| Cucumber (Cucumis sativus L.) is one of the most popular and world-wide commercial vegetables, it has been extensively investigated for genetic engineering. Despite the ability of cucumber to grow under a very wide range of climate and soil condition, problems such as viral, bacterial and fungal diseases and insect pests have contributed to significant reduction in yield, progress in overcoming these problems by conventional breeding has been slow. This has led to more emphasis on genetic engeering improvement of particular traits in cucumber. Plant transgenic approach offers an effective solution for cucumber breeding. Therefore, this research was (?)med to establishing a system of regeneration and genetic transformation of cucumber and obtaining some reporter gene transgenic cucumber materials via Agrobacterium-mediated transformation. The main results were as follow: 1. Confirmed regeneration media of different explants and genotypes ofcucumber.(1) Cotyledon explantTwo to three-day seedling cotyledons of cucumber were suitable explants for regeneration, and an suitable regeneration was achieved in MS medium supplemented with 1.0 mg·L-1 6-BAand 1.0 mg·L-1 AgNO3. Significant differences in the capacity of regeneration were observed among the genotypes . The regeneration frequencies of cultivars - 'IL 69', 'IL 103' and 'IL 67' were up to 94% ,88% and 87%, respectively. The good media of proliferating and elongation of regenerate shoots of cucumber cotyledon were MS+6-BA 2.0 mg·L-1+AgNO3 1.0 mg·L-1 and MS+6-BA 0.1～0. 2 mg·L-1, respectively. Shoot regeneration and multiplication of cucumber cotyledons were promoted by appropriate concentration of AgNO3 (1.0 mg·L-1). (2) Flamingo-bill explantThe suitable shoot inducing medium of flamingo-bill explants (FBE) of cucumber was MS+6-BA 0.5 mg·L-1, and the regeneration frequency was about 96％; There were no significant differences in the capacity of regeneration among the genotypes.(3) Root inducement from regenerate shoots of cucumber Root indutcement was very well from regenerate shoots of 2～3 cm in medium MS.2. Grafting of regenerate shoots of cucumberThe survivor frequency of grafting plants was up to almost 100％when the length of scion (regenerate shoots of cucumber) was about 2.5 cm and the rootstock seedling (Cucurbita moschata (Duch.) Poiret.) age was at the first true leaf stage. Grafting seedling was stronger than no-grafting regeneration's.3. Application of antibiotic(1) Kanamycin (Kan)Shoot regeneration from cotyledons and FBE of non-transformed cucumber cultivars—'IL 69', 'IL 103' and 'IL 67' were completely inhibited by 100 mg·L-1 and 125 mg·L-1 kanamycin respectively. Appropriate concentration of Kan (100 mg·L-1, 125 mg·L-1) selected the transgenetic Cucumber plants at first. Root regeneration from regeneration shoot of non-transformed cucumber was completely inhibited by 30 mg·L-1 Kan.(2) Cefotaxime (Cef)Shoot regeneration of cucumber cotyledon and FBE were not significantly affected in the medium supplemented with 100～400 mg·L-1 Cefotaxime.4. Examination for transformed plants of cucumber(1) Histochemistry examine of X-gluc for roots and leaves of resistant cucumber plants showed that the GUS gene had been transformed in cucumber genome.(2) Genomic DNA was extracted from some X-gluc positive transgenic plants, and the results of PCR confirmed that the GUS gene was integrated into the cucumber genome. In this study, transgenic plants from three genotypes, 'IL 69', 'IL 103',and 'IL 67' were obtained. 5. Comparation between two cucumber transform methodsTransform frequency of Flamingo-bill explant method was higher than cotyledon's; and this method greatly predigested the procedure of Agrobacterium-mediated genetic transformation of cucumber.
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