Morphology,fertility and cytogenetics of intergeneric hybrid between Roegneria kamoji Ohwi and Dasypyrum villosum (L.) Candargy (Poaceae: Triticeae)

The intergeneric hybrids between Roegneria kamoji Ohwi and Dasypyrum villosum (L.)Candargy were successfully obtained by means of embryo culture in vitro. Studies on morphology, fertility and chromosome pairing behavior in meiosis of the parents and their hybrid F_l were carried out in the present work. The results showed that: (1) there were ob vious morphological differences between R. kamoji and D. villosum, and spikes of F_l plants were morphologically intermediate between the two parental species; (2) the seed set of the cross was 11.63%; the hybrid plant was infertile, which indicated that strong repro ductive isolation existed between the parents and R. kamoji and D. villosum were inde pendent biological species; (3) The somatic chromosome number in root-tips of F_l hybrids was 28. Chromosome pairing at MI of PMCs in F_l hybrids was quite low. The meiotic con figuration was 26.72 Ⅰ + 0.62 Ⅱ + 0.02 Ⅲ, which indicated that very low homoeology was detected between the St, H, Y genomes of R. kamoji and the V genome of D. villo- sum, and the relationship between the parental species was remote.     

仲彬草属八个物种的核型

报道了仲彬草属 (KengyiliaYenetJ .L .Yang) 8个物种的核型 ,其中 4个种的核型为首次报道。核型公式是 :阿勒泰仲彬草K alatavica ,2n =6x =4 2 =36m 6sm ;长颖仲彬草K longiglumis,2n =6x =4 2 =36m 6sm ;大颖仲彬草K grandiglumis,2n =6x =4 2 =36m 6sm ;窄颖仲彬草K stenachyra ,2n =6x =4 2 =36m 6sm ;喀什仲彬草K kasgarica ,2n =6x =4 2 =32m 10sm ;梭罗仲彬草K thoroldiana ,2n =6x =4 2 =36m 6sm ;黑药仲彬草K melanthera ,2n =6x =4 2 =36m 6sm ;矮生仲彬草K nana ,2n =6x =4 2 =34m 8sm。它们的核型属于 1B或 2B型 ,染色体中均未发现随体     

接头蛋白Gab1的结构及功能研究进展

Gab1蛋白属于接头蛋白Gab家族,该家族蛋白因能与生长因子受体结合蛋白2（Grb2）相结合而得名。作为接头蛋白,Gab1蛋白能被多种受体酪氨酸激酶或非受体酪氨酸激酶激活,接受胞外多种生长因子、细胞因子和一些T/B细胞抗原受体的刺激,介导PI3K/Akt和Ras/MAPK等多条信号转导途径,具有促进细胞生长、迁移、调节免疫等多种生物学功能,与糖尿病、肿瘤、心血管疾病等的发生发展密切相关。     

Molecular Characterization of the pina Gene in Einkorn Wheat

Fifty-six sequences encoding the pina protein were characterized from three species or subspecies of einkorn wheat. These sequences contained 1,595 nucleotides, including 1,270 conserved sites, 21 single nucleotide polymorphisms (SNPs), and 16 indels. The average frequency of SNPs and indels was one out of 76.1 and 99.9 bases, respectively. Five SNPs and no indels were found in the translated sequences. Fourteen haplotypes were defined, and the accessions in each haplotype ranged from 1 to 18. There were nine haplotypes in Triticum monococcum ssp. aegilopoides, eight in T. monococcum ssp. monococcum, and two in T. urartu. Phylogenetic analysis showed that pina genes from different species or subspecies could be clearly differentiated based on the open reading frame. Genes from T. urartu grouped together, whereas genes from T. monococcum ssp. aegilopoides and T. monococcum ssp. monococcum were shared by three and two clusters, respectively. Both the haplotype and phylogenetic analyses indicated that T. monococcum ssp. aegilopoides was more diverse. These results would contribute to the understanding of functional aspects and efficient utilization of pina genes.     

Phylogeny and evolutionary history of Leymus (Triticeae; Poaceae) based on a single-copy nuclear gene encoding plastid acetyl-CoA carboxylase

Background  

Single- and low- copy genes are less likely subject to concerted evolution, thus making themselves ideal tools for studying the origin and evolution of polyploid taxa. Leymus is a polyploid genus with a diverse array of morphology, ecology and distribution in Triticeae. The genomic constitution of Leymus was assigned as NsXm, where Ns was presumed to be originated from Psathyrostachys, while Xm represented a genome of unknown origin. In addition, little is known about the evolutionary history of Leymus. Here, we investigate the phylogenetic relationship, genome donor, and evolutionary history of Leymus based on a single-copy nuclear Acc1 gene.     

Characterization of a novel variant HMW-glutenin gene from Elymus canadensis

High molecular weight (HMW) glutenin subunits (GS) play a key role in the determination of end-use quality of wheat and other cereal crops. In this study, we report the isolation and characterization of both promoter region and ORF of novel HMW-GS allele 1St1.3 from a perennial Triticeae species, Elymus canadensis. The amino acid (AA) sequences of E. canadensis 1St1.3 were deduced as 434 aa. Its protein primary structure comprises a signal peptide with a conserved N-terminal domain, a central repetitive domain and a C-terminal domain. E. canadensis 1St 1.3 possesses several distinct characteristics which are different from those of wheat HMW-GSs. The N-terminal domains of E. canadensis 1St 1.3 resemble that of y-type subunits, while their C-terminal domains are more similar to x-type subunits. The deletion of 85 bp fragment has been observed in promoter region of 1St 1.3, however which has not interrupted the expression of this gene. Our results indicate that 1St 1.3 is novel HMW-GS variants which will be valuable for enhancing our understanding of structural differentiation and the evolutionary relationship among HMW-GSs in Triticeae species.     

Characterization of barley <Emphasis Type="Italic">Prp1</Emphasis> gene and its expression during seed development and under abiotic stress

The pre-mRNA processing (Prp1) gene encodes a spliceosomal protein. It was firstly identified in fission yeast and plays a regular role during spliceosome activation and cell cycle. Plant Prp1 genes have only been identified from rice, Sorghum and Arabidopsis thaliana. In this study, we reported the identification and isolation of a novel Prp1 gene from barley, and further explored its expressional pattern by using real-time quantitative RT-PCR, promoter prediction and analysis of microarray data. The putative barley Prp1 protein has a similar primary structure features to those of other known Prp1 protein in this family. The results of amino acid comparison indicated that Prp1 protein of barley and other plant species has a highly conserved 3′ termnal region while their 5′ sequences greatly varied. The results of expressional analysis revealed that the expression level of barley Prp1 gene is always stable in different vegetative tissues, except it is up-regulated at the mid- and late stages of seed development or under the condition of cold stress. This kind of expressional pattern for barley Prp1 is also supported by our results of comparison of microarray data from barley, rice and Arabidopsis. For the molecular mechanism of its expressional pattern, we conclude that the expression of Prp1 gene may be up-regulated by the increase of pre-mRNAs and not be constitutive or ubiquitous.     

两系杂交小麦恢复系MR168抗条锈病基因遗传分析及分子标记定位

小麦条锈病是影响杂交小麦普及推广的重要因素。文章利用基因推导法和SSR分子标记技术,研究了温光型两系杂交小麦恢复系MR168的抗条锈性遗传规律及其控制基因染色体位置。结果表明,MR168对CY29、CY31、CY32、CY33等条锈菌生理小种表现高抗至免疫;对SY95-71/MR168杂交组合的正反交F1、BC1、F2和F3群体分单株接种鉴定显示,MR168对CY32号小种的抗性受1对显性核基因控制,该抗病基因来源于春小麦品种辽春10号。利用集群分离分析法(Bulked segregant analysis,BSA)和简单重复序列(Simple sequence repeat,SSR)分子标记分析抗病亲本MR168、感病亲本SY95-71及183个F2代单株,发现了与MR168抗条锈病基因连锁的5个微卫星标记Xgwm273、Xgwm18、Xbarc187、Xwmc269、Xwmc406,并将该基因初步定位在1BS着丝粒附近,暂命名为YrMR168;构建了包含YrMR168的SSR标记遗传图谱,距离YrMR168最近的两个微卫星位点是Xgwm18和Xbarc187,遗传距离分别为1.9 cM和2.4 cM,这两个微卫星标记可用于杂交小麦抗条锈病分子标记辅助育种。     

phKL基因诱导小麦远缘杂种部分同源染色体配对的能力界于Ph1和Ph2基因突变体之间

在普通小麦地方品种自然群体中天然存在促进小麦-外源杂种部分同源染色体配对的基因phKL。本研究比较了phKL基因与人工Ph基因突变系诱导小麦-Aegilops variabilis及小麦-黑麦杂种部分同源染色体配对的作用大小。研究结果表明,诱导小麦- Ae. variabilis(或黑麦)部分同源染色体配对作用的顺序是ph1b > phKL > ph2b > ph2a,即phKL基因的作用介于Ph1与Ph2突变体之间。