Studies On Agrobacterium-Mediated Genetic Transformation Of Turfgrasses

In the present study, some factors influencing plant regeneration from mature seed in tall fescue and perennial ryegrass were evaluated. A system for Agrobacterium tumefaciens- mediated genetic transformation of Festuca arundinacea and Lolium perenne was established. The primary results could be summarized as follows.-1. Wide differences were observed among the different auxins and concentrations in callus induction medium in relation to tissue culture of Festuca arundinacea and Lolium perenne. Dicamba was superior to 2, 4-D. From 0 to 9mg/l, the stepwise increase of the 2,4-D concentration in maltose containing callus induction medium obviously increased overall plant regeneration frequency. The supplement of 1 mg l-1 NAA in both the callus induction medium with 5mg l-12, 4-D and that with 5mg l-1 dicamba didn't improve plant regeneration frequency.2. inclusion of a low concentration of 6-BA(0.1 mg l-1) in the callus induction medium were effective for plant regeneration of Festuca arundinacea. However, higher concentrations of 6-BA obviously inhibited callus formation and exhibited lower regeneration rate.3. 2 mg r'ABA was tested in the callus induction medium. The results showed that the growth of shoot was suppressed and less calli were observed. There was a decrease in plant regeneration frequency of Festuca arundinacea.4. Among MS, B5 and M8 vitamins, the B5 vitamins were the most efficient for callus formation and plant regeneration of Festuca arundinacea and the MS vitamins were least.5. Proline, glutamine and casein hydrolysate at a low concentration(100mg l-1) improved plant regeneration of Festuca arundinacea. However, higher concentrations proved to be detrimental rather than beneficial.6. The replacements of maltose by sucrose in the callus induction medium significantly improved overall plant regeneration frequency of Lolium perenne.7. 50mg l-1 hygromycin supplemented in the callus differentiation medium resulted inhigher selection frequency.8. An Agrobacterium fa/we/ac/ens-mediated genetic transformation system for Festuca arundinacea and Lolium perenne was established. 46 Lolium perenne and 7 Festuca arundinacea plants were regenerated under selection. PCR analysis showed that 6 Lolium perenne and 1 Festuca arundinacea PCR-positive plants were obtained.