Effects of quince pollen pollination on fruit qualities and phenolic substance contents of apples

In the apple industry, the improvement of apple fruit aroma and polyphenol content has always been an important goal of breeding. In this study, pollination experiments of 'Yan 3 Fuji', 'Indo' and 'Ryokano kisetsu' apples were carried out by using pollen grains of quince (Cydonia oblonga Mill.). The results indicated that single fruit weight, fruit firmness, vitamin C content, sugar-acid ratio, total phenolics and total flavonoids were significantly affected by quince pollen, while quince pollen had no significant effect on fruit shape index, titration acid and total anthocyanins. In addition, valuable phenolic compounds, including catechin, epicatechin, chlorogenic acid, phloridzin, quercetin, and quercetin 3-D-galactoside, were significantly influenced by quince pollen. Moreover, esters such as acetic acid pentyl ester, acetic acid hexyl ester, butanoic acid hexyl ester, butanoic acid-2-methyl- hexyl ester and hexanoic acid hexyl ester in three kinds of apple were all increased after pollination by quince. Obvious metaxenia was observed between quince pollen and apple.