Diversity Of Aroma Components In Melon(cucumis Melo L.) Germplasm

Cucumis melo is an important fruit. The necessary quality for marketing is not just pretty look, great quality, long shelf-life, nice fragrance is also a factor that attract consumers'attention and improve competitiveness in marketing, so dedicating in quality breeding including fragrance is an significant objective in the 21 century.Cucumis melo is the most diversified species of the genus Cucumis. Quality and arama are of great variability. Breeding and biology research is depend on melon germplasm resources. In early studies on aroma, researcher generally focused on a few regular cultivars. 61 agronomic traits in 74 accessions covering 6 varieties of Cucumis melo were investigated and aroma components during fruit ripeness and senescence in various kinds of groups were detected by gas chromatography-mass spectrometry (GC-MS), the present experiment was carried out to explore the major characters of the melon breeding materials nowadays as a reference helping breeding. Results were summarised as follows:(1) Principal component analysis was performed on 36 morphological characters in 74 accessions, result shows that some melon breeding materials nowadays are mix character because of crossing between different groups.(2) The optimizing conditions used in detection of the volatiles in melon were :60℃, 30 min for extraction , 230℃, 5 min for exposure , the initial oven temperature was 40℃(held for 2 min), ramped at 5℃min-1 to 95℃,and then at 2℃min-1 to 160℃, then at 5℃min-1 to 230℃(held for 2 min).(3) There were 160 volatiles detected, including 88 esters, 31 alcohols, 10 aldehydes and 31 other volatiles such as ketone, acid, phenol, terpenoids and sulfur-containing compounds, etc. agrestis was rich in 3-thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl ester, decyl acetat and 1,2-dimethoxy-4-(2-propenyl)- benzene, etc. especially decyl acetate which is much more than in other groups. However chinensis showed a high concentration in aromatic components like 3-thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl ester, and isoeugenol methyl ether. European Cantaloupe was rich in acetic acid, butyl ester, butanoic acid, ethyl ester,1-butanol, 2-methyl-, acetate and acetic acid, hexyl ester and other acetate esters or butyrate esters. All in all, ester was the most distinguished compound in melon.(4)Comparison of the aroma components during ripening and senescence revealed that ester, alcohol and aldehyde increased in ripening and aldehyde keeed increasing while ester and alcohol changed depending on accessions, such as 3-(methylthio) propanoic acid ethyl ester, allyl methyl, sulfide, farnesene were abundant in Tianbao,Tedayangjiaosu (chinensis)and climacteric melon like Charentais(European Cantaloupe)during senescence.