Abstract:

A few papers reported the successful transformation and expression of woody plant cold-resistant gene in forest tree. Recently, we have obtained AmGS(galactinol synthase gene of Ammopiptanthus mongolicus)transgenic Photinia×fraseri ‘Red Robin’ plants.This paper reports the molecular identification of the transgenic plants by PCR, Southern blot and RT-PCR analyses. Results indicated that the AmGS gene had integrated into the genomic DNA of transgenic plants of R6 and R7 lines and expressed at transcriptional level. After 6 generations of propagation by shoot cuttings, it was found that the transformed AmGS gene was detected in all of the examined plants in all of the 6 generations propagated by cuttage. Results of cold resistance tests pointed out that in all of the low temperature treatments, the transgenic lines exhibited higher survival rates than that of the untransformed control plants. After cold treatment, transgenic plants had less increase in the relative electrical conductivity (REC) than untransformed control plants. LT₅₀ of transgenic lines of R6 and R7 was remarkable lower than that of the untransformed control plants. These results indicated that the imported AmGS gene increased the cold resistance of transgenic lines R6 and R7.

Key words: Photinia×, fraseri &lsquo, Red Robin&rsquo, transgenic plant, Ammopiptanthus mongolicus, AmGS gene, cold resistance, molecular identification