Abstract:
Genetic transformation was developed in 4 upland rice varieties namely Dog Payom, Nam Rhu, jaw Hor and R258. Mature seeds were subjected to callus induction and plantlet regeneration. The modified MS medium (R3) containing 2 mg/L 2,4-D and 500 mg/L each of casein hydrolysate and L-proline induced 100 and 88 percent embryogenic calli in Dog Payom and Nam Rhu, respectively. While the N6 medium containing 2 mg/L 2,4 D, 1000 mg/L casein hydrolysate and 500 mg/L L-proline induced 96 and 80 percent embryogenic calli in Jaw Hor and R258, respectively. For Dog Payom and $258, plantlets were successfully regenerated in the CC medium medium containing 20 g/L sucrose, 1 mg/L NAA and 4 mg/L BA. The Cc medium could also induce plantlet regeneration in Jaw Hor and Nam Rhu by adding 1 mg/L IAA and 4 mg/L BA, and 1 mg/L NAA and 3 mg/L BA, respectively. Callus dehydration up to 72 hrs. resulted in the increasing of planlets regeneratin to 82.14 percent in Dog Payom and 71.42 percent in Jaw Hor.Agrobacterium transformation was carried out to transform Jaw Hor with gus gene by using Agrobacterium tumefaciens strain EHA 105. Incubation of Jaw Hor Calli with 1:100 dilutions of AGrobacterium suspension having O.D.600 of 1.2 and 1.5, transformation percentages based on Gus activity were 12 and 30 percent, respectively. The PDS-1000/He particle gun was employed to bombard embryogenic calli. Two plasmids designated as p35SIGN and pCAMBIA 1301, both contain gus gene, were coated on 1 mu gold particles for target gene delivering. The highest expression of gus gene was obtained when embryogenic calli were bombarded under 1,100 psi helium pressure and the target distance between macrocarrier launch assembly and embryogenic calli at 6 and 9 cm. The PDR gene containing RRSV segment 5 antisense was successfully transformed into Dog Payom and R258 as confirmed by the genomic Southern blot analysis.