Responses of Photosynthetic Pigment, Phenol and Total Saponin Contents of Panax notoginseng to Supplemental UV-B under Field Conditions

大田条件下三七光合色素、酚类和总皂苷含量对增补UV-B的响应(英文)

[Objective] The aim of this study was to investigate the content changes and their correlations of the photosynthetic pigment,phenols,including total phenols,total flavonoids and anthocyanins,and total saponins of the one-year-old P.notoginseng plants under supplemental UV-B stress in fields.[Method] The one-year-old plants were irradiated by UV-B in field for 1 min per day,and the plants under the UV-B lamp were regarded as a circle center,achieving an annular leaf-sampling.The photosynthetic pigment,phenols and total saponins of the leaves were determined spectrophotometrically.[Result] With the increase of sampling radius,the supplemental UV-B intensity decreased significantly,the contents of chlorophyll （Chl） a,Chl b,Chl （a＋b）,carotenoid （Car） and total photosynthetic pigment （Chl＋Car） of the leaves increased extremely significantly,the Chl a/b and total phenol content （TPC） decreased extremely significantly,but the Chl （a＋b）/Car changes were not significant.The contents of total flavonoids,anthocyanins and saponins all increased due to the increasing of UV-B,displaying dose effects.The UV-B intensity was positively correlated with the Chl a/b,and negatively with the Chl a,Chl b,Chl （a＋ b）,Car and （Chl＋Car） contents; and the two of TPC,total flavonoid content （TFC）,total anthocyanin content （TAC） and total saponin content （TSC） were positively correlated,all reaching extremely significant level.The UV-B intensity was positively and significantly correlated with the total flavonoid content （TFC）,negatively and significantly with the Chl （a＋b）/Car,and positively and insignificantly with the TPC,TAC and TSC.[Conclusion] For one-year-old plants of P.notoginseng,UV-B can decrease the contents of the Chl a,Chl b,Chl （a＋b）,Car and （Chl＋Car） and increase the Chl a/b and TPC,and,furthermore,induce the increases of the TFC,TAC and TSC in a dose-dependent manner.However,UV-B can hardly change the Chl （a＋b）/Car.The supplemental UV-B of well-suited dose might be one of the effective measures to improve the TSC of P.notoginseng.

[目的]探究大田中增补UV-B胁迫条件下1年生三七植株光合色素、酚类(包括总酚、总黄酮和花色苷)和总皂苷的含量变化及其相关性。[方法]1年生三七植株在大田中每天被UV-B辐射1 min,在UV-B灯下的植株被作为圆心,实现叶片的环状取样;叶片光合色素、酚类和总皂苷含量用分光光度法检测。[结果]随着取样半径的增加,增补UV-B的强度显著下降,叶片叶绿素(Chl)a、b、Chl(a+b)、类胡萝卜素(Car)和总光合色素(Chl+Car)极显著增加,Chl a/b总酚含量(TPC)极显著下降,但Chl(a+b)/Car变化不显著。总黄酮、总花色苷和总皂苷含量均因UV-B强度的增加而增加。UV-B强度与Chl a/b呈正相关,与Chl a、Chl b、Chl(a+b)、Car和(Chl+Car)含量呈负相关;TPC、总黄酮含量(TFC)、总花色苷含量(TAC)和总皂苷含量(TSC)两两间呈正相关,且均达到极显著水平;UV-B强度与TFC呈显著正相关、与Chl(a+b)/Car呈显著负相关、与TPC、TAC和TSC间呈不显著正相关。[结论]合适剂量的增补UV-B可能是提高三七TSC的有效措施之一。