农业废弃物堆腐过程中氧化还原酶活性的变化

【目的】从酶学角度揭示好氧发酵的生物机理。【方法】选择在目前我国数量多、分布广的有机固体废弃物鸡粪和小麦秸秆及花椒籽粕为主要材料,采用堆腐装置,以未添加复合微生物菌剂作为对照(CK),研究复合微生物菌剂(加菌剂处理)对农业废弃物静态高温堆腐过程中氧化还原酶(过氧化氢酶、脱氢酶和多酚氧化酶)活性的影响。【结果】加菌剂处理和CK的过氧化氢酶活性分别在堆腐3和4 d达到峰值(1 705和1 697 mL/g);加菌剂处理和CK的脱氢酶活性分别在堆腐10和12 d达最大值(8.39和6.57μL/g);加菌剂处理和CK的多酚氧化酶活性分别在堆腐18和32 d达峰值(7.33和6.65 mg/g)。从堆腐的整个过程看,随着堆腐时间的延长,加菌剂处理的过氧化氢酶、脱氢酶和多酚氧化酶活性上升较快,而且这3种酶活性的最大值均比CK高。【结论】添加复合微生物菌剂可以提高堆腐过程中氧化还原酶活性,使酶活性峰值出现的时间提前,对堆腐过程中的物质分解具有促进作用。     

抗应激剂对高温高湿下蛋种公鸡的作用效果研究

试验选用海兰褐父母代蛋种公鸡32只,随机分为2组,每组2个重复。在日粮中,分别添加Omg／kg和667mg／kg抗应激剂,以提高种鸡热抗应激的能力。研究在夏季高温、高湿的生产条件下。以生产成本为参考因素时,抗应激剂对蛋种公鸡采食量和精液品质的影响。试验结果表明：日粮中添加抗应激剂对种公鸡采食量、精液量、精子活力均有不同程度的提高和改善。     

盐渍地人工苜蓿草地生产力与土壤改良研究

[目的]为改进和利用河西走廊盐渍化土地提供依据。[方法]在临泽县盐渍地种植苜蓿,测定1～5年生人工苜蓿草地的生产力,并研究苜蓿对盐渍化土地的改良效果。[结果]在盐渍地种植苜蓿后,苜蓿的主根长、主根直径和侧根数随着生长年限的增加而增加。从种植到第5年,盐渍地苜蓿的鲜草产量呈逐年增加的趋势。盐渍地种植苜蓿后,土壤有机质含量不断增加,而土壤盐离子含量不断下降。有机质含量的增加速度和盐离子含量的下降速度均在苜蓿种植后的生长前期较慢而生长后期较快。[结论]苜蓿的生产力与灌水量、灌水次数有关。一个生育周期应至少灌水4次,种植苜蓿的适宜灌水量为4275m3/hm2。     

生物修复菌剂的分类·应用及研究进展

由于人类的生产与社会活动,使得我们生存的自然环境遭到了前所未有的破坏。鉴于采用物理或化学方法修复环境,除去有害物质,易造成二次污染,寻找高效的生物修复方法成为了全世界的共同课题。微生物作为生态链中的分解者,由于其具有易繁殖、适应性强、代谢快等特性,是作为生物修复的极佳材料。对生物修复菌剂的分类、生产、应用及研究进展进行了综述。     

化学杂交剂SQ-1诱导糜子雄性不育效果研究

采用裂区试验设计, 以喷药时期为主区, 喷药剂量为副区, 探讨了用SQ-1诱导产生的雄性不育率、杂交率及自然授粉结实率3项指标评价应用效果。结果表明, 喷药时期、喷药剂量及时期与剂量一级互作显著或极显著影响不育率和杂交率。在雌雄蕊原基分化期, 喷药剂量为4.0和5.0 kg hm^-2时诱导雄性不育率、杂交率都在95％以上; 花粉粒分化形成初期, 喷药剂量为5.0 kg hm^-2时诱导雄性不育率和杂交率都在95％以上。喷药时期对自然授粉结实率影响不显著, 剂量及时期与剂量一级互作影响显著, 自然授粉结实率随着剂量的增加呈降低趋势。SQ-1用于糜子的最佳时期为雌雄蕊原基分化期, 最适剂量4.0 kg hm^-2。     

Morphological and cytogenetic studies on the hybrid between bread wheat and <Emphasis Type="Italic">Psathyrostachys huashanica</Emphasis> Keng ex Kuo

Psathyrostachys huashanica Keng ex Kuo (2n = 2x = 14, NsNs), a source of wheat stripe rust, take-all fungus, and powdery mildew resistance with tolerance to salinity and drought, has been successfully hybridized as the pollen parent to bread wheat without using immature embryo rescuing culture for the first time. All of the CSph2b × P. huashanica hybrid seeds germinate well. Backcross derivatives were successfully obtained. F₁ hybrids were verified as intergeneric hybrids on the basis of morphological observation, cytological and molecular analyses. The results obviously showed the phenotypes of the hybrid plants were intermediate between bread wheat and P. huashanica. Chromosome pairing at MI of PMCs in the F₁ hybrid plants was low, and the meiotic configuration was 26.80 I + 0.60 II (rod). Cytological analysis of the hybrid plants revealed the ineffectiveness of the ph2b gene on chromosome association between the parents. Eight RAPD-specific markers for Ns genome were selected for RAPD analysis, and the results indicated that F₁ hybrids contained the Ns genome of P. huashanica. Furthermore, the significance of the finding for bread wheat improvement was discussed.     

农学专业教学计划的现状及改革思路

针对农学专业教学计划从理论到实践的教学模式、课程安排前松后紧、学生后期学习压力大等现状,提出以实施专业课程精品化战略,强化基础知识和基本技能的培养,着力培养学生的实践能力为方向,通过在低年级开设专业实践课程,建立“实践-理论-实践”的教学模式,适当放宽外语考核,强化专业技能考核等措施,引导学生重视专业知识学习和专业技能的培养,增强学生的实际动手能力,使之真正成为新时期合格的高等农业院校大学生。     

Application of the Analytic Hierarchy Process to irrigation project improvement: Part II. How professionals evaluate an irrigation project for its improvement

Planning improvement of an irrigation project often depends on irrigation professionals who conduct the initial survey of the irrigation project. Accordingly, activities for improvement will be different depending on who evaluates the status quo of the irrigation project, because of the diversity of expertise and experience of professionals. A questionnaire survey was conducted to examine how irrigation professionals evaluate an irrigation project, that is, on what evaluation factors (EFs) they place the importance. In the questionnaire, professionals ranked the relative importance of EFs derived from internal process indicators of the Rapid Appraisal Process (RAP). Answers to the questionnaire were processed by the Analytic Hierarchy Process (AHP, Part I), and then local weights of EFs were obtained as a measure of relative importance of EFs. Those local weights were statistically analyzed by the Anderson-Darling normality test, the F-test and the t-test. Then, they were modeled by probability density functions. The results implied (a) that irrigation professionals give the first priority to water delivery services project-wide and (b) that they consider that irrigation infrastructure (hardware) of primary canals is more important than that of secondary canals. These findings infer that irrigation professionals first consider how well water is controlled and distributed project-wide and second how appropriately primary canals are designed and maintained. Also, their views are divided into two regarding importance of hardware and management, namely some insist that hardware is more important than management and the others insist that management is more important than hardware.     

棉花纤维发育的分子机理及品质改良研究进展

 棉花纤维细胞的分化与发育是一个复杂有序的过程,在不同的发育时期均有大量的基因表达,参与纤维细胞发育的调控。转录因子和植物激素在棉纤维细胞分化起始过程中起重要的作用。纤维细胞壁结构、细胞骨架和糖类、脂类代谢相关的基因以及激素信号分子与纤维细胞的伸长密切相关。棉纤维次生壁合成时期主要是纤维素的合成及沉积过程,蔗糖合成酶和纤维素合成酶等基因在这一时期起关键的调节作用。在棉纤维发育分子生物学研究的基础上,利用基因工程改良棉花纤维品质也取得了一些研究进展。     

广州近郊菜园土的土壤现状及地力调控对策

近年广州市蔬菜生产产业发展迅速,逐步向基地化和标准化方向发展,但近郊蔬菜生产因菜园土土壤养分失调、地力下降及存在重金素污染等问题,严重危害了郊区蔬菜产品品质.探讨了广州市近郊菜园土的土壤状况及存在问题,提出了调控近郊菜园土土壤地力的对策,以实现近郊蔬菜无公害生产,保障市民健康.