水稻SSR及Indel分子标记在籼粳交F_2群体的偏分离分析

偏分离是指遗传标记的观察频率偏离预期的孟德尔式分离频率的现象,其可以增加群体中杂合等位基因或者异型染色体的频率,是一种重要的进化动力。本研究以粳稻材料日本晴及籼稻材料千粒稻为亲本获得80株F2群体,构建了一张含92对SSR标记和44对Indel标记的遗传图谱。结果发现,F2群体中,116个标记表现为偏分离现象(85.29%),其中79个极度偏分离(68.10%)。偏分离标记中由合子偏分离引起的有20个,配子偏分离引起的93个,RM3484,RM3702,os7-38.4既不是由合子选择引起也不是由配子选择引起。Indel标记偏分离率(97.72%)明显高于SSR标记偏分离率(79.34%),且所有偏分离标记皆偏向于千粒稻。结合本研究结果,对偏分离现象产生的原因进行了分析。     

用SSR分子标记定位普通小麦品种正科1号中的抗麦蚜基因

通过对抗蚜小麦品种正科1号×感蚜品种石4185的F2分离群体(495株)进行田间自然抗蚜调查,发现正科1号的抗蚜虫性状受显性单基因控制,鉴定出的这个显性抗蚜基因,暂定名为dnY。运用分离群体分组法(BSA)筛选到3个在抗感亲本间表现多态性的SSR标记(Xwms350、Xgwm437、Xgwm44);进一步将该基因定位于7DS上,距离该基因最近的标记为Xgwm44,遗传距离3.29 c M。同时讨论了基因dnY在小麦遗传改良以桨标记在抗蚜基因标记辅助选择中的作用。     

玉米磷效率的主基因+多基因混合遗传分析

运用主基因+多基因模型分离分析法,对玉米082×掖107组合的磷效率P1、P2、F1、F2和F2:3五世代联合遗传分析.结果表明:玉米磷效率遗传符合一对加性-显性主基因+加性-显性多基因混合模型.F2和F2:3估计的主基因的遗传力分别为61.41%和62.59%,估计的微效多基因遗传力分别为38.60%和37.42%.主基因的遗传力都高于微效多基因,玉米082×掖107组合磷效率的遗传主要由一对加性-显性主基因控制,同时微效基因对玉米磷效率的影响较大.表明可以利用磷效率高的玉米亲本配制杂交组合,并且在育种的早期阶段选育磷效率高的单株或家系,以获得磷效率高的栽培玉米品种.     

Evidence of a major genetic factor conditioning freezing sensitivity in winter wheat

The inheritance of freezing tolerance in F₂‐derived F₄ populations from all possible crosses of winter wheat cultivars ‘Kestrel’, ‘Eltan’, ‘Tiber’, ‘Froid’ and germplasm line Oregon Feed Wheat #5 (ORFW) was investigated. When frozen to a temperature equal to the LT₅₀ of the least freezing tolerant parent (ORFW), survival frequency distributions were skewed to greater survival in six of the 10 crosses, however, very few of the progeny from the four crosses to ORFW survived. The inheritance of this freezing sensitivity was investigated with freezing of F_2:4 populations from the crosses of ORFW to ‘Eltan’ or ‘Tiber’ to the LT₅₀ of the hardier parent. Very few of the F_2:4 populations survived as well as ‘Eltan’ or ‘Tiber’, indicating a small number of strongly dominant genetic factors in ORFW that conditioned freezing sensitivity. Molecular analysis indicated these factors were not spring‐type vernalization alleles.     

偏分离条件下牙鲆生长性状QTL的主成分定位

本研究利用有丝分裂雌核发育建立牙鲆(Paralichthys olivaceus)双单倍体(Doubled Haploids,DH)群体,对牙鲆体重、全长、背鳍长、腹鳍长、体高、尾柄高、头高和躯干长共8组表型性状标准化处理后,进行主成分分析,得到可解释全部性状90.4%的表型主成分性状。然后,基于JoinMap 4、MapDisto、JoinMap 4-DistortedMap、MapDisto-DistortedMap构建4个连锁图谱,用偏分离标记矫正数量性状位点(Quantitative Trait Locus,QTL)基因型条件概率,采用Bayesian模型选择方法定位牙鲆表型主成分性状的加性QTL和上位性QTL。结果表明,用不同方法构建的遗传图谱和表型主成分性状QTL定位结果均有所不同。在图谱构建中,与基于JoinMap 4构建的图谱相比,基于MapDisto构建的图谱中偏分离标记的相对位置和遗传距离都发生了变化,甚至有5个偏分离标记没有被定位到相应的连锁群上;相对于基于JoinMap 4和MapDisto构建的图谱,经DistortedMap校正后的图谱中偏分离标记的相对位置没有发生变化,但是偏分离标记间遗传距离发生了变化。另外,在4个图谱中都检测到3个加性QTL,分别位于6号连锁群上,可解释表型变异的12.95%、14.85%、11.56%和11.76%,9号、22号连锁群上,具有负向加性效应;9号连锁群上,可解释表型变异的13.86%、13.27%、11.17%和11.25%,具有负向加性效应;22号连锁群上,可解释表型变异的5.68%、4.36%、4.97%和3.58%,具有正向加性效应。同时,分别检测到28对、19对、29对和20对上位性QTL,主要分布在6号、7号、9号、17号、20号和22号连锁群上,可解释表型主成分性状变异的2.19%~17.62%、2.40%~22.26%、2.08%~26.0%、3.16%~22.05%。研究结果表明,基于MapDisto软件构建、经DistortedMap软件包矫正后的图谱,定位结果更加准确,但仍需进一步验证。     

双清管器间充氮气置换在输气管道投产中应用

在输气管道投产中，最关键的环节是管道的天然转换工作，承担着为首都供的华北油田北京供气复线工程，为确保安全投产，采用了双清管器间加充氮气形供气任务的华北油田北京供气复线工程，为确保安全投产，采用了双清管器间加充氮气形成隔离带进行；转换的方法，该管道长６４．１６ｋｍ、管ＴＣＡ ５２９，，沿线穿越铁路，公路、河流较多，地处村庄广布、人口稠密地区，介绍了双清管器间加充氮气隔离置换工艺的实施过程，包括清管器     

Park availability,accessibility, and attractiveness in relation to the least and most vulnerable inhabitants

With this paper, we enrich the environmental justice debate by investigating differences in the provision of parks in Lodz, Poland, at three levels: availability, accessibility, and attractiveness. A park is ‘available’ when it exists within a suitable distance from where we live; it is ‘accessible’ when we feel that we are welcome there, and we can freely reach and safely use this park; it is ‘attractive’ when we willingly want to use it and spend time there. Our research hypothesis is that the most vulnerable groups of inhabitants concentrate around parks whose provision is affected by the largest number of barriers at each of the three levels, while the least vulnerable benefit from the vicinity of parks that are the least affected. Apart from the statistical analysis – the correlation between the indicators that represent the three levels of park provision and those that represent the most and least economically vulnerable using Pearson’s coefficient – we scrutinize three case study parks. The results confirm that there are inequalities at the level of attractiveness for the most vulnerable groups; meanwhile, no statistically significant results were recorded for the least vulnerable groups. The differences would probably be more explicit had socioeconomic segregation been higher in Lodz. The results may also be influenced by the unique postsocialist and postindustrial legacy of our city. The ongoing revitalization of the city center and the increased activity of developers may exclude the most vulnerable inhabitants and deepen segregation.     

Interspecific competition between restocked 0+ salmon parr (Salmo salar) and native fish species in a large European river

Atlantic salmon populations have experienced strong declines in most large European rivers. In the Loire Basin, France, a major restocking effort has been carried out on the Allier River to reduce the wild population decline. This study aimed at investigating the trophic insertion of hatchery‐reared salmon parr and whether they compete for resources with native fish species. For this purpose, two riffles located in the upstream and downstream parts of the restocked area have been surveyed monthly following the initial 0+ salmon fry release. 0+ parr densities remained high upstream, with autumnal values greater than those recommended to maximise smolt production. In contrast, downstream densities declined to weak values despite a faster increase in size, probably mainly due to summer temperatures rising above the discomfort threshold. By analysing the vulnerability to predation of ingested invertebrate prey, we highlighted the role of habitat constraints in driving most of the different fish species to a likely opportunistic utilisation of available food resources. As a result, species such as stone loaches and barbel juveniles exhibited narrow trophic niches and high overlaps with 0+ parr. Nonetheless, both abundant prey resources and spatial or temporal habitat segregation have limited interspecific competition, enabling competitive coexistence of sympatric species, except for barbel juveniles in certain circumstances. Therefore, our findings suggest that future restocking programmes should carefully consider the thermal and hydraulic conditions regarding further smolt production as well as their general trophic context, according to the potential inconvenience of restocked salmon fry arrival relative to native species.     

应用ISSR和SRAP标记构建李遗传连锁图谱

[目的]李(Prunus salicina L.)是我国东北地区极具经济开发前景的树种,具有重要的社会、经济价值.通过分子标记技术对李进行遗传连锁图谱构建,为李新品种选育提供理论基础.[方法]以吉林6号和龙园秋李为作图亲本,利用SSR引物对F,子代进行真实性鉴定,经多态性筛选,选出14条ISSR引物和16对SRAP引物...