| Watermenlon is an important economic crops. In China, Watermelon cultivation area is maintained at 1,000,000 hectares per year. Annual output of watermelon more than 30 million tons. Watermelon has a relatively rich genetic diversity. Different germolasm resources exist large differences of trarts. However, the research in watermelon on genetic diversities started too late, especially in the application of modern molecular techniques are inadequate. In order to explore a new method to study the molecular genetic in watermelon. We utilized albino lethal near-isogenic lines of watermelon, F2 generation and their parents for the experimental material. Then using SRAP and EST-SSR molecular markers combined with the main germplasm traits for genetic analysis. In addition, the experiment also explored stigma smear to transfer T-DNA and molecular marker research in watermelon. The main results as follows:We analysed a total of 8619 watermelon ESTs from GenBank and sought out 202 SSR contained in 191 EST sequences. The frequency of the SSRs was 2.31% and mean the distribution density was 1/19.1kb in watermelon. The dominant repeat motifs were dinucleotide and trinucleotide. AG/TG was the most repeat type in dinucleotide(46%) and AAG was the most repeat type in trinucleotide(43%).The most motif repeat times were 4 (17.8%), 7 (15.3%) and 11 (14.9%). The length was mainly distributed between 20 to 30bp.We obtained 24 primer pairs from 202 EST-SSRs in watermelon.Then utilized albino lethal near-isogenic lines of watermelon for verify these primers.We obtained 16 effective amplified primer pairs,accouting for 66.7% of the total number of designed primer pairs. The results suggest that use of public EST databases to develop EST-SSR primers of watermelon are effective method.We utilized albino lethal near-isogenic lines of watermelon and F2 generation for the experimental material. Then using SRAP technique and genetic analysis to research, the result is that we found no molecular marker tightly linked to albino lethal gene among 400 primer pairs.On the other hand,we got 9 SRAP primer pairs which amplified out of 10 difference bands that showed 3:1 separation. Genetic analysis expressed that the rind color,flesh color, fruit shape, seed size, fruit peduncle top shape and thickness of rind et.al. 7 major germplasm traits were not linked to albino lethal gene in watermelon excepted the seed colour. There was certain linkage between the 10 SRAP molecular marker and the 7 major germplasm traits. Among them, markers E6-M2-170 and E14-M2-240 were completely linkage with a distance of 0cM. Seed size was closely linked to thickness of rind at 5.6cM. Fruit peduncle top shape and development period were linked to fruit shape and thickness of rind at 8.0cM and 8.1cM, respectively.From the method of foreign DNA introduced to Arabidopsis thaliana via flowers dip, we used stigma smear to transfer T-DNA into watermelon and its molecular marker research. The results showed the highest fruit setting rate specie is ZXG01078 and its individual single fruit have deviant seedlings. The best concentration of kanamycin treating watermelon seeds is 500~700mg/L with differences among the species. The best position is spire leaf or youngleaf and the best concentration of kanamycin treating the watermelon leaf is 4000~8000mg/ L with no difference among the species. The offspring of individual single fruit can steadily produce no pointing and twinborn seedlings in two years experiment.
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