Potential Effects of Temperature Differences on the Soluble Sugar Content in Pear Fruit during the Growing Seasons of 2018 and 2019

The impacts of climate change on crop yields and fruit quality are projected to accelerate withincreased atmospheric carbon dioxide levels; however, few studies have focused on the impacts ofclimate change on the accumulation pattern and content of soluble sugars in pear (Pyrus pyrifolia)fruit. We compared the soluble sugars content and accumulation patterns during the 2018 and 2019growing seasons throughout the developmental stages of pear fruit with climate data collected overthe same period. Between the two years, we observed differences in the fructose and sucrosecontents at the maturation stage of the pear fruit, resulting from differences in sugar accumulationfollowing 132 days after full bloom (DAFB). Differences were also found in the meteorologicaldata measured over the two years. In particular, the daily average temperatures from late-June tomid-August (73 to 132 DAFB) were all higher in 2018 than in 2019, and differences in thecumulative amounts of both fructose and sucrose were observed since 132 DAFB. Notable differenceswere confirmed in the comparison of the meteorological variables for each time interval. Amongthe meteorological variables, those related to temperature showed clear differences between the twoyears. Correlation coefficient matrices showed that sucrose and fructose accumulation respondeddifferently depending on the meteorological variables over the two years. Furthermore, only accumulatedtemperature and air temperature were correlated with changes in the sucrose and fructose content in2018, unlike in 2019. Taken together, our results indicate that temperature differences may havecontributed to differences in the fructose and sucrose contents and their accumulation patterns overthe two years. KCI Citation Count: 0