Difference of pepper fruit quality in different planting areas and its correlation with meteorological factors

【Objective】 The quality differences of different pepper varieties in different planting areas were studied， and the correlation between quality indexes and meteorological factors was analyzed，which provided reference for improving the quality of pepper. 【Method】 In this study，2 pod peppers（Zunla 9，Zhuojiaoxin 52）and 2 line peppers （Layan 12，Dafang wrinkled pepper）planted in 3 different areas（Wulumuqi of Xinjiang，Majiang of Guizhou and Changsha of Hunan）were used to determine 7 quality indexes，including capsanthin，reducing sugar，total amino acids， crude fat，crude fiber，capsaicin and dihydrocapsaicin. Combined with 8 meteorological factors in each planting area，the nutritional quality of pepper and its relationship with environmental factors were comprehensively evaluated by difference analysis，correlation analysis and principal component analysis. 【Result】 There were great differences in the fruit quality indexes of the same pepper variety in different planting areas. Among them，line pepper planted in Xinjiang had the highest capsanthin content，while pod pepper in Guizhou had the highest capsaicin and dihydrocapsaicin contents；crude fat contents in line pepper and pod pepper were the highest in Hunan，crude fiber content was the highest in Xinjiang. The correlation analysis on 7 quality indexes of 4 pepper varieties was analyzed. The results showed that there was extremely significant positive correlation between capsaicin and dihydrocapsaicin（P<0.01，the same below），and the correlation coeffi‐ cient was 0.98. Capsanthin was significantly and negatively correlated with crude fat，and the correlation coefficient was 0.66. According to the contribution rate of each principal component，the eigenvalue of the first principal component was 2.662，and the contribution rate was 38.032%；among which，the highest load factor was dihydrocapsaicin，followed by capsaicin. The comprehensive evaluation results of the 4 varieties planted in 3 different planting areas showed Xinjiang> Guizhou>Hunan in Dafang wrinkled pepper，and Guizhou>Hunan>Xinjiang in the other 3 pepper varieties. The results of correlation analysis between fruit quality and meteorological factors showed that average annual temperature，the lowest temperature in the growing season，the total precipitation in the growing season，and the relative humidity in the growing season were extremely significantly and positively correlated with reducing sugar and crude fat. There was significant positive correlation between sunshine hours in the growing season and the average diurnal temperature difference in the growing season and crude fiber（P<0.05，the same below）. The highest temperature in the growing season was extremely significantly and negatively correlated with capsanthin，capsaicin and dihydrocapsaicin，and significantly negatively correlated with reducing sugar. 【Conclusion】 The quality of pepper is affected by genotype and environment. In production， the suitable pepper varieties should be planted according to the habitat conditions of each planting area to ensure the quality of pepper fruit.