Genetic Diversity Analysis And The Rice Genetic Transformation Of Trehalose-6-phosphate Synthase Gene Of Porphyra

It is very important to study the genetic diversity of Porphyra lines using molecular marker technique, which could promote the germplasm identification, protection and effectual exploiture of Porphyra. The genetic diversity of Porphyra lines was analysed using molecular marker techniques sequence-related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP) and restriction site amplified polymorphism (RSAP). And the trehalose-6-phosphate synthase gene from Porphyra yezoensis (PyTPS) cloned by our laboratory was transformed to rice variety TP309, in order to study the function of the gene PyTPS.SRAP, TRAP and RSAP analytic system were set up and successfully used in germplasm identification of Porphyra lines in this study firstly. The dendrograms and the DNA fingerprints of sixteen Porphyra lines were constructed according to the result of SRAP, TRAP and RSAP analysis. The dendrograms from 3 marker techniques were accordant with the conventional taxonomy basically. In the DNA fingerprints, each of the 16 Porphyra lines has its unique fingerprinting pattern and can be easily distinguished from each other. The PGI-SRAP, PGI-TRAP and PGI-RSAP (Porphyra germplasm identification developed by SRAP, TRAP and RSAP method) developed by DNA fingerprints could be used to germplasm identification of these Porphyra lines. In addition, seventeen specific RSAP markers were identified and six of them were sequenced. One of the 17 specific markers, R1/R3-8119 from P. yezoensis Y-9101, was successfully converted into sequence characterized amplification region (SCAR) marker.Trehalose-6-phosphate synthase gene from P. yezoensis (PyTPS) cloned by our laboratory was transformed into rice variety TP309 by Agrobacterium mediated method. Three T₂ homozygous lines were obtained by the selection with kanamycin resistance, PCR amplification and Southern blotting analysis. Results indicated that the PyTPS gene had been integrated into the genome of the transgenic rice plants. The tolerance to both salt and drought was compared between two homozygous lines TPS155-4, TPS191-1 and the non-transformed rice plants TP309, imposed 0.8% NaCl and 16% PEG-6000 treatments. The plant height and fresh weight per plant in transgenic plants were better than those of control plants under water, salt and drought stress. The difference between transgenic and control plants for drought stress was obvious. The result demonstrated that the transgenic plants showed apparently increased drought stress tolerance and the slightly increased salt stress tolerance.