Study On Differentiation Of Tomato/Eggplant Graft Union Tissue

Eggplant and tomato were used for in vitro graft system, shoot differentiation and variation of graft union tissue using tissue culture and cell suspension culture. The main results of this research are shown as follows.(1) The graft combination and plant growth regulator were studied for establishing simple in vitro graft system. The results showed that using tomato and eggplant as rootstock and scion respectively was optimal graft combination. Survival rate of graft was 96ï¼…, and length of scion was 1.43 cm. When the combination of plant growth regulators was 6-BA 0.1mg/L +KT 0.1mg/L+IBA 0.05mg/L in MS medium, survival rate of graft was the highest (93.3ï¼…).(2) Appropriate medium was sought to enhance survival rate, induction and differentiation of tissue. The results showed that high survival rate and low browning rate were obtained using MS and B₅ which were used for induction and differentiation of graft union tissue.(3) Combination of plant growth regulators in media was studied to promote differentiation of tissues. In MS, 2.0mg/L 6-BA+ 0.5mg/L IAA+ 0.05mg/L NAAå’Œ3.0mg/L 6-BA+ 0.05mg/L NAA produced highest differentiation rate (60ï¼…) which was significantly higher than any of other combinations, and more adventitious shoots were differentiated. In B₅, 0.5mg/L 6-BA+ 0.5mg/L IAAå’Œ2.0mg/L 6-BA+ 0.2mg/L IAA resulted in highest differentiation rate (above 60ï¼…).(4) Growth period and intermittent time of subculture was investigated to improve the culture behavior of graft union tissue. Survival rate, browning rate and growth status of graft union tissue which was acquired after 7～10 days were notably better than tissue which was acquired after 10 days. When intermittent time of subculture was about 20 days, high survival rate and low browning rate was achieved.(5) The cell suspension culture system for graft union tissues was preliminarily established although differentiation and plant regeneration of graft union tissues of eggplant and tomato were not realized.(6) The variation of regenerated plantlets from graft union tissues was observed. The variation types included having characters of both eggplant and tomato, having only characters of eggplant, having only characters of tomato and having new characters differing from the parents. The results indicated that graft union tissues could be regarded as source of genetic variation.