不同气候带的白三叶品比试验研究

在云南四个不同气候带条件下,分别对国外引进的15个白三叶品种的相对干物质产量进行比较,同时,观测各品种的物候发育和营养成分。结果表明,在云南北亚热带至寒温带气候区域,最优良的品种为海法白三叶,其次为草地胡依阿白三叶和南迪诺白三叶。本文旨在为云南及相似气候环境草地建植中白三叶的品种选用提供参考。     

Ccr-lncRNA172145靶向miR-206在锦鲤体色调控中的作用初探

为了解非编码RNA在锦鲤体色分化变异中的分子调控机制,在课题组前期对锦鲤皮肤组织转录组测序的基础上,筛选到4条在3种皮肤(黑色、红色、白色)组织中显著差异表达的lncRNA;基于RNAhybrid和TargetScan靶基因预测软件,发现lncRNA172145与黑色素合成通路中miR-206之间存在靶向结合位点.借助...     

Variations in leaf litter decomposition explain invasion success of Broussonetia papyrifera over confamilial non-invasive Morus alba in urban habitats

In urban environments, anthropogenic influences play an important role in determining the distribution of woody flora and consequently, the propagation of woody invaders. Land-use changes and disturbances associated with urbanization may intensify different invasive aspects of a species. Studying the extent by which invasive species vary from non-invasive species can strengthen our understanding of urban invasions. In this study, we compared leaf litter decomposition between two confamilial exotics, an invasive Broussonetia papyrifera, and a non-invasive Morus alba (both belonging to family Moraceae), growing in urban habitats. Senescent leaves of both the species and soil were collected from five study sites in Chandigarh, India. Litterbags filled with 10 g leaves each were placed in pots containing the soil collected from respective study sites. Mass remaining, decomposition constant, and soil elemental composition were determined after periodic harvesting of the pots. Decomposition was completed within 180 days in B. papyrifera and 330 days in M. alba. Initially, the decomposition rate was low in B. papyrifera; however, a rapid degradation occurred after 90 days. Species, time, and their interaction significantly affected most of the elements in soil, whereas the effect of habitat was not significant. The faster decomposition rate in B. papyrifera may result in greater turnover of nutrients over a shorter time span, thereby, favoring its colonization in the invaded regions. The difference in litter decomposition process explains the invasion success of B. papyrifera over its confamilial species, M. alba, in urban habitats.     

Analysis of differences in growth of cucumber genotypes under low light conditions in relation to night temperature

Summary Growth of four breeding lines and two cultivars of slicing cucumber with different growth at low temperature and light intensity was analysed in relation to night temperature. Plants were grown from 17 days after sowing at 20°C day temperature and 20, 15 or 10°C night temperature (NT), a light intensity of 24 W/m² visible radiation and a daylength of 8 hours. Data from six successive harvests, ending 47 days after sowing, were analysed according to a MANOVA procedure.RGR, NAR, LAR, SLA and LWR generally decreased with time. Ln W and RGR were largely similar at 20 and 15°C NT, but reduced at 10°C NT. LAR and SLA decreased at each lower NT, whereas LWR increased. NAR was only marginally affected by NT. Significant genotypic differences occurred for 1n W, LAR, SLA, LWR, stem length and percentage of dry matter in leaves and stems at all NT's and for RGR and NAR only at 20°C. Genotypic differences for 1n W could not be explained by differences for RGR, but by differences for initial plant weight.Significant genotype × night temperature interactions were present for LWR. Breeding lines increased LWR in response to lower NT, while that of cultivars remained fairly constant. Implications for breeding are discussed.Abbreviations and definitions L plant length - LA leaf area - W dry weight of the shoot - RGR relative growth rate (the increase in W per unit of time and unit of W) - NAR net assimilation rate (the increase in W per unit of time and unit of LA) - LAR leaf area ratio (the leaf area at time t per unit of W) - SLA specific leaf area (the leaf area at time t per unit of leaf weight) - LWR leaf weight ratio (the leaf weight at time t per unit of W) - RGR NAR × LAR - LAR SLA × LWR - MANOVA multivariate analysis of variance     

Optimization test on growth period of white enoki mushroom（Flammulina velutipes） with plastic bag cultivation under factorized production condition

通过白色金针菇袋式栽培各生产阶段优化试验,用数理统计的方法分析各生产阶段时间对金针菇整个栽培周期与产量的影响,提出最佳方案：当每公斤售价高于5.6元时,采用培养时间26 d、催蕾时间13 d、再生时间10 d、抑制时间6 d的方式进行生产;当售价低于5.6元时,采用培养时间26 d、催蕾时间9 d、再生时间10 d、抑制时间6 d的方式进行生产。     

Cutaneous antibodies in excised skin from channel catfish, Ictalurus punctatus Rafinesque, immune to Ichthyophthirius multifiliis

This study determined whether cutaneous antibodies were present in the excised skin of channel catfish, Ictalurus punctatus Rafinesque, immune to Ichthyophthirius multifiliis Fouquet (Ich). Theronts were immobilized on or near the excised skin from immune fish. The survival of immobilized theronts was significantly reduced after exposure for 8 h to the culture of excised skin from immune fish. Culture fluids from excised skin of immune fish immobilized theronts with a peak in the immobilization titre at 24 h post-exposure. Immobility of theronts in the culture fluid from immune skin was removed after immunoabsorption with theronts. Indirect immunofluorescent staining of theronts treated with culture fluid from excised skin of immune fish revealed strong and uniform fluorescence on the cilia and cell surface of theronts. Western blot analysis of the culture fluid from immune fish revealed a 70-kDa band which corresponded to the molecular weight of catfish immunoglobulin heavy chain. The results of this study show that cutaneous antibodies to Ich theronts were present in and released from the excised skin from fish immune to Ich. Immobilization and killing of the theronts are two characteristics of the antibody response that appear to prevent the successful invasion of theronts into excised skin.     

Effect of end-border condition on small-plot yield of cucumber

Summary Twelve or 14 cultivars and breeding lines (collectively referred to as lines hereafter) of pickling and fresh-market cucumbers (Cucumis sativus L.) were evaluated in 1.5 m long plots. The plots were harvested once when the check lines reached the 10% oversized fruit stage, and total, marketable, and early (oversized) number of fruits per plot was counted. The plots were planted with or without 1.5 m long end-borders to determine whether end-borders can be eliminated in small-plot trials where seed numbers and field space are limiting. Yield in unbordered plots was inflated 5 to 21% over bordered plots, but there was generally no significant effect in the analysis of variance for line x end-border condition. Therefore, end-borders are not needed when comparing different lines.     

基于线激光截面成像的棉花白色异性纤维检测方法

针对棉层表面散布绒毛或游离的纤维细丝,而异性纤维表面光洁无毛的特点,提出了一种基于线激光的样本截面图像获取方法,获取并显示了其微观结构在激光照射下的图像差异.在此基础上,根据激光照射下二者周围有无高亮度的星点,以及星点的分布特征,提出了一种棉花中白色异性纤维的识别算法.实验结果表明,该方法对棉花中典型白色异性纤维的识别率达到了86.9％.     

绿肥苦豆子草中植物生长刺激物质的初步研究

应用生物测定方法,测定了苦豆子草中生物碱的某些植物激素活性.结果表明,喹喏里嗪啶生物碱类具有明显的植物生长刺激作用:促进离体黄瓜子叶的扩张和干物质的积累;促进离体黄瓜子叶根的形成和根的生长.     

生物炭对设施黄瓜根际土壤养分和菌群的影响

以设施黄瓜根际土壤为试验对象,通过每hm2添加5、10、20、40、60 t不同生物炭量作为处理,研究黄瓜结果期养分和细菌群落变化规律,探讨生物炭调控二者间相互作用机制。试验结果表明:在生物炭添加量为5~60 t/hm2时,在黄瓜结果期可不同程度提高根际土壤碱解氮、速效磷、速效钾、有机碳含量和全氮质量比;在20~60 t/hm2时,可明显提高结果盛期根际土壤细菌中变形菌门、放线菌门、厚壁菌门丰度而降低酸杆菌门、绿弯菌门丰度;生物炭通过调控并提高变形菌门γ-变形菌纲、放线菌门放线菌纲放线菌目等细菌数量和比例,促进根际土壤碱解氮、速效磷、速效钾质量比的提高;经综合比较,20 t/hm2的生物炭量处理效果优于其他处理,与对照相比,在结果盛期可提高根际土壤碱解氮质量比39.86%、速效磷质量比135.95%、速效钾质量比81.35%、有机碳质量比82.89%、全氮质量比73.77%。