| Flavor quality is an important part of the fruit internal quality, which is determined by the composition and content of flavor matters. Recently, although the studies on pear flavor have made great progress, the studies on flavor of sand pear , F1 progeny and the action mechanisms of flavor matters remain little. In this study,'Whangkeumbae','Wonhwang','Suisho','Mansubae'pear varieties and 55 seedlings of F1 progenies were used as materials. Their constituents of aroma, sugar and acid were studied in different cultivars and at different storage days by gas chromatography-mass spectrometry (GC-MS) and Capillary Electrophoresis (CE). Based on this, the effect of ethylene inhibitors on flavor quality were studied. The destination of this experiment was to give theoretical support and reference for evaluation, regulation of pear quality and fruit storability breeding. The main results were as follows:1. 33 main aromatic components were identified (content more than 0.1μg?g-1) in fruits of'Yali','Xuehua','Chili','Whangkeumbae','Wonhwang'and'Mansubae'at commercial ripe stage. Alcohols, aldehydes, esters, ketones, hydrocarbons and heterocycles were main aroma categories, the content of aldehydes was highest, secondly were alcohols and esters. Most of characteristic flavor compounds had synthesized at commercial ripe stage, hexanal, 1-hexanol and acetic acid, hexyl ester were characteristic flavor compounds of six cultivars. The composition and content of aromatic components should were emphasized on quality evaluation and breeding of new cultivars, the content of hexanal, 1-hexanol and acetic acid, hexyl ester were higher in cultivars or strain, which should be selected firstly.2. 19 aroma compounds shared with parents in'Whangkeumbae','Wonhwang','Suisho','Mansubae'pear varieties and 55 seedlings of F1 progenies, ten components shared with parents, being successional variance, were not segregated in F1 generations and exhibited quantitative character inheritance, which were below mid-parent value. Nine compounds shared with parents segregated in ratio of 1:1, 1:3, 3:1 and 9:1 in F1 generations and exhibited qualitative character inheritance.3. Sugar, acid and their components showed successional variance in F1 progenies, the means of glucose were over mid-parent value, which indicated the inheritance of glucose exhibited not only additive genetic effect but also in additive genetic effect. The means of fructose, malate, citrate and total acid were below mid-parent value and suggested that their inheritance showed mainly additive genetic effect.4. Compared with'Whangkeumbae'and'Whasanbae', the change rate of fruit firmness, soluble solids contents, soluble sugar, vitamin c, esters and total aroma were much more than'Gamcheonbae'and'Mansubae', but the change rate of titratable acid, sugar acid ratio, alcohols and aldehydes are not significant difference. The correlation coefficient of fruit firmness, soluble solids contents, soluble sugar, vitamin c all reached very significantly level, esters and total aroma reach significantly level, alcohols and aldehydes had not reached significantly level.5. The evolution of ethylene was obviously reduced, firmness, total alcohols and total aldehydes were obviously delayed reducing, total esters was delayed increasing, activities of LOX, HPL, ADH and AAT were also inhibited significantly by 1μl·L-1 1-methylcyclopropene and 10μl·L-1 nitric oxide treatments. The treatments of 1-methylcyclopropene (1μl·L-1) under 18 hours and nitric oxide gas (10μl·L-1) under 2 hours respectively can maintain higher storage quality of the'Whangkeumbae'pear fruits, and the effect of nitric oxide (10μl·L-1) under 2 hours is better than 1-methylcyclopropene (1μl·L-1) under 18 hours treatment.
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