Growth,yield and silicon uptake of rice (Oryza sativa) as influenced by dose and timing of silicon application under water-deficit stress

Two experiments were conducted to evaluate the effects of dose and timing of silicon (Si) application on rice under limited water supply. The treatments for the first study included five Si doses (0, 75, 150, 300 and 600 kg Si ha^–1) under three soil moisture conditions (100%, 75% and 50% field capacity). For the second study, the treatments were four Si application timings [100% basal, 50% basal + 50% panicle initiation (PI), 25% basal + 75% PI and 25% basal + 50% PI + 25% heading] at the dose of 300 kg ha^–1 under the same moisture conditions. The highest number of panicle plant^–1 (14.6) and grain yield (13.6 g plant^–1) were obtained with the dose of 300 kg Si ha^–1. Similarly, an increase of 34–45% in grain yield was observed for different Si application timings compared with the control. Shoot dry matter and grain yield had positive linear relationship with shoot Si content. Grain yield and number of spikelet panicle^–1 were higher at the 300 kg Si ha^–1 dose applied as 100% basal, and hence could be a feasible option for RD57 Thai rice variety under water-deficit conditions.     

小鼠骨髓源CD103+DC分离培养及LPS对其形态与功能特征的影响

旨在建立C57BL/6小鼠骨髓源CD103⁺树突状细胞(CD103⁺ dendritic cell,CD103⁺DC)分离培养方法,阐述LPS对其形态与功能特征的影响。在无菌条件下分离C57BL/6小鼠骨髓细胞,并用重组GM-CSF和FLT3L对其进行体外联合诱导培养;利用光镜、扫描电镜、荧光显微镜和流式细胞术,分别对LPS作用前后细胞形态、表型及功能进行了分析。结果表明,细胞培养至第3天有零星集落出现,第13天后集落开始分散,可见典型的树突状突起,第15天后可得到大量的CD103⁺DC,加LPS刺激培养24 h后细胞表面树突样结构更加明显;分离培养的骨髓细胞能够表达表面分子CD103,其表达率达90%以上。RPMI-1640组(LPS未刺激组)可吞噬VOA的CD103⁺DC比例为25.70%,能够表达MHC-Ⅱ和CD83阳性细胞分别为41.31%和13.79%;LPS刺激组可吞噬VOA的CD103⁺DC比例为10.33%,能够表达MHC-Ⅱ和CD83的阳性细胞分别为68.10%和24.71%。MTT法检测结果显示,经LPS处理的CD103⁺DC刺激T细胞增殖的能力明显增强。综上所述,分离于C57BL/6小鼠的骨髓细胞,可在体外经FLT3L和GM-CSF共同诱导培养出CD103⁺DC,LPS可促进CD103⁺DC的成熟。     

协优57的高产性能与途径分析

通过对协优５７的“源、库”特征，即株型与产量结构的分布，说明其高产性能，进而提出相应的高产栽培途径。     

豫麦57的辐照改良

用60 Coγ射线照射开花期盆栽小麦 ,结果表明 ,小麦籽粒性状变异明显 ,对改良豫麦 5 7的籽粒品质产生了良好的效果。讨论了该方法的应用要点和育成新品系的应用前景。     

中晚熟玉米新杂交种九单57的选育

九单57以外引系444为母本，自选系1216为父本，于1998年育成，2004年通过吉林省农作物品种审定委员会审定．该品种生育期为127d，需≥10℃积温2650℃，属中晚熟玉米杂交种．具有高产、稳产、品质优良的特点，适宜我国各主要玉米产区推广应用．种植密度为5．0万株／hm^2．制种时父母本同期播种．     

DNA fingerprinting,metalaxyl resistance and mating type determination of the<Emphasis Type="Italic">Phytophthora</Emphasis> infestans population in the Republic of Ireland

Summary During the period 1995–1999 one hundred and sixty three isolates of P. infestans were collected in Ireland. The majority (150) were from the 1996 population. Isolates were analysed for mating type and sensitivity to metalaxyl, and subsets were also genotyped for mitochondrial haplotype (124) and RG-57 fingerprint (114). Four of the isolates tested were of the A₂ mating-type. Of four haplotypes known, only two were detected in the Irish population. RG-57 probe analysis determined that there were 12 genotypes present. However, clustering analysis demonstrated close relationships between many of the strains found. Metalaxyl resistance was predominantly associated with two closely-related genotypes. All A₂ isolates shared the same genotype. Due to the low population diversity, especially of A₂, sexual reproduction does not appear to be a factor in disease epidemiology.     

Changes of MAO-A and MAO-B Expressions in the Placenta of MPTP or MPP+ Treated Mice

In the present study, we evaluated the influence of intraperitoneal administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or 1-methyl-4-phenylpyridinium (MPP⁺) on the placenta. There was no increase in apoptotic cells in the placentas of C57BL/6 mice treated with 25.0 mg/kg MPTP or 17.1 mg/kg MPP⁺, indicating that a single injection of the chemicals may induce very slight cytotoxicity in the placenta at 12 hr after administration. The decrease in the expression of monoamine oxidase (MAO)-A in the labyrinth zone and that of MAO-B in the basal zone may be due to the decrease in cell activity, whereas the increase of MAO-B expression in the labyrinth zone after MPTP treatment may be due to a responsive reaction caused by MPTP, one of the substrates of MAO-B. The results represent histological evidence that MAO-B may be involved in the metabolism of MPTP to MPP⁺ in the labyrinth zone of the mouse placenta. In the present study, no increase in apoptotic cells indicates that MPTP and MPP⁺ are hardly toxic to the placenta, and the histological change in MAO-B expression may indicate the possibility of involvement of placental MAO-B in MPTP metabolism.     

Quantitative real-time PCR and culture examination of Mycobacterium avium subsp. paratuberculosis at farm level

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease in ruminants and may contribute to Crohn's disease in humans. The aim of this study was to determine the occurrence and quantity of MAP in cattle feces and milk in the Iranian context. In addition, we evaluated the effect of cattle age as well as farming system as risk factors contributing to MAP load. For this, a total sample of 373 consisting of 150 cattle feces (CF), 150 individual cow's milk (ICM), as well as 73 bulk-tank milk (BTM) was collected randomly and regardless of the cattle health status. The samples were assayed using F57 quantitative real-time PCR (qPCR) and culture method. According to the results of qPCR which was found ∼10 times more sensitive than culture assay, MAP was detected in 68.66% (103/150) of the CF, 12% (18/150) of the ICM and 52.05% (38/73) of the BTM samples. In contrast to the previous reports, the quantity of MAP in the BTM (2.03–5.97 log cfu/50 ml) was statistically (p < 0.01) higher than the ICM (0.90–1.97 log cfu/50 ml). Data suggested a direct relation (p < 0.01) between the cattle age and the quantity of MAP in the CF samples, while the relation was not statistically significant (p > 0.05) for the ICM. In addition, MAP load in the BTM samples obtained from traditional farms was significantly (p < 0.01) higher than that of the industrial ones, while the differences in CF and ICM was not significant (p > 0.05).     

链脲佐菌素诱导小鼠Ⅱ型糖尿病模型的研究

通过注射链脲佐菌素(STZ)诱导建立与人类Ⅱ型糖尿病(NIDDM)相似的昆明鼠和C57鼠模型,比较两种鼠建模剂量和成模率的差异。将昆明鼠和C57小鼠随机分为正常对照组(A)及低、中、高剂量(每天50、70、90 mg/kg)用药组(B)(n=10)。正常对照组(A)饲喂普通饲料,用药组(B)饲喂高脂高糖饲料;第4周开始,A组腹腔注射柠檬酸缓冲液,B组腹腔注射STZ,连续4 d。测定给药前和给药后3、7、15 d空腹血糖和体重,观察小鼠饮食、饮水和排尿情况。给药前空腹血糖A、B组间无显著性差异(P0.05);昆明鼠用药3 d后中、高剂量组均升高并达到建模标准,C57鼠用药7 d后中、高剂量组达到建模标准。两种小鼠用药3 d后各组体重均减低,并与对照组间有极显著差异(P0.01)。C57鼠,STZ注射剂量越高,体重减轻幅度越大;并且自造模成功后,各用药组体重均出现逐日降低的趋势。诱导建立NIDDM模型的适宜STZ剂量昆明鼠为每天50 mg/kg和70 mg/kg,并以后者为佳;C57鼠为每天70 mg/kg。     

B6-Co小鼠眼角膜组织观察及血管内皮生长因子的表达

[目的]观察血管内皮生长因子（VEGF）在遗传性角膜病小鼠（C57BL/6-cornea opacity,B6-Co）眼角膜组织中的表达情况,探讨B6-Co小鼠角膜混浊发病机制。[方法]观察比较B6-Co小鼠与正常B6小鼠在不同发育阶段（1、13、30、90d）的临床表现,并采用免疫组织化学法及实时荧光定量PCR法检测VEGF在角膜中的表达情况。[结果]B6-Co小鼠随着年龄的增长出现明显的角膜混浊并有大量角膜新生血管生成;免疫组化显示VEGF在不同发育阶段B6小鼠的角膜很少表达,而在B6-Co小鼠出生初期表达较少,13日龄后表达明显增强;实时荧光定量PCR检测VEGF mRNA表达上调,3月龄时与1月龄相比差异有统计学意义（P〈0.05）。[结论]VEGF在B6-Co小鼠角膜新生血管的形成过程中起重发作用,可能是导致角膜混浊的主要因素之一。