Hypodermal mesocarp disks from abscised muskmelon fruits (Cucumis melo L. var. reticulatus Naud.) were floated in 0.00, 0.04 or 0.16 M CaCl2 plus 0.35 M mannitol at ′20C in the dark for 10 days. Changes in chlorophyll, protein and total phospholipids all indicators of membrane senescence were assayed. The catabolism, percent retention, of chlorophyll, protein and total phospholipids was delayed by 0.04 M Ca, but accelerated by 0.16 M compared to no Ca. Loss of membrane integridity, increased free sterol: total phospholipid (umol./umol.), was delayed by 0.04 M Ca, hut accelerated by 0.16 M compared to no Ca. The degree of lipid saturation was inconclusive between Ca treatments. Muskmelon fruit disks membrane lipid degradation is slowed by 0.04 M Ca but accelerated by supraoptimal 0.16 M Ca treatment.
Delay of Membrane Lipid Degradation by Calcium Treatment during Cabbage Leaf Senescence
