罗非鱼耐盐数量性状位点(QTL)定位研究

采用190个微卫星分子标记对罗非鱼282个全同胞个体进行数量性状位点(QTL)定位,获得15个罗非鱼耐盐QTL,其中st-c、mst-a可分别解释19.2%的两性耐盐差异和19.1%的雄性耐盐差异,XY性别决定位点、钠钾氯协同转运蛋白2(NKCC2)基因分别定位于st-c、mst-a的峰值处。研究结果表明,罗非鱼海水养殖中采用全雄群体可能具有一定的耐盐优势,NKCC2基因可作为重要的候选基因用于耐盐罗非鱼选育。     

牙鲆身体纵轴生长相关性状QTL定位

以经紫外线灭活的真鲷(Pagrosomus major)精子作为异源精子,诱导牙鲆(Paralichthys olivaceus)卵子进行有丝分裂雌核发育,通过静水压方法获得165个双单倍体作为实验材料.测量牙鲆身体纵轴6个生长相关性状(体长、头长、背鳍基长、腹鳍基长、尾柄长和尾长),并用SPSS 19.0对其进行正态分布及相关性分析.运用MapQTL4.0中多座位QTL 模型(MQM)对控制6个性状的QTL进行定位及遗传效应分析.结果表明,所检测6个性状均符合正态分布,并且相互之间呈极显著相关(P<0.01).在全部24个连锁群上检测到22个控制相关性状的QTL,分布在10个连锁群上.其中与体长相关的QTL有4个,头长相关的QTL为3个,控制背鳍基长的QTL为4个,与腹鳍基长相关的QTL为3个,与尾柄长相关QTL 7个,控制尾长的QTL仅有1个.各QTLs的LOD 值在2.01~3.68之间,可解释3.7%~12.6%的表型变异.控制体长和尾长的 QTL存在共定位,控制体长的 QTL 还与控制背鳍基长及腹鳍基长的QTL存在共定位.本研究结果可为今后进一步辅助育种和改良性状提供参考.     

标记辅助选择在动物育种中的研究进展

随着生物科学的不断发展,遗传标记辅助选择(MAS)已经在动物改良中获得了较大的遗传进展,其中最关键的环节是识别有效的遗传标记,即这一标记应与控制这些数量性状的基因(QTL)处于连锁不平衡(linkagedise-quilibrium)状态。目前遗传标记技术在动物遗传育种中的研究已取得一定进展。     

全基因组选择育种策略及在水产动物育种中的应用前景

全基因组选择的概念自2001年由Meuwissen等提出后便引起了动物育种工作者的广泛关注.目前,澳大利亚、新西兰、荷兰、美国的研究小组已经应用该方法进行了优质种牛的选择育种,并取得了很好的效果.此外在鸡和猪的选择育种中也有该方法的应用,但在水产动物选育中尚未见该方法使用的报道.本文对“全基因组选择育种”的概念和提出背景进行了归纳,对全基因组选择育种的优势进行了阐述,并详细介绍了其具体的策略,总结了目前全基因组育种所广泛采用的方法以及取得的成果,旨在为该方法在水产动物育种方面的应用研究提供科学参考.     

小麦抗条锈病分子标记辅助育种研究进展

小麦条锈病是小麦生产的主要病害之一。在中国,尤其是西北麦区,小麦条锈病是小麦生产面临的最严重问题。筛选和培育抗锈基因是防治小麦条锈病最为经济、安全、有效的方法。综述了分子标记辅助育种技术在小麦抗条锈病育种上的研究概况和发展运用。     

棉花主要性状QTL定位的研究进展

棉花的许多农艺性状和经济性状都是数量性状,研究作物数量性状遗传对农作物育种具有十分重要的意义。综述了数量性状基因座QTL（quantitative trait locus）定位的原理和常用方法及近年来棉花的分子遗传图谱构建,主要性状,包括产量、纤维品质、抗性、生理、早熟性等QTL定位的研究进展,并对目前QTL定位存在的问题和发展前景进行了探讨。     

一种基于三维激光扫描系统测量树冠体积方法的研究——以油松为例

树冠体积在林业及其他领域得到越来越广泛的应用.该文介绍了三维激光扫描系统的组成、工作原理及工作流程;探讨了应用三维激光扫描系统,通过扫描获取单株树木的三维空间点阵数据,将树冠近似为多个圆台体,求它们的体积之和来计算树冠体积的方法.并在甘肃省小陇山林业局党川林场以油松为例进行了实验,而后对实测数据进行了精度分析,取得了较为满意的结果.研究表明,利用三维激光扫描系统测量树冠体积具有较强的实践意义和应用价值.     

遥感与GIS相结合的森林资源信息更新与制图方法研究

目前我国实行的森林经营单位水平上森林资源动态监测主要是通过森林资源规划设计调查 (简称二类调查 )来实现。重点是对森林资源动态、林业经营效果和森林资源监测的综合评价。通常 ,二类调查每 1 0 a复查 1次 ,这种方法所得到的森林资源调查结果可落实到地块 ,也是森林经营单位进行营林生产的重要基础数据 [1 ] 。但是这种常规调查方法也有许多不足之处 ,如 :(1 )复查间隔期长 ,无法及时满足森林经营单位对森林资源变化信息的需求 ;(2 )调查成果多是以报表、文字的形式提交 ,只能建立属性数据库 ,森林资源的空间信息较少通过计算机实现可视…     

A new approach and case study for estimating extent and rates of habitat loss for ecological communities

The pace and magnitude of biodiversity loss has led to wide recognition that efforts to conserve individual species must be complemented by assessment and planning at community and ecosystem levels. Emerging protocols for assessing the conservation status of communities include as central criteria the current extent, historical reduction and contemporary rate of decline in geographic distribution. Estimation of these parameters is confronted by methodological challenges, data limitations and uncertainties that may vary from case to case. We describe an approach to these issues comprising five steps: (1) classification of the community using an analysis of data from systematic ground surveys; (2) mapping to produce a contemporary baseline distribution (1980s); (3) interpolation to produce a historical distribution (pre-European settlement); (4) interpretation of satellite imagery to update the distribution (various dates up to 2004) and (5) assessment of change in extent over historical and contemporary time scales incorporating plausible bounds of uncertainty around best estimates. The bounds can be based on areas for which image interpretation produces uncertain diagnosis of clearing and differences between credible alternative base maps of the same area. We demonstrated the approach using a case study of Coolibah-Black Box Woodland, a declining semi-arid woodland community in Australia and found that 61% (plausible range 50-67%) of the woodland community had been cleared since European settlement and that during 1998-2004 the community continued to decline on average by 135.3(±21.7) km² each year, or 1.7(±0.3)% of each previous year’s distribution, apparently accelerating in recent years. Strengths of the approach include the use of biological data (cf. remote sensing) to distinguish the target assemblage from others, the use of historical and contemporary base lines to examine change over different time scales, and the use of bounded estimates to incorporate uncertainty into the assessment.     

The impact of small-scale design interventions on the behaviour patterns of the users of an urban wasteland

Urban derelict space can form a valuable complementary element to the formal green spaces of a city: wastelands are often biologically diverse and their unregulated status can provoke innovative spatial activities by a wide range of users. Using the case of an urban brownfield in Tallinn, Estonia, this paper examines how such a space is used and evaluates the magnitude of the impact of minor design interventions – so-called urban acupuncture – on the activities carried out by the users. The study used field observations and behaviour mapping to compare the spatial pattern of the users before and after small design interventions. Although there was widespread use beforehand there was both an increase in use and a different pattern afterwards, which was clearly detectable from the composite behaviour maps of both arrangements, where users follow the properties of the particular environment. The small improvements tested showed the largest effect on the female and the older user groups, raising the number of overall visits and increasing the occurrence of active behaviour almost five times. The research demonstrates that small, inexpensive and possibly temporary interventions can have a major positive effect.