Interaction Between Arabidopsis Thaliana And Phytopathogens And Genetic Analysis On Resistance Of A. Thaliana To Phytophthora.capsici

Until now, about 10 disease resistance genes have been cloned from Arabidopsis thaiana, a molecular biological model plant, with short development period, little plant, easily generating and induced mutating, 5 pairs of chromosomes, whose genomic has been sequenced. In order to screen disease resistance accessions of A. thaliana and localize the relative resistance genes, a few of studies focus on: (1) identifying the pathogenicity of parts of crop phytopathogens to A. thaliana; (2) identifying the pathogenicity of Phytophthora spp. De Bary to A. thaliana; (3) identifying the resistance of A. thaliana to P. capsici and P. melongena isolates; (4) establishing the excellent interaction system of P. capsici isolate and A thaliana; (5) Genetic analysis on resistance of A. thaliana to P. capsici isolate; (6) identifying the relative molecular genetic markers to P. capsici isolate resistant genes in A. thaliana. the results are as follows:1. A. thaliana accession Sy-0 was inoculated with the mycelia or spores of 21 species phytopathogens, of which 16 species can infect Sy-0, and other 5 can't infect it. The difference exists on the pathogenicity of all phytopathogens. to A. thaliana.2. A. thaliana accession Sy-0 was inoculated with the mycelia and the zoospores of P. melongenea isolate, the mycelia and the sporangia of P. capsici isolate, P. nicotianae. P. parasitica and P. sojae, of which 4 species Phytophthora spp. can infect Sy-0. The results of evaluation on inoculating Sy-0 with the mycelia and the spores of 5 species Phytophthora spp., showed that there was a significant positive relationship between the two results.3. There's significant difference within the resistance of A. thaliana to P.melongena isolate, among which accessions Eds-1 and C24 are high resistant, R8 is moderate resistant and the others are susceptible.There's significant difference within the resistance of A. thaliana to P. capsici isolate,too, among which accession Can-0 is resistant and Col-gl, Ws-0, Kas-1 are moderate resistant, while Ms-0 is moderate susceptible and the others are susceptible.4. The optimized interaction system was established by inoculating the sporangia to Can-O(R) and Ler(S) with 1.0 104spores/ml.5. The disease was not observed after inoculating Fl strain of Can-0 XLer with the mycelia and sporangia of P. capsici isolate. The result showed that the resistance of Can-0 to P. capsici isolate could confer to filial generation, suggested that the resistance was controlled by dominant genes. The chi-square test on p2 segregate populations of Can-0 XLer indicated that one pair of dominant genes control the resistance.6. The resistance and susceptibility populations were constructed respectively, which used 20 resistant and 20 susceptible individuals A. thaliana (to P. capsici isolate) from F2 segregate populations of Can-0 Ler, Genomic DNA was extracted and was amplified with a pair of special primers NIT1F/NIT1R for testing the quantity of the genomic DNA. Then, DNA of 8 resistance individuals selected from the resistance populations were mixed with equal each to construct the resistance sample pool(R bulk), and DNA of 8 susceptibility individuals selected from the susceptibility populations were mixed with equal each to construct the susceptibility sample pool(S bulk). 50 10-nucleotide random primers were used to amplify the DNA samples of the R and S bulks. A special DNA band in R bulk was identified through comparison the finger maps of RAPD production with the primer C1.