Studies On Seed-coating And Tissue Culture Of Verbena Hybrida Groenl. & Rumpler

Verbena hybrida Groenl.&Rumpler,the perennial herbaceous plants belonging to Verbenaceae,of which has been widely used as the layout of green belt for urban roads,flower beds and flower border with the feature of the rich colorful flowers,long flowering period and very high ornamental value,and great application in landscape configuration.At the same time,the whole plant can be used as medicine,with the effect of cooling blood,dispersing blood stasis,clearing heat,detoxifying,relieving itching,expelling parasite and detumescence etc.The breeding of V.hybrid mainly depends on the seed germination,but the reason of the low germination percentage of seed,slow germination,uneven germination lasting for 2³weeks,un-favorite drought,and the maternal excellent characteristics are easy to degenerate,the economic and social benefits of V.hybrid are not ideal,greatly affecting the commercial production.In this study,seeds,leaves,stems of V.hybrid were used as experimental materials to study seed coating and tissue culture.The main results were as follows:1.Three kinds of film forming agent,chitosan,sodium alginate and sodium carboxymethyl cellulose,can change the hardness and resilience of the coated seeds,reducing the hardness,increasing the resilience and having strong influence on the stickiness of the coating seed coat.Based on the evaluation of the physical index of the coating,the mechanical properties of the coating seed,and the coating seed germination and seedlings growth index,the sequence of film forming agent is 0.3g/L chitosan,0.2g/L carboxymethyl cellulose sodium,0.3g/L sodium alginate.2.Under drought stress,the growth effect of the control group CK₁?normal watering?was better than the control group CK₂?drought treatment?.The seeds coated with water retaining agent?potassium polyacrylate?showed different degrees of changes in physiological and biochemical indexes and growth indexes with the control group CK2?drought treatment?.Considering that the optimum concentration of water retaining agent is 2 g/L,it is more conducive to the improvement of enzyme activity,the accumulation of organic matter and the increase of root length and fresh weight of seedlings.3.By the single hormone of NAA and 6-BA coating V.hybrid,the study of germination index showed that 6-BA was stronger than NAA.The effect of NAA and6-BA compound hormone coating was better than NAA in terms of the germination index and plant height.but the effects on root length and root-shoot ratio were both promoted and inhibited than NAA alone.The comprehensive analysis showed that NAA300 mg/L+6-BA 10mg/L was better for seed germination rate,up to 75.67%.and NAA300 mg/L+6-BA 10mg/L was beneficial to increase root length and root-shoot ratio,up to 3.8cm and 83.67%,and significantly different from other groups?P<0.05?.4.75%ethanol 30 s+0.1%HgCl₂ 4 min is the best choice of disinfectant.The stem of V.hybrid is suitable for explants,and leaves as explants have the phenomenon of high pollution rate and low survival rate,the highest pollution rate is up to 90%,and the lowest survival rate is only 10%.5.The key factor to improve the axillary bud induction rate of the stem of V.hybrid was 6-BA,followed by NAA,light time and light intensity.The key factor to promote earlier induction of axillary bud of the stem was the light time,followed by 6-BA,NAA and light intensity.The best combination to improve the induction rate is A₁B₁C₂D₃?the light intensity 500lx+the light time 12h/d+1mg/L 6-BA+1mg/L NAA?,and the optimal combination to reduce the average induction time is A₁B₃C₂D₂?the light intensity 2000lx+the light time 12h/d+1mg/L 6-BA+0.5mg/L NAA?.The combination A₁B₁C₂D₃ is more beneficial to the axillary bud induction by extreme analysis and variance analysis,that is,the light intensity is 500lx,the light time is 12h/d,and the MS culture medium+1mg/L 6-BA+1mg/L NAA are more beneficial to the axillary bud induction of V.hybrid.6.The key factor to improve the multiplication of cluster buds is 6-BA,followed by culture medium,2,4-D and NAA.The key factors to promote the rooting of the cluster buds are the culture medium,followed by NAA,6-BA and 2,4-D.The optimal combination to improve the multiplication is A₂B₂C₃D₂?the 1/2MS culture medium+0.5mg/L NAA+2mg/L 2,4-D+3mg/L 6-BA?,and the optimum combination to improve the rooting rate is A₃B₁C₁D₂?the White culture medium+0.2mg/L NAA+0.5mg/L 2,4-D+3mg/L 6-BA?.The combination A₃B₁C₁D₂ is more beneficial to the multiplication and rooting of the cluster buds by extreme analysis and variance analysis,that is,the White culture medium+0.2mg/L NAA+0.5mg/L 2,4-D+3mg/L 6-BA are more beneficial to the multiplication and rooting culture of the cluster buds of V.hybrid.7.When the mixing ratio of peat and perlite was 1:1,the survival number and rate of V.hybrid were the highest,up to 81.7%,which was 13.1%higher than that of peat matrix cultivation,that is,the mixed matrix of peat:perlite=1:1 was more suitable for the transplant and seedlings growth of V.hybrid.