Production and identification of haploid dwarf male sterile wheat plants induced by corn inducer.

BACKGROUND: Using the cross of wheat and maize is a very useful way to produce wheat haploid plants by chromosome elimination. Dwarf male sterile wheat (DMSW) and corn inducer are potential important germplasm for wheat breeding by recurrent selection and doubled haploid strategies. There is no report yet to achieve the haploid plants from DMSW induced by maize inbred line and especially the corn inducer. RESULTS: Haploid plants of DMSW were successfully obtained in this study induced by both maize pollens of inducer line and normal inbred line. The efficiencies for wheat embryos formation and plantlets production induced by the two corn lines had no significant difference. All the eleven haploid wheat plants derived from the male sterile material were identified by botanic appearance, cytology, cytogenetics, and molecular markers. They were all haploid based on their guard cell length of 42.78-42.90 µm compared with the diploid control of 71.52 µm, and their chromosome number of 21 compared with the diploid control of 42. In addition, according to anthers, plant height, and molecular markers, the haploid plants were divided into two types. Eight of them showed dwarf, having no anthers, and the special band of Rht10, and the other three plants displayed normal plant height, having anthers, and not containing the special band of Rht10, indicating that they were originated from the MS2/Rht10 and ms2/rht10 female gametes, respectively. CONCLUSIONS: MS2/Rht10 haploid plants were successfully obtained in this study by using corn inducer and inbred line, and will be employed as candidate materials for the potential cloning of MS2 dominant male gene.

Synthesis, characterization, and DNA binding of a novel ligand and its Cu (II) complex.

A novel naphthalene-2,3-diamine-2-salicylaldehyde (NS) ligand and its mononuclear copper(II) complex (CuNS) have been synthesized and structurally characterized. The UV­vis absorption and emission spectra of NS showed obvious changes on addition of Cu2+ solution. The interaction of the compounds with calf thymus DNA and G-quadruplex DNA were investigated by spectroscopic methods and thermal melting assay. The nucleolytic cleavage activity of the compounds was investigated on double-stranded circular pBR322 plasmid DNA and G-quadruplex DNA by electrophoretic mobility shift assay. The results show that CuNS has a greater ability to stabilize G-quadruplex DNA over calf-thymus DNA. The cytotoxicity of the compounds toward HpeG2 cancer cells was also studied, and they showed significant potential for antineoplastic effects.

[Development of new PCR markers specific to a Thinopyrum intermedium chromosome 2Ai-2 and cloning of the St-specific sequences].

To meet the need of selecting translocation lines, some new RAPD markers for 2Ai-2 chromosome of Th. intermedium were identified in the paper. Out of 320 RAPD primers, 2 specific primers, OPO05 and OPM04, can amplify respectively a specific band with size of about 650 bp and 1400 bp in the BYDV resistant materials containing the chromosome 2Ai-2, including Th. intermedium, wheat-Th. intermedium partial amphipoild Zhong 4 Awnless, addition lines Z1, Z2 and Z6, F1(Z2/Wan7107) and substitute line ZD28 etc, but absent in all the materials lacking the 2Ai-2 chromosome, including susceptible wheat parents and other wheat-Th. intermedium addition lines L1 and Z4. The RAPD markers specific to chromosome 2Ai-2, OPO05(650) and OPM04(1400), may be located on the St genomic region of 2Ai-2 chromosome by PCR analysis on Th. intermedium (E1E2St), Pseuderogneria strigosa (St), Th. elongatum (E), Haynaldia villosa (V), Secale cereale (R), Hordeum vulgare (H), Aegilops squrrosa (D) and Triticum aestivum (ABD) genomic DNA. The specific bands of RAPD markers OPO05(650) and OPM04(1400) were isolated and cloned. After the clones were subjected to restrict digestion analysis, PCR and Southern hybridization analysis, some clones were sequenced. Based on the sequences, 1 pair of primers SC-O5(U + L) and 1 pair of primers SC-M4(U + L) were designed, synthesized and used to amplify the materials with and without 2Ai-2 chromosome. The results showed that the SCAR markers of chromosome 2Ai-2, SC-O5 and SC-M4, were converted successfully from the RAPD markers OPO05(650) and OPM04(1400). The Th. intermedium fragments amplified by the primers of SC-O5 (U + L) and SCM4(U + L) were cloned and analyzed. The results of Southern hybridization indicated that TiSCO5, the cloned fragment of Th. intermedium amplified by primers of SC-O5(U + L) was a low-copy sequence specific to St genome, and another sequence TiSCM4, the cloned fragment of Th. intermedium amplified by primers of SC-M4(U + L) was a repeat sequence specific to St genomic. The sequences will be new probes to detect St genomic chromatin.