Calcium alters senescence rate of postharvest muskmelon fruit disks
Gene Lester
Postharvest Biology and Technology Vol: 7 Issue: 1-2 Pages: 91-96
1996
บทคัดย่อ
Percent total chlorophyll loss in whole muskmelon (Cucumis melo L. var. reticulatus Naud.) fruit disks incubated in control (no salt), 0.02, 0.04, 0.08, 0.16 or 0.32 M CaCl2, MgCl2 or KCl plus 0.35 M mannitol for ten days at 22°C in the dark was delayed only in calcium solutions, with the greatest retention occurring in 0.04 M content. Percent total chlorophyll loss was hastened in 0.16 and 0.32 M concentrations regardless of the cation. Differences in the chemical, senescence-associated, properties of the plasma membrane (PM) from hypodermal mesocarp tissue of postharvest muskmelon disks were compared before and after floating disks in control, 0.04 or 0.16 M CaCl2, MgCl2 or KCl plus 0.35 M mannitol for ten days at 22°C in the dark. Total phospholipid, protein, and H+-ATPase (EC 3.6.1.35) activity loss, in the PM were delayed only with 0.04 M CaCl2 and hastened with most all other chloride solutions vs. no salt. The free sterol: phospholipid ratio and percent unsaturation of phospholipid fatty acids was the highest in the PM from fruit disks incubated in 0.04 M CaCl2 and were the highest and lowest, respectively, in 0.16 M CaCl2 vs. no salt. This study suggests that muskmelon fruit senescence is affected by calcium treatment, by affecting the PM, possibly involving the regulation of phospholipid composition and content.