《中兽医医药杂志》2001-2010年载文计量学分析与研究

依托＂中国知网＂的海量文献信息,采用文献计量学方法,利用中国引文数据库、中国学术期刊网络出版总库对《中兽医医药杂志》2001-2010年的发文量、下载量、被引情况、高被引论文栏目及学科分布、作者分布情况、基金论文比等相关指标进行统计分析,探索其中的变化趋势,并对其原因进行分析,以期为编辑部调整办刊及经营策略、更加科学地选题组稿、优化版面及栏目设计等提供参考依据。     

我国核桃种质资源及育种研究进展

本文概述了我国核桃的起源、分布、品种分类、种质资源以及品种选育方面的研究进展     

利用分子标记辅助选择培育水稻广亲和保持系

[目的]利用分子标记辅助选择培育水稻广亲和保持系,为水稻籼粳亚种杂种优势利用提供参考.[方法]用4个不育系博A、天A、青A、62A与24个水稻姊妹系杂交,测定其恢保性;同时利用与Sn5紧密连锁的SSR标记GXR6对24个姊妹系进行检测;再通过籼粳测交验证其亲和性.[结果]24个姊妹系中除B11、B13、B14、B15外,其余B1～B10、B12、B 16～B24等20个姊妹系花粉不育度均达100.0％,对4个不育系博A、青A、天A、62A均保持不育.SSR分子标记检测结果显示,B1、B2、B4～B7、B10～B12、B14～B16、B 18～B20、B22、B23等17个姊妹系均携带187R的广亲和基因Sn5;但与日本晴和巴利拉测交验证结果显示,仅B1、B4具有亲和性,B9虽未携带Sn5却具有亲和性,其测交组合F1代植株结实率极显著高于桂B测交的结实率(P＜0.01)而低于测验种自身的结实率(桂B结实率79.79％,日本晴76.87％,巴利拉73.65％),B1、B4和B9属于中亲和力品系.[结论]筛选获得的广亲和保持系B1、B4和B9,可用来改造现有不育系,充分发挥籼粳亚种杂种优势,提高杂交水稻产量,具有较好的应用前景.     

树种选择与配置对森林生态系统服务的影响

我国森林面积和蓄积量连续增长,但造林树种单一、林分幼龄化、径级持续偏小、单位面积蓄积量低。在气候变化挑战及全球经济一体化大背景下,如何发挥森林在木材生产、生物多样性保护、固碳、涵养水源及社会文化等方面的多重服务功能以满足经济社会发展对森林的多元化需求,是我国现代林业建设的当务之急。文中通过梳理国内外相关文献,分析不同树种与配置模式和不同森林经营选择对森林生态系统服务的影响,以及对森林生态系统服务影响的模拟预测方法与工具,进而总结当前研究与实践的总体趋势,以期为我国树种选择及其优化配置、增强森林生态系统服务功能提供决策参考。     

Intra‐cohort cannibalism in early life stages of pikeperch

Cannibalism has been described in 390 teleost fish species belonging to 104 families. In rearing conditions, intra‐cohort cannibalism is one of the major bottlenecks during the early life stages of pikeperch (Sander lucioperca). This study aims to describe precisely the occurrence and the onset of cannibalism of this species during the first two post‐hatching months. In a first step, the cannibalistic behaviour was analysed through observations in three experiments. In each experiment, the number of cannibalistic cases was similar. From 14 to 48 days post‐hatching (dph), more than 60 % of prey ingestions were realized by tail‐first, but after 48 dph, the number of prey ingestions by head‐first increased. In a second step, the behavioural sequence exhibited to attack and to capture a conspecific was analysed, taking into account the size ratio between the cannibal and its prey. The behavioural sequence to capture was always the same, similar to a predatory sequence and it seems that the cannibal chose its prey about 10 s before attacking. Moreover, prey choice by a cannibal was based more on the size ratio between the cannibal and its prey than the previous activity of the potential prey. These new results could lead to solutions to decrease cannibalism in pikeperch rearing.     

Identification of a major gene (Mex-1) from Coffea canephora conferring resistance to Meloidogyne exigua in Coffea arabica

Among the most damaging root-knot nematode species, Meloidogyne exigua is especially common in Latin America and constitutes a major agronomic constraint in all major coffee-growing ( Coffea arabica ) areas. Growing nematode-resistant coffee represents the most promising option for control of the pest. The present study aimed to determine the mode of inheritance of the M. exigua resistance transferred into C. arabica from a related species, Coffea canephora , and to identify associated molecular markers. Segregation data analysis of F ₂ progeny derived from a cross between the resistant introgression line T5296 and the susceptible accession Et6 showed that the resistance to M. exigua is controlled by a simply inherited major gene (designated the Mex -1 locus). The gall index distribution exhibited by the F ₂ individuals suggested incomplete dominant expression. Fourteen AFLP markers were found associated with the resistance to M. exigua and a localized genetic map of the chromosome segment carrying Mex -1 was constructed. Furthermore, the association of the identified AFLP markers with Mex -1 was confirmed by analysis of a set of genotypes involving 28 introgression Arabica lines either resistant or susceptible to M. exigua in field conditions. These results represent an important starting point to enhance backcross breeding programmes and to perform an early selection of resistant seedlings.     

Inter-and intraracial hybridization and selection for seed yield in early generations of common bean,Phaseolus vulgaris L.

Summary Five parents from each of four race groups of common bean (Phaseolus vulgaris L.) were hybridized to produce five crosses within each group. Also, five crosses were made for each of the six possible combinations among four groups. Parents, F₁ and F₂, and parents, F₂ and F₃ were evaluated for seed yield in 1990 and 1991, respecitively, at two locations in Colombia.Yield of parents belonging to Middle American races and crosses among them was higher than that of races of Andean origin. Positive correlations were found among the mid-parent value, F₁, F₂ and F₃. Also, the mid-parent value predicted the mean seed yield of all possible lines that could be derived from the F-generation in 42 out of 47 crosses. Four crosses, all between common bean races of Andean and Middle American origin, indicated a possible loss of favorable epistatic parental alleles. On average, mean yield of interracial F₁ hybrids was higher than that of intraracial ones.Positive heteroris (26.4%–123.8%) over the mid-parent in 31 crosses, and F₁s yielding higher (23.7%–91.8%) than the high parent in 20 crosses and yielding higher (22.1%–53.2%) than the highest control among all parents (MAM 13) in 12 crosses, were found. Heritability, estimated by the parent-offspring regression, ranged from 0.42± 0.07 to 0.49±0.04. Expected and realized gains from selection (at 20% selection pressure) ranged from 10.3% to 21.0% over the mean of F₁ hybrids and F₂ and F₃ population bulks.     

23个杨树无性系引种试验研究

通过对白城４１＃等２３个杨树无性系进行育苗、造林随机区组试验、差异性分析结果指出,各无性系之间苗期的高、径生长量都具有显著差异,但造林后第４ａ差异不显著（α〈０．０５）。系统聚类分析指出,２３个无性系可以分为６类：Ⅰ白城小黑等５个;Ⅱ桓仁等３个;Ⅲ金县等４个;Ⅳ箭杆杨;Ⅴ昌图等７个;Ⅵ健康杨等３个,在此基础上综合评价筛选出适合科尔沁沙地栽植的无性系为健杨、法库１＃、兴城、白林２＃、白城４１＃、鞍杂     

具有交易费用和马氏调制的均值-方差组合选择

研究了均值-方差准则下,最优投资组合选择问题.投资者为了增加财富它可以在金融市场上投资.金融市场由一个无风险资产和n个带跳的风险资产组成,并假设金融市场具有马氏调制,买卖风险资产时,考虑交易费用.目标是,在终值财富的均值等于d的限制下,使终值财富的方差最小,即均值-方差组合选择问题.应用随机控制的理论解决该问题,获得了最优的投资策略和有效边界.     

不同种源西南桦在云南景东的生长差异

从西南桦分布区内选择的13个种源在南亚热带山地进行筛选试验的结果表明:不同种源在生长、产量、形态 特征上都有很大差异。以胸径、树高、材积和干形等为指标,用坐标综合评定方法对13个不同种源进行综合评定, 结果表明:潞西、屏边和镇源3个种源生长和形态等各种特征都比其它种源好,位列前3名,是当地适生的好种源; 西马、龙陵和百色种源表现较好,属可利用种源;腾冲和西莲种源表现差,不好利用;平果、凭祥、靖西、景洪和田林5 种源表现一般,最好不发展。