优质樱桃番茄高效水氮耦合管理

【目的】水分和氮素是限制作物产量和品质的最重要因素,合理的水肥管理是农业生产高产高效的关键。结合同位素技术研究最优水氮耦合模式,为樱桃番茄生产中合理灌水和施氮,提高番茄果实品质及水分利用效率(WUE)提供科学依据。【方法】以樱桃番茄品种‘千禧’为试验材料,结合稳定同位素技术进行水肥耦合盆栽试验。试验设置3个灌溉水平(W)和3个氮素水平(N),灌溉水平包括90%土壤持水量(充分供水,WH),70%土壤持水量(中度水分胁迫,WM)和50%土壤持水量(重度水分胁迫,WL);氮素水平包括高氮(0.23 g/kg,NH),中氮(0.16 g/kg,NM)和低氮(0.08 g/kg,NL)。试验采用完全随机设计,共9个处理。在灌溉施肥处理60天后收获,分析测定了植株不同部位的生物量及碳、氮、氧同位素含量。【结果】在WH和WM条件下,增加氮素用量使番茄地上部干物质量和叶面积显著增加,增幅分别为19.8%~45.4%和29.4%~106.8%;相同氮素水平下,WH和WM的地上部干物质量和叶面积比WL分别增加24.7%~83.4%和17.6%~90.4%。WHNH处理干物质量和叶面积最高,WMNH处理次之,但后者耗水量低,具有最高的WUE。在WH和WM下,随着氮素用量的增加番茄植株的WUE和氮素含量同步增加。土壤水分水平下降提高了植株的WUE以及δ13C和δ18O,而WUE提高的主要原因是由于叶片气孔的优化调控,植株叶片的δ13C和δ18O可以用于表示灌溉施肥条件下长时间尺度上的WUE信息。WLNM处理提高番茄的糖分含量,而WHNM处理能降低番茄的有机酸含量,从而使番茄口感更好,提高番茄品质。【结论】中度水分胁迫和高氮处理(WMNH)能在促进番茄生长和提高氮素吸收和利用效率的同时减少水分用量,提高番茄的水分利用效率,为本试验的最优水氮耦合处理。     

Correction to: Prevention of hypermelanosis by rearing Japanese flounder Paralichthys olivaceus in net‑lined tanks

Fisheries Science - A correction to this paper has been published: https://doi.org/10.1007/s12562-021-01504-x     

Mammary gland secretory concretions contain non-collagenous bone matrix proteins

Secretory concretions in mammary gland alveoli are commonly of microscopical size. However, some concretions reach clinically palpable dimensions and may occlude teat canals and obstruct milk flow. We studied secretory concretions in sheep, goat and cow mammary glands, using routine histological staining methods, conventional histochemistry and electron microscopy. As concretions frequently mineralize, immunostaining for keratan sulphate and calcium-binding non-collagenous bone matrix proteins (bone sialoprotein, osteocalcin, osteonectin and osteopontin) was performed. Concretions consisted of organic matrix (condensed secretions) with calcium precipitates. Mineralized deposits mostly show concentric organization, bound haematoxylin, and were readily identified in H&E-stained sections. Mineral components of concretions reacted for calcium carbonate and phosphate, organic matrix was found to contain sialoglycan material. Immunohistochemistry revealed bone sialoprotein, osteonectin and keratan sulphate in cow and goat concretions. Osteocalcin was detected in sheep, cow and goat concretions, whilst osteopontin was not identified in any of the specimens studied. Our results indicate the presence of non-collagenous bone matrix proteins (except osteopontin) in mammary gland concretions. These glycoproteins are commonly thought to govern mineralization of organic matrix and are assumed also to promote mineral deposition in mammary gland secretory concretions. Besides caseins, these particular glycoproteins have to be considered as calcium-binding milk proteins.     

The debate on a loss of biodiversity: can we derive evidence from the monitoring of major plant pests and diseases in major crops?

Journal of Plant Diseases and Protection - The European commission directive EC 128/2009 calls for monitoring pests and pathogens of major crops. The monitoring data may be analysed for trends over...     

Immortalized goat milk epithelial cell lines replicate CAEV at high level

Primary milk epithelial cells were isolated from CAEV-uninfected goats and three cell lines designated TIGMEC-1, TIGMEC-2 and TIGMEC-3 were established. The three cell lines retained their morphological characteristics of epithelial cells and expressed specific epithelial cytokeratin marker as well as the immortalizing SV40 large T antigen. The kinetics of growth of TIGMEC1, TIGMEC2 and TIGMEC3 cell lines showed a doubling time of 24-48 hours while the parental cell lines became senescent after the passage 6 in cell culture. Like the parental primary cells, the three cell lines were found to be highly sensitive to CAEV-pBSCA, an infectious molecular clone of CAEV-CO strain, and to a French isolate CAEV-3112. TIGMEC cell lines infected with CAEV-pBSCA became chronically infected producing high virus titers in absence of cytopathic effects. These cell lines may be useful for study of the possible physiological alterations in mammary epithelial cells infected with small ruminant lentiviruses and their consequences on milk quality. On an other hand, these cell lines can be used to study their role in virus transmission and pathogenesis.     

Optimal conditions for visualizing water-conducting pathways in a living tree by the dye injection method

To elucidate the water-conducting pathways in living trees by the dye injection method, suitable sample preparation procedures are needed. We evaluated quantitatively the properties and concentrations of three dyes (acid fuchsin, basic fuchsin and safranin) widely used for this purpose, and determined the optimal conditions required to avoid artifacts after dye injection into the sap stream of Pieris japonica D. Don. Among the dyes tested, an aqueous solution of acid fuchsin at a concentration of 0.1% or more was the most useful for delineating water movement. In non-transpiring stem segments, the vertical movement of acid fuchsin by capillarity and diffusion from the dye injection site was limited. However, acid fuchsin moved rapidly in the horizontal direction by capillarity and diffusion, and most xylem cells were stained within 2 h. A delay of more than 2 h between dye injection and examination of the tissues greatly reduces the precision of the method. Use of the dye injection method without appropriate, well-defined experimental procedures may give rise to misleading information about the functional water-conducting pathway in living trees.     

Reversal of interlaminar signal between sensory and memory processing in monkey temporal cortex

The primate temporal cortex implements visual long-term memory. However, how its interlaminar circuitry executes cognitive computations is poorly understood. Using linear-array multicontact electrodes, we simultaneously recorded unit activities across cortical layers in the perirhinal cortex of macaques performing a pair-association memory task. Cortical layers were estimated on the basis of current source density profiles with histological verifications, and the interlaminar signal flow was determined with cross-correlation analysis between spike trains. During the cue period, canonical "feed-forward" signals flowed from granular to supragranular layers and from supragranular to infragranular layers. During the delay period, however, the signal flow reversed to the "feed-back" direction: from infragranular to supragranular layers. This reversal of signal flow highlights how the temporal cortex differentially recruits its laminar circuits for sensory and mnemonic processing.     

Interspecific hybrids betweenAllium fistulosumandAllium schoenoprasumreveal carotene-rich phenotype

Interspecific hybridization is an effective method to generate a new crop that gains available functions in a short time. Interspecific hybrids (2n= 16) betweenAllium fistulosumL. (2n= 16) andAllium schoenoprasumL. (2n= 16) were produced by reciprocal crossings through ovary culture, but the hybrids were much fewer in the combination usingA. schoenoprasumas a seed plant. All the hybrids have eight long chromosomes originated fromA.fistulosumand eight short chromosomes originated fromA. schoenoprasum. In addition, the hybridity was confirmed by randomly amplified polymorphic DNA (RAPD) analysis and cleaved amplified polymorphic sequence (CAPS) analysis of the rDNA internal transcribed spacer (ITS) region. The interspecific hybrids showed a vigorous growth habit; their foliage was slightly bloomy and deep green. The hybrids did not form bulbs, but rather propagated vegetatively by tillering. Carotene contents of the hybrids and both parents were quantified using high-performance liquid chromatography (HPLC). The contents of all edible parts of the hybrids were approximately seven times higher than those of either parent. These results indicate that the hybrid is a new and carotene-rich vegetable ofAlliumspecies.     

Increasing biodiversity of irrigated rice in Africa by interspecific crossing of Oryza glaberrima (Steud.) × O. sativa indica (L.)

The African rice Oryza glaberrima, traditionally cultivated since more than 3.500 years, is of poor agronomic performance but resistant/tolerant to various stresses and diseases. The introduction of these characters into O. sativa cultivars is difficult since crossing barriers cause spikelet sterility in F1. Backcrossing can restore fertility and recently facilitated the development of fertile O. glaberrima × O. sativa ssp. japonica hybrid progenies for rain fed systems. With the objective to gain access to African rice germplasm for improvement of irrigated rice, crosses were performed with eighteen O. glaberrima and twenty O. sativa ssp. indica accessions. In total about one hundred F1-hybrid grains were obtained. The F1 plants were all completely sterile and backcrossing (BC) to O. sativa was performed in order to restore spikelet fertility. Monitoring of Tog5681 × IR64 hybrid progenies under field conditions revealed a broad genetic diversity within the BC₁ and BC₂ populations. Some BC₁ and BC₂ progeny plants outperformed the O. sativa parent, indicating that the heterozygocity level and complementary gene action after two backcrosses are still sufficient to positively influence plant vigor. Spikelet fertility of progenies was highly variable, but almost complete fertility was already observed within the BC₁F₂ population. High spikelet fertility was preserved in one out of two analyzed BC₁F₃ families and inmost of the BC₂F₃ families. The ability to restore spikelet fertility within few generations and the potential of the genetic diversity present in interspecific progenies facilitates the development of plant types specifically designed for the African irrigated and lowland environment. This revised version was published online in August 2006 with corrections to the Cover Date.