甘蓝型油菜(Eru CMS)与甘蓝种间杂种的同工酶和蛋白质分析

经胚抢救获得甘蓝型油菜(Brassica napus L.)(Eru CMS)与甘蓝(Brassica oleracea L.var.capitata L.)种间杂种,前期经过流式细胞仪、柱头染色体数目、花粉活力等分析获得一些真杂种。利用电泳法,对真杂种植株的3种同工酶(SOD、EST、COD)和蛋白质进行详细分析,了解了杂种与亲本的同工酶和蛋白质的特性差异。结果表明,杂种与亲本之间的同工酶和蛋白质存在较明显的差异:杂种的SOD、COD的酶带表现为偏父本甘蓝型;杂种的EST的酶带表现为偏母本油菜型;杂种的蛋白质电泳表现为不仅具有双亲的特征蛋白带,也有其自身特征蛋白带。     

Multispecies genetic structure and hybridization in the Betula genus across Eurasia

Boreal and cool temperate forests are the major land cover of northern Eurasia, and information about continental‐scale genetic structure and past demographic history of forest species is important from an evolutionary perspective and has conservation implications. However, although many population genetic studies of forest tree species have been conducted in Europe or Eastern Asia, continental‐scale genetic structure and past demographic history remain poorly known. Here, we focus on the birch genus Betula, which is commonly distributed in boreal and cool temperate forests, and examine 129 populations of two tetraploid and four diploid species collected from Iceland to Japan. All individuals were genotyped at seven to 18 nuclear simple sequence repeats (nSSRs). Pairwise among the six species ranged from 0.285 to 0.903, and genetic differentiation among them was clear. structure analysis suggested that Betula pubescens is an allotetraploid and one of the parental species was Betula pendula. In both species pairs of B. pendula and B. plathyphylla, and B. pubescens and B. ermanii, genetic diversity was highest in central Siberia. A hybrid zone was detected around Lake Baikal for eastern and western species pairs regardless of ploidy level. Approximate Bayesian computation suggested that the divergence of B. pendula and B. platyphylla occurred around the beginning of the last ice age (36 300 years BP, 95% CI: 15 330–92 700) and hybridization between them was inferred to have occurred after the last glacial maximum (1614 years BP, 95% CI: 561–4710), with B. pendula providing a higher contribution to hybrids.     

Morphological, molecular and cytological analyses of Carica papaya×C. cauliflora interspecific hybrids

 Morphological, molecular and cytological analyses were performed to assess the hybridity of 120 putative interspecific hybrids of Carica papaya L.×C. cauliflora Jacq. In the putative interspecific hybrids the number of main leaf veins was intermediate between the two parents while the hermaphrodite flower sex form and the low vigour were distinctive features of these hybrids. Petiole length, stem diameter, leaf length, leaf width and flower colour were similar to C. papaya, whereas leaf shape, type, serration, venation, petiole hairiness and flower shape were similar to C. cauliflora. Markers generated by the polymerase chain reaction using 72 10-mer primers (random amplified polymorphic DNA) revealed a high level of polymorphism (64%) between C. papaya and C. cauliflora. Seventeen of these primers yielded reliable and easily scorable polymorphic banding patterns that were further screened to reveal hybrids. A range of 1–5 RAPD primers consistently confirmed that all 120 plants were genetic hybrids, with all of them containing at least one band from the male parent. Cytological analysis revealed that 7–48% of the cells in many of the interspecific hybrids were aneuploid suggesting that chromosome elimination was occurring. The frequency of aneuploid cells was negatively associated (r=0.88) with the number of bands from the male parent integrated into the hybrid. Pollen fertility of the hybrids was from 0.5 to 14.0% while C. papaya and C. cauliflora had 88.0–99.0% and 90.0–97.0% fertile pollen, respectively. Received: 28 February 1996 / Accepted: 27 September 1996     

Somatic hybrid plants produced by electrofusion between Solanum melongena L. and Solanum torvum Sw

Summary Somatic hybrid plants between eggplant (Solanum melongena) and Solanum torvum have been produced by the electrofusion of mesophyll protoplasts in a movable multi-electrode fusion chamber. Using hair structure as a selection criteria, we identified a total of 19 somatic hybrids, which represented an overall average of 15.3% of the 124 regenerated plants obtained in the two fusion experiments. Several morphological traits were intermediate to those of the parents, including trichome density and structure, height, leaf form and inflorescence. Cytological analyses revealed that the chromosome numbers of the somatic hybrids approximated the expected tetraploid level (2n=4x=48). Fifteen hybrid plants were homogeneous and had relatively stable chromosome numbers (46–48), while four other hybrids had variable chromosome numbers (35–48) and exhibited greater morphological variation. The hybridity of these 19 somatic hybrid plants was confirmed by analyses of phosphoglucomutase (Pgm) and esterase zymograms.     

外来种池蝶蚌与本地种三角帆蚌及其杂交种对三种生态因子的耐受力

为了探索外来种池蝶蚌引入的生态风险,对池蝶蚌(C)与三角帆蚌(S)及其杂交种正交F1(三角帆蚌♀×池蝶蚌♂,SC)、反交F1(池蝶蚌♀×三角帆蚌♂,CS)幼蚌的低氧、干露和重金属汞耐受力进行了比较研究.结果表明:4种幼蚌对低氧、干露和重金属汞均有不同程度的耐受能力.其中CS 的窒息点最低(0.92 mg·L-1),对低氧的耐受力最强,其次是C和SC,窒息点分别为1.04和1.10 mg·L-1,S窒息点最高(1.31 mg·L-1),方差分析表明S与其它3种差异均极显著(P＜0.01),耐低氧能力最弱.C、SC和CS的干露耐受力无明显差异,但要显著强于S(P＜0.01).根据4种幼蚌72 h和96 h对汞的半致死浓度的耐受力由强至弱依次为C＞CS＞SC＞S.表明池蝶蚌的耐受力显著强于三角帆蚌,今后应加强对池蝶蚌的监控和防范力度,以避免对中国的特有种三角帆蚌构成生存威胁.     

Introgression of bread wheat chromatin into tall wheatgrass via somatic hybridization

Regenerates were obtained following somatic hybridization between tall wheatgrass (Agropyron elongatum) and bread wheat (Triticum aestivum cv. Jinan177) protoplasts. Two lines (CU and XI) were self-fertile in the first (R₀) and subsequent (R₁ and R₂) generations. The phenotype of each R₁ population was uniform. All CU progeny were phenotypically similar to the tall wheatgrass parent, while XI progeny had thinner, smoother and softer leaves. Cytological analysis showed that more wheat chromatin was present in the hybrid callus than in the R₁ and R₂ plants, and that some intercalary translocations of wheat chromosome segments were retained in the R₂ generation. AFLP profiling confirmed the presence of wheat DNA in the introgression lines. Analysis of the high molecular weight glutenin subunit content of derived seed identified three novel subunits, not present in either the wheat or the tall wheatgrass parent. Microsatellite-based profiling of the chloroplast genome of the introgression lines suggested that only chloroplast sequences from the tall wheatgrass parent were present. The specifically inherited phenomena and possible application of these hybrids are discussed. Haifeng Cui and Zhiyong Yu were contributed equally to this article.     

Progress of chromosome engineering mediated by asymmetric somatic hybridization

Plant somatic hybridization has progressed steadily over the past 35 years. Many hybrid plants have been generated from fusion combinations of different phylogenetic species, some of which have been utilized in crop breeding programs. Among them, asymmetric hybrid, which usually contains a fraction of alien genome, has received more attention because of its importance in crop improvement. However, few studies have dealt with the heredity of the genome of somatic hybrid for a long time, which has limited the progress of this approach. Over recent ten years, along with the development of an effective cytogenetical tool ＂in situ hybridization （ISH）＂, asymmetric fusion of common wheat （Triticum aestivum L.） with different grasses or cereals has been greatly developed. Genetics, genomes, functional genes and agricultt, ral traits of wheat asymmetric hybrids have been subject to systematic investigations using gene cloning, genomic in situ hybridization （GISH） and molecular makers. The future goal is to fully elucidate the functional relationships among improved agronomic traits, the genes and underlying molecular mechanisms, and the genome dynamics of somatic introgression lines. This will accelerate the development of elite germplasms via somatic hybridization and the application of these materials in the molecular improvement of crop plants.     

Synthesis and biological evaluation of berberine–thiophenyl hybrids as multi-functional agents: Inhibition of acetylcholinesterase,butyrylcholinesterase, and Aβ aggregation and antioxidant activity

A series of berberine–thiophenyl hybrids were designed, synthesised, and evaluated as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and β-amyloid (Aβ) aggregation and as antioxidants. Among these hybrids, compounds 4f and 4i, berberine linked with o-methylthiophenyl and o-chlorothiophenyl by a 2-carbon spacer, were observed to be potent inhibitors of AChE, with IC₅₀ values of 0.077 and 0.042 μM, respectively. Of the tested compounds, 4i was also the most potent inhibitor of BuChE, with an IC₅₀ value of 0.662 μM. Kinetic studies and molecular modelling simulations of the AChE-inhibitor complex indicated that a mixed-competitive binding mode existed for these berberine derivatives. The biological studies also demonstrated that these hybrids displayed interesting activities, including Aβ aggregation inhibition and antioxidant properties.     

异源四倍体鲫鲤、三倍体湘云鲫和它们父母本线粒体DNA 12S rRNA基因遗传变异的分析

采用质粒克隆测序方法,获得了异源四倍体鲫鲤5个个体、异源四倍体鲫鲤雌核发育二倍体后代2个个体、三倍体湘云鲫2个个体及红鲫、湘江野鲤和日本白鲫各1个个体的线粒体DNA 12S rRNA基因的全序列。经对比发现,异源四倍体5个个体共享2种单元型,异源四倍体鲫鲤雌核发育二倍体后代2个个体、三倍体湘云鲫2个个体以及红鲫、湘江野鲤和日本白鲫各1个个体分别共享1种单元型。用MEGA 1.0 软件分析了它们的碱基组成和核苷酸序列差异,用邻接法构建系统进化树。它们间的序列同源性在95%~99%之间,异源四倍体鲫鲤、三倍体湘云鲫和它们母本（分别为红鲫和日本白鲫）之间的序列同源性大于异源四倍体鲫鲤、三倍体湘云鲫和它们父本（分别为湘江野鲤和异源四倍体鲫鲤）之间的序列同源性,结果表明：异源四倍体鲫鲤和三倍体湘云鲫在线粒体DNA 12S rRNA基因上具有母性遗传特征。本研究另一值得注意地方的是异源四倍体鲫鲤经过9代(F3-F11)繁殖后,在5个个体中发现了2种单元型,说明在四倍体基因库中存在遗传多样性,为四倍体基因库的繁殖、保护和种群复壮提供了一些有价值的信息。