Objective  Release of aromatics from floral organs of Malus Brandywine was studied for new variety breeding.

  Method   Freshly picked floral organ samples of the strongly fragrant Malus Brandywine in different flowering stages were analyzed for aromatic components by SPME-GC-MS.

  Result  (1) There were 23, 30, 30, and 32 volatiles detected in the floral organs from budding to full bloom stage. They included predominantly (Z)-3-hexen-1-ol, linalool, hexanoic acid-methyl ester, (Z)-3-hexen-1-ol, and 6-methyl-5-hepten-2-one, and α-farnesene. The total fragrance release was in an increasing trend initially to peak at the full bloom stage before decline toward the end. The released aromatics consisted largely of terpenes (14.47-37.30%) and aldehydes and ketones (21.64-38.78 %) with the highest relative contents of terpenes at full bloom, while aldehydes and ketones when large buds appeared. The terpenoids increased at opening of the flowers followed by a decline, while alkanes and esters decreased at first but rose later. A principal component analysis on the volatiles at different flowering stages showed a cumulative variance contribution of 87.64%. On PC1, linalool contributed the most and significantly correlated positively in the large bud stage, whereas nonanal the most and significantly correlated negatively in the initial flowering stage. (2) At full blooming, 28, 32, and 25 volatiles were detected in the petals, pistil (including calyx), and stamens, respectively. The greatest fragrance release in quantity came from the pistil and the least from the petals. A principal component analysis on the compounds in different organs yielded a cumulative variance contribution of 98.65 %. On PC1 and PC2, hexanoic acid-methyl ester, linalool, and α-farnesene contributed more and were the major aromatics in the petals, stamens, and pistils, respectively. The 3 floral organs were in different quadrants and significantly differed in the composition of the aromatics they released.

  Conclusion   (Z)-3-hexen-1-ol, linalool, hexanoic acid-methyl ester, (Z)-3-hexen-1-ol, 6-methyl-5-hepten-2-one, and α-Farnesene were the major volatiles in floral organs of Malus Brandywine. Terpenes were the dominant aromatics released during the full bloom stage. Significantly differences in the aromatic composition of the fragrance discharged from different floral organs. The releases of these volatiles took place mainly in the pistil.