干燥处理对水稻愈伤组织绿苗再生和若干生理生化特性的影响

本实验采用滤纸和硅胶干燥不稻愈伤组织能明显提高愈伤组织的绿苗分化频率。其中以干燥处理４天，愈伤失水量在５０％以上的增减效果较好。干燥处理能促进愈伤组织对矿物质元素的吸收、影响过氧化物同工酶的表达、降低脯氨的含量，而对细胞透性影响不大。     

小麦幼胚生长点转化的研究初报

本研究以日龄1~3 d及7 d的小麦幼胚为受体,利用携带GUS基因的农杆菌LBA4404侵染,恢复培养至3~5叶期时,取第三叶进行GUS组织化学染色分析;并做两个优化对比处理:(1)抽真空处理:在侵染过程中,0.1 MPa抽真空2 min;(2)干燥处理:在共培养阶段,将幼胚转入铺有干燥无菌滤纸的平皿中。结果表明:GUS瞬时表达率随日龄增加而降低,以2~3 d龄的幼胚为最高;抽真空和干燥处理均能显著提高GUS瞬时表达率。最终,在优化处理条件下,获得77株转化苗中,40株第三叶GUS染色显示阳性,高达57.14%。进一步提取GUS阳性小麦叶片基因组DNA,进行PCR扩增,有6株转化苗扩增出目的条带,转化率为7.79%。初步说明以小麦幼胚的生长点作为转化受体是可行的。     

Storability of onion seeds and effects of packaging and storage conditions on viability and vigour

Fresh onion seeds desiccated to 6.0% seed moisture content (SMC) were stored in various packaging materials under different storage conditions. Seeds packed in aluminum-laminated pouches beside those stored with silica gel at 25 °C maintained satisfactory germinability and vigour after 12 months. Desiccated seeds stored in moisture impervious containers produced more vigourous seedlings. Germination potential of onion seeds increased with reduced SMC besides storage in moisture impervious packets along with desiccants as physiological and biochemical attributes are regulated. Seed viability and vigour decreased with accelerated ageing due to increased lipid peroxidation, decreased activities of several free radical and peroxide scavenging enzymes. Electrical conductance of seed leachates also increased with ageing. Thus, adoption of appropriate storage temperature and moisture control techniques would significantly affect onion seed quality, which was due to minimum accumulation of free peroxide radicals and enhanced activity of free radical scavenging enzymes.     

超干处理对柳枝稷种子活力及幼苗生长特性的影响

研究超干处理对柳枝稷(Panicum virgatum L.)种子活力及幼苗生长特性的影响,为柳枝稷种子耐干性及贮藏提供理论基础。采用硅胶干燥法将柳枝稷种子含水量由9%分别降至7%,5%,3%,2%,1%,测定不同含水量条件下种子的活力以及种子萌发后第14 d幼苗的叶面积、根长、苗长、根冠比、鲜重、干重及相对电导率等指标的影响。柳枝稷种子含水量由对照9%降到2%的过程中,种子仍保持较高活力。含水量降至1%种子活力显著下降,但种子的相对电导率与种子活力没有显著相关性。超干处理后幼苗生长正常。柳枝稷种子属于正常型种子,其贮藏的安全水分下限为2%。超干处理并没有破坏柳枝稷种子细胞膜的完整性,也未对幼苗的生长造成损伤。     

黄土丘陵沟壑区山地苹果林土壤干化及养分变异特征

揭示不同树龄苹果林土壤剖面水分特征及土壤养分演变规律,探明土壤干化引起的养分失衡原因,对黄土高原丘陵沟壑区苹果林地土壤水分、养分科学管理以及果园合理施肥具有重要现实意义。以陕北米脂县为研究区,选取不同树龄山地苹果林为研究对象,分别测定了7 a、10 a、18a、25 a、30 a和41 a苹果林地0~1 000 cm土层土壤湿度和0~300 cm土层土壤有机质、全氮、全磷、碱解氮、速效磷、速效钾含量,分析测定了深度范围内土壤干化情况、各养分指标丰缺状况及其随种植年限和土层深度的变异特征及不同树龄苹果林地60~300 cm土层土壤水分与养分的相互关系。结果表明:黄土丘陵沟壑区不同树龄山地苹果林深层土壤均出现严重或强烈干化,0~1 000 cm土层平均土壤含水量随树龄增加呈先增加后降低再略有增加趋势。该地区不同树龄苹果林0~300 cm土层土壤有机质、全氮和碱解氮含量均处于极缺状态,全磷、速效磷含量较缺,速效钾含量中等。幼龄期果树土壤水分与有机质、全氮、碱解氮相关性显著,而盛果期及衰退期果树土壤水分与各养分含量相关性不显著。建议不同树龄果园除应采取蓄水保墒措施外,尤其应注重有机肥和氮肥投入,适当增施磷肥,可少施或不施钾肥。相较于由干化引起的养分失衡,该地区土壤干化问题更应引起关注。     

太阳能饲草干燥技术研究

针对饲草在田间干燥干物质损失大和营养成分保持率低的问题,本文从太阳能饲草干燥工艺的技术原理、技术装备、工艺路线,以及太阳能饲草干燥工艺与田间饲草干燥工艺对比试验效果等方面系统介绍了太阳能饲草干燥技术的创新性与先进性,并对太阳能饲草干燥技术及装备的应用前景进行了展望。      

不同发育阶段板栗种子的脱水敏感性

通过对不同发育阶段的板栗种子进行自然脱水,研究了板栗种子脱水敏感性的动态变化。在自然脱水过程中,花后80d板栗种子在脱水第9天时,胚轴和子叶中的含水量分别下降至26.9%、25.5%,却仍然保持着最高的生活力,表明此时其脱水敏感性最低;花后90d板栗种子中淀粉大量降解,可溶性糖迅速增加,胚轴中可溶性蛋白也大量降解,推断其已转入萌发状态,故脱水敏感性略上升。由此得出,顽拗性板栗种子的最佳采收期应是生理成熟脱落前。同时也发现,脱水敏感性与细胞膜的透性并不完全相关。     

2,4 D和干燥处理对小麦成熟胚愈伤组织诱导与分化的影响

为解决西北地区小麦栽培品种高频再生体系建立过程中的瓶颈问题,以不同品种、不同2,4-D浓度及对愈伤组织的不同干燥处理时间为变量,研究不同处理对小麦栽培品种成熟胚愈伤组织诱导与分化的影响。结果表明,甘春24、甘春20、西旱1号在2,4-D浓度为2.0～5.0mg·L-1时,愈伤组织诱导与分化较好,2,4-D浓度为5.0mg·L-1以上愈伤组织容易褐变,分化能力减弱,成苗率低;在转入胚性诱导培养基前,12h的干燥处理能促进各品种愈伤组织分化;通过正交设计分析,甘春24在2,4-D浓度为2.5mg·L-1,12h干燥处理条件下所建立的再生体系最好,是转基因中良好的受体;甘春20在2.0mg·L-1 2,4-D、12h干燥处理下愈伤组织形成与分化较好;西旱1号经3.0mg·L-1 2,4-D、12h干燥处理,能显著提高其愈伤组织的分化。     

Pre-harvest sprouting tolerance of different winter triticale cultivars in the Baltic Sea area

Abstract

Experiments were carried out to investigate 10 winter triticale cultivars for 1) genetic variability of patterns of resistance to pre-harvest sprouting, and 2) the simultaneity of seed maturation in spikes by determining the developmental stage and by measuring the rate of germination before and after physiological maturity. The cultivars used were Dagro, Fidelio, Lamberto, Lasko, Lupus, Modus, Prego, Tewo, Ulrika and Vision, and were compared by measuring the post-harvest grain falling number and by germination tests on harvested spikes during the grain filling period. Winter rye Vambo and winter wheat Kosack were used as controls. The moisture content of kernels at physiological maturity (PM) was affected by climatic conditions (r=0.38; p<0.05). Germination rate of kernels in spike before PM was influenced by cultivar only up to 17%; mostly it was affected by climatic conditions (coefficient of determination, 54%). Kernel germination rate after PM was dependent on cultivar up to 37%, but was dependent on precipitation amounts in August (coefficient of determination, 60%). The most resistant cultivar to germination during post-physiological maturity period was Modus, followed by Dagro and Prego. Kernels’ germination rate after PM was found to be an appropriate measure for selection of promising triticale cultivars for the climatic conditions, which are specific for the locations studied. The desiccation rate after PM affected significantly the duration of the period from PM up to harvest time (r=?0.50; p<0.01).     

Landfill sealing potentials of bottom ashes of sludge cakes

The main objective of this study is to determine if bottom ashes of dried sludge cakes (SC_bash) could be used as landfill cover or liner, a function which is normally performed with clay. Laboratory tests were performed to determine its particle size distribution, Atterberg limits, compaction characteristics, hydraulic conductivity, and shear strength parameters. The effects of desiccation and freeze–thaw on the hydraulic conductivity of SC_bash were also examined. The results of this investigation proved that properly compacted and stabilized SC_bash has the required properties to be used in landfill covers or liners. The SC_bash can be compacted into a dense mass with a low hydraulic conductivity of the order of 1.15×10⁻⁷ m/s. The compacted SC_bash showed also a good resistance to the increase in hydraulic conductivity caused by desiccation and freeze–thaw as compared to other compacted clays. The results also indicated that the compacted SC_bash has greater shear strength as typically expected for compacted clay, and therefore is likely to remain stable on a typical landfill slope designed and based on clay shear strength.