Comparative analysis of volatile compounds in different muskmelon cultivars in Xinjiang based on HS-SPME-GC-MS and transcriptomics
Yingying Fan, Binxin Jia, Xiaoqian Cao, Jun Yang, Xiaolong Li, Weizhong He, Fengjuan Liu, Cheng Wang
Abstract
Volatile flavor has stroked a great amount influence in acceptance and point of view in Fruit products. Melon (<italic>Pyrus communis</italic>) is an aroma-dense fruit, thus, the evaluation of volatile flavor is crucial to melon-breeding. The volatile compounds present in nine varieties of Xinjiang muskmelons were identified and analyzed using the headspace solid-phase microextraction and gas chromatography-mass spectrometry method. In addition, transcriptomics were used to discover the differential genes in fatty acid degradation pathways. It was found that a total of 170 volatile substances, including 52 alcohols, 41 esters, 24 aldehydes, 32 ketones, 14 acids and 7 phenols, were identified in the 9 melons. Results of PCA showed that 3-nonanol, 2-nonanol, bis (2-ethylhexyl) adipate, and 2-methylpropanal contributed more to the flavor of melon. It was verified that high activities of acyl-coenzyme A cholesterol acyltransferase (AAT) promoted the conversion of alcohols to esters, so that the melons have a high content of esters. Four genes of long-chain acyl-CoA synthetase were mainly responsible for the large difference in volatile substances. This practice may furtherance undermine the primary rationale for the breeding and promotion in different cultivars of muskmelon.