Replacement of dietary fish oil with olive oil in young yellowtail <Emphasis Type="Italic">Seriola quingqueradiata</Emphasis>: effects on growth,muscular fatty acid composition and prevention of dark muscle discoloration during refrigerated storage

Dietary fish oil (FO) was replaced by olive oil (OO) in young yellowtail Seriola quinqueradiata to investigate its effects on growth, muscular fatty acid composition and prevention of color deterioration of dark muscle during storage. Yellowtail were fed one of four diets, where FO (80 g/kg diet) was replaced by OO (0, 25, 50 and 100%) for 40 days. No significant difference in growth was seen among the diet groups. In addition, these experimental diets did not affect the proximate compositions of the dorsal muscle, ventral muscle and the liver in these fish. Serum total protein, glucose and total cholesterol levels did not show significant differences; however, serum triglyceride levels were significantly higher in fish fed 50 and 100% OO diets. Fatty acid composition of ventral muscle reflected the composition of the respective diets. Dark muscle discoloration was reduced in fish fed OO diets after 12 to 18 h during storage at 4°C. Furthermore, the redness value of fresh dark muscle increased depending on the extent of FO replacement. These results indicate that the partial or total dietary replacement of FO with OO prevents discoloration of dark muscle without affecting the growth of young yellowtail after 40 days of feeding.     

红土晒烟的烟叶成熟度标准

根据田间实践经验,详述红土晒烟烟叶成熟时叶色落黄、叶脉色泽、茸毛脱落、叶基离层、茎叶角度的变化和特征,确定鉴别烟叶成熟度标准。     

Ramet population structure of Fargesia nitida in different canopy conditions of the subalpine dark coniferous forest in the Wolong Nature Reserve, China

The bamboo Fargesia nitida, one of the giant panda’s main food sources and the dominant shrub species of the forest understory, is mainly distributed in the dark coniferous belt in western Sichuan and southern Gansu in China. To study the impact of different forest canopy conditions on subalpine dwarf bamboo populations, ramet population structures of clonal Fargesia nitida were surveyed in: forest understory (FU), moderate gap (MG), large gap (LG) and marginal open space (MOS). In order to determine how the ramet structures could be affected and its effects on these four canopy conditions, a field survey of the age structure of Fargesia nitida population, its morphological traits and biomass was conducted in the Abies faxoniana forest situated in the Wolong Nature Reserve, western Sichuan, China. The main results were as follows. First, at the ramet level, the structures of the ramet populations in four canopy conditions were significantly different, and as the canopy density decreased, the mean height, basal diameter and biomass of the populations increased following the order: LG<MG<FU. Second, the biomass proportions of ramets modularly varied with different canopy conditions and leaf biomass proportion was positively related to the canopy density except for the MOS where the biomass proportions of rhizome and roots were both higher than those in the three other canopy conditions. Third, ramet specific leaf weight increased in parallel with the decrease in canopy density. In the MG, the values of the individual leaf biomass and leaf area were the largest, followed by those in the MOS. Both the individual leaf biomass and leaf area were significantly different from those in the FU and LG. Leaf number per ramet was significantly different among the four different canopy conditions and the biggest in the LG. Fourth, the ramet population mortality was the lowest in the FU (Chi-square test, p < 0.01), while there was no significant difference in the average population age (Mann-Whitney test, p > 0.05). All the results indicated that it was not ramet age, but the morphological changes and biomass distribution that exhibited the response of the ramet population of Fargesia nitida to the changed canopy conditions. Translated from Acta Ecologica Sinica, 2006, 40(1): 730–736 [译自: 生态学报]     

赤霉素和低温打破牡丹上胚轴休眠技术研究

采用化学和物理手段处理已生根“凤丹白”牡丹种子，均能打破牡丹种子的上胚轴休眠。200mg／LGA，浸泡已生根牡丹种子2h，其发芽率达90．1％，发芽时间缩短为45d；4℃低温处理已生根牡丹种子20d，发芽率可达70．0％，发芽时间缩短为70d。而大田对照牡丹种子发芽率仅为52．0％，发芽时间长达190d。     

Determining levels of resistance to Tulip Breaking Virus (TBV) in tulip (Tulipa L.) cultivars

Summary The resistance of seven tulip cultivars to tulip breaking virus (TBV) was studied after mechanical inoculation by determining the number of infected plants and the level of virus in these plants over a period of one and a half years. Three cultivars (Apeldoorn, Kees Nelis and Lustige Witwe) appeared to be susceptible. Four cultivars (Cantata, Juan, Madame Lefeber and Princeps) showed a high degree of resistance. The number of infected plants of the latter cultivars was low and virus could not always be detected in the plants at the different sampling dates. Virus could not be detected in these plants after storage. These results indicate that the virus may disappear from or was not detectable in these plants. The levels of infection found are discussed with respect of its significance in studies of TBV in tulips.     

乙烯利和氮肥对玉米基部节间性状和抗折断力的调控研究

在大田条件下,以郑单958为玉米材料,在华北平原研究了乙烯利(0和180g/hm2)和氮肥水平(施氮量0、150、225和300kg/hm2)对玉米节间形态性状、化学成分和抗折断力的影响。结果表明:乙烯利显著提高基部节间最大直径、最小直径、单位节间长度干重和抗折断力,显著降低节间长度和干重。增施氮肥可以提高基部节间最大直径、最小直径、干重、单位节间长度干重和抗折断力,但是N225和N300处理之间差异不显著。乙烯利和氮肥均能显著提高各时期基部节间全氮含量。喷施乙烯利降低了成熟期基部节间纤维素和木质素含量;随着氮肥水平的提高,基部节间半纤维素、纤维素和木质素呈下降趋势。乙烯利和氮肥对2012年的节间直径、节间长度、干重和单位节间长度干重有互作效应,对成熟期节间全氮、半纤维素和纤维含量有互作效应。相关性分析可得,抗折断力与节间最大直径、最小直径、单位节间长度干重和全氮含量呈显著正相关,但是与节间长度、纤维素和木质素含量呈负相关。氮肥施用225kg/hm2的基础上配合拔节期喷施180g/hm2乙烯利可以塑造粗壮矮短的基部节间,有助于提高玉米的抗倒伏能力。     

苹果酸/盐对暗棕壤磷有效性及林木吸收磷的影响

模拟森林凋落物淋洗液中苹果酸/盐浓度范围,研究不同浓度苹果酸/盐对风干暗棕壤中磷有效性的影响及机制,同时采用盆栽试验,在自然暗棕壤中对苹果酸/盐提高磷的有效性进行验证,并探讨苹果酸/盐对落叶松和水曲柳幼苗吸收运输磷素养分的影响。结果表明：苹果酸/盐溶液显著促进A1层和B层风干暗棕壤磷的活化,释放量随浓度增加而增大,但B层释放效应较弱。对A1层和B层风干暗棕壤磷的释放作用苹果酸盐强于同浓度的苹果酸,因此推断,苹果酸/盐促进暗棕壤磷释放的主要机理在于苹果酸阴离子反应。苹果酸/盐对暗棕壤磷的释放具有累加性,土壤磷释放量主要由苹果酸阴离子累积载荷量决定,以苹果酸盐加入时,磷释放量Y与苹果酸阴离子累积载荷量X间回归方程为：Y=-0.0005 X2＋0.1929 X＋1.8192,R2=0.959 3,初步估算森林凋落物层溶出的苹果酸/盐对暗棕壤A1层的磷释放量为3.04kg/（hm2.a）,约相当于当地中龄林年吸收磷量的1/4～1/3。自然暗棕壤中的添加试验也证实,合适浓度苹果酸/盐对提高暗棕壤中磷的有效性具有积极作用。苹果酸/盐还促进落叶松和水曲柳幼苗对磷的吸收运输,以1.0mmol/L或5.0mmol/L浓度时影响最显著,且苹果酸盐的作用强于苹果酸的。     

便携式双滚切刀采茶机运动分析

对于名优茶青的机械化采摘来说,茶青破碎率是判断机械化采摘效果优劣的重要参数。为此,通过分析便携式双滚切刀采茶机刀具的运动轨迹,找到影响茶青破碎率的参数,并分析参数变化对其影响,从而为便携式双滚切刀采茶机的设计提供理论依据。     

Effect of hydrogen cyanamide,mineral oil and thidiazuron in combination with tip pruning on bud break,shoot growth and yield in ‘Bourjasotte Noire’, ‘Col de Damme Noire’ and ‘Noire de Caromb’ figs

Commercial fig production is relatively new to the Mediterranean-type climate Western Cape Province of South Africa. A lack of lateral branch development impedes tree structure development and therefore adequate yields of quality fruit. The chemical rest breaking agents, Lift^® (thidiazuron 3 g L⁻¹) at 6%, Dormex^® (hydrogen cyanamide, 520 g L⁻¹) at 4%, mineral oil at 4% and a combination of mineral oil and Dormex^® at 2% each were evaluated in a split plot design in combination with tip-pruning vs. no-pruning to overcome apical dominance and increase complexity (Experiment 1). During the 2008/2009 season, an additional investigation was conducted to evaluate the use of thidiazuron and hydrogen cyanamide for harvest scheduling (Experiment 2). Dormex^® at 3% and Lift^® at 6%, were applied to dormant trees on 30 June 2008, 3 August 2008, 15 August 2008 or 30 August 2008. In general, Lift^® can be used to increase the number of buds breaking in ‘Bourjasotte Noire’ and ‘Col de Damme Noire’, while tip pruning decreased bud break with a resultant increase in shoot length. Dormex^® and oil combined decreased bud break in these two cultivars but was effective on ‘Noire de Caromb’. Where bud break was increased the resultant N + 1 shoot length was decreased. RBAs increased the number of fruit in both the breba and main crop of ‘Noire de Caromb’, but decreased fruit size of the breba crop. Our data are not conclusive as to what the reason for low lateral bud break might be but leans towards strong AD in seasons with 400 Utah CU or more, but might include some delayed foliation response in seasons with less than 200 Utah CH.     

菲和Cu2+在黑垆土上的吸附及其交互影响

采用批平衡法,研究了菲和Cu2+在黑垆土上的吸附及其交互影响。结果表明,菲和Cu2+在黑垆土上的吸附动力学曲线较好符合一级动力学方程,菲在黑垆土上的吸附主要通过分配作用,其吸附等温曲线符合线性Henry方程,Cu2+的存在抑制菲在黑垆土上的吸附;而Cu2+在黑垆土上的吸附主要通过表面吸附和专性吸附作用,其吸附等温曲线符合Freundlich方程,菲的存在促进了Cu2+的吸附;对菲和Cu2+来说,pH均是影响黑垆土吸附的主要因素,黑垆土对Cu2+的吸附量随着土壤溶液pH值的增加而增加,而对菲的吸附量随着pH增加而降低。