植物物候模型研究

植物物候模型是基于植物对环境因子的响应机理而建立的可模拟植物生长发育的数学方程。本文介绍了树木物候模型和作物物候模型,根据对植物休眠解除过程的不同理解,树木物候模型主要有7种不同的类型;根据作物发育规律而建立的作物物候模型也大体相同。同时,还阐述和探讨了研究植物物候模型的意义、研究中存在的问题及其发展趋势。     

广东省极端降水事件的变化特征

[目的]分析广东省极端降水事件的分布特点并对其未来的变化趋势进行判断,旨在为该省的气候评估预测、生态环境建设及经济可持续发展方面的研究提供科学依据。[方法]利用广东省1960—2013年的逐日降水数据,根据百分位方法定义了极端降水事件的阈值,通过采用Mann-Kendall法、小波分析、Hurst指数等方法,对该区的极端降水事件频次和强度的变化特征及其变化趋势进行研究。[结果]广东省极端降水事件的发生频次、强度及极端降水量均呈上升的趋势,且极端降水量对总降水量的贡献率在50%以上。在空间上极端降水事件的发生频次呈现出北高南低的规律性,而强度正好相反。在未来的变化预测中,广东省大部分地区极端降水事件的频次和强度与过去变化趋势相一致,呈持续增加的趋势。[结论]极端降水事件的频繁发生给广东省造成了严重的损失,应加强极端气候事件的预防工作,针对不同成因的极端降水事件应采取不同的应对措施。     

应用RNA沉默技术获取抗黄瓜花叶病毒(CMV)和烟草花叶病毒(TMV)转基因烟草

RNA沉默是迄今最为有效的抗病毒策略,利用该策略不但能获得免疫转基因植株,且所得植株不易与其他病毒基因重组或异源包壳、生物安全性较高。将本实验室已构建的携带有烟草花叶病毒(TMV)部分移动蛋白基因(ΔMP)和黄瓜花叶病毒(CMV)部分复制酶基因(ΔRep)反向重复结构的植物表达载体pBIN438-MP-Rep(i/r),用农杆菌浸润法转化普通烟草品种K326,共得196株转化植株,经卡那霉素筛选和PCR检测发现128株为阳性转基因株;PCR-Southern和RT-PCR分析表明外源基因已整合到烟草基因组并在转录水平上得到表达;ELISA结果显示20.3%的转基因植株对CMV和TMV复合侵染表现免疫性。本结果为利用RNA沉默技术进行植物抗多种病毒育种提供重要数据,为防治其他多种病毒复合侵染提供借鉴。     

花生黄曲霉抗性与类受体蛋白激酶的相关性分析

LRR类受体激酶RH4基因在花生黄曲霉敏感品种发育种子的种皮中上调表达.基于这类受体激酶多由于序列的变异导致抗性的变异,笔者将数据库中花生抗黄曲霉和敏感品种相似基因编码的蛋白进行序列比较分析,发现抗性品种与敏感品种的类似蛋白序列有很大差别.用荧光定量PCR方法对抗性品种KB153与敏感品种JH1012发育中不同时期的果...     

A New Method for Measuring Bonding Shear Properties of Adhesives on Steel Substrates

Single-lap-joint adhesively bonded metal specimen which is the national standard experimental method in use has an extremely non-uniform distribution of shear stresses along the joint, and tensile stress concentration of high values is produced on the steel substrate interfaces. Therefore the test result, which is not the real bonding shear strength between adhesive and steel substrates, can only be used as a test index for qualities of adhesives not the strength criterion for load is capacity evaluation. The combined bonding disc specimen is adopted for measuring bonding shear properties of adhesive on steel substrates, has a very uniform distribution of shear stresses in adhesive and along the bonding surfaces of steel substrates, of which the uniform coefficient is greater than 0.97. Furthermore, when adhesive joint is treated as an arc and steel substrates are chamfered at both ends of the joint, tensile stresses on the bonding surfaces can be reduced to less than 20 MPa which can hardly cause tensile failure. Thus, the results of combined bonding disc specimens can actually represent the real bonding shear strength or bonding shear-compression strength between adhesive and steel substrates, which can be used as strength criterion for load capacity evaluation of bonding members.     

The EME rules of composed coal and rock samples with hard roof failure and their application

The electric magnetic emission (EME) rules of deformation and failure of composed coal and rock samples are studied by lab experiments and fractal theory. The results show that at the initial stage of loading, EME signals increase, then decline slightly and stay at a stable level. Substantial increase appears when the composed coal and rock samples are close to the main fracture, and EME signals decline slowly when they are in the stage of residual deformation. The EME signals have a positive exponent relation to roof ratio in the composed coal and rock samples. The EME pulse count has the fractal characteristic, and the fractal dimensions increase with the process of loading. When the composed coal and rock samples are close to main fracture, the fractal dimensions decline suddenly, and it has a positive linear relation to the ratio of roof in the composed coal and rock samples. With the achieved rules, the burst danger has been forecasted successfully in face 7251.     

果蝇对云南杨梅的危害及发生规律研究初报

通过对云南杨梅主产区的果蝇种类鉴定、栖息场所及危害发生规律调查,结果表明：危害云南杨梅果实的主要害虫为双翅目（Diptera）果蝇科（Drosopilidaes）果蝇属（Drosophila）果蝇.果蝇广泛分布于杨梅园及其周边多种生态环境,具有发酵物、潮湿阴凉的生态环境,是果蝇栖息的主要场所和主要虫源;成虫的日活动高峰期为清晨和黄昏;果蝇对杨梅发生危害时期较早,杨梅生长中后期,果实肉质生硬,味酸稍甜时即被果蝇取食危害,随着杨梅的不断成熟,危害加剧,且果蝇对不同杨梅品种的危害程度和空间分布存在显著差异.     

Simulation of Potential Production and Optimum Population Quantitative Indices for the Second Hybrid Rice

The article established the HDRICE model by modifying the structure of the ORYZA1 model and revising its parameters by field experiments. The HDRICE model consists of the modules of morphological development of rice, daily dry matter accumulation and partitioning, daily CO₂ assimilation of the canopy, leaf area, and tiller development. The model preferably simulated the dynamic rice development because of the thorough integration of the effects of temperature and light on the rates of rice development, photosynthesis, respiration, and other ecophysiological processes. In addition, this model has attainable grain yield in the test experiment that showed the potential yield of cultivar Xieyou 46 ranged from 11 to 13 tons ha⁻¹. Besides, the model was used to optimize the combinations of the transplanting date, seedling age and density for cultivar Xieyou 46 at Jinhua area, and the population quantitative indices to attain the potential yield such as maximum stems, effective panicles, filled grain number/leaf area, and so on. The result showed that the combination of transplanting date on July 25, seedling age of 35 days and base seedling density of 1.33×10⁶ha⁻¹ is the optimum combination for the second hybrid rice production in Jinhua County, China. And the maximum stems, the effective panicles, the filled grain per panicle, the peak of optimum LAI, LAI in later filling stage, and the filled grain number/leaf were 6.03×10⁶ha, 3.99×10⁶ha, 119.2, 8.59, 5–6, and 0.64, respectively.     

酒精发酵饲料对延边黄牛产肉性能的影响

探讨了酒精发酵饲料对延边黄牛体尺、体重、血液组成及生产性能的影响。试验结果表明:(1)试验组的体高、体长、胸宽、胸围、坐骨宽、髋宽、尻长的增长量均高于对照组,其中体高、坐骨宽、尻长、胸围差异极显著(P<0.01)。体长、髋宽、管围差异显著(P<0.05);(2)试验组与对照组的日增重分别为0.98 kg和0.77 kg,差异极显著(P<0.01);(3)血液指标中,试验组的血钙、无机磷、葡萄糖含量均高于对照组,其中无机磷、葡萄糖差异极显著(P<0.01),血钙差异显著(P<0.05),尿素含量低于对照组,差异极显著(P<0.01),其余各血液指标均差异不显著;(4)屠宰试验结果表明试验组和对照组的屠宰率分别为57.24％和52.84％,净肉率为45.62％和40.94％,差异显著(P<0.05),眼肌面积为85.64 cm2和80.02 cm2,差异极显著(P<0.01)。     

农科人才培养模式的研究与实践

创新农科人才培养模式,是提高农科人才培养质量的关键。经过几年的探索和实践,形成了围绕创新能力培养、实践技能和全面素质提高的人才培养模式,通过多种途径确保了人才培养目标的实现。