【摘要】 【目的】枣果实成熟期遇雨易开裂,会带来巨大的经济损失。明确引起枣果实开裂的水分吸收主要途径,为进一步探明枣裂果机制和科学防控提供依据。【方法】于2013—2015年,以易裂果的‘壶瓶枣’果实为试材,通过染液示踪结合体视镜观测枣果实不同部位的吸水分布,确定枣果实可能的吸水途径;通过蜡封果实不同部位结合浸水处理,测定枣果实不同部位单位时间内吸水量的差异;利用体视镜和扫描电镜观测枣果实表面结构特征,分析枣果实表面结构特征变化与吸水和裂果的关系。【结果】1)‘壶瓶枣’果实的果面、果梗和梗洼部位均可吸水,在易裂果的果实着色期3个部位的相对吸水量分别占51%～54%、31%～40%和9%～18%。2)枣果实发育成熟过程中,果面气孔木栓化形成皮孔,部分皮孔形成微裂隙,果面吸水量成倍增加;水分可以通过开放的皮孔和微裂隙进入果实,吸水途径包括共质体途径吸水和质外体途径吸水。3)自然降雨形成的裂果和浸水试验中的裂果上均普遍观察到宏观裂纹经过2个以上的果点连接成线、交叉裂口的交叉点为果点所在位置,证明枣果实表面气孔是引起果实宏观开裂的诱因。【结论】枣果面气孔在果实成熟进程中形成的皮孔和微裂隙是果实吸水的主要部位,也是枣果实吸水开裂的诱因;果实表面同时存在水分进入果实内部的共质体途径和质外体途径。更多还原

【Abstract】 【Objective】 Chinese jujube(Ziziphus jujuba) fruit is easy to crack at ripening stage during rainy season, which brings huge economic loss to the production. This study aimed to clarify the main ways of water absorption leading to jujube fruit cracking, and provide a basis for further exploring the mechanism of fruit cracking and its prevention and control.【Method】 The experiment was carried out from 2013 to 2015. Fruits of Z. jujuba ‘Huping’ with higher cracking susceptibility were used as test materials. The water absorption distribution of different parts of the jujube fruit was observed with dye tracer and stereoscope. The possible ways of water absorption of jujube fruits were determined, and the differences of water absorption per unit time in different parts of jujube fruits were determined by sealing the different parts of the fruit with wax and then incubating them in water. The surface structure characteristics of jujube fruit were observed with stereoscope and scanning electron microscope, and the relationship between surface structure characteristics and water absorption and fruit cracking of jujube fruit was analyzed as well.【Result】 1) The surface, stem and stalk cavity of ‘Huping’ jujube fruits were able to absorb water, and during the fruit coloring period, their relative water absorption accounted for 51%-54%, 31%-40% and 9%-18% of the total relative water absorption of the fruits, respectively. 2) In the process of fruit development and maturation, the fruit surface stomata were corked to form lenticels and some of the lenticels formed microcracks. At that time, water absorption on the fruit surface doubled and water could enter the fruit through open lenticels and microcracks by both symplastic and apoplastic pathways. 3) It was generally observed in both natural rainfall and water-incubation experiment that macroscopic cracks were connected in a line by more than two fruit points, and the cross point of cross cracks was the location of the fruit spot. The above results proved that jujube fruit surface stomata were the inducement of microcracks.【Conclusion】 During the fruit maturation process, the lenticels and microcracks formed from stomata on jujube fruit surface were the main ways for the fruit to absorb water, and they were also the main causes of water absorption and cracking of jujube fruit. On the jujube fruit surface, there existed both symplastic and apoplastic pathways by which water entered the fruit.更多还原