首批海岛棉基因组来源的微卫星标记的分离、评价和定位

海岛棉(Gossypium barbadense)是世界上最重要的栽培棉种之一。海岛棉纤维品质优良,是优质棉的重要产源。为了研究海岛棉的遗传多样性,为海岛棉育种提供参考依据,从海岛棉遗传标准系中分离基因组来源的微卫星标记用于海岛棉遗传评价。采用两种方法分离微卫星标记,一是用ISSR (inter simple sequence repeat) 引物扩增Pima3-79,克隆测序后从中开发微卫星标记;二是利用简并引物扩增Pima3-79,克隆测序后从中开发微卫星标记。共挑选1 447个克隆,筛选出239个独立克隆。测序后得到214个单一序列,其中包含微卫星并可用于引物设计的序列70个,获得86对引物。86对引物用于扩增56个海岛棉材料和4个陆地棉材料,16对引物没有扩增,43对引物在所有材料中没有多态性;27对引物在海岛棉和陆地棉之间有多态性,19对引物在海岛棉中表现多态性。利用Jaccard相似系数和UPGMA方法进行聚类分析可以明显区分陆地棉和海岛棉,并且将海岛棉分为4类。14对引物在BC₁群体中表现多态性,产生14个位点。9个位点整合到BC₁连锁图的7个染色体上,4个位于A亚基因组,5个位于D亚基因组。海岛棉微卫星标记扩展了棉花微卫星标记,有助于海岛棉遗传多样性的研究,有利于棉花遗传图谱的进一步丰富。     

水稻ygl80黄绿叶突变体的遗传分析与目标基因精细定位

通过化学诱变获得遗传稳定的水稻黄绿叶突变体ygl80。与野生型亲本10079相比,ygl80突变体在苗期和孕穗期叶片叶绿素分别下降76.64%和54.59%,类胡萝卜素含量分别下降53.85%和41.18%,成熟期株高、每株有效穗数、每穗着粒数、穗长和千粒重分别减少14.8%、16.5%、21.3%、9.1%和7.4%。遗传分析表明,ygl80的突变性状由1对隐性核基因控制。利用(ygl80/浙辐802) F₂作为定位群体, 将突变基因定位在第5染色体长臂InDel标记C2和C3之间,遗传距离分别为0.24 cM 和0.39 cM,两标记之间的物理距离约为90 kb,此区间内包含11个预测基因。基因组序列分析发现,ygl80突变体在编码叶绿素合酶的YGL1(LOC_Os05g28200)基因编码区第5027碱基处(位于第14外显子),碱基C突变为碱基T,使编码蛋白序列第348位的脯氨酸(Pro)突变成亮氨酸(Leu)。该基因是已报道的水稻ygl1黄绿叶突变基因的等位基因。ygl80突变体在整个生育期都表现为黄绿叶,而ygl1突变体在苗期叶片黄化,中期慢慢转绿,后期叶色以及总叶绿素和类胡萝卜素的含量接近野生型,这可能是YGL1基因编码的叶绿素合酶蛋白的氨基酸不同突变位点造成的。     

烟草航天诱变突变体叶形遗传分析及基因定位

利用航天诱变方法获得烟草品种NC89的突变体NC89-M,与野生型相比,NC89-M叶形呈宽椭圆,叶面褶皱,叶缘呈锯齿状.为明确烟草航天诱变突变体NC89-M叶形突变机理,挖掘突变体叶形突变基因,利用NC89-M与烟草品系2014-168杂交获得F2群体,对F2群体遗传分析表明突变体叶形性状受1对显性主效基因控制.通过...     

一个水稻抽穗期主基因Hd(t)的遗传分析及分子定位

从缙恢10/R21的杂种后代中发现了一个抽穗期稳定遗传的迟熟恢复系N91(110~114 d),以早熟不育系金23A(89~94 d)作为杂交和回交亲本,获得的F₂和BC₁F₁群体抽穗期均表现双峰分布,χ²检测表明其抽穗期受一对主基因控制,暂命名为Hd(t)。在400多对SSR引物中筛选出5对在早熟基因池和迟熟基因池中表现差异的引物,进行单株验证,用回交群体进行基因定位,发现位于第7染色体长臂末端的SSR标记RM1364和RM3555与Hd(t)连锁,遗传距离分别为32.7 cM和22.5 cM。在目标区域进一步合成8对SSR引物,将Hd(t)基因定位在RM22143与第７染色体末端之间,与RM22143相距12.9 cM。该结果为Hd(t)基因的精细定位、分子标记辅助育种和基因克隆奠定了基础。     

Comparative genetic mapping of loci affecting plant height and development in cereals

Restriction fragment length polymorphism (RFLP) mapping data for genes determining dwarfness (GA insensitive and GA sensitive), vernalisation response and photoperiodic response in wheat, rye and barley were compared and their homoeologous relationships discussed. The GA insensitive Rht genes of wheat are not related to the GA insensitive dwarfing genes of rye or barley; however, homoeology is present for two members of the GA sensitive dwarfing genes of wheat (Rht12) and rye (Ddw1), located on the translocated segments of the long arms of chromosomes 5A and 5R, respectively. The comparative mapping of the Triticeae group 5 vernalisation response genes of wheat, rye and barley, and the group 2 photoperiodic response genes of wheat and barley, show that both gene families are located in homoeologous regions of the particular chromosomes. This revised version was published online in August 2006 with corrections to the Cover Date.     

RFLP mapping of a new cereal cyst nematode resistance locus in barley

Cereal cyst nematode (CCN) ( Heterodera avenae Woll.) is an economically damaging pest of barley in many of the worlds cereal growing areas. The development of CCN-resistant cultivars may be accelerated with the application of molecular markers. Three resistance genes against the pest have been mapped previously to chromosome 2 ( Ha 1, Ha 2 and Ha 3). In this study, a third gene present in the Australian barley variety 'Galleon' derived from the landrace 'CI3576' was located. Segregation analysis of CCN resistance data derived from doubled haploid populations of the cross 'Haruna Nijo'×'Galleon' identified a single major locus controlling CCN resistance in the variety 'Galleon'. This locus mapped to the long arm of chromosome 5H estimated to be 6.2 cM from the known function restriction fragment length polymorphism marker XYL (xylanase). While five genes for CCN resistance, including Ha2, have been mapped to group 2 chromosomes in the Triticeae, no gene other than Ha4 has been identified on group 5 chromosomes.     

Occurrence of microsatellites in spinach sequences from computer databases and development of polymorphic SSR markers

Microsatellites are valuable tools as molecular markers in plant breeding. To establish genetic linkage maps or for population studies, information about the occurrence and usability of microsatellite markers in different species is necessary. Sequences of spinach Spinacia oleracea from computer databases were therefore searched for the presence of microsatellites. Sixty simple sequence repeats were found in 237 spinach sequences with a total of 349.4 kb DNA. After removing duplicated sequences, 50 different microsatellites with various motifs remained. Differences between nuclear and chloroplast DNA were not in the number of microsatellites but in their type and length. Chloroplast sequences from spinach contain only short strings of A and AT repeats, whereas nuclear sequences show a wider variety of motifs. Flanking primers for polymerase chain reaction (PCR) analysis were designed for 13 of these microsatellites and tested with two different varieties of spinach. Twelve primer pairs gave amplification products and seven of these showed polymorphisms in the variety ‘Wiremona’ but only one in the variety ‘Monatol’. These markers may be used for linkage analysis or population studies in spinach.     

有关土地测绘质量问题和处理研究

文章就土地测绘的内涵解析作为切入点,浅要论述了土地测绘质量问题的影响因素,并就土地测绘质量问题影响因素的处理提出了一些浅薄的建议。以期促进我国土地测绘质量的提升。     

浮动平底推杆等宽凸轮机构第Ⅱ类机构综合问题

以浮动平底推杆等宽凸轮机构为研究对象,通过引入往程、返程、向径标定线和等宽映射区间套等概念,阐述了往程/返程运动角、远近休止角的内在规律性关系,运动学尺寸、行程幅值和初位参数间的内在特征关系,输出摇杆返程角位移规律的求解,主副平底容许选择区段和凸轮基圆半径取值域确定,凸轮基圆半径、压力角和宽度的变化规律等,揭示了等宽凸轮机构的设计蕴含着诸多的异质性内涵。还对等宽凸轮机构、共轭凸轮机构进行了比较,得到了两种形锁合机构相同点、差异点。最后给出等宽凸轮机构的一个综合算例。     

水稻早衰突变体els-R7954的遗传分析和初步定位

为了深入研究水稻早衰机理,找到有效消除和延缓植株早衰的方法,本研究通过350Gy60Co-γ射线辐照水稻浙恢7954干种子,获得1份特异性水稻早衰突变体。观察该突变体生物学性状,发现苗期生长正常,分蘖末期叶片出现早衰现象,灌浆期整个植株枯黄,早衰现象非常明显,将其暂名为elsR7954(early leaf senescence)。遗传分析和基因定位发现,els-R7954受单隐性核基因控制,位于第2染色体SSR标记RM530和RM3774之间,距RM530约5.0c M。为进一步克隆该基因,丰富叶片早衰的分子机制奠定了一定基础,也为研究水稻早衰,最终提高产量和品质提供可能。