群改杨无性系材性性状遗传分析

对22个群改杨无性系的材性和生长性状进行综合评定,分别采用六项指标（纤维长度、壁腔比、纤维长宽比、密度、树高、胸径）评分法和三项指标（纤维性状、木材密度、材积）评分法,探讨了无性系评定方法。     

渔业配额权流转的制度分析

捕捞限额制度是《中华人民共和国渔业法》规定的一项新的管理制度,它的实施将是我国渔业管理的一次重大改革。在区分该制度中捕捞权与配额权的基础上,着重配额权流转的制度分析;根据我国渔业管理历史、现状及发展要求,提出了在我国即将实施的捕捞限额制度中可适当允许配额权流转及其配额权流转制度框架,包括明确的配额权性质、完善的配额权登记公示、良好的市场中介、完善的社会保障体系等;分析了影响流转的限制因素,如法律障碍、渔区经济发展水平、渔民自身素质等;最后,作者认为我国目前应加强进行对渔民宣传和教育、建立诚信制度、发展渔业第二三产业、消除法律障碍、明确配额权证书的性质、确定配额权位序、建立市场中介服务组织等工作。     

Physicochemical and Microbiological Changes in Dried Small-Spotted Catshark (Scyliorhynus canicula): Contributing to the Developing an Alternative Shark-Based Salted-Dried Seafood Product

Our aim is to contribute to the valorization and optimization of a salted-dried seafood product prepared from small-spotted catshark (Scyliorhynus canicula) akin to “litão seco,” the high-priced, traditional dried blackmouth catshark (Galeus melastomus). This work focused on studying the changes in physicochemical and microbiological parameters of S. canicula salted (for 3 h or 24 h) and dried (convection oven for 24 h or tray drier for 3 h). As expected, salting and drying reduced the water content and water activity, while chloride content in fillets increased. Also, significant but distinct changes in color, namely CIE L* and b*, were observed. Total viable counts were significantly reduced in the salted-dried shark, but the later still presented Staphylococcus aureus, though at marginally acceptable, non-hazardous levels. The abundance of yeasts was reduced by 3 log(cfu/g) in samples oven-dried for 24 h but only by 0.8 log after 3 h in the tray-drier. From our results, salted-dried S. canicula has the required physicochemical characteristics and microbiological quality to be apt for human consumption and is a suitable candidate for becoming a traditional seafood product comparable to “litão seco.”     

烟粉虱溶菌酶基因的鉴定及表达分析

【目的】鉴定烟粉虱（Bemisia tabaci）体内的溶菌酶基因,并对其序列特征、进化关系和表达模式进行分析,探索该基因在烟粉虱应对球孢白僵菌侵染过程中的作用,为进一步解析烟粉虱先天免疫过程提供理论依据。【方法】以第2代高通量测序的结果为依据,比对非冗余核苷酸数据库,筛选E值＜10^-5的基因为烟粉虱溶菌酶基因（lysozyme gene of Bemisia tabaci,BtLyz）,利用ORF Finder预测BtLyz的开放阅读框,并得到氨基酸序列;利用Pfam和SMART预测BtLyz的蛋白质结构域;利用SinglP 4.1 Server预测BtLyz序列的信号肽;利用MEGA6.0软件进行BtLyz的氨基酸多序列比对;利用MEGA6.0软件,对BtLyz与其他昆虫的31个同源蛋白序列进行系统进化分析,并利用邻接法构建系统进化树来进一步分析鉴定该基因;采用实时荧光定量PCR（qRT-PCR）分析球孢白僵菌侵染烟粉虱卵、若虫、成虫后,在12、24、36、48、60 h时目标基因的时空表达模式。【结果】鉴定出烟粉虱4个溶菌酶基因,分别命名为BtLyz1、BtLyz2、BtLyz3和BtLyz4,基因序列全长分别为1 819、1 149、829和928 nt,分别编码159、160、148和160个氨基酸,且均含有信号肽。蛋白质结构分析、氨基酸序列比对和系统进化分析发现,BtLyz1和BtLyz4属于i型溶菌酶,BtLyz2和BtLyz3属于c型溶菌酶。BtLyz-1与豌豆长管蚜ApLyz-i1位于同一进化支上,BtLyz4与柑橘木虱DcLyz-i3和豌豆长管蚜ApLyz-i2位于同一进化支上。BtLyz2和BtLyz3与褐飞虱NlLyz-c1和异色瓢虫HaLyz-c3位于同一进化支上。与对照相比,卵期4个溶菌酶基因和若虫期BtLyz4的相对表达量没有显著变化;若虫期BtLyz1的相对表达量先上调再下调,而后又有所上调的波动趋势,24 h时上调表达最明显,为对照组的4.55倍;成虫期BtLyz1和BtLyz4的相对表达量均为先上调再下调,而后又有所上调的波动趋势,60 h时上调表达最明显,为对照组的11.31和4.21倍;若虫期BtLyz2和BtLyz3的相对表达量均为先上调再下调表达,在诱导24 h时上调表达最明显,为对照组的5.09和8.31倍,而后急剧下调,在60 h时下调表达最明显,为对照组的0.19和0.13倍;成虫期BtLyz2和BtLyz3的相对表达量均为先上调再下调的表达趋势,在24 h时上调最明显,为对照组的5.56和8.84倍。【结论】从烟粉虱体内鉴定了4个溶菌酶基因序列,其中2个为c型溶菌酶序列,2个为i型溶菌酶序列;在球孢白僵菌侵染烟粉虱不同虫态、不同时间后,卵期的相对表达量与对照相比没有显著变化;在若虫和成虫期,不同BtLyzs表现出不同的表达趋势。4个BtLyzs可能参与了烟粉虱对真菌侵染的免疫反应,有可能成为烟粉虱生物防治的潜在新靶标。     

香蕉α-1,4-葡聚糖淀粉磷酸化酶基因家族全基因组鉴定与进化分析

为了研究香蕉(Musa nana Lour.)α-1,4-葡聚糖淀粉磷酸化酶(α-1,4-glucan starch phosphorylase,PHS)基因家族的特征和功能,利用生物信息学方法对香蕉PHS家族进行了全基因组查找、鉴定及相关分析。结果表明,在香蕉中共鉴定出2个成员,Ma PHS1的开放阅读框长度为2 784 bp,编码927个氨基酸,分子质量为104.8 ku,等电点为6.59;Ma PHS2的开放阅读框长度为2 517 bp,编码838个氨基酸,分子质量为95.09 ku,等电点为6.09。Ma PHS1和Ma PHS2分别含有17个和15个外显子;Ma PHS1和Ma PHS2均含有淀粉磷酸化酶的保守性基序,进化过程中比较保守。     

From the micro-scale to the habitat: Assessment of soil bacterial community structure as shown by soil structure directed sampling

Natural structural units of a luvisol under maize crop were studied to assess if soil structure directed sampling could improve the understanding of arrangements of bacteria in spatially constraint location. Three habitats were defined: (i) soil around fine lateral roots (rhizo-aggregates), (ii) soil close to basal roots (core clods) and (iii) unplanted soil between rows (bare soil clods). These habitats were also investigated with maize plants resulting from Azospirillum lipoferum CRT1 inoculated seeds as a model of enhanced fine root system. Rhizo-aggregates were clearly separated from each other (disconnected habitat) in contrast to micro-samples (fragments) from clods, which belong to cohesive macro-structures. Genetic fingerprints on metagenomic extracts were used to characterize the structure of bacterial communities on 95 micro-samples from the three habitats. For eubacteria, automated RISA (Ribosomal Intergenic Spacer Analysis) of ITS (Internal Transcribed Spacer) profiles were performed. PCR-RFLP on nifH gene were used to describe the N-fixer guilds. Exploratory multivariate analyses (PCA and MDS) revealed bacterial community patterns in the sampled habitats. On the basis of ITS profiles, rhizo-aggregates harboured closely related communities, distant from those of the unplanted soil, and each sampled rhizo-aggregate could therefore be considered as a sub-unit of the whole macro-habitat, comprising all the fine roots. The observed low dissimilarity of disconnected rhizo-aggregates is likely to result from the direct influence of maize root tips on the recruitment of rhizosphere bacteria. Molecular fingerprints of nifH from basal root clods (core) were more similar to bare soil than to rhizo-aggregates, indicating similar ecological conditions without, or with, at least, poor maize exudating root influence. Although our study was performed on a limited number of situations, the distribution of bacteria was revealed to be patterned by soil structure units, which is a first step to improve the modelling of microbial ecology in soils.     

Floristic and ecological differences between recent and ancient forests growing on non-acidic soils

The aim of this work was to investigate differences in soil chemistry and understory composition between recent forests (sites afforested in the last 170 years) and ancient forests growing on non-acidic soils. The study was carried out on hardwood forests at moderate elevation (400–600 m asl) in the Jura Mountains (N.E. France) on four main pedological substrates with different characteristics. The floristic composition of 127 stands from recent forests (n = 65) or ancient forests (n = 62) was surveyed. Some functional traits and the Ellenberg indicator values of the surveyed species were recorded. In addition, the topsoil from 30 stands was analysed. The composition of the flora was analysed by Detrended Correspondence Analysis and the species which were typical of one class of forest age were identified using a chi-square (χ²) test. The difference between forest classes for plant traits, their indicator values, or soil chemistry was tested using the generalized linear model and Bonferroni t-tests (or Kruskall–Wallis tests). The floristic composition of the ancient forests was significantly different from that of the recent forests and was characterized by a high occurrence of shrub species in recent forests. These differences were associated with higher specific leaf area, low-range seeds dispersal, and some life forms like geophytes. There was no clear difference in soil chemistry between the two classes of forests, except for δ¹⁵N values. The weakness of the difference in the soil between ancient and recent forests suggested that changes in soil chemistry caused by a former agricultural land use were not responsible for the differences in understory composition recorded. The differences in functional traits between the two forest classes supported this conclusion. We finally concluded that (i) past land use modifies the vegetation composition of current forests, even on neutral soils and that (ii) in our context, biological filters were probably responsible for these changes.     

邳州部分路段水杉死亡原因探析及复壮措施

近几年邳州市部分路段水杉出现死亡症状。从水杉生长环境的变化、发病水杉与正常水杉生长状况的比较两个方面分析其死亡原因,并提出复壮措施。     

Numerical Analysis of Acoustic Environment with Finite Element Method

The acoustic environment of highway tunnel is complex and has influences on the driving safety and comfort. In case of emergency, evacuation information is difficult to transfer. Finite element method is used for calculating highway tunnel acoustic modal and attenuation characteristics. The results show that acoustic mode of highway tunnel has symmetry in the horizontal pressure amplitude of symmetry regional is equal and phase is the same or opposite. The higher modal frequency, the greater sound pressure amplitude is, and the effect of tunnel length on modal frequency is smaller. Decay curves of pressure level at each point in the highway tunnel over time are nonlinear. After the source excitation, in 1.5 s, attenuation rate is faster than that of few seconds later and the attenuation time of sound pressure level 30 dB is 5.5 to 7 s.     

Direct and maternal additive effects are not the main determinants of Iberian piglet perinatal mortality

Data of 127,800 Iberian piglets were used to study genetic parameters of mortality at birth at the piglet level. These records proceed from three data sets: 4,987 litter of 2,156 sows of a dam line, 2,768 litter of 817 sows of a complete diallel cross between four Iberian strains and 7,153 litter of 2,113 sows of the Torbiscal composite line. Perinatal mortality was considered as a binary trait, and Bayesian threshold animal models were fitted to separately analyse the three data sets. The posterior means of direct heritability were 0.010, 0.004 and 0.003, and those of maternal heritability were 0.034, 0.011 and 0.014 for dam line, diallel cross and Torbiscal line, respectively. Important effects of litter size and parity order were inferred in the three data sets, of within‐breed cross‐breeding parameters in the diallel cross and of sex and sow handling in the Torbiscal line Therefore, the inclusion of perinatal mortality in the objective of selection is questionable in this breed and strategies for reducing piglet mortality successful in other breeds should be considered.