Study On Quality Characteristics And Fingerprint Of Blueberry

Blueberry is a berry with high economic value and nutritional value. After the success of the introduction, the planting areas of blueberry are increasing, and production continues to boom. Without the quality evaluation system of blueberry varieties, the comprehensive utilization rate of blueberry is relatively low. There is no uniform standard of blueberry in fresh and processing characteristics. Anthocyanins are the main nutritional components in blueberry, which directly affect the nutritional quality of blueberry. Some studies have indicated that blueberries in different producing areas and climate conditions have different profilings of anthocyanins. Thus, which plays an important role in studying the compositions and structures of anthocyanins of different blueberry varieties in different growth conditions to guide the introduction and cultivation in local blueberry production. In the production and management of blueberry varieties resources, there are also some problems in our country, such as varieties confusion and non-standard cultivar’s naming. The traditional identification of blueberry varieties can not meet the need of productions. Therefore, it is imperative to develop a genetic marker, which is stable, reliable, information rich and has strong distinguishing ability.In order to solve the above-mentioned urgent problems in the development of blueberry industry in China. In this study,28 samples of 14 blueberry varieties, which produced in China, were systematically researched in quality evaluation and classification of Blueberry, composition characteristics of anthocyanins in blueberry varieties, and blueberry biological fingerprint. The aim of the study was to establish the evaluation standard of quality grade in blueberries, to measure the composition and characteristics of anthocyanins of blueberry varieties, and to select the suitable primers to establish the ISSR fingerprint of blueberry.Through the study, the conclusions can be summarized as follows:1. The blueberry raw material quality analysis results showed that the quality indexes of 18 in different degree of coefficient of variation among different varieties. Coefficient of variation of fruit diameter, fruit high, Lvalue, pH value, and water content were less than 10%, which indicated that the five indexes were not significant difference among the varieties. The variation coefficients of all other quality indexes were more than 10%, significant difference were found in each quality index data. The results of blueberry samples index correlation coefficient analysis showed that there were 171 correlation coefficient, including 18 significant correlations at 0.05 level, and 15 significant correlations at 0.01 level. The vast majority of indicators had no significant correlation.2. Seven important quality evaluation indicators were selected from 18 indexes of blueberry, including fruit diameter, a value, b value, titratable acid content, total anthocyanins content, total soluble solid, and fruit hardness. By using the analytic hierarchy process, the weights of the core indexes were given, and the mathematical model of the comprehensive evaluation of the blueberry raw materials was established. Y= 0.3145x total soluble solid +0.3145×total anthocyanins content +0.1647× titratable acid content +0.0951×fruit diameter +0.0527× fruit hardness+ 0.0353×b value +0.0230xa value. The comprehensive score of 28 kinds of samples were calculated.3. The regression analysis result of sensory quality evaluation and comprehensive quality evaluation model of blueberry raw materials indicated that a good correlation existed in the two evaluation methods (R2=0.87243). The evaluation model can be used to evaluate the quality of blueberry raw materials. K-means cluster analysis was used to evaluate the grade of blueberry. The results of the two classification methods were similar. Both grade evaluation method and levers of evaluation indexes were suitable for the evaluation of the quality grade of blueberry.4. In this study,15 anthocyanins were identified and quantified by LC-MS in blueberries, including delphinidin 3-galactoside, delphinidin 3-glucoside, cyanidin 3-galactoside, delphinidin 3-arabinoside, cyanidin 3-glucoside, petunidin 3-galactoside,cyanidin 3-arabinoside, petunidin 3-glucoside,peonidin 3-galactoside, petunidin 3-arabinoside, peonidin 3-glucoside, malvidin 3-galactoside, peonidin 3-arabinoside, malvidin 3-glucoside, malvidin 3-arabinoside. The identities of anthocyanins among the cultivars were similar, but the proportions of each compound were cultivar-dependent. There was also significant difference among same cultivar samples from different areas. The anthocyanin compositions of Berkeley, St.Cloud, and Bluegold were significantly different from other varieties. Three cluster analysis results based on anthocyanins data showed that the anthocyanins characteristics can be used to identify and distinguish blueberry varieties.5. The PCR reaction system and reaction program were optimized by single factor experiment and the response surface methodology. By using the optimized experimental condition,20 primers screened from 100 primers were used for ISSR amplification. A total of 125 bands were obtained including 101 polymorphic loci. The average polymorphic frequency was 80.80%. The DNA fingerprints of 14 blueberry varieties were established by amplified bands from UBC845 and UBC855 primers. The NTsys 2.10e and POPGEN32 analysis showed that the genetic diversity was significantly different in 14 blueberry cultivars, and the genetic distance between the cultivars was far. The genetic distance between Bluetta and Bluecrop was the closest, St.Cloud has the farthest genetic distance with Northblue or Bluegold, respectively. UPGMA clustering result was very different from the cluster results based on anthocyanin data, this may be caused by the genetic difference between different cultivars and their parents.