Lawn Plant Horseshoe Gold Organ Culture And Protoplast Culture

Creeping dichondra (Dichondra repens Forest.) may be considered as a kind of excellent turfgrass and ground cover plants. It's organ culture and protoplast culture, being an important basic technique of rapid clonal propagation , selection of mutative plants , somatic hybridzation and genetic transformation, would be attached extensive attention, but still no definite report up to now. This article used "creeping dichondra", a cultivar being cultivated home and abroad, as material and studied it's cotyledon, hypocotyl, young leaf and protoplast culture and systematically established a series of technique of organs and protoplasts, which will provide important theoretic and technical bases for biotechnology breeding of creeping dichondra. The main results are as follows:1. By studies on effects of different hormone combinations on the induction of calli from different explants, the results indicated the combinations of 1.0 mg/L 2.4-D + 0.2mg/L 6-BA or 0.2mg/L KT were the best for cotyledons, 1.0 mg/L 2.4-D + 0.2mg/L 6-BA or 0.2mg/L KT and 0.5mg/L NAA + 0.5mg/L 6-BA for hypocotyls, 1.5mg/L 2.4-D + 0.2mg/L KT and 1.0mg/L 2.4-D + 0.2mg/L 6-BA for young leaves with 100 % of callus ratio and good growth. For cotyledon and hypocotyls, the adventitious roots could be induced when 0.5mg/L NAA existed. It also could be find that MS was perfect culture medium of the induction of calli of the cotyledon, hypocotyls, young leaf.2. The results of different hormone combinations on the differentiation of calli have been studied. The best condition was MS with 0.1mg/L 2.4-D, 2.0mg/L 6-BA and 3.0mg/L AgNO3, in which the ratio of differentiation was 20.7%. But the calli from hypocotyls could not differentiate through fair and foul.3. The highest protoplast yield and best activity was obtained from the solution of Cellulose R-10 2.0%, Pectinase 0.8% and 0.5M Mannitol with the treatment of 9h for the 12d cotyledon in the light.4. The results of different culture media, the culture density and the concentration and hormone combination on the division and growth of protoplast have been studied. Under the condition of 1.0 105/ml and KM8P without NH4NO3, 0.5mg/L 2.4-D, 0.5mg/L NAA and 0.5mg/L 6-BA is the best and beneficial of the division of protoplasts and the growth of calli.5. The thin layer method is very good in four of culture methods, in which the protoplasts divided early and had the highest frequency of division of 20.3% and the higest frequency of plating of 1.33%. For the solid embedded method, the protoplasts also divided early, but not divided continuatively into micro-calli, at the same time, bud division appeared.6. The effects of different hormone combinations on the differentiation of calli from protoplasts also have been discussed. Accordingly, the two hormone combinations of 0.2mg/L 2.4-D+ 4.0mg/L 6-BA and 0.2mg/L NAA + 4.0mg/L 6-BA had the frequency of differentiation of 22.2%, 20.0%, the seedlings without roots could become rooted on the MS of 0.2mg/L NAA.