The Research Of Rapid Propagation And Salt Stress On Tetraploid Robinia Pseudoacacia

Tetraploid Robinia pseudoacacia was an artificial induced polyploid species that introduced from the South Korea, introduced by Beijing Forest University from Korea in 1997, were used as test material in the study. With rapid growth, thick branches, drought-proof, salt resistance and alkali-resisted, and so on, it was a fine species for the soil and water conservation and the development of animal husbandry.(1)Tetraploid Robinia pseudoacacia, introduced by Beijing Forest University from Korea in 1997, were used as test material in the study. Sterilizations were done to the lateral buds, terminal buds and stems to find out which materials were the best explants; terminal buds and stems had been tested under the conditions of light or darkness, distinguishing the best condition; By use of different solution tests, the optimal budding-medium and rooting-medium had been selected; by use of technology of paraffin slice was to compare the cultured plants from different media, with the purpose to ascertain the different structures; in light/dark test, stems under the condition of light showed best; in tissue culture, the optimal budding- medium was MS+ NAA0.2mg/L +6-BA0.6mg/L, and 1/2MS+ NAA0.2mg/L was found to be the optimal rooting-medium.(2) Tetraploid Robinia pseudoacacia were used as the main experimental material and diploid Robinia pseudoacacia were used as the control experimental material. The changes law of their plant morphology, physiology, physiobiology and photsynthetic were tested under two salt stress.The results showed:1) Tetraploid Robinia pseudoacacia had opposite phenomenon, Water content and chlorophyll content had no obvious differences to the contral and salt injury wasn' t observed.2) Relative REC activity of Tetraploid Robinia pseudoacacia rised slightly, but they had no obvious differences to the contral. To diploid Robinia pseudoacacia relative REC activity were higher then the contral clearly. The POD, SOD and CAT as protecting enemy system kept higher activity at late period of Tetraploid Robinia pseudoacacia under salt stress, which contributed to salt tolerance, but they kept lower activity to diploid Robinia pseudoacacia which was sensitive to salt.3) The photsynthetic of Tetraploid Robinia pseudoacacia wasn't influenced obviously under salt stress. Pn and Gs had no obivious changes. Diploid Robinia pseudoacacia had opposite appearance.4) Tetraploid Robinia pseudoacacia under NaCl and Na₂SO₄ salt stress, the damage condition of mitochondria was more lighter and the influence of Na₂SO₄ on tetraploid Robinia pseudoacacia was more severity than that of NaCl. After NaCl treatment 10days, NaCl treatment 20days and Na₂SO₄ treatment 10days, the ultramicrostructure of chloroplast on Tetraploid Robinia pseudoacacia had no obviously changes. But after Na₂SO₄ treatment 20days, chloroplast appeared medium altitude, loose grana lamella and edge unsharpness membrane.Before salt stress, the dipositon of chloroplast was the mural margin of cell and tight to it. After NaCl treatment 10days, the chloroplast arragement on diploid Robinia pseudoacacia was ordering and tight to the mural margin of cell. But After NaCl treatment 20days, a lot of chloroplast were breaked away from the mural margin of cell and offered chance ditribution. After Na₂SO₄ treatment 10days, a part of chloroplast was breaked away from the mural margin of cell and located at the middle of cell. After Na₂SO₄ treatment 20days, almost of chloroplast were breaked away from the mural margin of cell. The arragement of chloroplast on tetraploid Robinia pseudoacacia had no obviously changes before and after treatment. They were the mural margin of cell and tight to it. The results made clear that tetraploid Robinia pseudoacacia had construction features which were adapted to salt tolerance and different salt had different mechanism of action to plant, which can be one of bases screening plant bearing salt.