Winkler Andreas, Riedel Deborah, Neuwald Daniel Alexandre, Knoche Moritz
Institute of Horticultural Production Systems, Leibniz University Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany.
Competence Centre for Fruit Growing-Lake Constance (KOB), Schumacherhof 6, 88213 Ravensburg, Germany.
Plants (Basel). 2020 Apr 2;9(4):440. doi: 10.3390/plants9040440.
Sweet cherries are susceptible to rain-cracking. The fruit skin is permeable to water, but also to solutes. The objectives of this study were to (1) establish whether a solute efflux occurs when a sweet cherry fruit is incubated in water; (2) identify the solutes involved; (3) identify the mechanism(s) of efflux; and (4) quantify any changes in solute efflux occurring during development and storage. Solute efflux was gravimetrically measured in wetted fruit as the increasing dry mass of the bathing solution, and anthocyanin efflux was measured spectrophotometrically. Solute and anthocyanin effluxes from a wetted fruit and water influx increased with time. All fluxes were higher for the cracked than for the non-cracked fruit. The effluxes of osmolytes and anthocyanins were positively correlated. Solute efflux depended on the stage of development and on the cultivar. In 'Regina', the solute efflux was lowest during stage II (25 days after full bloom (DAFB)), highest for mid-stage III (55 DAFB), and slightly lower at maturity (77 DAFB). In contrast with 'Regina', solute efflux in 'Burlat' increased continuously towards maturity, being 4.8-fold higher than in 'Regina'. Results showed that solute efflux occurred from wetted fruit. The gravimetrically determined water uptake represents a net mass change-the result of an influx minus a solute efflux.
甜樱桃容易出现裂果现象。其果皮对水具有渗透性，对溶质也具有渗透性。本研究的目的是：（1）确定甜樱桃果实置于水中时是否会发生溶质外流；（2）识别所涉及的溶质；（3）识别溶质外流的机制；（4）量化发育和储存期间溶质外流发生的任何变化。通过测量浸泡溶液干重的增加，以重量法测定湿润果实中的溶质外流，并通过分光光度法测量花青素外流。湿润果实的溶质和花青素外流以及水的流入量均随时间增加。裂果的所有通量均高于未裂果。渗透溶质和花青素的外流呈正相关。溶质外流取决于发育阶段和品种。在“雷吉娜”品种中，溶质外流在第二阶段（盛花后25天（DAFB））最低，在第三阶段中期（55 DAFB）最高，在成熟时（77 DAFB）略低。与“雷吉娜”不同，“布拉特”品种的溶质外流在成熟过程中持续增加，比“雷吉娜”高4.8倍。结果表明，湿润果实会发生溶质外流。重量法测定的吸水量代表净质量变化——水流入量减去溶质外流的结果。
