种子贮藏蛋白质丰度研究进展

种子贮藏蛋白质丰度研究是种子蛋白质组学研究的重要领域,对于明确蛋白质丰度与种子进化、结构和萌发的分子机制等具有重要意义,同时可应用于种质的分子改良,并能将种子作为转基因产物生产的优良平台。对不同类型种子发育和萌发过程中的贮藏蛋白质丰度研究进展进行了概述,同时介绍了蛋白质丰度研究中贮藏蛋白质的样品制备方法。     

河套地区甜菜含糖与相关因素的调查

调查结果表明,甜菜收获前割擗叶子、过量施氮肥和低密度种植是影响河套地区甜菜糖分的主要因素,可降低含糖3.0～4.0锤度;其次是提前收获,可降低含糖约2.0锤度。该区有利于提高甜菜含糖的适宜保苗密度为6.7～7.5万株/hm2,种肥适宜用量为:氮30～75kg/hm2,磷60～120kg/hm2,钾22.5kg/hm2;追肥适宜用量为:氮120～180kg/hm2,磷45kg/hm2,钾60kg/hm2。同时要注意选用优良品种,它是影响甜菜含糖的内在因素。     

中国长江流域冬麦区小麦品种试验精确度回溯分析

为全面评价长江流域小麦品种区域试验精确度的发展水平,分析了2011—2021年度中国长江流域冬麦区单年单点和一年多点小麦区域试验的试验精确度和品种比较精确度,对产量、穗数、穗粒数、千粒重、生育期、株高、基本苗和最高茎数等性状的试验精确度差异进行了比较。结果表明,长江流域冬麦区单年单点品种试验精确度较好,试验误差变异系数(CEV)在5%和10%以下的试点数占比分别在60%和95%以上,但品种比较精确度(RLSD_0.05)在3%以下的试验比例不到10%,长江上游和中下游单点品种试验RLSD_0.05在10%以下的试点数分别占比约60%和90%。一年多点区域试验精确度和品种比较精确度显著优于单年单点试验,上游和中下游试验平均CEV分别在8%和5%以下。采用试点固定模型时,长江上游和中下游试验平均RLSD_0.05分别为2.19%和1.49%,符合国家小麦品种审定标准对品种比较精确度的要求;但采用试点随机模型时,小麦品种试验尚无法鉴别出品种间3%的产量差异。试验对生育期、株高、基本苗、千粒重和穗数的RLSD_0.05优于产量性状,而最高茎数和穗粒数的RLSD_0.05较低。     

Developing a dynamic growth model for teak plantations in India

Background： Tectono grandis （teak） is one of the most important tropical timber species occurring naturally in India. Appropriate growth models, based on advanced modeling techniques, are not available but are necessary for the successful management of teak stands in the country. Long-term forest planning requires mathematical models and the principles of Dynamical System Theory provide a solid foundation for these.
Methods： The state-space approach makes it possible to accommodate disturbances and avarying environment. In this paper, an attempt has been made to develop a dynamic growth model based on the limited data, consisting of three annual measurements, collected from 22 teak sample plots in Karnataka, Southern India.
Results： A biologically consistent whole-stand growth model has been presented which uses the state-space approach for modelling rates of change of three state-variables viz., dominant height, stems per hectare and stand basal area. Moreover, the model includes a stand volume equation as an output function to estimate this variable at any point in time. Transition functions were fitted separately and simultaneously. Moreover, a continuous autoregressive error structure is also included in the modelling process. For fitting volume equation, generalized method of moments was used to get efficient parameter estimates under heteroscedastic conditions.
Conclusions： A simple model containing few free parameters performed well and is particularly well suited to situations where available data is scarce.     

Proteomic Characterization of Equine Cerebrospinal Fluid

Cerebrospinal fluid (CSF) is a biofluid that is reflective of overall health. Although proteomic profiling of human CSF has been performed in the context of a variety of disease states, this report represents the first comprehensive proteomic analysis of equine CSF. A total of 320 proteins were confidently identified across six healthy horses, and these proteins were further characterized by gene ontology terms mapped in UniProt, and normalized spectral abundance factors were calculated as a measure of relative abundance. Theses results provide an optimized protocol for analysis of equine CSF and lay the groundwork for future studies involving the study of equine CSF in the context of pathogenic disease states.     

Efficiency of presence-absence sampling used to estimate the mean abundance of fish eggs

ABSTRACT:   Statistical properties of estimators relating to the mean abundance of fish eggs were investigated using the data from the presence-absence sampling (PAS) and counting sampling (CS). PAS, which focuses on the presence-absence of eggs in a sample, is more cost-effective yet is unlikely to give more precise estimates than CS, which counts the number of eggs. But when limitations are given on the sampling cost and number of sampling stations, PAS may have advantages. This study shows that the mean square error (MSE) of the maximum likelihood estimator (MLE) based on PAS may become smaller than the MSE of the MLE based on counting data when the number of observations for PAS becomes larger. The observation number for PAS is determined, which minimizes the MSE of a combined estimator from the two MLE under a restriction of the total cost of observation. A dual problem is also solved. It is shown that MSE of the MLE in PAS is a monotone increasing function of the oversight probability. PAS becomes more informative as the distribution of the number of eggs is more aggregated.     

Experimental infections with Lepeophtheirus salmonis (Krøyer) on threespine sticklebacks, Gasterosteus aculeatus L., and juvenile Pacific salmon, Oncorhynchus spp

Experimental infections with Lepeophtheirus salmonis (Krøyer) were established on threespine sticklebacks, Gasterosteus aculeatus L., juvenile pink, Oncorhynchus gorbuscha (Walbaum), and chum, Oncorhynchus keta (Walbaum), salmon. The prevalence and abundance of infections were initially higher on sticklebacks than on either salmon species. The initial prevalence and intensity of infections on chum salmon were higher than those on pink salmon, and declined on both species during louse development. The rate of parasite development to adult stages was similar on all species although development beyond the preadult stage was not observed on sticklebacks. These results confirm previous field observations on the occurrence and development of L. salmonis on threespine sticklebacks.     

Spatial and temporal trends in abundance of Atlantic salmon, Salmo salar, in Newfoundland with emphasis on impacts of the 1992 closure of the commercial fishery

Closure of the Newfoundland commercial Atlantic salmon, Salmo salar L., fishery in 1992 was the most restrictive measure introduced to help rebuild depressed local stocks of salmon. Here, the effects of the closure are evaluated by analysing trends in abundance since 1984, and estimates of survival in both freshwater and marine environments derived from enumeration of salmon at fish counting facilities. While freshwater production of smolts generally has been maintained, marine survival rates remain low (2–10%), and highly variable. Overall, total stock size differs little from that prior to the closure of the commercial salmon fishery. Spawning escapements have increased by a factor of 2 or 3 in some rivers, but in other areas total returns are lower on average than those prior to the fishery closure. Factors other than exploitation are contributing to lack of stock recovery, resulting in continued conservation concerns.     

Survival of reared Atlantic salmon and sea trout in relation to marine conditions of smolt year in the Baltic Sea

The marine survival of hatchery-reared Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) was examined in relation to marine conditions during post-smolt migration and in relation to stock traits. In 1970–2001, Carlin-tagged smolts were released in the Iijoki and Oulujoki rivers, the northern Baltic Sea. When both species were analysed together, the abundance of the three prey fish, herring (Clupea harengus), smelt (Osmerus eperlanus) and vendace (Coregonus albula) correlated positively with the survival of salmonids. In addition, the increase in smolt size appeared to improve the survival rate. Sea surface temperature (SST) may have affected indirectly through the abundance of prey fish during the post-smolt migration of salmon and sea trout. The smelt and vendace showed a statistical effect on survival only when the temperature effects were not included in the models. In sea trout, an increasing smolt length was not significantly correlated with the survival in good herring recruitment years, but in poor years survival increased very rapidly with increasing smolt size. The recapture rates of the salmonids tended to decrease between the years 1970 and 2001. During the same time period, the June SST slightly decreased. The positive correlation between the annual summer SST and recapture rate of salmon may partly explain the decreasing trend in recapture rates. An increase in smolt size did not compensate for the decline in the recapture rate of either species.     

Density effects on length at maturity of walleye pollock <Emphasis Type="Italic">Theragra chalcogramma</Emphasis> off the pacific coast of northern Japan in the 1990s

To determine how stock abundance fluctuations of walleye pollock Theragra chalcogramma are related to variations in reproductive characteristics, the length at 50% maturity of the fish sampled off the Pacific coast of northern Japan from 1990 to 1999 was examined. In both sexes, the fish density increased, and the body length of age-3-5 fish decreased, but the condition factor and the age at 50% maturity showed no clear trend during this period. Male length at 50% maturity decreased, while value for females showed no clear trend. In both sexes, significant negative correlations were found between density index (combined age-3-5) and each body length at age-3-5. Significant positive correlations were seen between each body length at age-3-5 and length at 50% maturity in males. Positive correlation between body length at age-5 and length at 50% maturity was significant in females from 1990 to 1999, except for the samples in 1998. We suggest that the fish density might affect the length at maturity in males and possibly also in females.