Key message

Xylem functionality is the primary determinant of the Ca relations of developing sweet cherry. Calcium influx is positively related to transpiration and decreases as xylem functionality is progressively lost during development.

Abstract

Fruit calcium (Ca) may be associated with susceptibility to rain cracking in sweet cherry but little background information is available on the fruits’ Ca relations. The objectives of the study were to identify the key determinants of the Ca content in developing sweet cherry fruit. The masses of Ca and K in the flesh (mg per fruit) increased continuously through to maturity. However, their dry mass ratios [mg per g dry mass (DM)] decreased continuously. The decrease in Ca/dry mass ratio was to about 30% of the transition stage II/III value, and for K to about 55%. These decreases occurred in all cultivars investigated. Moreover, the Ca mass per fruit and the Ca/dry mass ratio were normally distributed and wide ranging; the maximum recorded values were about twice the minimum ones. Within a fruit, the Ca/dry mass ratio was two to three times higher in the stem end than in the stylar scar end. Fruit held under low relative humidity (26.2%) contained more Ca per fruit and had a higher Ca/dry mass ratio compared with fruit held under high humidity (91.6%). There was a positive relationship between Ca mass per fruit and cumulative transpiration. Our results indicate xylem functionality is the primary determinant of the Ca relations of sweet cherry fruit.

中文翻译：

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甜樱桃果实的钙生理

关键信息

木质部功能是开发甜樱桃的Ca关系的主要决定因素。钙的涌入与蒸腾作用呈正相关，并随着发育过程中木质部功能的逐渐丧失而减少。

抽象

水果中的钙（Ca）可能与甜樱桃中的开裂敏感性有关，但是关于水果的Ca关系的背景信息很少。该研究的目的是确定开发甜樱桃果实中钙含量的关键因素。直到成熟为止，果肉中的钙和钾的质量（每果毫克）不断增加。但是，它们的干质量比[mg / g干质量（DM）]连续下降。Ca /干质量比的降低到过渡阶段II / III值的约30％，而K降低到约55％。这些减少发生在所有调查的品种中。此外，每个果实的钙质量和钙/干质量比呈正态分布，分布范围广。记录的最大值约为最小值的两倍。在水果里 茎干端的Ca /干质量比是茎上的疤痕端的两倍至三倍。与保持在高湿度下（91.6％）的水果相比，保持在低相对湿度下（26.2％）的水果每个果实含有更多的钙，并且具有更高的钙/干质量比。每个果实的钙质量与累积蒸腾量之间存在正相关关系。我们的结果表明木质部功能性是甜樱桃果实中Ca关系的主要决定因素。