Genetic characterization of Portuguese brown trout (Salmo trutta L.) and comparison with other European populations

Abstract– Allozyme and other protein loci were examined to study the genetic structure of Portuguese brown trout ( Salmo trutta ) populations. A total of 247 individuals from three tributaries of the Lima hydrological basin and a hatchery, all located in northern Portugal, were analyzed. Four of 22 protein coding loci were found to be polymorphic: CK-A1^*, GPI-A2^*, MPI-2^* and TF^*. A new allelc at the latter locus was found in Atlantic populations. The data obtained for Portuguese brown trout were compared with published data for 14 European populations and three hatchery stocks. Six polymorphic loci (CK-A1^*, GPI-A2^*, GPI-B2^*, LDH-C^*, ME^* and MPI-2^*) were used in a cluster analysis. This showed the similarity of Portuguese natural populations and northern Iberian populations and that Portuguese hatchery fish have an autochthonous origin, distinct from that of other Atlantic hatchery stocks.     

An advisory model for control of Puccinia recondita in winter wheat

Epidemics ofPuccinia recondita and resulting yield loss of winter wheat were studied in field experiments over three seasons in the Netherlands. Results are reported and used to construct an advisory model for control of brown rust, based on rust monitoring. If the fraction of leaves with rust (I) at a certain development stage is determined, the average number of rust sori per leaf (M) was estimated by: M=EXP(1.84+1.39ln(ln[1/(1-I)]). The final number of sori per leaf (Mf) at early dough was forecast by an exponential growth: Mf=M·EXP(RGR·t). The relative growth rate (RGR) averaged 0.163/day and the forecasting period, t, until early dough, was derived from published data. The forecast number of sori-days per leaf (S, AUDPC-value) was then obtained by: S=(Mf-M)/RGR. Yield loss (kg/ha) by brown rust was 1.15 times the number of sori-days per leaf at low rust intensities. The efficacy of the fungicides used was 85%. The forecast avoidable yield loss (L, kg/ha) was calculated by: L=0.85 (1.15 S). Economic thresholds for brown rust control at different development stages are given for Dutch wheat fields at a cost level of 270 kg/ha for one fungicide application.     

Postponed germination of Puccinia recondita urediospores deposited on wheat seedlings. II. Infectivity of urediospores after postponed germination

Urediospores ofPuccinia recondita f.sp.tritici were applied to wheat seedlings. Inoculated plants were placed in a growth chamber to expose the spores to dry periods from zero to nine days at near-optimal temperatures (ca 18 °C). The dry period was followed by a wet period varying from 2 to 24 hours for germination of spores and infection of plants. Infection results were subjected to analysis of variance. The main effects dry period, wet period, and temperature were highly significant. The dry period×wet period interaction was significant. The interaction implied that the effects of post-detachment, ripening of germinable spores appeared in their resulting infectivity. There were two forms of post-detachment ripening, a slow ripening during the dry period and a faster ripening during the wet period. The two forms of ripening showed a non-additive compensatory interaction. The effect of post-detachment ripening on infectivity of germinated spores was more pronounced at 15 than, at 18 or 20 °C; the effect was strongest during the first day of the dry period. At dry periods of over 6 days, infectivity of germinated spores decreased, especially at the higher temperatures. Prolonged exposure, of spores to a dry period apparently damages the spores even though they are still able to germinate.Samenvatting Uredosporen van de bruine roest van tarwe (Puccinia recondita f.sp.tritici) werden over het eerste blad van tarwekiemplanten verstoven. De aldus geïnoculeerde planten werden in een klimaatkamer geplaatst bij ca. 18 °C om de sporen bloot te stellen aan droge perioden van 0 tot 9 dagen. De droge perioden werden gevolgd door natte perioden van 2 tot 24 uur om de sporen te laten kiemen en de planten te infecteren. Na de natte periode werden de planten bij verschillende temperature geplaatst om de latente periode en de vorming van sporenhoopjes te bepalen. De hoofdeffecten op de vorming van sporenhoopjes waren zeer significant: duur van de droge periode, duur van de natte periode en temperatuur. Twee vormen van sporenrijping werden gevonden bij rijping vnn sporen, die los op het blad lagen (rijping, buiten de sporenhoopjes), een langzame rijping tijdens de droge periode en een snelle rijping tijdens de natte periode. Deze twee vormen van rijping vertoonden statistische interactie met enige wederzijdse compensatie. Het effect van deze sporenrijping (buiten de sporenhoopjes) op de infectiviteit van gekiemde sporen was bij 15 °C duidelijker dan bij 18 en 20 °C; het effect was het sterkst tijdens de eerste dag van de droge periode. Bij droge periodes langer dan 6 dagen daalde de infectiviteit, vooral bij de hogere temperaturen.     

杂交稻新组合抗优80对褐稻虱抗性的初步研究

通过对褐稻虱苗期抗性测定,杂交稻新组合抗优80对褐稻虱表现抗性,抗性级别为1.0级,对褐稻虱存活率、取食量、种群建立等有很强的抑制作用;田间系统调查,抗优80上的虫量仅为感性品种汕优63上的1/7～1/20。因此,在褐稻虱中等或偏重发生年,抗优80上的虫量达不到防治指标,不需进行防治。     

抗性品种与天敌对褐稻虱种群的协同调节作用

褐稻虱(Nilaparvuta lugens)是我国水稻的主要害虫。以往的粳稻品种,感褐稻虱;近几年来一系列抗褐稻虱品种如秀水620、秀水664已经育成,1990年已种植150万亩。种植抗性品种可少用或不用杀虫剂,能大量保存天敌,抗性品种与天敌的协同作用,对控制褐稻虱种群,改善防治策略,具有现实意义。该文报道了田间和实验室观察调查多种天敌的数量和捕食或寄生效果,估计了在不同抗感品种上褐稻虱种群趋势指数1值,并分析了粳稻抗性品种与蜘蛛类抑制褐稻虱的协同作用。     

Hematology and serum chemistry values of the European brown hare

Background: Hematology and serum biochemistry values can be useful for evaluating the health of populations of captive and free-living European brown hares ( Lepus europaeus ). However, current information is fragmented and incomplete.
Objective: The objective of this study was to determine normal hematology and serum chemistry values for a population of captive European brown hares and to investigate differences related to sex and age.
Methods: Routine hematology and serum chemistry values were determined for 48 captive European brown hares in Catalonia (northeastern Spain): 21 young (6 males and 15 females) and 27 adult (14 males and 13 females) hares. Blood was obtained by auricular venipuncture while animals were physically restrained. Results were expressed as the mean ± SD, and reference intervals were calculated as the mean ± 2SD.
Results: RBC count, PCV, concentrations of hemoglobin, total protein, albumin, gamma globulin, urea nitrogen, and creatinine, and alanine aminotransferase activity were significantly higher in adults than in young hares, and alkaline phosphatase activity and total bilirubin concentration were lower. Sex differences were not observed.
Conclusions: Hematology and serum chemistry results obtained in this study are considered representative for healthy captive European brown hares. A single reference interval can be used for values from male and female hares, however, age-specific intervals are needed for some analytes.     

辛烯基琥珀酸淀粉酯在酸奶中的应用

对辛烯基琥珀酸淀粉酯作为酸奶稳定剂及其应用效果进行了研究。结果表明，添加0．5％-1．0％取代度0．02左右的辛烯基琥珀酸淀粉酯能改善酸奶的组织形态、降低离心沉淀率、增加黏度。     

Phylogenetic analysis based on ITS sequences and conditions affecting the type of conidial germination of Bipolaris oryzae

One taxonomic characteristic of Bipolaris species is the bipolar germination of conidia, but conidia of Bipolaris oryzae , the causal pathogen of brown spot in rice, are regularly observed to show intercalary germination, a characteristic of Drechslera species. The effect of selection, culture media and culture age on type of conidial germination was determined for three brown spot isolates from Cavinti, San Pablo and Palawan in the Philippines, obtained from infected leaves showing typical disease symptoms. Based on the analyses of their ITS1, ITS2 and 5·8S rDNA nucleotide sequences, the local isolates were clearly identified as B. oryzae . Selection for colonies of the three isolates derived from single conidia with either bipolar or intercalary germination had no effect on the number of spores showing bipolar germination in subsequent cultures. Germination on seven different culture media was tested; of these, rabbit food agar and water agar increased the percentage of bipolar germination of conidia, although this varied between isolates. Incubation of the cultures of all three isolates for longer periods prior to harvesting conidia increased the percentage of bipolar-germinating conidia from c . 40 to c . 90% with 5-day-old and 30-day-old cultures, respectively.     

褐飞虱不同为害状损失率测定研究

本研究旨在为褐飞虱为害损失的调查提供直观、准确的参考依据。研究表明,褐飞虱各种田间受害状都有产量损失,各症状的产量损失率为２５．８％～９４．０％。以百穗实粒干重为统计标准,Ｆ＝１８８．７０４＊＊,达极显著差异水平。ＳＳＲ多重比较,不同水稻被害状之间损失梯度明显。产量因素剖析表明,褐飞虱的为害主要是导致结实率和千粒重显著降低。文中举例说明了研究结果的应用方法。     

Pre-stocking acclimatisation of brown trout Salmo trutta: effects on growth and capture in a fast-flowing river

Abstract  A field experiment was carried out over two consecutive years in a fast-flowing river to evaluate the effects of a 5-day acclimation period on the subsequent growth and capture of stocked juvenile brown trout, Salmo trutta L. Post-stocking growth of both acclimated and non-acclimated fish remained very poor for at least 44 to 50 days. After this slow start, all fish grew significantly but acclimated trout performed 40.1% better than non-acclimated individuals. However, the better growth did not lead to higher capture rates. Capture success post-stocking was low, regardless of acclimation. Flooding, combined with low fitness of the stocked fish in the first weeks was considered the main reason for the unsatisfactory stocking success. It was concluded that in-stream acclimation aids rapid adaptation of stocked trout and thus imparts some growth advantages, although this does not necessarily result in higher yields.