Development of ‘naked-tufted’ seed coat mutants for potential use in cotton production

Use of chemical mutagenesis has been highly successful in most major crops. The objective of this research was to develop ‘naked-tufted’ seed mutants and to incorporate this genetic trait into cotton to enhance crop quality and reduce processing costs. In 1997, six commercial cultivars were treated with 2.45% v/v ethyl methane sulfonate. In 1999, three M₃ plants were identified that had partially naked seed coats. The trait was stabilized through individual plant selections from 2000 to 2004. During 2005 and 2006, the homozygous naked-tufted M₈ mutant lines were evaluated for lint yield, lint percent, fibers/seed, fibers/mm², fiber quality, seed oil content, ginning efficiency and yarn spinning performance. Overall, the naked-tufted seed mutants had lower lint yield, lower fibers/seed, lower lint/seed, and lower fibers/mm² when compared with their original fuzzy parents. The lint turnout from the mutants was similar to the fuzzy parents and the commercial cultivars. The naked-tufted seed mutants had higher seed oil percent, 6–17% lower short fiber contents, significantly reduced seed coat neps (37–42%), higher elongation and yarn tenacity than their fuzzy counterparts. Preliminary data also showed that the naked-tufted mutants required less energy to gin.     

Estimation and economic evaluation of aboveground carbon storage of <Emphasis Type="Italic">Tectona grandis</Emphasis> plantations in Western Panama

Tropical tree plantations may play an important role in mitigating CO₂ emissions through their potential to capture and sequester carbon from the atmosphere. The Clean Development Mechanism (CDM) as well as voluntary initiatives provide economic incentives for afforestation and reforestation efforts through the generation and sale of carbon credits. The objectives of our study were to measure the carbon (C) storage potential of 1, 2 and 10-years old Tectona grandis plantations in the province of Chiriquí, Western Panama and to calculate the monetary value of aboveground C storage if sold as Certified Emission Reduction (CER) carbon credits. The average aboveground C storage ranged from 2.9 Mg C ha⁻¹ in the 1-year-old plantations to 40.7 Mg C ha⁻¹ in the 10-year-old plantations. Using regression analysis we estimated the potential aboveground C storage of the teak plantation over a 20 year rotation period. The CO₂-storage over this period amounted to 191.1 Mg CO₂ ha⁻¹. The discounted revenues that could be obtained by issuance of carbon credits during a 20 year rotation period were about US$460 for temporary CER and US$560 for long-term CER, and thus, contribute to a minor extent (1%) to overall revenues, only.     

电控汽油车排放物的稳态工况法（ASM）检测分析

介绍了将稳态工况法（ASM）检测技术应用于底盘测功机上,采用稳态加载、带负荷测试的方法,由分析仪器自动、定量、准确地检测出车辆排放污染物CO、HC和NOx的数值。通过对汽油车排放污染物、有害气体的净化、ASM稳态工况的检测原理、测试程序以及测试结果的分析研究,对测试不合格的电控汽油车采取有针对性的措施,以提高车辆检测的通过率。     

柴油汽车排放物的分析与环保检测

阐述了柴油发动机的发展进程,分析了柴油汽车排放物产生的机理和化学成分,并对柴油汽车排放物的环保检测标准和检测方式等进行了深入探讨。     

小波分析在刀具磨损状态检测中的应用

提出一种基于小波分析的声发射刀具磨损状态的判别方法,将占有声发射信号主能量的频段区间提取出来进行信号重构作为识别刀具磨损状态的特征向量。实验证明,该方法具有较高的准确性。     

Utilization of pine (Pinus pinea L.) cone in manufacture of wood based composite

Physical and mechanical properties of medium density fiberboards (MDF) made from various mixtures of wood fibers and stone pine (Pinus pinea L.) cones were evaluated using European standards. MDF panels were manufactured using standardized procedures that simulated industrial production at the laboratory. Six panel types were made from mixtures of wood fiber/cone flour, 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 percents, respectively. Addition of the cone flour into the MDF significantly reduced formaldehyde emission from the panel. In addition, the addition of 10% cone flour also improved water resistance of the MDF panels made using urea–formaldehyde (UF) resin. However, further addition of the cone flour into the panel negatively influenced their water resistance. Flexural properties and internal bond strength decreased with the increase of cone flour content in the panel. The UF resin is the main source of formaldehyde emission from the UF-bonded wood-based panels. Depending on addition of the cone flour in the panels, the formaldehyde emission values ranged from 2.6% to 55.3% lower than the panels made from 100% wood fiber. Based on the findings obtained from this study, pine cone can be used as a renewable biological formaldehyde catcher as an alternative to the traditional formaldehyde catchers for E1 Class MDF manufacture.     

汽油清净剂对发动机沉积物影响的试验研究

在M111发动机台架上,采用GB/T19230.6-2003中所规定的试验方法,研究不同油品对发动机进气阀、燃烧室等部位沉积物的影响。结果显示:对不含汽油清净剂的汽油,其沉积物严重,尤其是其进气阀沉积物严重,加入有效的汽油清净剂可降低发动机沉积物。     

EMS诱变玉米花粉M_2代生物学效应研究

对EMS玉米花粉诱变的M2代进行了观察、选择和鉴定。结果表明,玉米M2苗期以叶色变异为主,其中黄化苗变异比例最大,而成株期以早熟和雄性不育变异为主。株高、穗位高等性状变异率较高。M2代果穗各性状的变异程度大都显著高于对照。     

农业废弃物与煤共燃发电的温室气体减排效益分析

农业废弃物燃烧能实现CO2零排放,并避免其自然腐烂所产生的CH4,具有双重减排效果。为此,以农业废弃物与煤共燃发电作为清洁发展机制(CDM)项目,分析了农业废弃物与煤共燃的燃烧和污染物排放特性,计算了其单位碳减排成本。结果表明,在不同混燃比例下,单位碳减排成本范围在107～126$/(t.CO2)之间,与其他可再生能源项目相比,具有明显的竞争力。     

Identification of low lectin mutants in soybean

Lectin is one of the known antinutritional factors that deteriorate the soybean protein quality and development of cultivars with low lectin content will help to improve nutritional quality of soybean [Glycine max (L.) Merrill]. Therefore, attempts were made to induce mutations for low lectin content in the cultivar ‘MACS 450’. Soybean cultivar ‘MACS 450’ was subjected to combination treatments of γ‐rays and ethyl methane sulphonate (EMS) with an objective to induce variability for low lectin content. The treatments of different combinations of γ‐rays and EMS were 50 Gy + 0.2% EMS, 50 Gy + 0.4% EMS, 100 Gy + 0.2% EMS and 100 Gy + 0.4% EMS. Of the 3200 treated M₁ seeds sown, 16 400 M₂ plants were raised. In M_2, 72 plants were identified for low lectin content [<40 × 10⁵ haemagglutination unit (HAU)/mg] and were carried up to M₅ generation. In M₅ generation, lectin content in ‘MACS 450’ was 39.23 to 50.0 × 10⁵ HAU/mg, and was compared with the nine true breeding lines identified having low lectin content, ranging from 2.3 × 10⁵ to 27.46 × 10⁵ HAU/mg. Three mutants were found to possess very low lectin content (ranging from 2.0 × 10⁵ to 3.0 × 10⁵ HAU/mg). Thus, the identified mutant lines with low lectin content will greatly improve soybean protein quality, thereby reducing financial burden on the soybean industry for processing soybean meal and also making it suitable for human consumption. All the mutants showed normal seed development, having soluble protein content similar or higher than that in the parent (32.0 mg/ml). This indicates that the change in lectin content does not have any negative impact on the plant growth and protein content.