火炬松与湿地松染色体的荧光带型

文章利用ＣＭＡ和ＤＡＰＩ两种荧光染料,处理火炬松和湿地松染色体。结果表明：火炬松染色体ＣＭＡ荧光带型是２对染色体为着丝粒区和臂间区均有荧光带纹的中间着丝粒染色体;４对染色体为臂间区有荧光带纹的中间着丝粒染色体;２对染色体为着丝粒区有荧光带纹的中间着丝粒染色体;４对染色体为无荧光带纹的中间或近中着丝粒染色体。     

魔芋染色体核型及带型的研究初报

试验采用F-BSG法,制取魔芋4个不同种的染色体标本,并对其核型及Giemsa带型进行分析,探讨其进化程度。结果表明:4个种的染色体均为2n=2x=26,基本带型为C带,个别为W带和T带,核型类别属于2B类型,它们的着丝点部位、臂指数及N·F值都有不同,这3个指标说明了花魔芋的染色体不对称性程度最高,白魔芋不对称性程度最低,南蛇棒与东川魔芋介于它们之间。由此得出,枝魔芋是较进化的种,白魔芋是较原始的种。4个种核型的差异在其植物学性状和生物学特性上有相应表现:较进化的花魔芋属植株高大生长势强的大型种;较原始的白魔芋属植株矮小生长势弱的小型种;进化程度介于两者之间的东川魔芋和南蛇棒其植株高矮及生长势强弱也介于两者之间。     

八倍体节节麦-燕麦部分双二倍体的细胞遗传学鉴定

通过对节节麦、野燕麦、八倍体节节麦－燕麦部分双二倍体的Ｃ分带的研究,表明八倍体节节麦－燕麦部分双二倍体中含有小麦的Ｂ组和Ａ组染色体。通过对节节麦、野燕麦、八倍体节节麦－燕麦部分双二倍体与中国春小麦回交后代的花粉母细胞减数分裂过程中染色体配对行为的研究,表明回交一代中含有１４个左右的二价体,而不是预期的７个二价体;通过对八倍体节节麦－燕麦部分双二倍体与中国春小麦回交后代花粉母细胞中染色体的原位杂交研究,表明八倍体节节麦－燕麦部分双二倍体中含有１４条左右的燕麦染色体。因此,认为八倍体节节麦－燕麦部分双二倍体不是真正的节节麦与野燕麦的杂种,而可能是某一四倍体小麦与燕麦的杂交后代。     

杂交三倍体泥鳅染色体C带及rDNA序列的FISH定位

对杂交三倍体泥鳅(4n♀×2n♂)的胚胎染色体进行了C带及染色体荧光原位杂交(FISH)分析,首次探讨了杂交三倍体泥鳅C带特征,为准确鉴别染色体提供依据,研究了核糖体5.8S+28S r DNA在杂交三倍体泥鳅胚胎中期染色体上的数目和位置。C带结果表明,杂交三倍体泥鳅的染色体C带包括臂端C带和着丝粒C带,没有发现臂间C带。M染色体只有1号染色体既有臂端C带又有着丝粒C带,但臂端C带均比着丝粒C带大,信号也比着丝粒的强;而其他M染色体及SM染色体、T染色体只有着丝粒C带。FISH分析显示,核糖体5.8S+28S r DNA清楚地定位在杂交三倍体泥鳅中期染色体中部着丝粒染色体(M)的端部区域,在杂交三倍体泥鳅中期染色体上可以检测到三簇杂交信号。该结果从分子细胞遗传学层面进一步证实了杂交三倍体泥鳅是含有三套染色体组的遗传三倍体。     

江西遂川候鸟通道初探

从遂川县志中得知，遂川县西部山区群众历来有捕鸟猎食的习惯，当地人认为此地有条“千古鸟道”。为了探索“鸟道”之迷，2002-2005年在遂川县营盘圩乡开展鸟类环志，进行张网捕鸟、鉴别测量、环志建档、放飞和栖息地生态环境等内容的研究。同时开展的社区宣传教育活动使当地群众爱鸟护乌及保护候鸟停歇栖息地生态环境的意识有了提高，并取得了多项成果。     

经营田鼠染色体核型与G带分析

采用骨髓法制备经营田鼠染色体标本片,并对其染色体核型和G带进行分析。结果表明,经营田鼠体细胞染色体数为2n=38,雄性染色体核型由18对常染色体和1对异配型性染色体XY组成,雌性为18对常染色体和1对同配型性染色体XX组成。1～9号为端着丝粒（t）染色体（包括Y染色体）,10号为近端着丝粒（st）染色体,11～18号为中央着丝粒（m）染色体（包括X色体）。19对染色体共分布有370条G带（雄性365条）,其中深带190条,浅带180条。因此,经营田鼠的染色体数目、G带具有明显种的特征,与其他鼠类不同。     

水稻染色体随体显带的研究

用风油精法对５个水稻品种的染色体随体进行了研究，结果表明，在辐新，低脚鸟尖，金包银品种的染色体随体上，显示Ｇｉｅｍｓａ染色浅的窄带纹２－３条，同源染色体随体的带纹基本一致，在金包银和辐新的部分细胞中，随体有伸长和淡化现象，随体淡化到一定程度时，即不易被识别，这可能与水稻染色体随体数目的多样性有关。风油精法显示染色体随体带纹，丰富了植物染色体显带的内容。     

Cytological identification of 1B/1R wheat-rye translocations in winter wheat breeding lines

Summary The incorporation of rye (S. cereale L.) chromatin into winter wheat (T. aestivum L.) cultivars is often achieved via hybridization of unadapted wheat-rye translocation lines with adapted wheat germplasm. Identification of progenies possessing the translocated chromosome has traditionally involved phenotypic screening for the desired rye characteristics. In this study, the Giemsa N-banding technique was evaluated as a potential screening tool for detection of 1B/1R wheat-rye translocations. Five breeding lines were examined from the pedigree Aurora/2^*TAM W-101. The differential banding patterns of chromosome 1B contributed by TAM W-101 and chromosome 1B/1R contributed by Aurora allowed unequivocal identification of translocation genotypes. Three of the lines were found to be heterogeneous, whereby plants were homozygous for either the normal 1B or the translocated 1B/1R chromosome. The remaining two lines were observed to be homozygous and homogeneous for the translocated 1B/1R chromosome. The implication of N-banding chromosomal analyses to wheat breeding is presented.Contribution No. J-5172, Department of Agronomy, Oklahoma Agriculture Experiment Station, Oklahoma State University, Stillwater, OK74078.     

Evaluation of common bean cultivar relationships by means of isozyme electrophoretic patterns

Summary Electrophoretic isozyme technique was applied on primary leaf, stem, and root tissues from seedlings of 34 U.S. major common bean (Phaseolus vulgaris L.) cultivars belonging to 19 commercial classes (Great Northern, Kidney, Navy, Pinto, Red Mexican, Tropical Black, California Small White, Idaho Flat Small White, Pink, and Cranberry). Among the isozyme systems studied, peroxidase (PER) and esterase (EST) were found to be suitable for cultivar identification within most commercial classes and for estimating the genetic relationships among the cultivars of the same class or among the classes. Acid phosphatase (PHOS), due to high proportions of monomorphic bands, could not be considered a good system for such purposes. Within each isozyme system, no pattern was found to be exclusive to any particular commercial class.Based on the number of polymorphic bands in common between each cultivar pair, a banding-similarity index was calculated. The indices were found to be highly significantly correlated with genetic distances obtained by Principal Component Analysis (PCA). In those comparisons where a pedigree relationship could be calculated, a non-significant correlation with similarity indices was obtained. Certain cultivar pair relationships, a minority of the whole, were incorrectly predicted by the isozyme technique. Caution is indicated when this technique is the only basis of assigning relationship. In a few cases, the similarity indices pointed either to close genetic relationships or the lack of such relationships, whereas the reverse is known from pedigree or PCA distance estimates. The reason for such discrepancies is discussed.Some isozymes were unique to a certain tissue, while others were present in more than one. Upon the compilation of bands from all the cultivars, for the leaf, stem, and root tissues respectively. 6, 4, and 0 EST, 9, 10, and 8 PHOS, and 7, 6, and 7 PER bands were obtained.     

马尾松染色体组型和带型的研究

本文对马尾松染色体的组型和带型进行了分析。结果表明,马尾松染色体的数目为2n=24。在分裂中期,其长度为7.62—12.935μ:第1—6及第7—11染色体的长度相近:最短染色体12约为最长染色体1的41%。