积累等生长特性和品质指标。结果表明,不同蔬菜种类对营养液浓度要求有显著差异,不同蔬菜品种也表现出不同的生长特性。与0.5剂量营养液浓度相比,1.0剂量营养液浓度促进或保持生菜生长发育,显著降低生菜硝酸盐含量。0.5剂量营养液有利于小白菜生长,显著提高小白菜Vc含量,有效减少硝酸盐积累。供试的小白菜和生菜品种在不同浓度水培营养液下叶片数趋于一致。意大利奶油生菜叶部横径小于弘农生菜叶部横径,但根系明显长于弘农生菜根系。小白菜叶绿素含量显著高于生菜叶绿素含量。0.5剂量下意大利奶油生菜单株鲜重显著高于该浓度下的五月慢小白菜单株鲜重。小白菜Vc含量在不同浓度水培营养液下均显著高于生菜Vc含量。较低浓度营养液下四月慢小白菜的Vc含量最高,而较高浓度营养液更有利于五月慢小白菜Vc含量积累。     

史丹利大量元素水溶性肥料对小白菜产量和品质的影响研究

为研究在水溶性肥料中添加多种微量元素对蔬菜产量和品质的影响问题,以小白菜为试验材料,采用盆栽试验方法对添加多种微量元素的史丹利20-20-20大量元素水溶性肥料在其产量和品质方面的影响进行了研究。研究结果表明:施用史丹利大量元素水溶性肥料的小白菜形态指标及品质指标均优于普通大量元素水溶性肥料及硫基复合肥料处理。史丹利20-20-20大量元素水溶性肥料处理小白菜整个生育期叶色浓绿,茎秆粗壮,其根长、株高、叶片数及叶片宽度均明显高于对照处理,且处理间差异明显;史丹利20-20-20大量元素水溶性肥料处理维生素C含量,较普通水溶性肥料、17-17-17硫基复合肥料对照分别提高8.8%、15.1%,可溶性糖含量分别提高9.4%、11.8%,可溶性蛋白含量分别提高9.2%、10%,对比组间差异具有统计学意义;硝酸盐含量与对照相比明显下降,分别降低7.9%、10%;小白菜鲜重,较对照分别增产8.8%、13.1%,增产效果显著。综上所述,施用添加多种微量元素的史丹利大量元素水溶性肥料对小白菜的生长发育具有较显著促进作用,可提高小白菜维生素C、可溶性糖、可溶性蛋白的含量,降低硝酸盐含量,明显改善小白菜的品质,增加小白菜的产量。     

芹菜对铁的吸收及铁对其生长和品质的影响

通过调节水培营养液中铁浓度分别为0,0.7,1.4,2.8,5.6,8.4,11.2和14.0.mg/L的8个水平种植4个芹菜品种,研究了不同铁供应水平对芹菜生长和植株铁含量及其品质的影响。结果表明,0.7mg/L浓度下,芹菜生长良好,没有表现缺铁症状,1.4mg/L浓度时,叶片中的铁含量达最大值,2.8mg/L浓度下,芹菜产量,Vc、蛋白质、叶绿素含量较高,硝酸盐含量较低。在各铁供应水平下4个芹菜品种均未出现铁中毒现象。供铁以后,其供应量对芹菜叶中钙、镁含量影响不大;锌含量与营养液中铁浓度呈负相关,铁锌之间表现出离子竞争作用。     

不同用量生物质炭对小白菜和大蒜产量与品质的影响

研究不同用量生物质炭对土壤性质、蔬菜产量和品质的影响,探索生物质炭对小白菜和大蒜种植的最佳用量,为生物质炭在蔬菜上的应用提供科学依据。盆栽试验共设4个生物质炭用量处理,包括CK、C1、C2、C3,分别以0、1%、2%、3%的添加量施入,每个处理5次重复,监测小白菜和大蒜生长季数据。结果表明,生物质炭能够显著增加土壤有机碳,增幅为23.86%~93.54%;施用3%的生物质炭处理显著增加了小白菜和大蒜生长季土壤全氮11.33%和23.09%;生物质炭能够显著增加土壤有效磷和速效钾含量,增幅分别为18.77%~80.04%和80.19%~396.18%;生物质炭显著增加土壤pH值,增幅为6.03%~17.19%。生物质炭能够显著增加小白菜地上部鲜重和干重,增幅分别为60.11%~86.11%和57.89%~76.32%;施用3%的生物质炭显著增加了大蒜地上部鲜重、地上部干重和地下部干重,增幅分别为36.89%、32.00%和61.56%。施用2%和3%的生物质炭显著增加了小白菜可溶性蛋白含量9.07%和9.37%,同时,生物质炭能够显著降低小白菜可溶性糖和硝酸盐含量,降低幅度分别为6.72%~7.00%和38.62%~93.20%;施用2%和3%的生物质炭显著增加了大蒜可溶性蛋白含量9.83%和9.56%,而施用3%的生物质炭显著降低了大蒜可溶性糖和硝酸盐含量,降低幅度分别为17.98%和39.27%。综上所述,生物质炭能够显著改善土壤化学性质,对小白菜和大蒜起到稳产增产效果,同时还能显著提高蔬菜品质。同时,小白菜和大蒜最佳的生物质炭用量为1%和3%。     

保护地小白菜硝酸盐积累的效应分析与调控

通过营养液配制对小白菜硝酸盐的积累进行调控,为降低小白菜硝酸盐含量提供理论依据。采用416-B混合最优设计,利用SAS软件建立不同氮源(NO-3-N、NH+4-N)、磷、钾与保护地小白菜硝酸盐含量关系的数学模型。结果表明,氮是影响小白菜硝酸盐含量的最主要原因,营养液中硝态氮含量与小白菜硝酸盐的积累呈正相关关系;铵态氮则可降低小白菜硝酸盐的积累。磷、钾也是影响小白菜硝酸盐积累的主要因素,在适宜的浓度条件下,有利于硝酸盐含量的降低。不同氮源、磷、钾之间的互作效应也是影响硝酸盐积累的重要因素。通过调节营养液中的不同氮源、磷、钾的数量及相互比例,可对小白菜硝酸盐的积累进行调控,降低其硝酸盐含量。     

纳米制剂对小白菜生长及氮肥利用率的影响

为提高肥料利用率,研发环境友好型肥料,从源头上控制农业面源污染,采用土培试验,研究了纳米制剂对小白菜产量、养分吸收量、氮肥利用率、叶片叶绿素含量及部分品质指标的影响。结果表明,氮肥中添加纳米氢醌和纳米茶多酚均可提高小白菜产量和叶片叶绿素含量、增加氮磷钾养分吸收量、提高氮肥利用率,以上效果在纳米制剂添加量增加时更加明显。在本试验所设的4种添加纳米制剂处理中,以4%茶多酚处理的效果最好,与未添加纳米制剂处理相比,小白菜产量增加44.6%,氮肥利用率增加134.1%。添加纳米制剂对小白菜品质的影响却不同,可溶性糖含量变化不大,硝酸盐含量有所提高,维生素C含量也有提高趋势,但干重增加最多的（4%茶多酚）处理维生素C含量并没有提高。总之添加纳米制剂可以提高作物产量并能提高肥料利用率。     

利用无土栽培研究不同肥料对蔬菜产量与品质的影响

采用无土栽培的方法对蔬菜进行盆栽试验,研究在施用不同用量的化肥和有机肥的条件下蔬菜的产量和品质变化。结果表明,在蔬菜无土栽培中,施用有机肥比施用化肥可显著提高蔬菜的品质,并能达到较高的产量。无论是生菜还是芹菜,其抗坏血酸(Vc)的含量都是有机肥处理明显高于相应的化肥处理。而对人体有害的硝酸盐含量则恰恰相反,供试有机肥处理大大低于化肥处理。另外,施用有机肥可降低蔬菜体内有机酸含量。和化肥相比,有机肥明显具有长效作用,它对第3茬蔬菜仍然有效。利用消毒有机肥进行蔬菜的无土栽培要优于营养液浇灌的方式。     

菠菜水培不同营养液浓度的产量、品质、元素利用效率主成分分析研究

为了探究营养液浓度对水培菠菜的产品、质量、水肥利用效率的影响。通过植物工厂水培菠菜试验,以日本园试配方标准营养液为基准,设置1,3/4,1/2,1/4,1/8倍,比较不同浓度对菠菜产量、品质、营养元素利用效率、水分利用效率的影响。结果表明:1/2倍浓度园试配方产量显著高于其他处理;1/8倍浓度处理硝酸盐显著较低,1,3/4,1/2倍处理下的硝酸盐均超出国家标准,1,3/4倍处理的Vc含量显著较高;营养液水分利用效率最高的处理是1/2倍浓度,在低浓度处理下的元素利用效率普遍较高;通过主成分分析综合评价,得分最高的前3名是:1/8,1/4,1/2倍浓度,分别得分1.600,1.544,1.541。     

不同营养液浓度对小白菜生物量及硝酸盐含量的影响

[目的]为明确在不影响小白菜生物量情况下,有效降低硝酸盐含量的最佳水肥供应方式,以期为实际生产中采取的经济环保且硝酸盐低残留的施肥方法提供依据。[方法]本研究以小白菜为原料,采用无土栽培,探讨不同浓度营养液对小白菜生物量、吸水量及其体内硝酸盐含量的影响。[结果]结果表明：小白菜定植10 d内,营养液浓度的改变对其生理指标没有显著影响。定植10 d后到收获,当营养液浓度＜2.4 dS/m 时,小白菜的生理指标随着营养液浓度的增加而增加;营养液浓度≥2.4 dS/m 时,营养液浓度的增加对鲜质量没有显著影响。小白菜收获时EC值≥2.4 dS/m时提高营养液浓度会显著增加小白菜体内硝酸盐的积累。小白菜的吸水量和营养液浓度呈正相关,当营养液浓度为2.4 dS/m时,小白菜的水分利用率最高。[结论]因此,在小白菜定植10 d内使用1.2 dS/m浓度的营养液进行栽培,定植10 d后营养液浓度逐渐增加至2.4 dS/m直至栽培结束,能够最大程度提高产量和水分利用率并把硝酸盐含量维持在一个较低水平。     

不同形态氮素替代部分硝态氮对水培小白菜的生长和品质的影响

摘 要：为了研究水培生产上营养液中氮素形态对小白菜产量和品质的影响,本实验以华南农业大学叶菜B配方为基础, 研究了水培条件下不同形态氮素（铵态氮、酰胺态氮、氨基酸态氮）替代部分硝态氮对水培小白菜的生长和品质的影响。结果表明,氨基酸态氮和酰胺态氮部分替代硝态氮可以显著促进小白菜的生长,提高小白菜的产量;铵态氮部分替代硝态氮利于小白菜叶绿素和类胡萝卜素含量的增加;氮素为纯硝态氮时,小白菜的根系活力最高,酰胺态氮的替代部分硝态氮后,小白菜根系活力显著下降,但可溶性糖、可溶性蛋白和维生素C的含量显著提高;不同形态的氮素替代部分硝态氮后,降低了小白菜体内硝酸盐的含量,尤以酰胺态氮替代后降幅较大。综合小白菜收获时的产量品质等因素,酰胺态氮替代部分硝态氮对水培小白菜的栽培效果最好。     

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.     

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.     

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.     

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.