枣果实组织结构及果皮中矿质元素含量对裂果的影响

Effects of anatomical structure and mineral contents in pericarp on fruit cracking in jujube fruit

【目的】研究枣果实解剖结构及果皮中矿质元素的含量与枣裂果的关系。【方法】供试材料为抗裂品种‘圆铃枣’及易裂品种‘俊枣’,从花后20 d起,每10 d采样1次。对花后80 d的果实进行浸果诱裂实验,统计裂果率。制作石蜡切片观察各时期样品的解剖结构,测定各时期样品果皮中的N、P、K、Ca、Mg及各化学形态的Ca含量。【结果】浸果诱裂实验显示,‘俊枣’裂果率显著高于‘圆铃枣’,且在浸水72 h时达到最高。果实结构观察发现,‘圆铃枣’角质膜厚度在花后80 d及90 d时显著高于‘俊枣’,各时期表皮厚度均显著高于‘俊枣’;‘圆铃枣’表皮细胞在花后70~90 d时显著小于‘俊枣’,两品种果肉细胞无显著差异。两品种各时期果皮中N、P、Mg的含量差异不显著,花后90 d及100 d时‘圆铃枣’果皮中的Ca含量明显高于‘俊枣’,且NaCl-Ca含量差异显著。【结论】枣果实表皮厚度及果皮中Ca含量与裂果密切相关,且NaCl-Ca为果皮中Ca的主要存在形态。相对于果肉细胞大小,果皮细胞排列紧密程度与裂果更相关。

[Objective]The aim of this study was to decipher the impact of anatomical structure and mineral contents of pericarp on fruit cracking in jujube fruit. [Method]In this study, the cracking-resistant ＇Yuanling＇ and the susceptible ＇Jun＇ were used as materials. During the fruit development period, the samples were taken every 10 days from 20 to 100 days after full bloom. The anatomical structure of fruit was observed and the contents of N, P, K, Ca, Mg and different calcium forms in periearp were deter- mined. The fruit cracking percentage of the two cuhivars 80 d after full bloom were also determined by wa- ter immersion experiment. [Result]The results showed that the fruit cracking percentage of ＇Jun＇ variety was significantly higher than that of ＇ Yuanling＇ and the cracking rate of ＇ Jun＇ variety reached the highest 72 h after immersion. The observation of anatomical structure showed that the epidermal thickness of ＇ Yuanling＇ was significantly higher than that of ＇ Jun＇ at different development stages, so was for the cu- ticle thickness of the two varieties 80 d and 90 d after full bloom. The size of epidermal cell of ＇ Yuanling＇ was significantly smaller than that of ＇ Jun＇ jujube during 70 to 90 days after full bloom. However, the size of flesh cell showed no difference between the two varieties. The contents of N, P, Mg in pericarp of fruit was not significantly different between the two cultivars, whereas the Ca contents of the pericarp of ＇Yuanling＇ was significantly higher than that of ＇jun＇ jujube during 90 and 100 days after full bloom, especially for NaCl-Ca. [Conclusion]The thickness of epidermis and contents of Ca in pericarp of jujube fruit was closely related to fruit cracking and NaC1-Ca was the important form of Ca in pericarp. The extent of pericarp cell compactness was more closely related to fruit cracking than the size of flesh cell.