长薄鳅池塘移植养殖试验

从长江上中游江段获取的长薄鳅移植至微流水的小面积养殖池中养殖。平均每池放养２６￣３６尾,投喂水蚯蚓、小杂鱼和虾,生长良好。１ａ后每池存活１８￣２０尾,每尾年增重８７．９￣１１４．２ｇ,增长４．９￣７．４ｃｍ。试验证明长薄鳅能在池塘中进行养殖。     

Residual plant nutrients in crop residues – an important resource

With increasing demand for sustainable production, the need to effectively utilise site-based resources increases. One such resource is the remaining crop residues, both above and below ground, after harvest. In order to assess the magnitude of this resource, this study determined the plant nutrient contribution of residues from 17 different crops in seven different regions of Slovakia over a nine-year period. The soil profile 0.0–0.3?m was taken into account at belowground residues sampling. The results showed that winter rape, mustard, corn maize, triticale, winter rye with straw and sunflower left the most residues, exceeding 8 tons of dry biomass per hectare. Root crops (sugar beet, potatoes) and peas left less than 3 tons of residual dry biomass per hectare. Using these data, the nutrient potential coefficient, i.e. the amount of nutrients left by production of one ton of the main product was calculated by polynomial regression. With these coefficients and the known yield of a given crop, it was possible to calculate how much nitrogen, phosphorus and potassium each crop leaves in the soil after harvest. It was found that the amount of nitrogen left ranged from 20 to 132?kg, phosphorus from 2 to 24?kg and potassium from 13 to 218?kg per hectare. This has to be taken into account when calculating the fertiliser requirement of the subsequent crop in order to achieve better resource utilisation, thereby reducing the risk of eutrophication and improving farm profits by reducing expenditure on fertiliser.     

Effects of Silver on the Photocatalytic Degradation of Gaseous Isopropanol

Water, Air, & Soil Pollution - The decomposition of gaseous isopropanol (IPA) by UV/TiO2 process in an annular photoreactor was studied under various conditions such as UV light intensity and...     

Modified complementation test of male sterility mutants in pepper (Capsicum annuum L.): preliminary study to convert male sterility system from GMS to CMS

The male sterility system in hybrid seed production can eliminate the cost of emasculation and ensure seed hybridity through avoidance of self pollination. GMS and CMS are two types of male sterility system that currently employed in pepper breeding. Conversion from GMS to CMS will increase the male sterility proportion of female parent from 50 to 100%. In this study, segregation analysis of four male sterile mutants consisting of one CMS mutant (CA1) and three GMS mutants (GA1, GA3 and GA4) showed that each had single recessive gene inheritance. A modified complementation test was performed by replacing male sterile mutants with their maintainer line as male parent. The nuclear restorer gene for CMS was independent of all nuclear restorer genes for GMS and all nuclear restorer genes for GMS were independent each other. Further observation on CMS and GMS male sterility loci revealed that GA1 and GA3 had mutated in both nuclear restorer genes for CMS and GMS, while CA1 and GA4 each carried mutation in single male sterility system of nuclear restorer gene for CMS and GMS, respectively. Conversion from GMS to CMS in the case of lines carried mutations in both sterility systems required only S-type cytoplasm donor, while lines carried mutation in single nuclear restorer gene for GMS required not only S-type cytoplasm but also rf allele donors. The important finding is the broader function of maintainer line in certain male sterility system that can be used as a maintainer or restorer line for other male sterility systems. We also confirmed that line CC1 is the general restorer for both CMS and GMS systems.     

Ultrasound evaluation of the gonadal structure in sex-reversed rainbow trout females

Ultrasound approach has been used to assess morphology of the gonadal structure in the sex-reversed rainbow trout females (neomales) provided in the course of 11β-hydroxyandrostenedione treatment applied within gonadal differentiation period. Eighteen matured individuals (in range 38.0–48.6 cm of body length and 802–1644 g of body weight) were scanned using digital ultrasound apparatus (DP-6900 model) Mindray Ltd., during the spawning season. After screening, fishes were killed to validate the morphological configuration and position of the gonads in the body cavity. The favorable place for cross-sectional imaging of gonadal lobes was half of the distance between the pectoral and pelvic fins below lateral line of neomales. Most of the examined specimens (61 %) had properly shaped, paired testis. Moreover, presence of individuals with asymmetrical gonads (33 %) and one bisexual fish was confirmed. There were no differences between total volume of sampled semen and sperm motility, but statistically significantly different in sperm concentration within selected (with symmetrical and asymmetrical testis) groups of neomales. It was confirmed that ultrasonic imaging is an efficient and accurate method to determine the state of gonads of mature sex-reversed rainbow trout females during spawning season and offers the opportunity for non-invasive detection of any morphological anomalies in their gonads.     

Adsorption of metal and uranyl ions onto amidoximated Pinus densiflora bark

Pine (Pinus densiflora) bark was chemically modified by grafting with acrylonitrile (AN) through Fenton reaction and conversion of the cyano group to an amidoxime group by reaction with hydroxylamine. Treatments of pine bark with 160 mM H₂O₂ at 40°C yielded ~70% grafting in 6-h reaction. After alkali hydrolysis of amidoximated pine bark (AOPB), its adsorption capacity (q _e) for copper ions was largely increased from 0.5 to 1.8 mmol/g. Adsorption of the hydrolyzed AOPB (HAOPB) followed the pseudo-second-order kinetic model. Among the metal ions tested, the order of adsorption capacity (q _e) predicted by the kinetic model at equilibrium time was Hg²⁺ > UO₂ ²⁺ > Cd²⁺ > Cu²⁺ > Zn²⁺ > Ni²⁺. The adsorption process was pH-dependent, and the adsorption equilibrium was observed in the pH range of 6–7 for all the metal ions. Even though pine bark is a good adsorbent for Hg²⁺ and UO₂ ²⁺ ions, it had a poor affinity for the other ions tested. It was obviously found that HAOPB had very high adsorption abilities for heavy metal and uranyl ions.     

作物株型相关性状分子机理的研究进展

作物株型是通过对光合产物的形成和籽粒填充物的储藏的影响进而决定产量的综合农艺性状,而株高、分蘖数、分蘖夹角和叶夹角是其主要影响因素。对关于控制这些性状的分子机理进行了综述,分析了利用这些基因通过基因工程改良株型进一步提高单位面积产量的可行性。     

苦菜和蒲公英中总黄酮含量及其抗氧化活性分析

为加强苦菜和蒲公英的进一步开发利用,研究了乙醇浓度、料液比和提取时间对苦菜和蒲公英总黄酮得率以及不同浓度提取物对苦菜和蒲公英抗氧化活性的影响。结果表明：苦菜和蒲公英总黄酮提取的最优化条件为提取液乙醇的浓度为60％,料液比为1：30,超声提取时间为0．5h,总黄酮得率分别为6．44％和17．56％。苦菜和蒲公英提取物对DPPH自由基清除率随样品提取物浓度的增大而升高,在浓度为9．6rag·mL^-1时,苦菜和蒲公英提取物的DPPH自由基清除率都达到最大,分别为76．47％和80．39％。     

Fertigation rate,leaching fraction,and growth of potted poinsettia

Single‐pinched poinsettia (Euphorbia pulcherrima ’V‐14 Glory') in 15‐cm pots received constant fertigation with 50, 100, 200, and 300 mg.L^‐1 nitrogen (N) from a 20N‐4.4 phosphorus (P)‐16.6 potassium (K) fertilizer with a leaching fraction (LF) of 0, 0.2, or 0.4. Plants received 25 irrigations during the 13‐week study. The shoot fresh and dry masses with 50, 100, and 300 mg.L^‐1 N at the 0.4 LF were 30% larger than at the 0 LF. The 300 mg.L^‐1 N fertigated plants had approximately 15% more leaf area and almost 122% more bract area than the 50 mg.L^‐1 N fertigated plants. The leaf N concentration of plants fertigated with 100, 200, and 300 mg.L^‐1 N was near or in the normal range of 4 to 6%, but was below the critical level of 3.5% with 50 mg.L^‐1 N fertigation. In contrast, the leaf P concentration approached or exceeded the toxic level of 0.9% with 100 to 300 mg.L^‐1 N. The N fertigation of 100 to 200 mg.L^‐1 is adequate for producing a quality poinsettia crop. Quality poinsettias can be grown at a 0 LF if quality irrigation water is available. With 11 mg.L^‐1 P via fertigation, the leaf P concentration was in the acceptable range. The P concentration in the 20N‐4.4P‐16.6K complete fertilizer was excessive for poinsettia and would contribute to unnecessary P leaching.