利用SCIE和JCR数据库检索与分析系统正确选择投稿期刊

简要介绍ISI Web of Knowledge平台中的《科学引文索引》和《期刊引证报告》数据库。同时,为研究工作者较为详细地介绍如何获取SCIE来源期刊信息、如何利用SCIE和JCR检索与分析系统来选择投稿期刊以及如何快捷投稿的方法。     

大青杨群体变异及其选择的研究

大青杨种内群体间变异十分丰富,为了选出最佳群体,直接用于造林,进行了全分布区群体选择的研究。本试验在大兴安岭地区对9个产体群体的大青杨做了生长、生根、抗寒、抗锈病的主要经济性状的测定,然后进行综合评定,选择出最佳群体。     

猴丰1号新菌株的选育及其酯酶同工酶分析

采用子实体组织分离与系统筛选法,从福建猴头的变异株中选育出了定名为“猴丰1号”的新菌株。该菌株菌丝体生长势强,发菌迅速;子实休菇形大,产量高。鲜菇产量比出发株福建猴头增加69.3％,比著名的常山99菌株增加16.8％。酯酶同工酶分析显示:猴丰1号的酯酶谱型与福建猴头相似,但有1条酶带发生了变异。由此说明,它确是源于福建猴头的自然变异株。     

Selection for ovulation rate in rabbits

An experiment of selection for ovulation rate was carried out. Animals were derived from a synthetic line first selected 12 generations for litter size, then 10 generations for uterine capacity. Selection was relaxed for 6 generations. Selection was based on the phenotypic value of ovulation rate with a selection pressure on does of 30%. Males were selected from litters of does with the highest ovulation rate. Males were selected within sire families in order to reduce inbreeding. Ovulation rate was measured in the second gestation by a laparoscopy, 12 days after mating. Each generation had about 80 females and 20 males. Results of three generations of selection were analyzed using Bayesian methods. Marginal posterior distributions of all unknowns were estimated by Gibbs sampling. Heritabilities of ovulation rate (OR), number of implanted embryos (IE), litter size (LS), embryo survival (ES), fetal survival (FS), and prenatal survival (PS) were 0.44, 0.32, 0.11, 0.26, 0.35, and 0.14, respectively. Genetic correlation between OR and LS was 0.56, indicating that selection for ovulation rate can augment litter size. Response to selection for OR was 1.80 ova. Correlated responses in IE and LS were 1.44 and 0.49, respectively. Selection for ovulation rate may be an alternative to improve litter size.     

PrP genotype and lamb birth weight in a scrapie-free environment: Is there an association?

The National Scrapie Plan (NSP) for Great Britain includes selective breeding programmes. These aim to reduce the frequencies of the ovine prion protein (PrP) genotypes at high risk of developing clinical disease (principally those containing the VRQ allele) within the national flock, and select for the low-risk ARR-containing genotypes. The aim of this work was to use available data from embryo transfer programmes in guaranteed scrapie-free environments to investigate whether there was a difference in lamb birth weight associated with the lamb's PrP genotype, which might affect survival. The first analysis utilised data from 355 Cheviot lambs born between 2001 and 2004. The analysis was then repeated using a larger data set of 737 Cheviot, Dorset and Suffolk lambs born between 1999 and 2003. The most important determinants of mean lamb birth weight were litter size, sex and recipient ewe breed, plus lamb breed in the three breed analysis. In both analyses the effects of all these variables are consistent and of the same order of magnitude. In the first analysis there was evidence for an apparent increase in mean lamb birth weight for the ARR-containing genotypes of 0.3 kg (95% C.I. 0.1–0.5 kg). Whereas, in the second data set there was evidence for a decrease in mean lamb birth weight for the VRQ-containing genotypes of − 0.6 kg (95% C.I. − 0.8 to − 0.4 kg). This had been masked in the first analysis by the categorisation of these genotypes with the ARQ/ARQ genotype. Within these flocks, in a scrapie-free environment, neither finding provides support for concerns that selection for low risk ARR-containing genotypes would be detrimental to lamb birth weight, which is considered to be the most important determinant of lamb survival. Extension of this work into field flocks, where scrapie-status cannot be easily assured, will require the collection of sufficient data to adjust for known direct effects as well as any additional potential confounding effects.     

Annual, career or single race records for breeding value estimation in race horses

The racing careers of 2, 3, 4, and 5-year-old Thoroughbreds and French trotters born in France between 1995 and 1999 were analysed. The horses were evaluated on a set of traits, with particular attention to annual or career earnings and number of starts.

As expected, the distributions of earnings corrected for year, age and sex are very skew and thus inappropriate for breeding value estimations. However, Log transformation results in near normal distributions more suitable for this purpose.

Another problem of annual or career earnings required a more complex approach. As most horses did not win any money in France (67% of the trotters and 41% of the Thoroughbreds), it is difficult to correctly evaluate these horses. On the other hand, a linear adjustment of the Log of earnings by the Log of the number of starts (exponential adjustment of the earning index) leads to regression coefficients close to 1. It justified the use of the Log of earnings per start and explained its higher heritability in literature. A quadratic adjustment of the Log of earnings by the Log of the number of starts (sigmoid adjustment of the earning index) improves the adjustment for the Thoroughbred only and should be implemented for these horses.

The probability of a horse to be placed according to the number of starts was also studied. It is shown that the observed percentage of non-placed horses p_s according to the number of starts, s, is in all cases inferior to the expected percentage (p_s < p₁^s). Therefore, races of the same horse cannot be considered as independent events. The percentage of horses placed and the mean earnings for each age can be combined in order to estimate the economical weights for each age class. Economical weights for the French trotter were 0.00, 0.21, 0.40, and 0.39 for 2, 3, 4, and 5-year olds respectively. They were 0.11, 0.45, 0.26 and 0.18 respectively for Thoroughbreds of the same age categories. The current tendency to move from annual or career criteria towards criteria at the race level is discussed. However, the question on how to evaluate the important proportion of horses born that never appeared in a race still remains open and should focus future research.     

Integrating patterns across multiple genetic markers to infer spatial processes

Landscape geneticists can take considerable advantage of differences in the action of evolutionary forces (mutation, migration, selection, and drift) on different loci within the genome. Appropriate comparisons among loci allow researchers to isolate and study the effects of these processes. For example, the organelles are typically inherited maternally (but occasionally paternally), and so will experience migration only when females or seeds disperse (males or pollen in the paternally inherited organelles). Thus, the comparison with biparentally inherited loci allows inferences about the differential migration rates of male vs. female animals or of seeds vs. pollen in plants. Conversely, all biparentally inherited nuclear loci should experience the same levels of migration and drift. Thus, loci that show unusually large levels of variation across the landscape (as compared with the bulk of loci) may be reflecting the action of spatially varying natural selection (local adaptation). Such comparisons are conceptually straightforward, but are complicated by the high intrinsic variability of stochastic neutral processes. Careful statistical analysis is needed to avoid over-interpreting differences among loci. Inferences will be most robust when both genetic and non-genetic data can be integrated, and the collaboration of landscape ecologists with geneticists promises to be particularly fruitful.     

吉林省肉牛品种选择与开发利用初探

结合我省肉牛生产发展的实际，从未来牛肉消费市场需求和进一步开发的可能，就肉牛品种的选择、建立肉牛杂交配套系和配套系的品种组合等方面进行了探讨。     

欧美杨优良无性系选择

经过5年欧美杨优良无性系选育研究，综合生长性状及独立淘汰法，初步选择出适于吉林省中东部河流冲积平地和四旁绿化造林的欧美杨优良无性系为N2、N12。平均单株材积分别是对照的414．9％和398．5％；最大单株树高、胸径分别为7．80m和7．6cm，在造林地表现出明显的生长优势。     

鄂豫陕接壤区山楂品种选优研究

在对鄂豫陕接壤区引种栽培的26个山楂品种进行品比试验和调查分析的基础上,对其中13个引种时间较长,栽培面积较大的品种,采用合理——满意度和多维价值理论的并合规则,进行了综合评价。结果表明,晋京南1号、山东大敞口、大红袍釉山西798202性状表现最佳,可以大力推广;山东大金星和豫北红等次之,可适当发展;北京小金星和朱砂红表现欠佳,应考虑及时淘汰。