Establishment Of Regeneration In Vitro And Genetic Transformation Systerm In Cucumber (Cucumis Sativus L.)

Cucumis sativus L. is a kind of important vegetable crop, which is cultivated in worldwide area in the world. With the progress of molecular techniques, genetic transformation technology has been applied in genetic improvement of many plants. However, in cucumber this technique is still far from application for its breeding. Bitterness genotype of cucumber was controlled by Bi dominant gene, which severely affected the taste of cucumber and should be improved.This study focused on improving plantlet regeneration from cucumber cotyledon handles by selection of genotype and hormone combination, and establishment of cucumber Agrobacterium-mediated transformation system. The results obtained are as follows:1, Establishment of planlet regeneration system. The experiments showed that the requirement for nutrition varied among genotypes. The suitable medium for G8was MS+1.5mg/16-BA+0.5mg/l ABA+2.0mg/l AgNO3which gave4.1buds per explant in average. For chuanbai1792and9930, the suitable medium was MS+2.0mg/16-BA+1.0mg/1ABA+2.0mg/l AgNO3which gave6.5and5.1buds separately per explant in average. For banna, the suitable medium was MS+6-BA1.0mg/l+ABA0.5mg/l+AgNO32.0mg/l which gave3.7buds per explant in average.2, Genetic transformation and plant regeneration. We improved Agrobacterium-mediated transformation system of G8cucumber including suitable infection time of15min and As concentration of20uM.10resistant plantlets were confirmed by PCR, qRT-PCR and HPLC analysis. The result showed that expression of Bi in3lines increased compared to the control pantlets.