28个中国紫苏属种质资源的染色体核型分析

为了探明我国紫苏属（Perilla Linn.）植物的染色体特点,本研究采用常规压片法对我国紫苏属的28份材料的染色体核型进行分析研究。结果表明：供试的28份紫苏属材料,染色体基数均为x=20,其中3个为四倍体,2n=80,其余25份皆为二倍体,2n=40;28份材料中均有发现至少一个随体,染色体类型包含m,sm,st 3种,核型有2A,3A,2B,3B 4个类型,最长染色体/最短染色体值1.50~2.80,臂比大于2的染色体占染色体总数的百分比为10%~65%,核型不对称系数59.69%~68.52%;通过核型分析,回回苏和多倍体紫苏类型可能具有更高的进化地位,而野生紫苏与之相反。这些数据表明了我国紫苏属植物资源在细胞学方面具有较为丰富的多样性,同时本研究也对我国紫苏属植物的分类、鉴定等提供了理论参考。     

野豌豆属43份牧草种质的染色体形态观察与分析

野豌豆属(Vicia)牧草为自花授粉二倍体植物,具有很好的防风固沙及保水作用,适宜在高寒和高海拔地区种植,是我国高原牧区重要的蛋白饲料来源。本研究从中国、美国、德国、埃塞俄比亚等22个国家,收集了43份野豌豆属牧草种质,对其根尖细胞的有丝分裂中期染色体进行核型分析。结果表明,染色体数目有5种:10、12、14、16、24。核型分类有6种:2A、1B、2B、3B、2C、3C。本研究统计了野豌豆属43份种质的核型数据,为揭示野豌豆属细胞学特性和演化趋势奠定了基础。     

不同类型苏丹草染色体数目及核型分析研究

本文对苏丹草[Sorghumsudanense（Piper）Stapf]种内的黑壳（黑颖）、红壳（红颖）、白壳（白颖）3种类型进行染色体数目及核型研究，结果表明3种不同类的苏丹草染色体数目均为2n＝20，核型公式均为Zn＝4x=18m＋2SAT，其染色体均为中部染色体，均具有一时带随体染色体，核型类型均为1A型，属于较对称性核型。苏丹草在种内其染色体及核型特征无明显差异。苏丹草与同属植物高梁的染色体、数目及核型特征有明显的属内一致性。     

野大麦染色体的核型分析

用根尖压片法对野大麦染色体核型进行研究的结果表明，野大麦是四倍体植物，体细胞染色体数为2n=4x=28，染色体基数为x=7，染色体组成为2n=4x=28=22m(4SAT) 6sm(2SAT)，属不对称性核型(ⅡB型)。野大麦[Hordeum brevisubulatum(Trin．Link)]是禾本科大麦属植物。在我国主要分布于东北、华北、新疆各地，本文对其染色体进行了研究，以求为野大麦的细胞学研究和植物遗传育种提供科学依据。     

青藏高原东缘３种风毛菊属植物的核型研究

 本研究报道了产于青藏高原东缘３种风毛菊属植物的染色体数目和核型。研究结果表明,３个种的染色体数目和核型如下：甘肃风毛菊为２ｎ＝２ｘ＝３２＝１２ｍ＋１６ｓｍ＋４ｓｔ,核型属２Ｂ型;大耳叶风毛菊为２ｎ＝２ｘ＝２６＝１０ｍ＋１４ｓｍ＋２ｓｔ,核型属２Ａ 型;波缘风毛菊为２ｎ＝２ｘ＝２６＝６ｍ＋２０ｓｍ,核型属２Ｂ型;这３个种均为二倍体,并且在染色体中均未发现随体和Ｂ染色体。     

顶羽菊染色体的核型分析

用根尖压片法对顶羽菊染色体核型进行研究的结果表明,顶羽菊是二倍体植物,体细胞染色体数为2n=26,染色体基数为13,染色体组成为2n=2x=26=22m+4sm,属不对称核型(IB型).     

牧草染色体核型和带型分析研究进展

植物染色体的核型和带型分析对物种基因图谱的构建、亲缘关系的确定、种质资源的保存、进化过程的探索、植物学分类及育种等方面的研究具有重要作用.分析了植物染色体核型和带型研究的异同点,并从取材、预处理、固定、解离、制片及染色等方面系统综述了牧草核型和带型分析的研究进展.核型和带型分析方法需要进一步的规范和标准化,在种质资源评价、种子劣变生理等方面将成为牧草核型与带型分析研究的重点.     

芒属部分类群花粉形态观察研究

芒属植物因其拥有适宜作为新一代能源植物开发利用的巨大潜力而广受关注。为了积累中国芒属植物孢粉学研究的资料,本研究利用光学显微镜和扫描电子显微镜对芒属的芒(Miscanthus sinensis)、五节芒(M. floridulus)、荻(M. sacchariflorus)、南荻(M. lutarioriparius)、尼泊尔芒(M. nepalensis)、双药芒(M. nudipes)等类群的共39份材料的花粉进行了观察。结果表明,芒属植物花粉的表面纹饰呈2种类型:颗粒状突起与疣状突起。根据突起程度不同,疣状突起又可分为3种亚类型:不明显疣状突起、疣状突起和明显疣状突起。芒、五节芒、荻、南荻的花粉形态相似性高,表明它们之间的亲缘关系密切。尼泊尔芒和双药芒的花粉形态与芒属其他类群的差异较明显,研究结果支持将它们从芒属中分离出来成立另一个属,即本研究支持双药芒属(Diandranthus)成立。本研究同时表明五节芒比芒演化水平高。为了从孢粉学角度探讨芒属各分类类群之间的亲缘及演化关系,进一步开展花粉外壁的内部结构研究也许是非常有必要的。     

基于叶绿体atpB-rbcL序列探讨猬草属和赖草属植物的系统发育和母系起源

对小麦族猬草属、赖草属(NsXm)、披碱草属(StH)及含不同染色体组(St、H、Ns、E^b、E^e、P、F 、V、W)的近缘二倍体属共46个类群的叶绿体基因间隔区atpB-rbcL序列进行系统发育分析,探讨猬草属和赖草属植物系统发育关系及母系起源。结果显示,1)猬草属模式种H. patula与拟鹅观草属和披碱草属物种聚为一支,表明H. patula与披碱草属植物亲缘关系近,其母本来源为含St染色体组的拟鹅观草属物种;2)猬草、长芒猬草、4个新麦草属物种及滨麦和所有欧亚分布的赖草属物种聚在一支,说明猬草、长芒猬草与欧亚赖草亲缘关系较近,其母本供体来自含Ns染色体组的新麦草属物种;3)高丽猬草和东北猬草与北美赖草及冰草属、旱麦草属、大麦属物种处于同一分支,表明高丽猬草和东北猬草与北美赖草具有较近亲缘关系,其母本供体为未知来源的Xm染色体组。研究结果支持将H. patula组合到披碱草属中,猬草、长芒猬草、高丽猬草和东北猬草应组合到赖草属中。     

蒙古冰草分子核型分析

利用荧光原位杂交技术,在蒙古冰草染色体组上进行5S rDNA、45S rDNA以及重复序列pAs1 DNA序列的定位,通过荧光原位杂交信号的强弱、数量、位置进行蒙古冰草染色体的配对及核型分析。结果表明:蒙古冰草染色体组总长度为91.788μm,平均绝对长度为13.113μm,最长染色体与最短染色体的长度比值为1.446,具有2对随体,分别位于第2号染色体和第4号染色体的短臂上,没有臂比大于2∶1的染色体,核型不对称系数为56.96%,核型类型属于1A型,核型公式为2n=2x=14=10m(2SAT)+4sm(2SAT)。5S rDNA序列和45S rDNA序列分别位于第2号和第4号染色体的短臂上,有5对染色体两端都检测到明显的pAs1 DNA荧光信号,有2对染色体只有一端检测到明显的pAs1 DNA荧光信号。荧光原位杂交技术大大提高了染色体核型分析的可靠性,为冰草属内植物的分类和育种提供了细胞学依据。     

芒属植物分蘖数性状的QTL定位

芒属植物是一种多年生C₄高大禾草,是一种重要的生物能源作物。分蘖是芒属植物重要的农艺性状之一,在调控其产量方面具有极其重要的作用。以五节芒和荻的种间杂交群体为材料,利用前期已构建的五节芒和荻的种间基因组遗传连锁图谱,结合2014年泰安、2015年泰安和东平3次重复调查的分蘖数表型数据,进行该重要性状的QTL遗传定位研究。结果表明:分蘖数频率分布呈现正态连续分布,符合数量性状遗传的特征;采用MQM复合区间作图法共定位到16个与分蘖数性状相关的QTL,单个QTL可解释的表型变异范围为11.4%~21.5%,LOD值为3.06~6.09。其中,3个QTL在3次定位分析中可重复检测到,qmfTI-2可分别解释12.7%、12.0%和15.5%的表型变异,qmsTI-1可分别解释12.0%、12.1%和19.8%的表型变异,qmsTI-2可分别解释21.5%、20.2%和13.4%的表型变异;3个QTL在2次定位分析中可重复检测到,qmfTI-1、qmfTI-3和qmsTI-4分别解释12.4%和11.4%、13.8%和13.2%、12.1%和14.3%的表型变异。通过对芒属植物分蘖数性状QTL分析,为芒属植物种质资源改良、分子标记辅助选择以及遗传学研究奠定基础。     

3种催熟剂对芒属植物的催熟效果比较

以五节芒02142（Miscanthus floridulus）和杂交种湘杂芒2号（M.sinensis×M.lutarioriparius）为材料,比较了3种催熟剂（农挞、乙烯利及二者的混合制剂）对芒属植物的催熟效果。结果表明,3种催熟剂均明显降低了芒属植物叶片的叶绿素相对含量（SPAD值）,其中农挞与农挞 乙烯利混合制剂效果相当,而乙烯利效果最差;3种催熟剂均明显促进了芒属植物植株脱水,其中农挞 乙烯利混合制剂效果最好,乙烯利效果最差,但与农挞配制后有明显的增效作用;在对芒属植物植株氮、磷和钾含量的影响上,乙烯利多表现出增大作用,而农挞与农挞 乙烯利混合制剂则表现出明显降低作用,以农挞（10 mL·L-1）+乙烯利（2 mL·L-1）处理的效果最好。综合来看,农挞 乙烯利混合制剂催熟效果最佳,且最佳浓度为农挞（10 mL·L-1）+乙烯利（2 mL·L-1）。     

草地早熟禾的石蜡切片制作技术的优化

以草地早熟禾为材料,在传统石蜡切片方法的基础上,结合草地早熟禾组织结构特点,对脱水、透明、染色等重要制片环节进行改良。结果显示:脱水过程中,将乙醇逐级梯度脱水时间增加,有利于后续浸蜡,避免石蜡切片上的植物材料脱落;透明过程中,将纯二甲苯增加更换频率,同时减少每次处理时间,其透明更彻底;有效的番红固绿染色时间组合处理,使草地早熟禾解剖形态更为清晰。一系列针对草地早熟禾石蜡切片的优化,使得解剖图像染色均匀、图像清晰,不易出现植物材料脱落及组织结构不完整的情况,是观察草地早熟禾形态结构的有效方法。     

不同诱变处理对芒多倍体诱导效果的研究

以芒（Miscanthus sinensis）种子为外植体诱导出愈伤组织,对愈伤进行处理,探讨秋水仙素、诺考达唑、安磺灵3种不同诱变剂在相应条件下对芒多倍体诱导的作用效果。通过流式细胞仪进行DNA含量测定、染色体制片技术进行染色体数目鉴定和比较四倍体与二倍体叶片中气孔保卫细胞大小和密度等手段检测再生植株的倍性。结果表明：在对芒的愈伤进行处理时,最佳组合为安磺灵浓度10 μmol·L^-1,温度5℃,1.02 mmol·L^-1的Ca²⁺浓度,处理15 min,其诱导率为35.19%。诱变剂对材料的毒害作用表现为秋水仙素毒害作用最大;诺考达唑和安磺灵对材料的毒害作用次之,且二者无显著差别。     

基于图像识别技术的豆科牧草分类研究

利用计算机图像处理技术,依据植物叶片图像的形状特征对14种豆科牧草进行分类识别。通过对叶片图像进行预处理,提取出叶片的轮廓。在此基础上提取了叶片形状的全局特征和局部特征;全局特征包括叶片的横纵轴比、矩形度、圆形度等8项几何特征和7个图像不变矩特征;局部特征为叶缘粗糙度。利用PNN(Probabilisticneural network)和BPN(Back propagation network)作为分类器进行识别分类,实现了对豆科牧草叶片图像的分类。识别结果表明,PNN网络的平均识别率为85.1%、BPN网络的平均识别率为82.4%。     

Long-term chemotherapy with lomustine of intracranial meningioma occurring in a miniature schnauzer

A 14-year-old male miniature schnauzer was referred to us because it was circling to the right. A mass in the diencephalon was noted on brain magnetic resonance images. The dura was thickened with marked linear enhancement after contrast administration. Based on diagnostic image analysis, this lesion strongly suggested meningioma. The patient's symptoms were well controlled by a combination therapy of prednisolone and lomustine (CCNU), and survived for thirteen months after diagnosis. This case was diagnosed as a meningioma based on histopathological findings. This report describes the clinical findings, imaging characteristics, and pathologic features of a diencephalic and mesencephalic meningioma and long-term survival after lomustine and prednisolone therapy.     

草地植被盖度的近距离遥感测定

盖度或者覆盖度是植物群落结构的一个重要数量指标。通常的目视估测植物群落盖度方法不仅精度低,而且因人而异。本研究采用近距离遥感方法测定草地植物群落盖度,该方法主要包括数据获取、图像处理、像元数量提取和盖度计算4个部分。精度评价表明,该方法测定的绿色植被盖度误差很小,与目视估测方法比较,它具有客观、一致和精度高的优点。     

Using Very-Large-Scale Aerial Imagery for Rangeland Monitoring and Assessment: Some Statistical Considerations

The availability of very-large-scale aerial (VLSA) imagery (typically less than 1 cm ground-sampling-distance spatial resolution) and techniques for processing those data into ecosystem indicators has opened the door for routinely using VLSA imagery in rangeland monitoring and assessment. However, for VLSA imagery to provide defensible information for managers, it is crucial to understand the statistical implications of designing and implementing VLSA image studies, including consideration of image scale, sample design limitations, and the need for validation of estimates. A significant advantage of VLSA imaging is that the researcher can specify the scale (i.e., spatial resolution and extent) of the images. VLSA image programs should plan for scales that match monitoring questions, size of landscape elements to be measured, and spatial heterogeneity of the environment. Failure to plan for scale may result in images that are not optimal for answering management questions. Probability-based sampling guards against bias and ensures that inferences can be made to the desired study area. Often collected along flight transects, VLSA imagery lends itself well to certain probability-based sample designs, such as systematic sampling, not often used in field studies. With VLSA image programs, the sample unit can be an entire image or a portion of an image. It is critical to define the sampling unit and understand the relationship between measurements and estimates made from the imagery. Finally, it is important to statistically validate estimates produced from VLSA images at selected locations using quantitative data of the same scale and more precise and accurate than the VLSA image techniques. The extent to which VLSA imagery will be useful as a tool for understanding the status and trend of rangelands depends as much on the ability to build the imagery into robust programs as it does on the ability to quickly and relatively easily collect VLSA images over large landscapes.     

A Direct Approach for Quantifying Stream Shading

Management and regulatory standards for stream shading have been established to mitigate excessive stream temperature. Existing shade assessment tools, however, are inadequate for monitoring extensive stream networks. Our objectives were to develop and evaluate an efficient, low-cost field technique for sampling stream-surface shading using digital images and to evaluate the efficiencies and effectiveness of eight different digital image analysis techniques for shade assessments. We developed a quadrat-based technique and associated field equipment to directly photograph stream-surface shading. Sampling at random points (pixels) within the resultant digital images was the most accurate, efficient, and robust image analysis technique. An approach pairing the photographic field technique and the random point-sampling image analysis technique should enable managers to conduct ground-based assessments of stream shading over extensive stream networks. This approach may also provide an efficient means of collecting ground truth samples for even broader scale, remote sensing–based stream-shade assessments.     

MULTISCALE IMAGE PROCESSING AND ANTISCATTER GRIDS IN DIGITAL RADIOGRAPHY

Scatter radiation is a source of noise and results in decreased signal-to-noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film-screen radiograph). Full-size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five-point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.