Biochemical Characteristics of Apple Rot Caused by Macrophoma sp. II. Phenolic Compound Content in Infected Fruits

Macrophoma sp.에 의한 사과 부패의 생화학적특성 II. 감염과일의 페놀함량

Changes in levels of phenolic compounds such as total phenols, flavonols and anthocyanins in Macrophoma-infected apples were studied at various developmental stages of apple fruits. The amounts of total phenols in apple fruit flesh and peel drastically decreased as apples became mature. Apple rot resulted in concentration of total phenols somewhat lower than those of healthy apple flesh. The decline in amount of total phenols was distinct in infected fruit flesh of the cultivar Fuji, which was more susceptible to Macrophoma sp. than the cultivar Miller. Higher amounts of total phenols were found in infected than in heathy fruit peel. In the case of the cultivar Miller, increased accumulation of total phenols was pronounced in infected peel. Apple rot resulted in concentrations of flavonols much higher than those of healthy apples. In particular, the drastically increased accumulation of flavonols was detected in infected peel at the first collection on 10 July, when the cultivars tested were completely resistant to Macrophoma sp. Production of anthocyanins was increased considerably by apple rot: anthocyanins in infected fruits of the cultivar Miller increased markedly as compared with their concentration from healthy fruits. These results suggest that the altered phenolic metabolism in apple fruits may be associated with the development of apple rot.

사과 부패병균(Macrophoma sp.)에 감염된 과일에서 총페놀, flavonol, anthocyanin 함량의 병화를 사과의 여러 발육시기에서 조사하였다. 사과가 성숙됨에 따라 과육, 과피의 총페놀함량은 급격히 감소하였다. 부패병균에 감염된 과육에서 건전한 과육보다 다소 총페놀함량이 낮았으며 품종밀러보다 더 감수성인 후지의 감염된 과육에서 이의 감소가 뚜렷하였다. 건전한 과피에서 보다 감염된 과피에서 높은 페놀함량을 보였으며 밀러에서 이의 증가가 현저하였다. 부패된 사과에서 flavonol 함량이 건전 사과보다 높았으며 7월 10일에 Macrophoma에 완전 저항성이었던 사과의 감염된 과피에 flavonol이 크게 축적되었다. anthocyanin 생성도 감염된 과피에 상당히 증가되었으며 품종 밀러에서 뚜렷했다. 이들 결과에서 미루어 사과의 페놀대사변동은 사과 부패병진전과 관계가 있을지 모른다.