喷钛对甜叶菊糖苷含量和积累量的影响

Effect of spraying titanium on the glycoside content and accumulation in stevia leaves

为探索喷钛对甜叶菊叶片中糖苷、甜菊苷（St）和莱鲍迪苷A（RA）的含量、积累量及其比例的影响，为中药材的施肥提供科学依据，应用盆钵培养方法，在甜叶菊生长前期和中期进行叶面喷钛。结果表明：菊隆5号的最佳喷施区间12．22-19．36mg·kg^-1，在喷钛浓度为19．36mg·kg^-1。时含量达到最高；新品种2号的最佳喷施区间为12．10-16．71mg·kg^-1，在喷钛浓度为16．71mg·kg^-1时含量达到最高；喷钛后新品种2号St所占比例的最高增幅为156．71％，菊隆5号St的最高增幅为42．28％。喷钛可明显提高糖苷含量和积累总量，与对照相比，差异显著；经回归发现糖苷含量或积累量与喷钛浓度间存在二次曲线关系，相关极显著；喷钛可以增加2个品种糖苷中St的比例。

In order to provide a scientific basis of fertilization for traditional Chinese medicinal plants, an indoor simulation experiment was carried out. A titanium solution was sprayed on the leaf surface of stevia at the early and middle growth stages. The effects of different concentrations of titanium on the contents, accumulation, and proportion of glycoside, St, and RA in the stevia leaf were studied. Results showed that the optimum concentration of spraying titanium was in the range of 12.22 - 19.36 mg·kg^-1 for Julong No.5 and 12. 10 - 16.71 mg·kg^-1 for variety No.2, respectively and the maximum content of glycoside was obtained when the concentration reached to 19.36 mg·kg^-1 and 16.71 mg·kg^-1, correspondingly. The highest increase rate of St after titanium spraying was 156.71% in new variety No.2 and 42.28% in Julong No.5. In conclusion, the glycoside content and accumulation in the stevia leaf were significantly increased by spraying titanium. There was a significant statistical difference between the treatment and the control was observed. Regression analysis indicated that a significant correlation and quadratic curve relation between glycoside content and accumulation and titanium concentration existed. The proportion of St in glycosides in both varieties was increased by titanium application.