Institute for Horticultural Production Systems, Leibniz-Universität Hannover, Hannover, Germany.
PLoS One. 2022 Aug 15;17(8):e0273180. doi: 10.1371/journal.pone.0273180. eCollection 2022.
Water soaking is a common disorder of field-grown strawberries (Fragaria × ananassa Duch.). It develops when ripe fruit is exposed to rain. Here we investigate the effects of Ca on water soaking. Fruit was incubated in solutions of various Ca salts and the extent of water soaking quantified using a simple rating scheme. Exposure to CaCl2 (10 mM) decreased water soaking and anthocyanin leakage but had no effect on water uptake. The decrease in water soaking due to CaCl2 was not limited to a single cultivar but occurred in all cultivars examined. Incubating fruit in a chelating agent (EGTA) increased water soaking compared to the water control. Calcium salts of different acids varied in their effects on water soaking. Only CaCl2 reduced water soaking significantly. The chlorides of different cations, also varied in their effects on water soaking. Those of the monovalent cations had no effects on water soaking, while those of the divalent cations (CaCl2, BaCl2 and SrCl2) and of the trivalent cations (FeCl3 and AlCl3) were all effective in decreasing water soaking. Overall, CaCl2 decreased microcracking of the strawberry cuticle as compared to deionized water. Furthermore, CaCl2 also reduced the leakage of anthocyanins from flesh discs, irrespective of the osmotic potential of the incubation solution. Our results indicate that CaCl2 reduced water soaking by decreasing cuticular microcracking, by decreasing leakage of plasma membranes and, possibly, by increasing the crosslinking of cell wall constituents.
水浸是田间生长的草莓（Fragaria × ananassa Duch.）的一种常见病症。当成熟的果实暴露在雨中时，就会发生这种情况。在这里，我们研究了 Ca 对水浸的影响。将果实浸泡在各种 Ca 盐溶液中，并使用简单的评分方案来量化水浸的程度。暴露于 CaCl2（10 mM）可减少水浸和花青素渗漏，但对水分吸收没有影响。CaCl2 引起的水浸减少不仅限于单一品种，而且发生在所有检查的品种中。与水对照相比，用螯合剂（EGTA）孵育果实会增加水浸。不同酸的 Ca 盐对水浸的影响不同。只有 CaCl2 能显著减少水浸。不同阳离子的氯化物对水浸的影响也不同。单价阳离子的氯化物对水浸没有影响，而二价阳离子（CaCl2、BaCl2 和 SrCl2）和三价阳离子（FeCl3 和 AlCl3）的氯化物都能有效减少水浸。总的来说，与去离子水相比，CaCl2 减少了草莓表皮的微裂纹。此外，CaCl2 还减少了果肉圆盘中原花青素的渗漏，而与孵育溶液的渗透压无关。我们的结果表明，CaCl2 通过减少角质层微裂纹、减少质膜渗漏以及可能增加细胞壁成分的交联，从而减少水浸。
