枇杷种质资源果实糖组分及含量特征

以66份枇杷种质资源成熟果实为试材,用高效液相色谱法分析测定可溶性糖组分含量。结果表明:枇杷种质成熟果实中均含有果糖、葡萄糖、蔗糖和山梨醇,果糖含量最高,平均39.49 mg·g-1 FW,山梨醇含量最低,平均为3.03 mg·g-1 FW。4种糖组分的变异系数为29.50%~71.95%,并且山梨醇蔗糖葡萄糖果糖;果糖含量11.01~63.98 mg·g-1 FW,占总糖的19.01%~67.83%;葡萄糖含量5.29~37.53 mg·g-1 FW,占总糖的7.18%~41.63%;蔗糖含量1.10~55.92 mg·g-1 FW,占总糖的1.44%~69.72%;山梨醇含量0.64~11.90 mg·g-1 FW,占总糖的0.88%~12.21%。不同种质资源成熟果实的糖分构成存在差异,果糖/葡萄糖为1.12~3.62,果糖/蔗糖为0.27~43.85,蔗糖/葡萄糖为0.05~8.75;聚类分析结果将枇杷种质资源分为果糖、葡萄糖和蔗糖含量差异显著的2大类5个组群,综合分析认为枇杷种质资源糖积累类型可分为果糖积累型、己糖(果糖+葡萄糖)积累型和蔗糖积累型。

Characteristics of Components and Contents of Soluble Sugars in Mature Fruits of Loquat Germplasm

The aim of this work was to determine the contents and components of soluble sugars in mature fruits of 66 loquat germplasms using the high performance liquid chromatography（HPLC）. The soluble sugars in loquat were comprised of fructose，glucose，sucrose and sorbitol. The content of fructose was the highest with a mean of 39.49 mg ? g-1 FW，and the content of sorbitol was the lowest with a mean of 3.03 mg ? g-1 FW. The variation coefficients of the contents and components of soluble sugars were 29.50%–71.95%，and the sequence was sorbitol > sucrose > glucose > fructose. The content of fructose ranged from 11.01–63.98 mg ? g-1 FW accounting for 19.01%–67.83% in the total sugar. The content of glucose ranged from 5.29–37.53 mg ? g-1 FW accounting for 7.18%–41.63% in the total sugar. The content of sucrose ranged from 1.10–55.92 mg ? g-1 FW accounting for 1.44%–69.72% in the total sugar.The content of sorbitol ranged from 0.64–11.90 mg ? g-1 FW accounting for 0.88%–12.21% in the total sugar. A significant difference of sugar component was found among different cultivars. And the ratios of fructose/glucose，fructose/sucrose and sucrose/glucose ranged from 1.12–3.62，0.27–43.85 and 0.05–8.75，respectively. Based on the UPGMA cluster，66 loquat germplasms could be classified into 2 major types or 5 species groups，which were significantly different among the contents of fructose，glucose and sucrose in mature fruits. Comprehensive analysis on the sugar accumulation modes of loquat germplasm resources could be divided into fructose accumulation-mode，hexose accumulation-mode and sucrose accumulation-mode.