A Study on coloration physiology of fruit in two red chinese sand pear cultivars ‘Meirensu’ and ‘Yunhongli No.1’ | ‘美人酥’和‘云红梨1号’红皮砂梨果实的着色生理

Китайский. 【目的】研究两个不同遗传背景的红皮砂梨品种在其着色过程中色素的变化与相关酶活性及糖积累的关系,旨在了解砂梨果实着色的一般规律。【方法】选择两个云南地区主栽的红皮砂梨品种‘美人酥’和‘云红梨1号’,系统研究果实整个生长发育过程果皮中花青苷、叶绿素、类胡萝卜素、类黄酮、总酚等色素含量和花青苷积累相关的酶活性,以及果肉中糖含量的变化。花青苷含量采用pH示差检测法测定,叶绿素、类胡萝卜素、类黄酮和总酚含量采用比色法测定。苯丙氨酸解氨酶（PAL）活性采用比色法测定,类黄酮半乳糖苷转移酶（UFGT）活性采用高效液相色谱法测定。糖含量采用高效液相色谱法测定。【结果】在果实整个生长发育过程中,两个品种呈现了相似的生理变化趋势。果实生长前期,果皮中叶绿素、类胡萝卜素、类黄酮和总酚的含量不断上升,几乎没有花青苷的积累;果实生长中后期（花后13周）开始,叶绿素急剧降解,花青苷不断积聚并在成熟时达到最高值。在果实着色始期,PAL和UFGT活性相继达到最高值;之后随着花青苷的快速合成,PAL活性急剧下降,但UFGT活性一直保持在很高的水平。果实整个发育过程中可溶性总糖含量持续上升,其中蔗糖开始有明显积累的时期与花青苷开始大量积累的时期相吻合。【结论】红皮砂梨花青苷的合成积累主要是在果实生长发育后期,伴随着果实的成熟,花青苷含量达最大值。PAL与花青苷合成的启动有关,UFGT与花青苷的积聚密切相关。花青苷的积累伴随着果肉中可溶性总糖的上升。

Английский. 【Objective】 In order to understand the mechanism of coloring of red Chinese sand pears, the relationships between pigments biosynthesis and related enzymes activities as well as the contents of soluble sugars were studied in genetically different red Chinese sand pear cultivars. 【Method】 Two red Chinese sand pear cultivars ‘Meirensu’ and ‘Yunhongli No.1’ were used to investigate the changes in the concentrations of anthocyanin, chlorophyll, carotenoid, flavonoid, total phenolics, and the activities of PAL and UFGT in fruit peel as well as the contents of soluble sugars in fruit flesh during the period of fruit development. The total anthocyanin was estimated by a pH differential method. The concentrations of chlorophyll, carotenoid, flavonoid and total phenolics were determined by colorimetric assay. The activity of PAL was measured by a colorimetric assay, but the activity of UFGT was assayed by HPLC. The concentration and composition of soluble sugars were detected using HPLC. 【Result】 Although the trends of physiological changes were similar in two cultivars, the concentration of anthocyanin in ‘Yunhongli No.1’ was higher than in ‘Meirensu’ at the maturation stage of fruit. At the early stage of fruit development, the concentrations of chlorophyll, carotenoid, flavonoid and total phenolics all increased, but the concentration of anthocyanin was too small to detect. From the beginning of 13 weeks after anthesis, anthocyanin accumulated rapidly with degrading chlorophyll and reached the highest content when fruit harvested. The activities of PAL and UFGT were high when anthocyanin began to biosynthesize in fruit peel. With the accumulation of anthocyanin, the activity of PAL decreased, but the activity of UFGT remained at a high level later. During the fruit development, the content of total soluble sugars increased gradually and the accumulation of sucrose was in parallel with the increase of anthocyanin. 【Conclusion】 Fruit coloration in red Chinese sand pear is accompanied by fruit maturation. Chlorophyll degradation and anthocyanin accumulation made the fruit skin red. Anthocyanin biosynthesis might be induced by PAL, while anthocyanin accumulation is closely related to UFGT activity. Anthocyanin biosynthesis is determined primarily by genotypes and the potential of anthocyanin synthesis is higher in Yunhongli No. 1 than in Meirensu. The accumulation of anthocyanin is in parallel with the changes of total soluble sugar.