[Construction of genetic linkage map and localization of NBS-LRR like resistance gene analogues in cauliflower (Brassica oleracea var. botrytis)].

Nucleotide binding site (NBS) profiling, a new method was used to map resistance gene analogues (RGAs) in cauliflower (Brassica oleracea var. botrytis). This method allows amplification and the mapping of genetic markers anchored in the conserved NBS encoding domain of plant disease resistance genes. AFLP was also performed to construct the cauliflower intervarietal genetic map. The aim of constructing genetic map was to identify potential molecular markers linked to important agronomic traits that would be particularly useful for development and improving the species. Using 17 AFLP primer combinations and two degeneration primer/enzyme combinations, a total of 234 AFLP markers and 21 NBS markers were mapped in the F2 population derived from self-pollinating a single F1 plant of the cross AD White Flower x C-8. The markers were mapped in 9 of major linkage groups spanning 668.4 cM, with an average distance of 2.9 cM between adjacent mapped markers. The AFLP markers were well distributed throughout the linkage groups. The linkage groups contained from 12 to 47 loci each and the distance between two consecutive loci ranged from 0 to 14.9 cM. NBS markers were mapped on 8 of the 9 linkage groups of the genetic map. Most of these markers were organized in clusters. This result demonstrates the feasibility of the NBS-profiling method for generating NBS markers for resistance loci in cauliflower. The clustering of the markers mapped in this study adds to the evidence that most of them could be real RGAs.

[Stable carbon isotopic composition in PM 2.1 in Nanjing Region].

Stable carbon isotopes (delta13C) in aerosol fine particles (PM2.1) collected in Nanjing Normal University representing urban area, and in Nanjing College of Chemical Technology standing for suburban industrial area, were analyzed using EA-IRMS. Besides, sources of carbonaceous contents were studied and the pollution characteristics of total carbon (TC) were evaluated. The annual average concentrations of TC in urban area and suburban industrial area were 15.94 microg.m-3 and 17.17 microg.m-3, respectively. The proportions for TC in PM2.1 were 17.18% and 16. 40% , indicating that carbonaceous pollution was more serious and the pollutants were more complex in suburban industrial area. The average delta13C for winter, spring, summer and autumn were -24. 42 per thousand +/- 1. 12 per thousand, -25. 19 per thousand +/- 1. 92% per thousand, - 25.79 per thousand +/- 0.45 per thousand and - 25.58 per thousand + 0. 65 per thousand, respectively in urban area and - 25.34 per thousand +/- 1. 18 per thousand, -25. 55 per thousand +/- 1. 50 per thousand, -25. 31 per thousand +/- 0. 55%o and -25. 38 per thousand +/- 0. 82 per thousand, respectively in suburban area. Correlation analysis and isotopic signatures of potential sources suggested that carbonaceous contents mainly came from gasoline vehicles exhaust in urban area, and might be attributed to the vehicle exhaust emissions and industrial emissions in suburban area. In addition, coal combustion,biomass burning and geological sources might have important contribution to aerosols in winter and spring. Back trajectory analysis implied that the long-range transport had considerable contribution to the carbonaceous aerosol in winter and spring. However, the major sources might be attributed to local emissions in the other two seasons.

[Isolation and identification of specific sequences correlated to cytoplasmic male sterility and fertile maintenance in cauliflower (Brassica oleracea var. botrytis)].

Analysis of ISSR (Inter-Simple Sequence Repeat) and DDRT-PCR (Differential Display Reverse Transcriptase Polymerase Chain Reaction) was performed between cytoplasmic male sterility cauliflower ogura-A and its corresponding maintainer line ogura-B. Totally, 306 detectable bands were obtained by ISSR using thirty oligonucleotide primers. Commonly, six to twelve bands were produced per primer. Among all these primers only the amplification of primer ISSR3 was polymorphic, an 1100 bp specific band was only detected in maintainer line, named ISSR3(1100). Analysis of this sequence indicated that ISSR3(1100) was high homologous with the corresponding sequences of mitochondrial genome in Brassica napus and Arabidopsis thaliana,which suggested that ISSR3(1100) may derive from mitochondrial genome in cauliflower. To carry out DDRT-PCR analysis, three anchor primers and fifteen random primers were selected to combine. Totally, 1122 bands from 1 000 bp to 50 bp were detected. However, only four bands, named ogura-A 205, ogura-A383, ogura-B307 and ogura-B352, were confirmed to be different display in both lines. This result was further identified by reverse Northern dot blotting analysis. Among these four bands, ogura-A205 and ogura-A383 only express in cytoplasmic male sterility line, while ogura-B307 and ogura-B352 were only detected in maintainer line. Analysis of these sequences indicated that it was the first time that these four sequences were reported in cauliflower. Interestingly, ogura-A205 and ogura-B307 did not exhibit any similarities to other reported sequences in other species, more investigations were required to obtain further information. ogura-A383 and ogura-B352 were also two new sequences, they showed high similarities to corresponding chloroplast sequences of Arabidopsis thaliana and Brassica rapa subsp. pekinensis. So we speculated that these two sequences may derive from chloroplast genome. All these results obtained in this study offer new and significant information to investigate the molecular mechanism of cytoplasmic male sterility and fertile maintenance in cauliflower.

[Identification of molecular markers linked to the fertility restoring gene for the CMS Capsicum annuum L].

Bulked segregant analysis method was used to identify random amplified polymorphic DNA (RAPD) markers linked to the fertility restoring gene for the cytoplasmic male sterility (CMS) capsicum annum L. Totally 336 random primers were screened on the DNA samples of restorer and sterile bulks. Primer S418 produced a special band in restorer line. It was about 3000 bp, including two fragments 1515 bp and 1162 bp. Fluorescence in situ hybridization(FISH) indicated the fragment of 1515 bp only existed in restorer line.It was designed to S418(1515). Analysis of the sequence indicated S418(1515) was unknown before. The homology of blastn was less than 40%, however the homology of tBlastx indicated this sequence was high homologous with the part sequences of rice which were distributed on 2,4,7,10 chromosomes. It suggested this sequence might have the similar function with them. This result offered a good foundation to research the molecular mechanism of fertility restoration for CMS capsicum. Based on the sequence, special primers were designed to transform the RAPD marker to PCR marker. The result indicated that these primers could be used to screen the restorer lines from a large quantitive of candidate lines.