| Stellera chamaejasme widely distributes in most parts of the northeast, northwest, north and southwest of China. Stellera chamaejasme spreading in pasture caused a loss to livestock, so we would like to wipe out Stellera chamaejasme from pasture and restore the natural grassland. On the other hand, Stellera chamaejasme has good medical value and many other utility value, so we hope to discover and make use of its value. In this paper, through research for the seed structure, breaking dormancy and germination characteristics, we intend to reveal the occurrence rule of Stellera chamaejasme, so as to explore the effective way to prevent or take advantage of it. This research mainly acquire the following results:1. It can be seen from the paraffin longitudinal sections of the seed of Stellera chamaejasme that the seed is a typical dicotyledonous plant seed, including seed coat, cotyledons, radicle, hypocotyl, germ and other structures. Cells arrange closely and neat in the seed, indicating that all parts of the seed have developed fully and stored much nutrient. It can be seen from the paraffin sections stained with PAS reaction and the freezing sections stained with oil red O that there is much polysaccharide and axunge stored in Stellera chamaejasme, and the axunge distributes unevenly.2. The low budding rate of Stellera chamaejasme seeds is due to the limits of seed coats. Seed coats broken and treated by concentrated sulfuric acid can obviously improve the budding rate and shorten the time of germination. Treated with concentrated sulfuric acid by 4 minutes and then treated by 200mg/L gibberellin, the budding rate can be higher. This combination treat can improve the budding rate from 12.67% to 78%, and shorten the time of germination from 7 days to 3 days. In addition, gibberellin GA3 and cytokinin 6-BA can reduce the inhibitory effect on seed germination that ABA causes in a certain extent.3. During the germination of Stellera chamaejasme seeds, the trends of α- amylase,β-amylase and total amylase activity are similar. The amylase activity increased rapidly during the suction stage, and reached the peak value on the third day, then slightly decreased. The α- amylase activity in dry seeds is very low, and β- amylase activity is much higher than the α- amylase during germination. There is a large amount of soluble sugar in the dry seeds, and its content decreased rapidly during the fast suction stage. Then the content of soluble sugar stabilized after 48h, and it indicated that at this time the soluble sugar which was greatly needed by the metabolism was supplemented by amylolysis, making the content of soluble sugar kept relatively stable. The lipase activity rose slowly during the germination, and reached the peak value on the fourth day, then declined on the fifth day. Grease in the seeds was degraded into fatty acids and glycerol to provide a lot of energy and carbon for germination. The content of fatty acids reduced gradually during the germination, and it reduced more during the rapid suction stage. The content stabilized after one day and increased slightly on the fourth day. The continuously active metabolism needs a lot of fatty acid for carbon source and energy, and then lipases break down stored fat constantly to get fatty acids, so the content of fatty acid can keep stable.4.The chloroplast gene psbA-trnH, trnL and nuclear gene ITS of Stellera chamaejasme in Garang, Guide, Xining, Qinghai were cloned and sequenced. The alignment result of ITS sequence showed that the highest similarity is Stelleropsis antoninae of Stelleropsis, and the identities can be 99%. The high homologous species with Steller a chamaejasme all comes from thymelaeceae, but unfortunately in NCBI there is no result about the genes or transcriptome of germination of these species. |
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