| Spatholobus suberectus Dunn is a traditional Chinese medicine that has been used for thousands of years in China.It is also a genuine medicinal material in Guangxi.This species has the functions of tonifying and promoting blood circulation.Due to the increasing market demand,the wild resources of S.suberectus have been gradually scarce in recent years.Its artificial cultivation will inevitably become the main supply channel in the future.Although some studies have been carried out on artificial planting of S.suberectus in current years,its efficient artificial cultivation technology is still not developed and improved.Research on its planting and growth under the forest is still in initial stage.In order to improve the yield and quality of artificial S.suberectus under the forest,it is particularly important to study the growth rules of S.suberectus and the correlation between the content of medicinal ingredients and so on.In view of this,this experiment took three-year-old S.suberectus as the material which from Pinus ellidata forest of Qipo Forest Farm in Guangxi,and set quadrats to observe the effects of different factors(whether covered with forest litter,climbing or creeping growth,layering treatment or not,different number of trunk branches)on the growth of S.suberectus.At the same time,stem samples of S.suberectus were collected to study the contents of five kinds of flavonoids in S.suberectus under different diameter classes,different branchings,and different storage methods,and to explore their change rules.The following results were obtained:(1)The environmental factors affecting the growth of S.suberectus were investigated and analyzed,and it showed that the diameter growth and stem volume of S.suberectus covered by litter or weeds were significantly higher than those of the uncovered S.suberectus,indicating that the increase of ground moisture caused by covering may promote the thickening and growth of S.suberectus;The stem of S.suberectus with branches and leaves growing along the tree stem was thicker than that of S.suberectus growing along the ground,which indicated that sufficient light in the branch and leaves was an important prerequisite for the growth of S.suberectus.(2)The thickening growth of stem by layering treatment was significantly inhibited from its base to the layering parts,which was significantly less than that of S.suberectus without layering treatment.This suggested that layering propagation at young stage of S.suberectus could limit the stem growth of rattan.(3)The correlation analysis between the number of branches at the base of S.suberectus and the stem growth per plant showed that the net growth of each branch decreased with the increase of the number of branches at the base of S.suberectus.It implied that the artificial control of branch number(pruning)could be conductive to the formation of S.suberectus with large diameter to a certain extent.(4)The correlation analysis between the stem size of S.suberectus and its five kinds of flavonoid compounds content in the stem showed that the concentrations of protocatechuic acid,catechin,epicatechin and formononetin were significantly positively related with the stem diameter of S.suberectus.It means these four flavonoid compounds increased as it grows in diameter.However,the content of licorice was negatively correlated with the diameter of S.suberectus,indicating that licorice was more concentrated in phloem rather than xylem.(5)Correlation analysis of the contents of five flavonoids in different branch grades of the same plant showed that the contents of protocatechuic acid,catechin,epicatechin and formononetin decreased with the increase of branch grades,while the contents of glycyrrhizin were on the contrary,which was consistent with conclusion(4).(6)The differences of five flavonoids contents between in air-dried samples and freeze-preserved fresh samples showed that the contents of catechin and epicatechin in air-dried samples were significantly higher than those in frozen fresh samples;The contents of protocatechuic acid,glycyrrhiza and formononetin were not significantly different among groups.It suggested that air-dried preservation does not significantly affect their flavonoids medicinal constituents.In conclusion,the yield of S.suberectus with large diameter could be improved by planting S.suberectus under the forest through man assisted tree climbing,covering the stem base with litter and controlling the branch number manually.The content of several major flavonoids(protocatechuic acid,catechin,epicatechin and formononetin)in S.suberectus with large diameter were relatively higher than those of smaller size,except glycyrrhizin.It inferred the glycyrrhizin may be more in phloem because of its higher content in stems with small grade and lateral branches with relatively high phloem ratio.The above results provided some guidances for the cultivation of S.suberectus under the forest. |
