Callus Induction And Plant Regeneration Of Japanese Lawngrass (Zoysia Japonica Steud.) From Mature Seed

Japanese lawngrass (Zoysia japonica Steud.), commonly used as warm-season turfgrass, has many attractive characteristics for a turf, such as stress tolerant and low water and fertilizer requirements. In good condition of soil and climate, an established and well-maintained zoysiagrass will make a very dense and attractive lawn. The grass is extensively planted in courtyard, playground, golf course, aerodrome, sport field, etc. However, it is susceptive to some disease and insect and the green period is relatively short. The integration of conventional and modern breeding technique, especially modern biology technique, will be able to decrease the period of breeding greatly.The major object of this study was to establish the in vitro plant regeneration system of zoysiagrass which will be valuable for the genetic improvement by genetic engineering means. The major results as following:1. The best media for callus induction was ND+3. 0 mg/L 2,4-0+0.2 mg/L NAA and the ratio of callus induction was 57. 3%. The addition of 500mg/L Proline to the media is beneficial to callus induction. Comparing to the culture under light, the culture under dark can form granule and compact calli more efficiently.2. The best media for callus subculture was MSD+1.0 mg/L 2,4-D. Transformation the sucrose from 30g/L to 40g/L was advantageous for the increasing of the number of granule, compact calli.3. The best differentiation media was MSD+0. 3 mg/L NAA+0. 5 mg/L KT+0. 05 mg/L BA and the ratio of differentiation was 36. 7%. By supplement of 1-5 u mol/L copper to the media the plant regeneration frequency was not evidently increased. And the addition out of 10u mol/Lcopper to the media showed a negative effect: That is the growth rate decreased;Callus became brown and some of calli dead and the ratio of differentiation decreased eventually.4. Some factors and phenomena that affecting callus induction and differentiation were discussed such as the sterilize and treatment of caryopses, the callus induction, the regulation of callus state in subculture and the differentiation of callus.