Characteristics of soluble sugars in longan germplasm

【Objective】Components and contents of soluble sugars of 63 longan germplasm were deter-mined.【Methods】The high performance liquid chromatography(HPLC) was used to detect the compo-nents and contents of soluble sugars in ripening longan fruits,and the data were analyzed by cluster analy-sis.【Results】The results showed that the major components of soluble sugars in longan fruits were fruc-tose,glucose and sucrose. Sucrose had the highest content and with a mean of 94.14 mg·g-1,which ac-counted for 62.5% of the total sugar. Fructose and glucose contents were similar,which accounted for19.3% and 18.2% of the total sugar separately. The variation coefficient of the three sugars contents were25.0%~ 25.5%,and the value of the sucrose/mono were 0.75-4.83. The total sugar and sweetness value,sucrose and total sugar showed significantly positive correlation(r=0.99**,0.82**). Fructose and glucoseshowed significantly and linearly positive correlation,the slope is 1.060 5(R2=0.958 3). 63 longan germ-plasm could be classified into 2 groups and 5 subgroups,and these proportion showed extremely signifi-cant between different groups.【Conclusion】The major components of soluble sugars in ripening longan fruits were fructose,glucose and sucrose,which had abundant diversities. The sucrose content was thehighest one,fructose and glucose contents were similar. 63 longan germplasm could be classified into 2groups and 5 subgroups.