self-(in)compatibility almond genotypes: A review

To compile self-(in)compatibility almond genotypes, a review of 133 commercial cultivars of wide geographical origin was made. The information gathered from own and mainly published work will be useful for both grower's cultivar choice when planting and for breeder's cross design when planning. The almond S genotypes compiled were identified using five different methods: biological (pollination tests in the field and in the laboratory) and molecular (RNases, PCR and sequencing). In most cases, genotypes were assigned after combining more than one technique. Cultivars were classified into three categories: self-incompatible (99), self-compatible (16) and doubtful self-incompatible (18). The database is divided in 9 fields (name, origin, parentage, obtention year (crossing, selection or release), S genotype, technique used, reference, consensus genotype, and cross incompatibility group). A study of the 27 S alleles already identified and their geographical distribution within the cultivated almond is also presented. The study was divided into cultivars of known and unknown parentage and the distribution of S alleles frequencies was uneven among the 133 cultivars. S allele frequencies are related to geographical origin. Some alleles (S ₁, S ₅, S ₇ and S ₈) are more frequently observed than the others among cultivars of both known and unknown parentage. In the cultivated almond, the S f allele is only found in the Puglia region, Italy. The S _f frequency is three times higher in cultivars released from breeding programmes than in cultivars selected by growers. From the 351 resulting possible genotypes by combination of the 27 S alleles identified only 20 CIG (0-XIX) have been established, which represents a small fraction of the whole genetic diversity of this polymorphic gene in almond.     

穗离体培养下温度对小麦蛋白质及其组分和产量性状的影响

本实验采用穗离体培养的方法研究了不同培养温度对小麦蛋白质及其组分和小麦产量性状的影响.试验表明:在扬花前3天至乳熟期间,温度对小麦籽粒总蛋白质的含量影响不大,但对蛋白质组分影响较大,低温有利于清蛋白的形成,高温有利于醇溶蛋白和谷蛋白的形成;同时试验还表明低温条件下小麦茎杆总蛋白含量高于高温培养下的茎杆含量;不同培养温度对小麦结实率和粒重也有影响,小麦1.2小花和整穗可见花结实率随温度增高而上升,到20℃时达到最大,分别为96.36%和72.11%,百粒重随温度的升高而增大,呈线性相关,相关系数为0.974013.另外本试验还对受温度影响的13个指标进行了因子分析,分析结果表明13个指标可以压缩为3个因子,因子1可以命名为产量因子,决定总变异的48.045 4%,因子2和因子3可合称为蛋白质组分和粒重因子决定总变异的51.9546%.     

Biological effects of El Niño on the Galápagos penguin

Long-term monitoring of physical and biological parameters is essential for understanding the effects of El Niño on bird populations, particularly for small or declining populations. We examined the biological effects of El Niño activity from 1965 to 2004 using instrumental sea-surface temperatures from the Galápagos Islands and 20 years of census counts of the Galápagos penguin. Between 1965 and 2004, nine El Niño events were recorded of which two were strong and seven were weak. The two strong El Niño events of 1982-1983 and 1997-1998 were followed by crashes of 77% and 65% of the penguin population, respectively. The evidence suggests that the increased frequency of weak El Niño events limits population recovery. The 2004 penguin population is estimated to be at less than 50% of that prior to the strong 1982-1983 El Niño event. We discuss the biological effects of increased El Niño intensity and frequency within the context of a 6000-year record of El Niño influence and in the light of increasing anthropogenic threats operating after 1535, when the Archipelago was discovered by Europeans.     

土壤速效养分空间变异研究

选择山西省一年两作和一年一作两种种植制度下的两个自然村作为试点,通过网格方法采取土样,应用土壤养分系统研究法进行了养分分析,并应用传统统计学和半方差函数对土壤养分变异进行了研究。结果表明,不同种植制度下,土壤养分性质均存在着空间变异,受农业传统施肥措施影响较大的N、P和OM,变异相对较大;而Ca、Mg、K、Cu、Fe、Mn等养分,传统施肥投入较少,土壤变异相对较小;土壤养分性质存在半方差结构,拟合模型包括球型、线型和指数型,但同一养分拟合半方差模型不尽相同。即使模型一致,最大相关距离也不一样,而且空间变异性强弱程度也不尽相同。Ca、N、Mn显示有较强的空间相关性,K、P、S显示具有中等的空间相关性。     

Seasonal changes in periphyton nitrogen fixation in a protected tropical wetland

Cyanobacteria are important for global nitrogen cycle and often form complex associations referred to as cyanobacterial mats or periphyton that are common in tropical, limestone-based wetlands. The objective of this study was to monitor the nitrogen fixation rate using the acetylene reduction assay of these cyanobacterial mats in a tropical, unfertilized, and protected wetland. To account for temporal and spatial variation of nitrogenase activity, we were interested in seasons in a hydrological cycle (dry, rains, and end of rains), sites with different vascular vegetation, and rates of nitrogenase activity in a 24-h cycle. The annual average of nitrogenase activity was 22 nmol C₂H₄ cm⁻² h⁻¹, with a range of <6 to 35 nmol C₂H₄ cm⁻² h⁻¹, and the annual nitrogen fixation rate of our study site (9.0 g N m⁻² year⁻¹) is higher than similar estimates from other freshwater wetlands. There was a clear temporal pattern in nitrogenase activity with a maximum rate occurring during the rainy season (August) and a maximum nitrogenase activity occurring between 0600 and 1200 hours. We found spatial differences in nitrogenase activity among the four sites that could be attributed to variations in species composition within the periphyton.     

茴香脑衍生物的合成工艺研究

以茴香脑为原料经H2O:氧化合成茴香脑环氧化物2-(4-甲氧基苯基)-3-甲基环氧乙烷,产率91%,并研究了溶剂配比、物料配比、催化剂用量、反应温度、反应时间等因素对产物产率的影响.实验结果表明:乙腈与甲醇体积比为1:5、茴香脑与H2O2的物质的量之比为1:2.5、原料与无水碳酸钠的物质的量之比为1:0.8、反应时间为...     

中国古典园林设计手法在现代园林中的应用

以中国古典园林的分类为基点,分析古典园林的特点,总结了中国古典园林的设计手法,提出将其造园手法运用于现代园林的方法和措施,为我国现代园林设计提供一定的理论帮助和参考依据.     

玉米根系形态对光照、氮水平反应的基因型差异

用溶液培养的方法 ,研究了光照、以及氮水平对不同氮效率玉米自交系根系形态养分吸收的影响 ,研究结果表明 ,提高光照水平有助于光合产物向根系分配 ,表现为总根长、根体积、根系重量等显著增加。在不同光照水平低氮胁迫时 ,氮低效品种白瓷与其它三个品种相比 ,根系的形态指标均有不同程度的降低。在高光强 ,0 .4 mmol/ L氮水平胁迫时 ,与氮高效品种 4 78相比 ,根系体积减少 2 7.54% ,根干重减少 2 1.2 4 % ,并降低了根系的吸收效率 ,同时也表明 ,光照与氮水平对光合产物的分配具有耦合效应     

An analysis of formation conditions for DBD transported charges of multineedle-to-cylinder

Dielectric barrier discharge (DBD) can produce homogenous discharge in normal temperature and atomsphere with low energy consumption, so it has broad development prospects in industrial applications. An experimental study is carried out to optimize the needles arrangement and supply parameters aiming at the multineedle-to-cylinder reactor with orthogonal design in combination with Lissajous figures. As it is konwn, the process of discharge is also the process of charge transfer; hence, the more charges are transported, the higher reaction efficiency in plasma is. The orthogonal design is established with transported charges as the goal factor, and supply voltage, supply frequency, needles length(NL), interneedle rotation angles(INRA) as factors. Variance analysis results show that the largest influence factor is supply voltage, followed by supply frequency; the electrode configuration of NL=(3.5+2) mm and INRA=45° matched with f=21 kHz makes transported charges per cycle biggest. The orthogonal experiment results are verified by further experiments, which is significant to improve the DBD plasma reaction efficiency.     

城市近郊蔬菜基地环境影响评价

阐述了在我国开展蔬菜基地建设项目环境影响评价工作的必要性;选择蔬菜基地的选址规划、指标体系建立、环境污染预测、生态影响分析以及效益分析等几个环境影响评价重点专题,就城市近郊蔬菜基地的环境影响评价工作开展进行了探讨。