Variation Characteristics Of Glucosinolate Contents In Leaf Mustard

Mustard is an annual or biennial herb of Brassica in Cruciferous family,and is one of the important vegetables native to China.Glucosinolates are a class of important secondary metabolites containing sulfur and nitrogen in plants,which play an extremely important role in plant defense,sulfur regulation,as well as endowing plants with special flavor and anti-cancer.In my experiments,60 leaf mustard resources which from Beijing,Hunan,Fujian and Guangxi were used as experimental materials.To observe the agronomic traits of leaf mustard resources,we used genetic diversity analysis,cluster analysis,correlation analysis and other analysis methods.The change law of glucosinolates content in leaf mustard resources and the dynamic change rule of glucosinolates content in the whole growth period of leaf mustard were studied,and the results were as follows:1.Phenotypic identification of the resources showed that the coefficient of variation ranged from 11.24% to 193.33%.In qualitative traits,the variation coefficients of leaf warts,leaf bristles and leaf gloss ranked first,which were 193.33%,180.00% and 136.67%,respectively.In quantitative traits,the variation coefficients of plant height,petiole width,rosette number and number of flower stalksts ranked first,which were 43.45%,40.41%,39.80% and 37.20%,respectively.2.A total of 9 glucosinolates were detected in leaf mustard.They were progoitrin(PRO),sinigrin(SIN),n-hexyl-GLS,gluconapin(NAP),glucobrassicanapin(GBN),4-hydroxyglucobrassicin(4OH),glucobrassicin(GBC),4-methoxyglucobrassicin(4ME)and neoglucobrassicin(NEO).And the highest contents in leaves of leaf mustard were sinigrin(SIN).3.The contents of total glucosinolate in leaf mustard resources ranged from1.2023 μmol/g to 30.7310 μmol/g,with an average value of 10.1074 μmol/g,standard deviation of 6.5620 and coefficient of variation of 50.83%.The total glucosinolate contents of JC 18-13 was the highest(30.7310 μmol/g),while the JC 18-54 was the lowest(1.2023 μmol/g).JC 18-37 contained the most abundant glucosinolates,which a total of 9 glucosinolates were detected.4.Cluster analysis of 60 leaf mustard resources was carried out.According to their phenotypic characteristics,leaf mustard resources could be divided into three categories,and the significant impact factors of classification were plant height,plant width,leaf shape and plant type.In the same way,according to the changes of glucosinolate contents,they can also be divided into three groups,which were low glucosinolates group,medium glucosinolates group and high glucosinolates group.5.Glucosinolates were detected in different tissues of leaf mustard during the whole growth period.The main glucosinolates detected in the roots of leaf mustard were 4-methoxyglucobrassicin(4ME),while sinigrin(SIN)in other parts of leaf mustard.The glucosinolates were the most abundant in the alabastrums at the bolting stage,with a total of 9 glucosinolates were detected.Which contents of glucosinolate reached the maximum value(140.1257 μmol/g DW)in the whole growth period of leaf mustard.The contents of glucosinolate in different parts of leaf mustard were determined as follows: alabastrums > seeds > flowers > siliques > leaves > flowering woods > stems > roots.6.Based on the correlation analysis results of glucosinolate contents in different parts of different periods in leaf mustard(JC 18-56),the following hypotheses are proposed in combination with previous studies: the main parts of glucosinolate synthesis in mustard were roots,leaves and young flower buds.There are two modes of glucosinolate transport during the growth process: during the vegetative growth stage and bolting stage,glucosinolates were synthesized in the roots and leaves of leaf mustard,and there was no transport between the aboveground and underground parts.When mustard reaches flowering stage and later,glucosinolates are synthesized in roots,leaves and alabastrums and transported to other parts through stems and flowering woods.Eventually glucosinolates accumulate in the seeds.This hypothesis does not clarify its mechanism at the molecular level and has some limitations.