Mature Sweet Cherries Have Low Turgor
Mature Sweet Cherries Have Low Turgor
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DOI：
10.21273/jashs.139.1.3
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发表时间：
2014-01-01
影响因子：
1.9
通讯作者：
Schlegel, Henrik Juergen
中科院分区：
文献类型：
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作者：
Knoche, Moritz;Grimm, Eckhard;Schlegel, Henrik Juergen
以成熟甜樱桃（Prunus avium L.）果实被认为是雨裂的重要因素。然而，据我们所知，这种压力从未被直接量化。本研究的目的是量化：1）使用细胞压力探针（CPP）和蒸气压渗透压计（VPO）的水果中的细胞膨压（Psi（cell）（P））;和2）使用水果压力探针（FPP）和压缩板技术（CP）的水果中的组织压力（Psi（水果）（P））。成熟甜樱桃果实中果皮细胞的Psi（cell）（P）值，在200 ~ 400 μ m处，桑巴舞为28.1kPa，山姆为17.5kPa。由VPO法测定的离体中果皮圆片的组织水势（Psi（tissue）= -2968 ~-4035kPa）和渗透势（Psi（fruit）（Pi）= -3020 ~-4116kPa）计算的Psi（cell）（P）（不同品种的范围为38 ~ 64 kPa）与CPP法的结果在同一数量级上。通过FPP获得了类似的低Psi（果实）（P）值（在品种间范围为8.0至11.8 kPa）。果实的Psi（P）始终低于CPP或VPO测量的Psi（细胞）（P）值。中果皮的Psi（果实）（P）值随着表面以下深度的增加而略有增加。然而，Psi（水果）（P）总是可以忽略不计（例如，“桑巴舞”Psi（水果）（P）= 10 kPa）与Psi（水果）（Pi）（“桑巴舞”Psi（水果）（Pi）= -2395 kPa）或计算的水势（Psi（水果））（“桑巴舞”Psi（水果）= -2385 kPa）进行比较。当受到完整的水果CP，所施加的力和所产生的不平坦区域之间的线性关系。通过CP获得的Psi（果实）（P）值（甜樱桃中的范围为18.4至36.1kPa）略大于通过FPP获得的Psi（果实）（P）值（甜樱桃中的范围为8.0至11.8kPa）。将果实在去离子水中孵育长达7.5小时或在封闭在干燥硅胶上方的空气中孵育长达96小时对Psi（果实）（P）没有可测量的影响。低Psi（细胞）（P）和低Psi（果实）（P）值并不是甜樱桃独有的。同样数量级的值也在成熟的酸樱桃（樱桃）中获得，欧洲李（Prunus arctica L.），葡萄（葡萄属葡萄属L.），醋栗（Ribes uva-crispa L.），红醋栗（Ribes rubrum L.），黑醋栗（Ribes nigrum L.），蓝莓（Vaccinium corymbosion L.），和番茄（Solanum lycopersicum L.）。讨论了Psi（细胞）（P）和Psi（果实）（P）值很低的可能解释。
The pressure inside a mature sweet cherry (Prunus avium L.) fruit is thought to be an important factor in rain cracking. However, to our knowledge, this pressure has never been quantified directly. The objectives of this study are to quantify: 1) the cell turgor (Psi(cell)(P)) in fruit using a cell pressure probe (CPP) and a vapor pressure osmometer (VPO); and 2) the tissue pressure in a fruit (Psi(fruit)(P)) using both a fruit pressure probe (FPP) and a compression-plate technique (CP). The value of Psi(cell)(P) in mesocarp cells of mature sweet cherry fruit averaged 28.1 kPa in 'Samba' and 17.5 kPa in 'Sam' at depths below the fruit surface between 200 and 400 mu m. A Psi(cell)(P) (range 38 to 64 kPa for different cultivars) calculated from the tissue water potential (Psi(tissue) = -2968 to -4035 kPa) and the osmotic potential (Psi(fruit)(Pi)) (Psi(fruit)(Pi) = -3020 to -4116 kPa) of excised mesocarp discs as determined by VPO was of the same order of magnitude as that by CPP. Similar low Psi(fruit)(P) values were obtained by FPP (range 8.0 to 11.8 kPa across cultivars). The Psi(fruit)(P) were consistently lower than the Psi(cell)(P) values measured by CPP or by VPO. The Psi(fruit)(P) value in the mesocarp increased slightly with increasing depth below the surface. However, Psi(fruit)(P) was always negligible (e.g., 'Samba' Psi(fruit)(P) = 10 kPa) compared with either Psi(fruit)(Pi) ('Samba' Psi(fruit)(Pi) = -2395 kPa) or calculated water potential (Psi(fruit)) ('Samba' Psi(fruit) = -2385 kPa). When subjecting intact fruit to CP, linear relationships were obtained between the forces applied and the resulting aplanation areas. The Psi(fruit)(P) values obtained by CP (range in sweet cherry 18.4 to 36.1 kPa) were somewhat larger than the Psi(fruit)(P) values obtained by FPP (range in sweet cherry 8.0 to 11.8 kPa). Incubating fruit for up to 7.5 h in deionized water or for up to 96 h in air enclosed above dry silica gel had no measurable effects on Psi(fruit)(P). The low Psi(cell)(P) and the low Psi(fruit)(P) values are not unique to sweet cherry. Values of the same order of magnitude were obtained also in mature sour cherry (Prunus cerasus L.), european plum (Prunus domestica L.), grape (Vitis vinifera L.), gooseberry (Ribes uva-crispa L.), red currant (Ribes rubrum L.), black currant (Ribes nigrum L.), blueberry (Vaccinium corymbosion L.), and tomato (Solanum lycopersicum L.). Possible explanations for the very low values of Psi(cell)(P) and Psi(fruit)(P) are discussed.