ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Chlorophyll fluorescence and whole fruit senescence in 'Golden Delicious' apple.

Ahmad Mir, N.; Perez, R.; Beaudry, R. M.;

Acta Horticulturae Year: 1998 Issue: No. 464 Pages: 121-126 Ref: 19 ref.

1998

บทคัดย่อ

Chlorophyll fluorescence was used as a non-invasive probe to study senescence in refrigerated air-stored Golden Delicious apple fruits. When the fruit surface was excited by a continuous source of light 72% of variable fluorescence was quenched. Most of the quenching was photochemical. DCMU completely prevented the quenching of variable fluorescence in the whole fruit and photosynthetic O2 evolution in the peel discs. Under air storage conditions, all fluorescence parameters studied generally declined over time; and the rate of reduction was maximal from day 3 to 12. While the chlorophyll content decreased in a trend similar to that of fluorescence, the Chl a:b ratio remained unchanged during air storage. The capacity of peel discs to generate O2, via photosynthesis, declined as the fruit aged. The trend of the decline in O2 evolution was similar to the trend for Chl degradation. In contrast, variable fluorescence quenching was found to be independent of chloroplast photosynthetic activity in th

e later stages of fruit senescence. It is suggested that a Mehler-type O2 reaction may account for large amounts of variable fluorescence quenching in apple fruit. Chlorophyll fluorescence appears to be a promising tool for estimating whole fruit senescence.