Genotypic And Nitrogen Effects On The Sulforaphane Content In Radish(Raphanus Sativus L.)

Radish(Raphanus sativus L.,2n=2x=18),belonging to the Brassicaceae family,is an economically important root vegetable crop containing significant anti-cancer substance sulforaphane.Some studies have suggested that sulforaphane is able to significantly reduce the risk of many types of cancer such as liver,stomach and breast.Recently,many studies on medicinal values of sulforaphane have been widely reported.However,the reports on variation of sulforaphane content in different radish organs and how to improve the sulforaphane content are still scarce.In this study,we developed an efficient and accurate method for quantitative analysis of sulforaphane using the HPLC method,and determined the sulforaphane content in different radish organs from different genotypes of radish.In addition,we study the effect of nitrogen on the sulforaphane content in radish.Based on these results,some elite radish germplasms with high sulforaphane content were screened.In detail,the main results obtained in this study were listed as follows:(1)Establishing the optimum conditions for sulforaphane extraction.The optimum conditions for sulforaphane extraction was as follows:Phosphate buffer solution pH was 7.0 for radish glucosinolate auto-hydrolysis at room temperature.The proportion of sample to ethyl acetate volume,times,extraction time and temperature were:1/20(g/mL),2,4h.25?.This method was successfully applied for the quantification of sulforaphane in different radish germplasms.(2)Analysis of sulforaphane content in diverse radish genotypes and different plant organs.Sulforaphane contents within 48 accessions of radish fleshy roots were detected ranging from 0.0088-0.6466?mol·g-1 DW.According to these results,two radish germplasms with high sulforaphane content were obtained.For different organs,the extents of sulforaphane content in leaves,skins,fleshy and sprouts were located within 0.0080-0.0363?mol·g-1 DW,0.0468-0.1806?mol·g-1 DW,0.0554-0.1824?mol·g-1 DW and 0.0901-0.1838?mol·g-1 DW,respectively.Based on the results above,we can conclude that the organ with highest content of sulforaphane was the radish sprouts,while the lowest content was found in the radish leaves.(3)A hydroponic experiment was conducted to investigate the effect of nitrogen treatment on sulforaphane content.Results indicated that nitrogen supply significantly affect the sulforaphane contents in the roots.