不同小麦品种钾吸收,分配特性及其钾营养效率的差异

盆栽试验结果表明,钾效率系数（ＥＩ）和施外效率（ＫＥ）能很好评价小麦品种在钾缺乏条件下的钾营养效率,钾高效品种能在缺钾条件下区得较高产量;钾低效品种ＥＩ值小,但ＫＥ值大,施钾能获主产;押高效品种在钾缺乏或充足条件下均能维持功能叶（３～４叶）中较主的钾含量,功能叶中（第３～４叶）钾钾高效品种籽粒中甸积累量及其占总量的自分数较高,钾你效品种植物功能叶中的钾含量低效,茎、叶、叶间钾钾高效品种籽粒中钾积累     

Effect of soil potassium availability on soybean root and shoot growth under unrestrained rooting conditions 1

The development of soybean (Glycine max (L.) Merr.) root systems was Investigated in two greenhouse pot experiments utilizing a modified cage technique. One soil at two levels of K availability was used to observe the effect of soil K fertility level on root weight and root length in 3 cm depth Increments to 24 cm. Experiments were terminated prior to restraint of root growth by the containers. Shoot mineral accumulation and dry matter partitioning between root and shoot components were Investigated.

High K plants were shorter and had a greater root:shoot mass ratio than low K plants. A trend for greater root dry matter production in soil layers below 12 cm under high K conditions was observed. There were no differences in root length between the treatments at any depth. Tissue K content was greater in the high K treatments and this Increase was equivalents offset by decreased tissue Mg concentrations. The taller low K plants had a greater leaf area and a lower specific leaf weight, resulting in part from decreased starch content. Daily evapotranspirational water losses per pot tended to be greater under the low K availability regime. This Information led to the speculation that under low K conditions, the soybean plant may increase K accumulation by promoting transpirational water use, aiding soil K acquisition by mass flow and diffusion. Tissue carbohydrate analyses suggest greater translocation of photosynthate out of the leaf in the low K plants for use in root absorption metabolism, rather than for production of increased root dry matter and/or increased root length.     

Liquid water absorption in uncoated Norway spruce (Picea abies) claddings as affected by origin and wood properties

Abstract

Uncoated Norway spruce specimens from different spatial positions within stems from two origins with different growth conditions were exposed to liquid water over a prolonged time, and apparent diffusion coefficients and rates of void filling were calculated from sorption curves. Both apparent diffusion and rate of void filling were significantly affected by origin and by the difference between inner and outer boards. The differences between inner and outer boards were explained by heartwood proportion and density, but some effects of origin remained when these properties were accounted for. The apparent diffusion coefficient was reduced by increasing density, and increased by increasing heartwood proportion. Void filling rate was reduced by both increasing density and increasing heartwood proportion. Since the effect of heartwood proportion was more pronounced in the material from the highly productive area, it may have been confounded with properties of juvenile wood.     

Ileal absorption of L-carnitine from diets used in reproductive polar fox (Alopex lagopus L.) nutrition

Abstract

Five mature ileorectal anastomosed blue foxes (6.18±0.15 kg) were used in digestibility experiments to evaluate the L-carnitine apparent ileal absorption from diets used in reproductive polar fox nutrition over the year-long farm-feeding period on two domestic farms (A and B) differing in reproduction results. The concentration of L-carnitine was higher in diets from farm B (136.1–241.7 mg kg^?1 DM) than in the diets from farm A (88.5–135.2 mg kg^?1 DM). The coefficients of ileal apparent absorption of L-carnitine ranged from 60.23 to 75.57% for diets A (farm A) composed mainly of fish and poultry offals. The coefficients of ileal apparent digestibility of L-carnitine were higher for diets B (farm B) (83.75–94.78%; P<0.05) based on beef offals. These data indicate high concentration and efficient ileal apparent absorption of L-carnitine from diets used in reproductive polar fox nutrition on both farms examined.     

含氟水性聚氨酯的合成及其性能研究

以异佛尔酮二异氰酸酯(IPDI)、聚己内酯二元醇(PCL)、2,2-二羟甲基丙酸 (DMPA)、1,4-丁二醇(BDO)为原料合成聚酯型水性聚氨酯。通过氟单体（甲基丙烯酸十二氟庚酯(MBFA-12)）的引入,制备具有互穿网络结构的含氟水性聚氨酯(WPU-F)。研究了MBFA-12含量对WPU-F涂膜的乳液粒径、粘度、耐水性能、硬度、附着力以及耐磨性能的影响。结果表明,氟单体MBFA-12的加入,明显提高了涂膜的耐水性能。当氟单体含量为40%时,涂膜的接触角从未改性的60.5°提高到113.0°,吸水率也从未改性的60.20%降低至1.54%。但由于在反应过程中MBFA-12本身容易自聚产生一些低聚物,对WPU涂膜的硬度和耐磨性能产生不良的影响。     

水稻氮素吸收低效型突变体osnad1的生理和遗传分析

水稻突变体osnad1（Oryza sativa nitrogen absorption deficit 1）是从经EMS诱变的水稻突变体库中筛出的一株性状稳定遗传的氮素吸收低效型突变体,为了进一步明确其生理和遗传特性,本研究从表型分析、氮代谢生理、光合特征和遗传分析等4个方面对突变体osnad1及其野生型日本晴（Nippenbare）进行了比较。研究结果表明：（1）与野生型相比,突变体osnad1株高降低,根系长度缩短,叶色发黄,植株生长受阻;（2）与野生型相比,突变体osnad1植株体内总氮积累量大大降低,通过扫描离子选择性电极技术（scanning ion-selective electrode technique,SIET）对其根系表面氮源离子净流动速率的测定发现,osnad1根系对NH₄ ⁺的吸收速率较野生型大幅降低。突变体osnad1根系中谷氨酰胺合成酶（GS）活性随之降低。（3）与野生型相比,突变体osnad1叶片中叶绿素a、叶绿素b、类胡萝卜素含量降低,一系列光合相关参数,如净光合速率、气孔导度、胞间二氧化碳浓度和蒸腾速率降低,干物质积累受阻。（4）遗传分析结果表明：F₂群体中正常表型与突变表型植株数量之比符合单基因突变的3∶1。综合上述,突变体osnad1是一个氮吸收低效型的单基因隐性水稻突变体,该研究为后续的基因克隆及其功能分析提供参考。     

长期施用秸秆生物炭对土壤养分及作物生长的影响

于2011—2020年在山西榆次区开展田间定位试验,设不施肥(CK)、不施肥施生物炭(CK+B)、施氮磷钾肥(NPK)和氮磷钾肥配施生物炭(NPK+B)共4个处理,种植模式为玉米-高粱轮作,研究有机碳施用5 a和10 a对0～20 cm土层土壤有机质、全氮、有效磷、速效钾含量和土壤蔗糖酶、脲酶、碱性磷酸酶、过氧化氢酶活性的影响,及各处理累积秸秆干物质量、养分积累量和籽粒产量的变化。结果表明：(1)生物炭施用5 a和10 a后,与CK比较,CK+B处理土壤有机质含量分别提高了46.3%和61.2%;与NPK比较,NPK+B处理土壤有机质含量分别提高了67.8%和77.7%。施用10 a后CK+B处理全氮含量显著高于CK处理,但NPK+B和NPK处理土壤全氮含量间没有显著差异。生物炭对土壤速效钾含量提升效果显著,施用10 a后CK+B和NPK+B处理土壤速效钾含量较CK和NPK处理提升86.4%～46.6%。(2)生物炭施用10 a显著提升了土壤蔗糖酶和碱性磷酸酶的活性,增幅分别为11.4%～11.9%和7.9%～16.2%,但对脲酶、过氧化氢酶和有效磷没有影响。(3)生物炭施用10 a明...     

坡地间隔覆盖配施土壤改良剂的实用性研究

本文采用间隔覆盖配施土壤改良剂方法,利用室内人工降雨实验与土柱实验研究该方法对土壤水分运动及分布的影响,进而为其实际应用奠定理论基础。结果表明:(1)间隔覆盖法可增加入渗区蓄水量,面积比为1:1时,土壤蓄水量可达到降雨量的1.83倍。配施土壤改良剂情况下,雨强I=60 mm/h,面积比1:1时,降雨入渗率可达到未施加改良剂处理的2.60倍。湿润锋分布较深,水分分布均匀程度也有所提高。(2)对土壤水分蒸发及吸持水能力的研究发现,在施加土壤改良剂条件下,水分蒸发受到抑制,而土壤吸持水能力增强,但两方面作用均与PAM用量密切相关。虽然研究结果证实此种方法的实用性,但土壤改良剂的适宜用量、间隔覆盖法的适宜面积比、水分的实际调控效果及其对作物的影响需进一步研究。     

改性红辉沸石吸油值和吸水量的研究与应用初探

通过饱和滴定法研究了广西天然红辉沸石的吸油值、吸水量,并且将不同目数的沸石经过硫酸改性后,分析了其吸油值与吸水量的变化。实验结果表明：红辉沸石本身具有一定的亲油性,且随着沸石粒径的减小而增大,对其进行酸改性可以令沸石的亲水性减弱,亲油性增强,为后续研究添加红辉沸石的室内环保水性涂料配方提供了参考依据。     

碱化处理对稻草板表面吸收性能的影响

采用pH值8~14的氢氧化钠溶液,对不同密度的稻草板试件进行碱化处理,测定处理后试件表面对蒸馏水、甘油、酒精等3种液体的吸收性能。结果表明:经过处理,稻草板对3种液体的表面吸收性能均增强,且随着处理溶液pH值的增大而增强。稻草板碱化处理溶液适宜的pH值为7~11,可提高其表面吸收性能,有利于后续表面加工。