Variations Of Coloring And Soluble Suger Content In Red-Skinned Pear Pear Fruit And The Influences Affected By Soluble Sugars Spraying Treatments Measurement During Different Fruit Development Stages

Pear occupies an important place in the national economy. In the situation that common pear supply is over demand in contrast to red pear supply is unable to meet the demand. Besides, red pear has good appearance quantity and high market value. Therefore, red pear varieties have a brighter future. However, mechanism of red pigment development of red pear is lack, which will not be benefieial of ration utilization of these cultivars. To examine the variations of anthocyanin, sugars and acid contents in Peach and the Influences affected by soluble sugars spraying treatments measurement during different fruit development stages, Anthocyanin,Sugars and acid contents were determined by high-performance liquid chromatography(HPLC), Effect of the ’Hongxiangsu’ and ’Hongtaiyang’ coloration with spraying soluble suger and the relationship between Red-skinned Pear Coloration and soluble sugars were also studied. The Phenylalanine ammonia-lyase(PAL) and Chalcone isomerase (CHI) activities were also assayed.1. The ’Hongxiangsu’ and ’Hongtaiyang’ fruit development showed in an ’S’curve under natural conditions displayed slow-fast-slow growth rhythm. But ’Zhongliyihao’and ’Hongbali’fruit development showed in slow-fast growth rhythm. The change trend of anthocyanin content have two synthesis peak in the growth and development of fruit. And the biggest is the coloured area of fruit during fruit filling and ripen ing. Besides, Anthocyanin biosynthesis of ’Hongbali’accumulating largly in fruit maturation period. In the meantime, the chlorophyll concentration decreased, the carotenoids increase during the three pears development, and they could affect anthocyanin accumulation in certain degree. The anthocyanin concentration increase variation trend in ’Zhongliyihao’ with little amount, and the chlorophyll concentration displayed slow-fast growth rhythm until the fruit picking season.2. Changes in the level of anthocyanin and the activities of enzymes of anthocyanin biosynthesis including plenylalanine ammonia lyase (PAL), chalcone ismoerase (CHI), were studied in the pear of’Hongxiangsu’、’Hongtaiyang’ and ’Hongbali’ during the pigment formation period. The result showed that With the accumulation of anthocyanin,the activities of PAL reach the highest, when the activity of PAL decreased, the activity of anthocyanin remained at a high level later. Activity of PAL was apparently not limiting to colour development and was not a key enzyme for colouration, while CHI activity had a positive correlation with the synthesis of anthocyanin.3. There was a significance positive correlation or extremely significant positive correlation between anthocyanin concentration in pear peel and sugars cocentration in Pear flesh varied with Pear cultivars. Anthocyanin concentration in ’Hongxiangsu’、’Hongtaiyang’ had a extremely significant negative correlation with fructose, while in ’Hongbali’ had a significant negative correlation with fructose. Btween anthocyanin concentration and sucrose, glucose observed correlates poorly in the three red pears.4. After the treatment of the soluble, the protein content and the soluble sugar content has increased, the anthocyanin concentration has increased, chlorophyll content is descended. Fructose and sucrose spraying treatments could increased PAL and CHI activities in red-skinned pear, Which indicated that PAL and CHI had relations to anthoeyanin synthesis, and improve the anthocyanin accumulation effectively, and inhibited the breakdown of chlorophyll, and the synthesis of cyaniding-3-galactoside in ’Hongxiangsu’was promoted larger by sugars spraying treatment than ’Hongtaiyang’. And the treatment of2%fructose was the most effective way. The treatment of the soluble affected the pigment from the skin, Soluble sugar content, PAL and CHI activity, It shows that the sugars spraying acts on the red-skinned Pear is not base on the influence of some material, but by the way of improving the nutritional condition entirely to improve fruit qualities and enhance the value of pears.5. Effect of fruit sugars spraying treatment on the synthesis of anthocyanin of red-skinned Pear were studied in this study. HPLC chromatography of pear skin anthocyanins showed ’Hongxiangsu’ and ’Hongtaiyang’ had one major peak, which was cyaniding-3-galactoside;’Hongbali’had two major peaks, which were cyanidin-3-galactoside and peonidin3-galactoside, representing cyanidin-3-galactoside with the largest peak found in apple and pear and peonidin-3-galactoside with the smaller peak.