| By treating shoot segments and cluster buds with colchicines, two tetraploid plants of Acid jujube and one tetraploid plant of 'Dongzao' were first obtained by tissue culture . The induction system in vitro was set up. At the same time, with the diploid plants as comparison, the cytological and morphological characters of tetraploid were studied systematically. The simplified course of ploidy identify was selected out. The tetraploid plants propagation and shooting system were studied. The main results are as following:1 Different materials and methods make the double effect different . The order of doubling effect is mix-culture for cluster buds, soaking for shoot segments, soaking for cluster buds, mix-culture for shoot segments. The optimum compages of concentration and time of colchicines for Acid jujube and 'Dongzao' is MS medium added by 50mg/L colchicines for 40d. The doubling effect is 36.67% and 26.27% separately; The shoot segments of Acid jujube treated by 0.4% colchicines for 4d leaded the highest doubling effect: 23.33%; The shoot segments of 'Dongzao' treated by 0.4% colchicines for 2d leaded the highest doubling effect: 16.67%. Mix-culture is the optimum method for cluster buds induction, soaking is the optimum method for shoot segments induction. In contrast, the doubling ability of Acid jujube is superior to 'Dongzao' .2 Different materials and methods make the death rate different. The order of death rate is soaking for shoot segments, mix-culture for shoot segments, soaking for cluster buds, mix-culture for cluster buds. The maximum death rate of shoot segments of Acid jujube in soaking by 0.6% colchicines for 6d is 66.70%; The maximum death rate of shoot segments of 'Dongzao' in soaking by 0.6% colchicines for 6d is 86.70%. The maximum death rate of shoot segments of Acid jujube in mix-culture by 100mg/L colchicines in medium for 40d is 30.00%; The maximum death rate of shoot segments of'Dongzao' in mix-culture by 100mg/L colchicines in medium for 40d is 70.00%; In contrast ,the soaking method does more harm to materials, shoot segments are more harmed than cluster buds, the endureness to colchicines of Acid jujube is superior to'Dongzao' .3 Some means can improve the doubling effect of treated materials distinctly. Such as pre- culture for 4d, darkness treatment for 15d ,adding 0.5% DMSO and so on. Adding 1.5mg/L active carbon can decrease the materials browning.4 By tissue culture, chimeras were purified by incision. The tetraploid partments of chimeras were separated after incision 3~4 times. When propagated and rooted, the ploidy of different apparatus was inspected. The number of chromosome is 48, which indicated the chimera was purified successfully. After propagated 8 times, the ploidy of different apparatus was inspected once again, The number of chromosome is also 48, which indicated the tetraploid was stabled successfully by tissue culture.5 Comparing with their original diploid plants, the induced tetraploid plants showed that the leaves become longer, wider and thicker. And the serration of the leave become larger than CK, but the serration number per centimeter is less than normal leaves. The leave index and internode length show smaller than CK at the beginning of inducing and recover at the stability. Basing on the stomata density obviously decreased, the guard cells are larger and the chloroplasts in the guard cells are more than the average ones. The microstructure olefin slice of shoot tip and leaves show that the size of cells of diffirent layers of shoot apexy of tetraploid is larger than diploid; The thickness of tetraploid leaves is thicker than diploid; the leading tissue is upgrowther.6 The optimum multiplication and shooting medium of Acid jujube tetraploid plants are MS with BA2.5mg/L and IBA0.2~0.6mg/L, the propagation is 3.6; 1/2MS with IBA1.0mg/L, the rooting rate is 100%. The optimum multiplication and shooting medium of 'Dongzao' tetraploid plants are MS with BA3.5mg/L and IBA0.2~0.6mg/L, the propagation is 3.2; 1/2MS...
|
PDF Full Text Request