茶叶标本室建设及其在茶学实践教学中的作用

《茶叶审评与检验》课程是茶学本科专业的主干课程之一,课程以实践教学为主,茶叶标本室建设可有效保证本课程实验教学质量.结合青岛农业大学“茶学专业茶叶审评标本室建设”项目的实施,介绍了该校茶叶标本室建设概况,并讨论了其在《茶叶审评与检验》等课程教学中的作用.     

Sensitive detection of the c‐KIT c.1430G>T mutation by mutant‐specific polymerase chain reaction in feline mast cell tumours

Here, we describe the establishment of mutant‐specific polymerase chain reaction (PCR) for detection of a c‐KIT c.1430G>T mutation in feline mast cell tumours. Several mutations in feline c‐KIT have been identified, with the c.1430G>T mutation accounting for a significant portion of feline mast cell tumour mutations. The c.1430G>T mutation in c‐KIT exon 9 was detected in 15.7% (11 of 70) of samples by mutant‐specific PCR but in only 7.1% (5 of 70) by PCR–restriction fragment length polymorphism (RFLP) in the genomic DNA isolated from 70 formalin‐fixed paraffin‐embedded sections or cells collected by fine needle aspiration. Mutant‐specific PCR showed remarkably higher detection rate than did PCR–RFLP. DNA sequence analysis did not always yield identical results to those of mutant‐specific PCR, suggesting heterogeneity of tumour cells. Mutant‐specific PCR is a valid and efficient screening tool for detection of the c‐KIT c.1430G>T point mutation in feline mast cell tumours compared with PCR–RFLP and sequencing analysis.     

Evaluation of ultrasonic sensor for variable-rate spray applications

Automatic variable-rate sprayers require accurate measurement of canopy size. An estimate of canopy size is made by measuring the distance to the canopy at several elevations above the ground; an ultrasonic sensor was used to determine canopy distance in this study. It is sometimes necessary to conduct spray operations during harsh operating conditions. In this study ultrasonic sensors were subjected to simulated environmental and operating conditions to determine their durability and accuracy. Conditions tested included exposure to extended cold, outdoor temperatures, cross winds, temperature change, dust clouds, travel speeds and spray cloud effects. The root mean square (RMS) error in a series of measurements of the distance to a simulated plant canopy was used to test for significant difference among treatments. After exposure to outdoor cold conditions for 4 months, the RMS error in distance measured by the ultrasonic sensor increased from 3.31 to 3.55 cm, which was not statistically significant. Neither the presence of dust cloud nor the changes in cross-wind speeds over a range from 1.5-7.5 m/s had significant effects on the mean RMS errors. Varying sensor travel speed from 0.8 to 3.0 m/s had no significant influence on sensor detection distances. Increasing ambient temperature from 16.7 to 41.6 °C reduced the detection distance by 5.0 cm. The physical location of the spray nozzle with respect to the ultrasonic sensor had a significant effect on mean RMS errors. The mean RMS errors of sensor distance measurements ranged from 2.3 to 83.0 cm. The RMS errors could be reduced to acceptable values by proper controlling the sensor/spray nozzles spacing on a sprayer. In addition, multiple-synchronized sensors were tested for their measurement stability and accuracy (due to possible cross-talk errors) when mounted on a prototype sprayer. It was found that isolating the pathway of the ultrasonic wave of each sensor reduced detecting interference between sensors during multiple sensor operation. Test methods presented herein may be useful in the design of standardized testing protocols for field use distance sensors.     

温室测控技术的发展及我国温室测控面临的问题

介绍了国内外温室测控技术的发展历史、现状、发展趋势及研究动向,提出了进一步发展我国温室测控技术、提高我国温室现代化程度所亟待研究和解决的问题.     

Rejuvenation of juvenile growth characters in picea abies

Cuttings were made from six‐year‐old seedlings of Picea abies L. (Karst.) that had been studied in the Stockholm phytotron. The seedlings belonged to four full‐sib families, one being of French origin, one of North‐Swedish origin and two being hybrids between parents of North‐Swedish and French origin. Nine clones from each family were included. After the rooting phase, the cuttings were exposed to the same cultivation regimes as the seedling ortets. Characteristics of growth rhythm, percentage free growth and leader length were recorded during the 2nd to the 5th growth period (GP). Plagiotropic growth habit was recorded in the 3rd to the 5th growth period, and, characteristics of the rooting phase were studied. A juvenile behaviour very similar to that characterizing growth periods 2–3 of the seedlings was observed for growth rhythm characteristics and for free growth capacity during GP2 of the cuttings. The absolute value of the differences between each observation of the seedling ortets in GP6 and the means of the cuttings in GP2 produced a new variable that quantified the degree of rejuvenation. This new variable was meaningfully calculated only for growth rhythm and growth pattern variables. A gradual reversion of the growth rhythm occurred for the cuttings, which corresponded to the change with increasing age for the seedlings. The capacity for free growth, on the contrary, disappeared already in GP3 for the cuttings, except for the French family. A large variation in the rejuvenation ability between families was observed. Furthermore, the rejuvenation ability was negatively correlated with the ability to grow plagiotropically.     

我国西北、西南地区牧草种子质量及其影响因素分析

１９９３和１９９４年，对我国西北、西南７省（区）主要生产、经销的１１种１１０个种批的牧草和草坪草种子进行了现场扦样、质量检验和质量定级，并对影响种子质量的因素进行了调查与分析。结果表明：被检种的平均合格率为７１．４％，其一、二、三级及不合格种子分别占３６．０％、１２．７％、２２．７％和２８．６％。种批的质量以进口坪用草地早熟禾、多年生黑麦草和国产苇状羊茅（坪用）和老芒麦质量最好，种批平均质量均达一级；其次为国产多年生黑麦草（坪用）和毛苕子，虽然各含三级和／或二级种子，但合格率为１００％。其它被检种质量较低，尤其是紫花苜蓿（１９９３年检）、沙打旺（１９９４年检）、苏丹草和红豆草，不合格种批率分别为６０％、７０％、８０％和１００％。种子质量低的主要表现为多数种杂质含量高和杂草种子严重超标，部分种发芽率低以及个别种水分含量过高。影响种子质量的主要因素为（１）种子生产不规范，技术落后；（２）生产和经营者缺乏必备的种子收获、清选机具以及种子收后质量管理知识；（３）种子经营混乱，信息不畅，产销脱节等。就如何尽快提高我国牧草种子质量以及加强种子质量管理等问题提出了建议。     

兴安落叶松容器苗的测土施肥实验

针对各苗圃的地力下降和营养不均衡状况,进行了测土施肥试验。以兴安落叶松容器苗作为样材,采用正交设计方法,分别对新播容器苗和芽移容器苗进行测土施肥。结果表明:在该立地条件下,新播苗肥料的最佳配比为1∶14,最佳施肥量为磷酸二铵45.5g/m2;芽移苗肥料的最佳配比为1∶23,最佳施肥量为尿素6.5g/m2、磷酸二铵39.0g/m2,使苗木当年达到出圃标准。     

玉米DUS测试标准品种在华南亚热带生态区的表现与优化

通过大田试验,对玉米DUS测试指南中的37份标准品种在华南亚热带生态区广州测试站的表现与玉米DUS测试指南中的代码和描述进行了差异性分析。结果表明,玉米测试指南中的35个测试性状中有29个性状的符合系数大于0.95、占82.86%,其中散粉期、雄穗小穗密度、雄穗一级侧枝数目和籽粒排列形式这4个性状的符合系数为1.00;符合系数小于0.95的6个性状均为数量性状,并进一步对这6个性状的14个表达状态的标准品种进行了进一步的优化。     

Real-Time Soil CO2 Respiration Rate Determination and the Comparison between the Infrared Gas Analyzer and Microrespirometer (MicroRes®) Methods

Soil carbon dioxide (CO₂) respiration is one of the important soil health parameters that provides a general assessment of soil microbial activity and soil quality. Soil respiration rates, however, have not been widely applied in soil testing protocols mainly because the traditional methods are either inconvenient, technically cumbersome or too expensive. Currently, only two methods are available for a true real-time soil respiration rate determination (<2 h): the infrared gas analyzer (IRGA) and the microrespirometer (MR or MicroRes^®) methods. We analyzed the real-time soil respiration rates of 20 soil samples from fifteen states after various periods of incubation using the IRGA method and the MR method. The measured soil respiration rates ranged from 0.4 µL CO₂/h/g to 9.0 µL CO₂/h/g. Both methods show precision in soil respiration determinations (CV = 12.7% and 11.9%, respectively). Comparison of the results between the IRGA and MR methods indicates high degrees of agreement (r² = 0.914). This study shows that the MR method is a simpler and more cost-effective alternative for real-time soil respiration rate determinations.     

Evaluation of smallholder pig production systems in North Vietnam: Pig production management and pig performances

This study investigated the productive adaptability of pig breeds under different smallholder production conditions in Vietnam, comparing an indigenous with a Vietnamese improved breed. Fieldwork was conducted in four villages with different remoteness in North Vietnam from 2001 to 2002, in 64 households keeping the improved Mong Cai or indigenous Ban as sow breeds and progeny for fattening. Four visits per farm yielded 234 structured interviews. Reproductive performances were derived from 135 litters. Individual weights of pigs (n = 755) were obtained. Data were analysed by regression, linear and generalised linear, especially loglinear models.

Two distinct pig production systems were identified, that differed in remoteness, market access, resource availability, distribution of pig breeds and pig production intensity. Higher performances of 1.4 and 1.5 litters year^− 1, 8.4 and 8.4 piglets weaned litter^− 1, 66.6 and 93.0 kg piglets weaned sow^− 1 year^− 1, and 136 and 177 g day^− 1 ADG were found in two villages near town with semi-intensive production conditions and a high rate of improved Mong Cai sows and MC and LW × MC offspring in the observed population. Lower performances of 1.1 and 1.1 litters year^− 1, 4.6 and 5.5 piglets weaned litter^− 1, 20.5 and 30.9 kg piglets weaned sow^− 1 year^− 1, and 66 and 85 g day^− 1 ADG were observed in parallel to higher incidences of indigenous Ban pigs away from town under extensive conditions. Total live weight offtake per household per year was higher near town and in one village distant to town. MC and LW × MC remained even under demand-driven conditions below the performance potential reported for improved genotypes. Under resource-driven conditions with a saving-oriented production pattern, the higher-yielding but more demanding Mong Cai might not be an efficient production alternative as a further performance reduction can be assumed. A considerable live weight output was observed under resource-driven conditions and with a higher percentage of crossbred LW × Ban offspring in the population, possibly representing a promising production alternative. Factors influencing the performance expression of pigs, and the suitability of different methods for the assessment of performance parameters on-farm are discussed.