优化水肥与传统水肥对冬小麦叶片生长、群体光分布及产量的影响

与传统水肥相比 ,优化水肥、秸秆还田优化水肥处理冬小麦主茎上第四叶叶面积和厚度略微减少 ,叶倾角、消光系数、各层透光率与传统水肥处理差异很小 ,株形尚好。优化水肥和秸秆还田优化水肥处理冬小麦籽粒产量略高于传统水肥处理。与优化水肥处理相比 ,秸秆还田优化水肥处理有利于增加光合面积 ,提高叶片质量 ,改善冠层结构和光分布状况 ,增加单位面积籽粒产量。     

双连栋节能日光温室的设计建造及其温光性能观测

通过对温室墙体材料、方位角、采光屋面角、后屋面角、保温覆盖材料、温室辅助加热等进行分析计算,设计并建造了一种双连栋日光温室,经过对温室温光性能观测,其保温能力最高达18℃,透光率最高84%,正常年份辅助加温时间60~70 d,其保温能力好,节能效率高,土地使用率较高,是一种适合在北方发展的符合国情的温室形式,值得进一步的探索和研究。     

大兴安岭不同演替阶段白桦种群光合生理生态特征

应用LI-6400光合作用测定系统,研究了大兴安岭不同演替阶段白桦光合生理生态学特征。结果表明:无论是最大净光合速率,还是表观最大量子效率,非演替顶极群落中的白桦[(7 79μmol/(m2·s)、0 0698mol/mol)]都大于演替顶极群落中的白桦[(7 59μmol/(m2·s)、0 0457mol/mol)],这表明非演替顶极群落中白桦的实际光合能力和潜在光合能力都大于演替顶极群落中的白桦。2个不同演替阶段中白桦的光饱和点相差不大,但是演替顶极群落中白桦的光补偿点却低于非演替顶极群落,这表明演替顶极群落中白桦的呼吸作用有所下降。此研究结果揭示了大兴安岭顶极群落中白桦退出主林层的生理生态学机制。     

Effects of hereditary retinal degeneration due to a CEP290 mutation on the feline pupillary light reflex

Objective To understand how progressive rod cone degeneration due to a mutation in CEP290 affects the pupillary light reflex (PLR) in domestic cats. Animals studied Domestic cats identified as either normal wildtype (WT; n = 6), or homozygous for the rdAc mutation in CEP290 and having early stage retinal degeneration (stage 2, S2; n = 4), or advanced retinal degeneration (S4; n = 6). Methods The effect of light on pupil size was measured over a series of 10‐s pulses of white and chromatic light in cats lightly sedated with medetomidine. Results In WT cats, the PLR was characterized by a pronounced initial constriction that rapidly re‐dilated during the stimulus (pupil escape), to a stable or sustained constriction. There was then a marked constriction at stimulus offset. Each component of the PLR was retained in affected cats, but with progressively reduced irradiance sensitivity from early to advanced retinal disease. Conclusions The PLR of cats had multiple phases, with a remarkably high‐amplitude ‘paradoxical’ off‐constriction even in the absence of retinal disease. In rdAc cats, reduced irradiance sensitivity was consistent with progressive loss of rod and cone function. Based on previously characterized retinal pathology, this suggests the visual streak of the retina has a proportionally large contribution to PLR input. These findings support the hypothesis that the efficacy of planned therapeutic trials can be determined by careful evaluation of the PLR in cats.     

Behavioural response of farmed Atlantic salmon (Salmo salar L.) to artificial underwater lights: Wavelet analysis of acoustic telemetry data

Biological, environmental, economic and ethical issues become increasingly pertinent as the scale of the aquaculture industry expands. This study used acoustic telemetry data and wavelet analysis to investigate behavioural patterns of Atlantic salmon when exposed to artificial underwater lights in fully stocked production cages located on the Norwegian coast. Using acoustic depth sensor tags, time series of depth registrations were gathered from 21 individual salmon distributed over three cages during a five-month experimental period. Underwater lights, normally used to suppress pre-harvest sexual maturation amongst Atlantic salmon, were installed at eight-metre depth and switched on in the middle of the experimental period. Swimming depth registrations initially showed a typical diurnal swimming behaviour, manifested by registrations generally in deeper waters during day-time than during night-time. The diurnal swimming behaviour abruptly ceased after the onset of lights. The change in swimming behaviour was detected by wavelet analysis and coincided with the introduction of underwater lights. Results from this study demonstrate the utility of wavelet analysis as a timely surveillance tool when investigating behavioural patterns of a periodic nature in fish, and specifically the individual response of farmed salmon to artificial lighting in a genuine industrial setting.     

Wheat and barley cultivars show plant traits acclimation and increase grain yield under simulated shade in Mediterranean conditions

Agroforestry systems are reported as climate‐resilient productive systems, but it is yet unclear how tree shade affects crops performance. The aim of this work was to assess how the phenology, plant traits and grain yield of wheat and barley were affected by shade. In an open greenhouse experiment, we cultivated in pots nine cultivars differing in precocity for each species and imposed three artificial shading levels (S0 ~ 0%, S1 ~ 25%, S2 ~ 50%) at the start of cereal booting. Our results showed that shade speeded up first growth stages in both species, until the starting of milk development. Barley showed consistent phenological responses to the three irradiance levels among cultivars, but not wheat that showed larger phenological differences among cultivars at moderate shade. Deep shade prolonged the time needed for wheat grain ripening. Both species increased grain yield by 15%–20% with shade, driven by shade‐acclimations of plant traits that differed among species. For wheat, grain yield was determined by the assemblage of traits that contribute to yield, such as grain weight, precocity and non‐photochemical quenching, while, for barley, SPAD value, precocity to reach phenological stages, grains per spike and plant height had the strongest influence. These traits varied widely among cultivars and seem of interest to identify best suited cultivars for shading conditions of Mediterranean agroforestry systems.     

Morphological study of the lingual papillae in the fruit bat (Rousettus amplexicaudatus) by scanning electron microscopy and light microscopy

This study was carried on the tongues of ten normal, healthy and adult fruit bats (Rousettus amplexicaudatus, also known as the nyap biasa bat) in Yogyakarta, Java Island, Indonesia. The tongue was protrusible, elongated and flat with a rounded apex, and its width and thickness increased gradually towards to lingual root. There were two main types of lingual papillae, mechanical (filiform) and gustatory (fungiform and circumvallate). The tongue was divided into three parts (apex, corpus and radix), and then, each part was subdivided into three regions (two lateral regions and a median region). There were six subtypes of the filiform papillae—three types on the anterior part (small, scale-like and giant), one type on the middle part (leaf-like papillae) and two types on the posterior part (rosette-shaped filiform and conical filiform papillae)—in addition to transitional papillae presented on the corpus and radix. Two types of gustatory papillae were represented by a small number of fungiform papillae that are scattered among the filiform papillae on the lingual apex and corpus, while three circumvallate papillae on the posterior part are arranged in a “V” shape pointing directly at the larynx.     

我国谷子轻简高效生产技术研究进展

随着我国现代农业的快速推进、土地流转加快,新型经营主体对谷子生产技术提出了规模化、轻简化的强烈需求,传统生产技术已难以满足。近年来科研人员进行了谷子轻简化生产技术的研发,目前我国谷子轻简高效生产技术已取得突破性进展。综述并分析了我国谷子轻简高效生产技术的发展现状,包括谷子化学间苗与除草技术、抗除草剂谷子育种与简化栽培技术、配套谷子农业机械以及谷子轻简高效生产技术集成等,调研分析了谷子轻简高效生产技术模式的应用效果,并针对当前我国谷子轻简高效生产技术发展中存在的问题提出相关建议,以期为我国谷子轻简高效生产提供理论基础。     

中国太阳日辐射量分布图研究

太阳日辐射量(mol/(m2·d))记录每一天里所接受的光合有效光子通量,是一种非常有效地度量与植物生长相关的太阳光照的方法。利用中国45个气象观测站点在1973—2002年期间观测的水平面太阳辐射数据,建立了中国太阳日辐射图。这一地图记录了各个地区在每个月所接受的太阳日辐射量月平均值。每年12月,北部地区太阳日辐射量最低,为5~10 mol/(m2·d);然而,每年的5月至7月,西北地区的太阳日辐射量最高,为45~50 mol/(m2·d)。每年10月至次年3月,太阳日辐射量大致呈东西向的水平条带状分布。每年5月至8月,中国东西部地区太阳日辐射量分布差异较大。在每年春分、秋分时节,太阳日辐射量变化最大。中国太阳日辐射图可以估测各个地区在每个月所接受的太阳日辐射量,同时也可以为温室人工光照的使用提供参考。