工业专用型高芥酸油菜新品种选育

高芥酸油菜品种是在工业上具有广泛用途的专用型品种。本研究通过两个常规芥酸品种杂交,采用以单株和单粒筛选相结合对芥酸含量正向选择为核心的技术,育成了芥酸含量达60%的甘蓝型高芥酸油菜新品种高芥1号。同时阐明了在高芥酸含量背景下各种脂肪酸间的相关性,为相关育种提供了—些理论依据。     

Effect of light intensity on early ontogeny of African sharptooth catfish,Clarias gariepinus (Burchell)

Light intensity during the early life stages of fish can have profound effects on their survival, developmental rate, yolk utilization efficiency and body size. Here, these aspects were analysed during two separate experiments (with or without exogenous food) on two distinct progenies of African sharptooth catfish, at five different light intensities (<0.1, 70, 500, 2500 and 8000 Lx; 24L:0D, 27.2°C). The duration of the egg incubation period (from 1.01 to 1.25 days post fertilization, dPF) was inversely proportional to light intensity, as hatching took place at more precocious developmental stages with increasing light intensity, i.e. at significantly (P < 0.05) shorter body length and slightly more abundant remaining yolk at 8000 Lx in comparison to <0.1 Lx. At the start of exogenous feeding (4 dPF), most of these differences had vanished. During the period of mixed feeding (until the end of yolk absorption, 11 dPF), growth decreased significantly with increasing light intensity. Daily mortality rates after hatching varied very little between light intensities. Mortality during egg incubation increased significantly (P < 0.05) with increasing light intensity, whereas it varied very little between light intensities thereafter, with the best survival rates since fertilization until the end of yolk absorption obtained at intermediate light intensities (70–2500 Lx). These results could be useful for improving the performance of African sharptooth catfish hatcheries.     

Growth and nutrient conversion of white shrimp Litopenaeus vannamei (Boone) and Nile tilapia Oreochromis niloticus L. in an integrated closed recirculating system

We investigated the effects of the stocking density of white shrimp (Litopenaeus vannamei) on shrimp and tilapia growth and nutrient conversion in an integrated closed recirculating system both with and without Nile tilapia (Oreochromis niloticus). A 2 × 3 factorial design involving tilapia presence/absence and shrimp stocking densities of 40, 80 and 120 m^?2 was applied, using a tilapia:shrimp ratio of 0.025. There were no significant interactions between tilapia presence and shrimp stocking density in terms of shrimp growth performance or feed utilization. The presence of tilapia had no effect on the shrimp growth rate, survival rate or total weight gain (%). Shrimp growth declined significantly with increased shrimp stocking density, but the growth of tilapia was not significantly different among the three shrimp densities tested. The conversion of feed nitrogen and phosphorus into total harvested animal biomass was significantly higher in the presence than in the absence of tilapia. The nutrient conversion rate at the lowest shrimp density (40 m^?2) was significantly higher than at the highest density tested (120 m^?2).     

Comparisons of growth and economic performance among monosex and mixed-sex culture of red mud crab (Scylla olivacea Herbst, 1796) in bamboo pens in the tidal flats of mangrove forests, Bangladesh

An experiment was conducted in a randomized block design to compare growth and economic performance between monosex and mixed-sex culture of red mud crab ( Scylla olivacea Herbst, 1796) fed with trash fish at 5–10% body weight per day in the mangrove tidal flat at Burigoaliny Union of Satkhira District, Bangladesh. The experiment had three treatments in triplicate each: (a) all-male culture, (b) all-female culture and (c) mixed-sex culture. Crabs of 80–120 g in size were stocked at a density of 0.5 crab m⁻² and cultured for 100 days. Specific growth rates (SGRs) by weight and internal carapace width (ICW) in the all-male culture were significantly higher than those in the all-female culture ( P <0.05), while SGRs in the mixed-sex culture showed no significant differences from those in the all-male and all-female culture ( P >0.05). No significant differences in final mean body weight, ICW, daily weight gain, survival rate, gross and net yields were found among all the treatments ( P >0.05). The area of high water level with mangroves gave significantly better results in terms of feed conversion ratio, survival rate, gross and net yields than the area of low water level ( P >0.05). The experiment suggests that the all-female culture in the area of high water level with mangroves could be suitable in developing commercial pen culture of red mud crabs in Bangladesh.     

制浆处理方法对芹菜纸机械性能的影响

采用机械法制浆,分析不同处理方法对芹菜纸机械性能的影响.设计了4种组合方法,在中试条件下制备了4种标样芹菜纸.利用L&W纤维分析仪提供了纤维分析报告,利用Olympus测量显微镜表征了芹菜纸的结构.纤维、结构、性能分析结果表明,4种标样芹菜纸中最高抗张强度为1.029 kN/m,最低抗张强度为0.583 kN/m,可以通过整棵打浆、分切后打浆、打桨粗细等不同处理方法得到较高抗张强度的芹菜纸.     

The degradation of residual pesticides and the quality of white clover silage are related to the types and initial concentrations of pesticides

In order to understand the degradation of different residual pesticides of white clover silage and their influence on silage quality, three commonly used orchard pesticides with different concentrations were added to the white clover and fermented for 90 days. The results showed that the degradation rate of cypermethrin and its toxic degradation product 3-phenoxybenzoic acid (3-PBA) was the highest after silage, at different concentrations, both were 100%. The degradation rate of Tebuconazole and chloropyridine was 72.47–80.27% and 47.76–64.82%, of which 3,5,6-trichloro-2-pyridinol (TCP) content, poisonous toxic degradation product, increased 0.0525–0.253 mg·kg⁻¹. The residues of beta-cypermethrin and tebuconazole had reached safety standards after silage. As compared with the control, the contents of lactic acid, acetic acid, and propionic acid increased in the treated samples. The higher concentrations of three pesticides all significantly reduced the lactic acid content of silage (p<0.05). Pesticides had different effects on the nutritional components of white clover silage. Conclusively, silage is a potential way to expand the utilization of covering plants in orchards.     

运用灰色综合评判法综合评价国家黄淮海夏大豆区试品种

运用灰色综合评判法,对2015年国家黄淮海夏大豆品种区域试验南片B组试验数据进行分析。综合15个主要性状指标,对10个参试品种的表现进行综合评价,排出了各参试品种(系)的综合评判等级次序,结果总趋势与实际产量表现基本一致,与联合方差分析的结果也基本一致,个别品种位次有变动。灰色综合评判法是传统评价方法的一种直观补充,简便易行,在育种材料的评价中可以广泛应用。该研究可为夏大豆新品种(系)的选育和合理评价提供科学依据和方法。     

中小型沼气工程撬式沼气提纯系统设计与应用

根据中国中小型沼气工程分布范围广、地区差异性大、统筹规划难的现状,考虑到中小型沼气工程中出现的沼气净化提纯效率低、净化提纯效果差、成本高等问题,该研究设计了1套撬装式集约型的沼气提纯净化系统,分别从脱硫系统、脱碳系统、控制系统等方面设计出适合于装置制造的工艺方法。系统集成了干法脱硫、膜法脱碳和分子筛工艺,在进气量为500 Nm3/d、粗沼气压力为104 kPa的沼气工程条件下,进行了工程应用试验。通过检测,该装置稳定运行35 min后,提纯气中CH4质量分数可以达到97.88%,CO2低于2.5%,H2S质量浓度仅为16.7 mg/m3,CH4回收率为86.5%。设备运行成本为0.09元/Nm3沼气,且投资回收期仅为1.5 a。经过对比,该装置的提纯指标达到了国内生物天然气相关标准,且具有移动灵活、提纯效率高、成本低等优点。通过对本装置的应用研究表明,沼气提纯净化可实现中小型沼气工程生物天然气的高值化利用,为中小型沼气工程的发展拓宽途径。     

UvWhi2 Is Required for Stress Response and Pathogenicity in Ustilaginoidea virens

Some stress response-related genes have been identified in Ustilaginoidea virens, but it is not clear whether and how defects of stress responses affect the pathogenesis processes of U. virens. In this study, we identified a general stress response factor UvWHI2 as a homolog of Saccharomyces cerevisiae Whi2 in U. virens. The relative expression level of UvWhi2 was significantly up-regulated during infection, suggesting that UvWHI2 may be involved in pathogenesis. Furthermore, knockout of UvWhi2 showed decreased mycelial growth, increased conidiation in the potato sucrose medium and a defect in pathogenicity. In addition, the RNA-Seq and phenotypic analysis showed that UvWHI2 was involved in response to oxidative, hyperosmotic, cell wall stress and nutrient limitation. Further studies revealed that the defects of stress responses of the ΔUvwhi2 mutant affected the formation of secondary spores on the nutrient limited surface and the rice surface, resulting in a significant reduction of pathogenicity of U. virens. Our results suggest that UvWHI2 is necessary for fungal growth, stress responses and the formation of secondary spores in U. virens. In addition, the defects of stress responses can affect the formation of secondary spores on the rice surface, and then compromise the pathogenicity of U. virens.