Establishment Of DNA Fingerprinting Of Backbone Parental Lines Of Hybrid Rice And Study On Heterologous Expression Of PyTPS Gene Increasing The Resistance Against The Osmotic Stress Tolerance In Transgenic Rice

The study composed of two parts,in one of them,simple sequence repeat(SSR)analyses were performed to identify 18 hybrid rice varieties, including major gene donors of Y58S,a photo-thermo-sensitive genic male sterile(PTGMS)line,seven other rice PTGMS lines related to Y58S and 5 backbone restoring lines widely used in hybrid rice breeding in China.After 60 pairs of SSR primer were screened,cluster analysis was carried out based on the data from 12 of them.Three of the 12 pairs were used to establish the DNA fingerprints of the 18 hybrid rice varieties. The developed DNA fingerprints and the complementary amplification are particularly valuable in the identification of hybrid rice lines.In the other study,Two transgenic rice lines TPS191-1and TPS155-4 were used for genetic transformation of the TPS gene from Porphyra yezoensis(PyTPS)enhance osmotic tolerance.Genomic DNA PCR and southern blotting analyses were performed to detect the PyTPS gene in transgenic rice lines.Osmotic stress induced by drought stress and salt stress were simulated with a gradient of PEG 6000 and NaCl concentrations supplemented in the nutrient solution.The differences of phenotypic resistances were tested by comparing plant height and electrical conductivity between the transgenic rice lines and wild type (WT).Osmotic stress in rice plants.Phenotypic difference was analysed in height and electrical conductivity of transgenic rice lines and wild type (WT).A reverse transcription-PCR(RT-PCR)assay was utilized for the detection of PyTPS gene transcription in transgenic rice.Main results are listed as follows.1.Cluster analysis showed the genotypes could be divided into two major groups(Groupâ… and Groupâ…¡)givern a similarity level of 0.672.Groupâ… contains Y-liangyou-1,Liangyou Pei-9 and their male parent(9311)and Groupâ…¡included all of PTGMS lines and the remaining restoring lines.Groupâ…¡was categorized into two groups at a similarity level of 0.72,and all of the PTGMS lines belonged to one of them.2.Fourteen bands that were stably and repeatedly amplified by RM164,RM18 and RM258 were used to develop the DNA fingerprints of the 18 hybrid rice varieties,each of which has its unique DNA fingerprinting pattern and can be distinguished from the others.3.A pair of SSR primer,RM164,makes a complementary amplification of two leading super hybrid rice varieties(Y-liangyou-1 and Liangyou Pei-9)and their corresponding parental lines.4.A specific band RM164301,amplified by SSR marker RM164, was only obtained from Lemont,Y58S and Y-liangyou-1,which had related genetic background.5.PyTPS gene had been integrated into the genomes of two transgenic rice lines TPS 191-1 and TPS 155-4.As a result,the osmotic stress tolerance in the two transgenic rice lines was strengthened as well.One of the transgenic lines,TPS155-4,was more osmotic stress tolerant than TPS 191-1.